# ent

id: cord-252772-f3fctcru
type: DNA
entity:
  SOCS1 and miR 30c 5p levels Error bars mean SEM n 3 independent experiments P 0 05 P 0 01 P 0 001 and NS not significant infection Figure 3E


id: cord-010053-kniq2mbw
type: PROTEIN
entity:
  truncated S cytoplasmic tail 0 100 0 nsp10 405 100 0 100 0 100 0 100 0 100 0 100 0 99 2 1 nsp11 54 100 0 100 0 100 0 100 0 100 0 100 0 100 0 nsp12


id: cord-265679-7gzont7l
type: DNA
entity:
  Virus date 2018 09 18 journal Viruses DOI 10 3390 v10090507 sha dce34f36e8a1d8b4692c1e54852d6942da5d065a doc_id 265679 cord_uid 7gzont7l Porcine epidemic diarrhea PED


id: cord-279598-xzionafe
type: DNA
entity:
  pcDNA3 1 PEDV S 1 435 V5 His pcDNA3 1 PEDV S 1 485 V5 His pcDNA3 1 PEDV S 1 501 V5 His pcDNA3 1 PEDV S 1 509 V5 His pcDNA3 1 PEDV S 1 575 V5 His pcDNA3 1 PEDV S 1 639 V5 His and pcDNA3 1 PEDV S V5 His


id: cord-279598-xzionafe
type: ORG
entity:
  Identification of Neutralizing Monoclonal Antibodies Targeting Novel Conformational Epitopes of the Porcine Epidemic Diarrhoea Virus Spike Protein


id: cord-292734-2g2ym81n
type: CHEMICAL
entity:
  MgCl 2 pH 8 3 1 2 lL of each dNTP 0 2 mM 29 lL of 2 5 units of Taq polymerase and 67 2 lL of distilled water


id: cord-286831-ni7qfjk9
type: CELL_LINE
entity:
  ATCC American Type Culture Collection Manassas VA USA PEDV CV 777 porcine epidemic diarrhea virus was obtained from national veterinary


id: cord-286831-ni7qfjk9
type: DNA
entity:
  PEDV 5 CGGTTCTATTCCCGTTGATG 3 and 5 CCACAACCGAATGCTATTGA 3 actin 5 GCCATGTACG TTGCTATCCAGGCTG 3 and 3 AGCCGTGGCCATCTCTTGCTCGAAG 5 PCR amplified products


id: cord-286831-ni7qfjk9
type: GGP
entity:
  interferon riboflavin tannic acid quercetin apigenin luteolin catechin quercetrin genistin hesperidin rutin


id: cord-286831-ni7qfjk9
type: CHEMICAL
entity:
  glycyrrhizin interferon riboflavin tannic acid quercetin apigenin luteolin catechin quercetrin genistin hesperidin rutin


id: cord-259794-6qoksn00
type: PROTEIN
entity:
  chemokine CXCL16 10 translation elongation factor 1 alpha 11 cellular pyruvate kinase protein 12 and 14 3 3 13 Comparative


id: cord-259794-6qoksn00
type: GGP
entity:
  RepoRts 7 39700 DOI 10 1038 srep39700 has been reported to bind to the arginine rich basic region of the human T cell leukemia virus protein Rex


id: cord-259794-6qoksn00
type: WORK_OF_ART
entity:
  The Cellular Interactome of the Coronavirus Infectious Bronchitis Virus Nucleocapsid Protein and Functional Implications for Virus Biology Molecular Characterizations of Subcellular Localization Signals in the Nucleocapsid Protein of Porcine Epidemic Diarrhea Virus


id: cord-260107-gqbtkf0x
type: PROTEIN
entity:
  N D b ND ND ND ND ND ND ND ORF1a 12 354 ND ND ND ND ND ND ND ND ORF1ab 20 345 N D ND ND ND ND ND ND ND S 4 161 21448 A A A A C C C 272 K K K K T T T 21756 C T T T T T T


id: cord-275499-25dp6u68
type: TAXON
entity:
  Rotavirus Coronavirus Escherichia coli Clostridium perfringens C difficile Cryptosporidium spp Giardia spp Cystoisospora suis


id: cord-290819-zhywlf6r
type: CHEMICAL
entity:
  N terminal alpha helical structure of human viperin protein helps to anchor it to the endoplasmic reticulum In order to explore the specific mechanism of interaction between viperin and the PEDV N protein the domains of viperin was analyzed and a truncated form of the gene was constructed Viperin


id: cord-268010-1m5h3krw
type: DNA
entity:
  5 untranslated region open reading frame 1a 1b ORF1a 1b S E M nonstructural protein 6 NS6 N nonstructural protein 7 NS7 and 3 UTR


id: cord-261043-f9w310tp
type: GGP
entity:
  herds 9 3 5 farrow feeder 3 3 16 farrow finish 10 6 17 nurseries 11 3 7 wean finish facilities 4 6 91 finisher sites 60 3 and 1


id: cord-261043-f9w310tp
type: WORK_OF_ART
entity:
  a Language and Environment for Statistical Computing Data Mining for Business Analytics Concepts Techniques and Applications in R rpart


id: cord-280564-kgoczioe
type: DNA
entity:
  NetoVIR protocol Conceição Neto et al 2015 A 10 weight volume fecal suspension in viral transport medium DMEM 10 P S 5 gentamycin and 0 01


id: cord-280564-kgoczioe
type: DNA
entity:
  Human Coronavirus Strain OC43 Phylogenetic Relationships to Bovine and Murine Coronaviruses and Influenza C Virus A Profile Hidden Markov Model for Signal Peptides


id: cord-280564-kgoczioe
type: WORK_OF_ART
entity:
  DIAMOND Improving the Identification Rate of Data Independent Label Free Quantitative Proteomics Experiments on Non Model Crops A Case Study on Apple Fruit Preparation of Protein Extracts


id: cord-280564-kgoczioe
type: WORK_OF_ART
entity:
  Farrow To Finish Pig Farms RNA Virus Mutations and Fitness for Survival MUSCLE Multiple Sequence Alignment with High Accuracy


id: cord-292690-1p1gnpgf
type: PROTEIN
entity:
  recombinant L acidophilus pRc CMV2 S1 Rep 8014 L acidophilus S1 and L acidophilus pRc CMV2 S2 Rep 8014 L acidophilus S2


id: cord-257136-zpeh8pmc
type: DNA
entity:
  PEDV R 2 0 998 Eff 96 04 PDCoV R 2 0 992 Eff 91 38 TGEV R 2 0 998 Eff 94 57 and PEAV R 2 0 999 Eff 98 60


id: cord-292958-k5d5fo3i
type: PROTEIN
entity:
  structural proteins 150 220 kDa glycosylated spike protein S 7 kDa envelope protein E 27 36 kDa membrane protein M and 58 kDa nucleocapsid protein N


id: cord-252121-s1zxu5vo
type: EVENT
entity:
  Luc Main Rodger title Role of Transportation in Spread of Porcine Epidemic Diarrhea Virus Infection United States


id: cord-302286-wu6csxve
type: PROTEIN
entity:
  À 1 B À b Control À À À À À À À À 2 2 A À À À À 2 B À b Control À À À À À À À À 3 3 A À À À À À Control À À À À À À À À


id: cord-279813-mrei5kih
type: GGP
entity:
  NF kappa B p65 subunit RELA interferon regulatory transcription factor IRF TNF receptor associated factor TRAF interleukin IL tumor necrosis factor TNF Interferons IFN domain


id: cord-255773-b4re5bky
type: PROTEIN
entity:
  PEDV nonstructural and structural genes PEDV strain USA Colorado 2013 Restriction enzyme recognition sequences


id: cord-276542-lxwls664
type: DISEASE
entity:
  coronavirus cross species transmission Coronavirus Spike Protein and Tropism Changes Clinical features of patients infected


id: cord-298401-4szmu1dh
type: GGP
entity:
  spike S membrane M envelope E and nucleocapsid N and four non structural proteins including 1a 1b 3a


id: cord-289026-v09m2fzw
type: PROTEIN
entity:
  S1 subunits S1 CTDs 17 19 20 Human coronavirus 229E HCoV 229E 21 22 and TGEV 23 24 utilize aminopeptidase N APN


id: cord-289026-v09m2fzw
type: CELL_LINE
entity:
  Henan Agricultural University China Vero cell line African green monkey kidney epithelial cell line Drosophila S2 cell line pMT BiP V5 His A vector


id: cord-289026-v09m2fzw
type: PROTEIN
entity:
  recombinant pAPN ectodomain residues 63 963 PEDV S1 protein residues 21 793 and S1 truncated variants residues 21 249 253 638 and 505 629


id: cord-289026-v09m2fzw
type: DISEASE
entity:
  coronaviruses severe acute respiratory syndrome coronavirus SARS CoV 2 3 4 5 6 and Middle East respiratory syndrome coronavirus MERS CoV


id: cord-298922-k568hlf4
type: PROTEIN
entity:
  polyclonal antibodies anti tubulin anti integrin 3 anti cystatin C anti protein S100 A2 anti apolipoprotein E4


id: cord-302083-9q1i20o6
type: WORK_OF_ART
entity:
  Neutralizing Antibody Response in Mammary Secretions Reactivity of Porcine Epidemic Diarrhea Virus Structural Proteins to Antibodies against Porcine Enteric Coronaviruses Diagnostic Implications


id: cord-302083-9q1i20o6
type: WORK_OF_ART
entity:
  Swine The Role of Non animal Origin Feed Ingredients in Transmission of Viral Pathogens of Swine A Review of Scientific Literature Frontiers


id: cord-302083-9q1i20o6
type: ORG
entity:
  Immunoglobulin Transporting Receptors Are Potential Targets for the Immunity Enhancement and Generation of Mammary Gland Bioreactor


id: cord-288253-wqrhiq08
type: ORG
entity:
  the Technology Development Program for Agriculture and Forestry Ministry for Food Agriculture Forestry


id: cord-288058-oilurica
type: GGP
entity:
  cells 3 2 0 8 Figure 6 Double immunofluorescence staining was further performed to assess the role of SA on TGEV replication TGEV Miller could infect both SA positive cells 1 7 0 3


id: cord-305156-w6iqeayr
type: DNA
entity:
  virus date 2018 10 11 journal Vet Microbiol DOI 10 1016 j vetmic 2018 09 025 sha 9f42d98dcc8fb72f1808fbefb5a020581aa0d80a doc_id 305156 cord_uid w6iqeayr PEDV


id: cord-302819-oj33i2ma
type: DNA
entity:
  PEDS mod 1581 F 5 0 CCAACCTTATTGCATCT GAC 3 0 map positions 22214 22233 and S R1 5 0 CAT CTT TGACAACTGTGT 3 0 map positions 24825 24842


id: cord-305315-0qt7eth0
type: DNA
entity:
  murine leukemia virus reverse transcriptase GBI Labs Golden Bridge International Inc Mukilteo WA USA


id: cord-307408-6wfx0wey
type: CHEMICAL
entity:
  MgCl 2 2 0 ll of dNTPs 2 5 mM 0 5 ll of each specific primer 10 pmol 1 ll of Taq DNA polymerase Promega Madison WI and autoclaved filtered 0 2 lm distilled water


id: cord-310579-tnxokfwu
type: WORK_OF_ART
entity:
  Improving the Accuracy of Demographic and Molecular Clock Model Comparison While Accommodating Phylogenetic Uncertainty MEGA2 Molecular


id: cord-310579-tnxokfwu
type: CHEMICAL
entity:
  N gene Figure 4 Supplementary Figure S5 The complete list of nonsynonymous changes was given in the Supplementary Figure S5 Genogroup N1 differed from genogroups N2 and N3 by 7 nonsynonymous substitutions A84G K205N


id: cord-307110-eiobmxp2
type: CELL_LINE
entity:
  CCL81 human hepatoma cells Huh7 pig kidney epithelial cells LLC PK1 human embryonic kidney 293 cells


id: cord-313126-7hrjzapj
type: WORK_OF_ART
entity:
  Diagnosis to Detect Porcine Transmissible Gastroenteritis Virus TGEV by Optical and Transmission Electron Microscopy Techniques Complete


id: cord-317496-6o2upns3
type: CHEMICAL
entity:
  oligonucleotides Pac S VS 5 GGATTAATTAAGAAGGGTAAGTTGCTCATTAGAAATAATGGTAAGTTACTAAACTTTGGTAA CCACTTCGTTAACACACCATGAAGTCTTTAACCTAC 3 PacI restriction site in


id: cord-322475-i29t7ce8
type: ORG
entity:
  Project Management for Agricultural Science and Technology Achievements Transformation Fund 2010GB2C400209 Science and Technology Major Project of Fujian


id: cord-321739-dnuu6jok
type: WORK_OF_ART
entity:
  the Role of Potentially Contaminated Feed as a Source of the First Detected Outbreaks of Porcine Epidemic Diarrhea


id: cord-314751-i9rxesrg
type: PROTEIN
entity:
  PEDV S1 immunogen PEDV S1 immunogen 4 Placebo Placebo Placebo a Placebo cell culture medium and protein PEDV S1


id: cord-331509-p19dg1jw
type: PROTEIN
entity:
  Beitrag zur kollektiven Behandlung pharmakologisher Reihenversuche MAFFT multiple sequence alignment software version 7


id: cord-330475-mameyzih
type: PROTEIN
entity:
  NoLS IBV N protein 34 NoLS PRRSV N 20 NoLS HTLV 1 Rex 35 NoLS HSV gamma1 34 5 36 NoLS MDM2 37 NoLS MDV MEQ 38 NoLS NF kappa 39 NoLS Nuclear VCP


id: cord-330475-mameyzih
type: PROTEIN
entity:
  protein NVL2 40 NoLS p 120 41 NoLS surviving deltaEx3 42 NoLS GGNNV protein alpha 43 BHV 1 BICP27 44 Earning associated protein 1 19 45 HSV 1 ICP27 46 NoLS angiogen


id: cord-330825-apfcql4m
type: DNA
entity:
  Philippines date 2016 06 28 journal Arch Virol DOI 10 1007 s00705 016 2938 0 sha 7740faa25788c48ed6796fc578d102bcb13879bf doc_id 330825 cord_uid apfcql4


id: cord-322683-wkrj6n1d
type: ORG
entity:
  the Severe Acute Respiratory Syndrome Coronavirus Identification of Severe Acute Respiratory Syndrome Coronavirus Replicase Products and Characterization of Papain Like Protease Activity Transmissible Gastroenteritis Virus


id: cord-344309-6c2wttxg
type: TAXON
entity:
  porcine kobuvirus PKV porcine bocavirus PBoV porcine norovirus PNoV porcine circovirus type 2 PCV2 porcine


id: cord-327000-oyg3oyx1
type: LAW
entity:
  PEDV The Accessory Protein ORF3 Contributes to Porcine Epidemic Diarrhea Virus Replication by Direct Binding


id: cord-327000-oyg3oyx1
type: WORK_OF_ART
entity:
  Localization and Effect on Type I Interferon Response of Porcine Epidemic Diarrhea Virus Nsp7 Host Factors in Coronavirus Replication Coronavirus Endoribonuclease Activity in Porcine Epidemic Diarrhea Virus


id: cord-327000-oyg3oyx1
type: CHEMICAL
entity:
  N genes Figure 1 39 40 41 The N terminal ORF1a and ORF1b encode two large replicase polyprotein precursors pp1a and pp1ab


id: cord-339546-m7rqr886
type: DNA
entity:
  PEDV strain 7 14 21 25 IgM IgA IgG IgM IgA IgG IgM IgA IgG 4 11 44 0 7 0 22 36 0 0 8 0 0 7 0 0 0 0 0 0 0 0 0 14 0 0 0 0 0 0 8 0 0 0 21 0 44 35 38 14 0 220 586 0 29 46 267 2136 25 0 156 1137 247 0 7 97 34 0 49 163 1038 478


id: cord-330772-i7cfmw9x
type: DISEASE
entity:
  Bacillus subtilis BC1212 Publisher s Note Springer Nature remains neutral with regard to jurisdictional claims


id: cord-332811-kjgah8ts
type: DNA
entity:
  chicken IL 6 forward 5 0 CAAGGTGAC GGAGGAGGAC 3 0 chicken IL 6 reverse 5 0 TGGCGAG GAGGGATTTCT 3 0 chicken IL 8 forward 5 0 CCAAG CACACCTCTCTTCCA 3 0 chicken IL 8 reverse 5 0 GCAAGGTAGGACGCTGGTAA 3 0 chicken TNF


id: cord-332811-kjgah8ts
type: GGP
entity:
  chicken glyceraldehyde 3 phosphate dehydrogenase GAPDH forward 5 0 GGTGGTGCTAAGCGTGTTAT 3 0 chicken GAPDH reverse 5 0 ACCTCTGTCATCTCTCCACA 3 0


id: cord-342923-prgorr3d
type: DNA
entity:
  primer and probe sequences PEDV forward primer 5 CGTACAGGTAAGTCAATTAC 3 PEDV reverse primer 5 GATGAAGCATTGACTGAA 3 PEDV Taq Man probe FAM


id: cord-342923-prgorr3d
type: PROTEIN
entity:
  cytoplasmic virus Multiple Type A B Heterogeneous Nuclear Ribonucleoproteins hnRNPs Can Replace hnRNP A1


id: cord-340438-9q3ic0ye
type: PROTEIN
entity:
  amino acid residues 1 219 499 638 636 789 and 1371 1377 19 20 21 22 The aminopeptidase N protein APN


id: cord-341469-7guojyay
type: ORG
entity:
  the Department of Veterinary Medicine Virology Laboratory College of Veterinary Medicine Seoul National University


id: cord-334218-bkjfy66e
type: DNA
entity:
  PEDV outbreak 19 January 2015 to 18 November 2015 S1 Table Overall the control and improvement of impact of PEDV


id: cord-349249-jwvz1ux2
type: CHEMICAL
entity:
  N 8 2 ml of 10 5 TCID 50 ml intramuscular and oral route each and Group 3 irradiated PEDV vaccine group N 8 2 ml of 10 5 TCID 50 ml intramuscular and oral route each


id: cord-321953-yql6gpd3
type: WORK_OF_ART
entity:
  Tracking the Origin and Deciphering the Phylogenetic Relationship of Porcine Epidemic Diarrhea Virus


id: cord-321953-yql6gpd3
type: ORG
entity:
  Department of Veterinary Population Medicine College of Veterinary Medicine University of Minnesota St


id: cord-316908-8ti75mru
type: PROTEIN
entity:
  dynamin II siDyn Sus scrofa 5 CAC CTC ATG ATC AAT AAC A 3 Chlorocebus sabaeus 5 CCT ACA TCA ACA CGA ACC A 3 clathrin heavy chain siCHC Sus scrofa 5 CCC ATA CCA TGA CTG ATG A 3 Chlorocebus sabaeus 5 GAT GAA CCT TAT GCA TGC A 3 EPS 15 siEPS15 Sus scrofa 5 CCT GTG GAT ATT CTT GGA A 3 Chlorocebus sabaeus 5


id: cord-316908-8ti75mru
type: GGP
entity:
  dynamin II siDyn Sus scrofa 5 CAC CTC ATG ATC AAT AAC A 3 Chlorocebus sabaeus 5 CCT ACA TCA ACA CGA ACC A 3 clathrin


# bib

id: cord-000699-2mfbqs8i
title: Outbreak of Porcine Epidemic Diarrhea in Suckling Piglets, China
author: Sun, Rui-Qin
date: 2012-01-17
txt: ./txt/cord-000699-2mfbqs8i.txt
cache: ./cache/cord-000699-2mfbqs8i.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3381683/
doi: 10.3201/eid1801.111259
abstract: nan
summary:
  To the Editor: Beginning in October 2010, porcine epidemic diarrhea (PED), caused by a coronaviral infection affecting pigs, emerged in China in an outbreak characterized by high mortality rates among suckling piglets. The partial S gene deduced amino acid sequences were compared and also showed a high degree of homology (98.0%-100.0%); they had 85.3%-98.7% identity with all reference strains listed in online Technical Appendix Table 2 , 98.0%-98.7% with Thailand strains, and 93.3%-94.7% with vaccine strain CV777 (data not shown). These results showed that PEDV was present in sow milk (online Technical Appendix Table 3 ), but the detection rate was lower for these samples (40.8%) than for the fecal samples (82.0%). Our fi ndings show that PEDV was identifi ed not only in fecal samples from sick piglets, as expected, but also in the milk of the sow, which suggests vertical transmission of the virus.


id: cord-001658-algzczs8
author: Theuns, Sebastiaan
date: 2015-05-21
txt: ./txt/cord-001658-algzczs8.txt
cache: ./cache/cord-001658-algzczs8.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4440965/
doi: 10.1128/genomea.00506-15
summary:
  title: Complete Genome Sequence of a Porcine Epidemic Diarrhea Virus from a Novel Outbreak in Belgium, January 2015 Here, we report the complete genome sequence (28,028 nt) of a PEDV strain isolated during a novel outbreak in Belgium. Therefore, the complete genome of this novel isolate, BEL/15V010/2015, was unraveled by next-generation sequencing, in order to assess its genetic relation to other PEDV isolates circulating around the globe. Complete genome sequence of a highly prevalent isolate of porcine epidemic diarrhea virus in South China Complete genome sequence of a novel porcine epidemic diarrhea virus in south China Complete genome sequence of porcine epidemic diarrhea virus strain USA/Colorado/2013 from the United States Emergence of Porcine epidemic diarrhea virus in the United States: clinical signs, lesions, and viral genomic sequences Isolation and characterization of porcine epidemic diarrhea viruses associated with the 2013 disease outbreak among swine in the United States

title:
  Complete Genome Sequence of a Porcine Epidemic Diarrhea Virus from a Novel Outbreak in Belgium, January 2015

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a member of the family Coronaviridae and can cause severe outbreaks of diarrhea in piglets from different age groups. Here, we report the complete genome sequence (28,028 nt) of a PEDV strain isolated during a novel outbreak in Belgium.


id: cord-001956-jpk854i3
author: Choe, Se-Eun
date: 2016-02-18
txt: ./txt/cord-001956-jpk854i3.txt
cache: ./cache/cord-001956-jpk854i3.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4759056/
doi: 10.1128/genomea.00002-16
summary:
  title: Complete Genome Sequence of a Porcine Epidemic Diarrhea Virus Strain from Vietnam, HUA-14PED96, with a Large Genomic Deletion A highly virulent strain of Porcine epidemic diarrhea virus (PEDV) causing severe diarrhea has recently emerged in Vietnam. Genomic sequences from a novel strain, HUA-14PED96, isolated from a Vietnamese piglet with serious diarrhea show relatively high identity with U.S.-like PEDV strains, and have a 72-nt deletion in the open reading frame 1a (ORF1a) gene. In this study, we sequenced the complete genome of a Vietnamese strain of PEDV, HUA-14PED96, and analyzed it to understand the molecular characteristics and diversity of PEDVs in Vietnam. Phylogenetic analysis using the nucleotide sequences of the full-length genomes of PEDVs revealed that HUA-14PED96 belonged to the G2 group. The complete genome sequence of PEDV strain HUA-14PED96 has been deposited in GenBank under accession no. Complete genome characterization of porcine epidemic diarrhea virus in Vietnam A novel strain of porcine epidemic diarrhea virus in Vietnamese pigs

title:
  Complete Genome Sequence of a Porcine Epidemic Diarrhea Virus Strain from Vietnam, HUA-14PED96, with a Large Genomic Deletion

abstract:
  A highly virulent strain of Porcine epidemic diarrhea virus (PEDV) causing severe diarrhea has recently emerged in Vietnam. Genomic sequences from a novel strain, HUA-14PED96, isolated from a Vietnamese piglet with serious diarrhea show relatively high identity with U.S.-like PEDV strains, and have a 72-nt deletion in the open reading frame 1a (ORF1a) gene.


id: cord-003328-vvle1q1e
title: Lack of LTβR Increases Susceptibility of IPEC-J2 Cells to Porcine Epidemic Diarrhea Virus
author: Altawaty, Tawfeek
date: 2018-11-21
txt: ./txt/cord-003328-vvle1q1e.txt
cache: ./cache/cord-003328-vvle1q1e.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6262443/
doi: 10.3390/cells7110222
summary:
  To examine whether CRISPR/Cas9-mediated gene editing could generate LTβR null alleles in IPEC-J2 cells, we randomly selected two biallelic mutation clones (1-10# and 1-22#) and compared their LTβR expression levels to those of wild-type IPEC-J2 cells (hereafter designated LTβR +/+ ) by real-time PCR. Since PEDV infection destroys epithelial barrier integrity [22] , and LTβR signaling was reported to limit mucosal damage through the IL-22-IL-23 pathway [10] , we examined the expression levels of LTβR downstream genes by semi-quantitative PCR, including VCAM1, IL-22 and IL-23, in PEDV-infected cells. We detected expression levels of IL-6 and IL-8 in infected cells, and the data showed that both genes were significantly decreased in infected LTβR −/− IPEC-J2 cells ( Figure 5C ). Since it has been demonstrated that PEDV infection destroys epithelial barrier integrity [22] and LTβR signaling limits mucosal damage through the IL-22-IL-23 pathway [10] , we detected expression levels of VCAM1, IL-22 and IL-23 in both cell types by semi-quantitative PCR.

abstract:
  The essential requirement of the lymphotoxin beta receptor (LTβR) in the development and maintenance of peripheral lymphoid organs is well recognized. Evidence shows that LTβR is involved in various cellular processes; however, whether it plays a role in maintaining the cellular function of intestinal porcine enterocytes (IPEC-J2), specifically during porcine epidemic diarrhea virus (PEDV) infection, remains unknown. In this study, we generated LTβR null IPEC-J2 cells using CRISPR/Cas9 to examine the importance of LTβR in cell proliferation, apoptosis, and the response to PEDV infection. Our results showed that the lack of LTβR leads to significantly decreased cell proliferation, potentially due to S phase arrest in LTβR(−/−) IPEC-J2 cells. Label-free digital holographic microscopy was used to record the three-dimensional morphology of both cell types for up to 72 hours and revealed significantly increased numbers of LTβR(−/−) cells undergoing apoptosis. Furthermore, we found that PEDV-infected LTβR(−/−) null IPEC-J2 cells exhibited significant suppression of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) target genes (interleukin (IL)-6 and IL-8) and mucosal barrier integrity-related genes (vascular cell adhesion molecule 1 (VCAM1) and IL-22), which may explain why LTβR(−/−) cells are more susceptible to PEDV infection. Collectively, our data not only demonstrate the key role of LTβR in intestinal porcine enterocytes, but also provide data for the improved understanding of the cellular response to PEDV infection.


id: cord-003503-t6cnjwpd
title: Phylogeographic investigation of 2014 porcine epidemic diarrhea virus (PEDV) transmission in Taiwan
author: Sung, Ming-Hua
date: 2019-03-06
txt: ./txt/cord-003503-t6cnjwpd.txt
cache: ./cache/cord-003503-t6cnjwpd.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6402684/
doi: 10.1371/journal.pone.0213153
summary:
  Acknowledging the absence of a thorough investigation at the geographic level, we used 2014 outbreak sequence information from the Taiwan government''s open access databases plus GenBank records to analyze PEDV dissemination among Taiwanese pig farms. The data indicate that the 2014 Taiwan PEDV epidemic resulted from the spread of multiple strains, with strong correlations identified with pig farm numbers and sizes (measured as animal concentrations), feed mill numbers, and the number of slaughterhouses in a specifically defined geographic area. To determine specific temporal and geographic relationships associated with PEDV strain transmission, we used phylogenetic, phylodynamic and phylogeographic methods to systematically evaluate potential temporal and spatial transmission routes among Taiwanese swine farms during the 2014 outbreak. However, to date very few research efforts in Asia have utilized full genome sequencing for determining geographic structures due to the high costs and enormous amounts of computational time Phylogeographic investigation of 2014 porcine epidemic diarrhea virus transmission in Taiwan required for analyses [33, 34] .

abstract:
  The porcine epidemic diarrhea virus (PEDV) that emerged and spread throughout Taiwan in 2014 triggered significant concern in the country’s swine industry. Acknowledging the absence of a thorough investigation at the geographic level, we used 2014 outbreak sequence information from the Taiwan government’s open access databases plus GenBank records to analyze PEDV dissemination among Taiwanese pig farms. Genetic sequences, locations, and dates of identified PEDV-positive cases were used to assess spatial, temporal, clustering, GIS, and phylogeographic factors affecting PEDV dissemination. Our conclusion is that S gene sequences from 2014 PEDV-positive clinical samples collected in Taiwan were part of the same Genogroup 2 identified in the US in 2013. According to phylogenetic and phylogeographic data, viral strains collected in different areas were generally independent of each other, with certain clusters identified across different communities. Data from GIS and multiple potential infection factors were used to pinpoint cluster dissemination in areas with large numbers of swine farms in southern Taiwan. The data indicate that the 2014 Taiwan PEDV epidemic resulted from the spread of multiple strains, with strong correlations identified with pig farm numbers and sizes (measured as animal concentrations), feed mill numbers, and the number of slaughterhouses in a specifically defined geographic area.


id: cord-003587-zminzrov
author: Wang, Xueyu
date: 2019-04-15
txt: ./txt/cord-003587-zminzrov.txt
cache: ./cache/cord-003587-zminzrov.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6466714/
doi: 10.1186/s12917-019-1851-7
summary:
  title: Visual detection of porcine epidemic diarrhea virus using a novel reverse transcription polymerase spiral reaction method The aim of this study was to establish a novel reverse transcription polymerase spiral reaction (RT-PSR) assay for the rapid detection of porcine epidemic diarrhea virus (PEDV). This new method for PEDV detection was 10 times more sensitive than the conventional reverse transcription-polymerase chain reaction (RT-PCR) assay. To decrease the time required for PEDV detection, PCR-related methods focused on the amplification of viral nucleic acids have been developed, which have been shown to be more efficient, highly sensitive and specific, even at different stages of the disease, when compared to immunological diagnostic methods. The polymerase spiral reaction (PSR) [14] is a novel nucleic acid isothermal amplification method that has the advantages of simplicity, rapidity, accuracy, and low cost when compared to conventional PCR.

title:
  Visual detection of porcine epidemic diarrhea virus using a novel reverse transcription polymerase spiral reaction method

abstract:
  BACKGROUND: Porcine epidemic diarrhea virus (PEDV) is a major etiological agent of porcine epidemic diarrhea around the world. Point-of-care testing in the field is lacking owing to the requirement for a simple, robust field applicable test that does not require professional laboratory equipment. The aim of this study was to establish a novel reverse transcription polymerase spiral reaction (RT-PSR) assay for the rapid detection of porcine epidemic diarrhea virus (PEDV). For the assay, a specific RT-PSR primer pair was designed against a conserved region in PEDV ORF3. RESULTS: The RT-PSR was optimized, and PEDV could be detected after a 50 min incubation at 62 °C, in addition to the 15 min required for reverse transcription. No cross-reaction with other porcine infectious viruses was observed. This new method for PEDV detection was 10 times more sensitive than the conventional reverse transcription-polymerase chain reaction (RT-PCR) assay. The positive rates for 65 clinical samples using the new RT-PSR assay and the conventional RT-PCR assay were 58.46% (38/65) and 53.84% (35/65), respectively. In the RT-PSR assay, the addition of a mixture of dyes allowed a positive reaction to be directly observed by the naked eye. CONCLUSIONS: These results indicate that this RT-PSR assay is capable of accurately detecting PEDV, and has the advantages of high specificity and sensitivity for the detection of PEDV.


id: cord-003899-a4w2nnos
author: Yang, Jiwen
date: 2019-08-29
txt: ./txt/cord-003899-a4w2nnos.txt
cache: ./cache/cord-003899-a4w2nnos.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6770734/
doi: 10.3390/ani9090627
summary:
  title: Dietary 25-Hydroxyvitamin D(3) Supplementation Alleviates Porcine Epidemic Diarrhea Virus Infection by Improving Intestinal Structure and Immune Response in Weaned Pigs We found that high dose 25-hydroxyvitamin D(3) supplementation could ease intestinal injury and inhibit intestinal immune response induced by porcine epidemic diarrhea virus (PEDV), suggesting that feeding a high dose of 25-hydroxyvitamin D(3) could be used as an approach against PEDV infection. ABSTRACT: We conducted this experiment to determine if feeding 25-hydroxyvitamin D(3) (25(OH)D(3)) to weaned pigs would alleviate porcine epidemic diarrhea virus (PEDV) infection and immune response. Porcine epidemic diarrhea virus (PEDV) infection causes severe damage to the intestinal function and barrier integrity of pigs [1] , leading to diarrhea, vomiting, dehydration, and high mortality in piglets [2] . In summary, the results of the current study indicate that dietary supplementation of 155.5 µg/kg 25(OH)D 3 alleviated the severity of diarrhea of piglets infected with PEDV by improving the intestinal structure and immune response, and maintaining regular intestinal function.

title:
  Dietary 25-Hydroxyvitamin D(3) Supplementation Alleviates Porcine Epidemic Diarrhea Virus Infection by Improving Intestinal Structure and Immune Response in Weaned Pigs

abstract:
  SIMPLE SUMMARY: Porcine epidemic diarrhea is one of the major problems in current swine husbandry worldwide, and effective measures for prevention and treatment are scarce. We found that high dose 25-hydroxyvitamin D(3) supplementation could ease intestinal injury and inhibit intestinal immune response induced by porcine epidemic diarrhea virus (PEDV), suggesting that feeding a high dose of 25-hydroxyvitamin D(3) could be used as an approach against PEDV infection. ABSTRACT: We conducted this experiment to determine if feeding 25-hydroxyvitamin D(3) (25(OH)D(3)) to weaned pigs would alleviate porcine epidemic diarrhea virus (PEDV) infection and immune response. Forty-two weaned pigs were allotted to 1 of 6 dietary 25(OH)D(3) treatments (5.5, 5.5, 43.0, 80.5, 118.0, 155.5 μg 25(OH)D(3)/kg diet) for 26 days. On day 22 of the trial, all the treatments were orally administrated with PEDV except for one of the 5.5 μg 25(OH)D(3)/kg treatments, which was challenged with the same volume of sterile saline and served as control. Another 5.5 μg 25(OH)D(3)/kg group for PEDV challenge was named CON-PEDV. Average daily gain (p < 0.05) was reduced by PEDV infection. PEDV administration also induced severe diarrhea (p < 0.05), reduction of villous height and the ratio of villous height to crypt depth, and increase of crypt depth and serum diamine oxidase activity (p < 0.05). Serum IgM and complement component 4 levels were increased by PEDV challenge. However, 155.5 μg 25(OH)D(3)/kg supplementation alleviated intestinal damage (p < 0.05) compared with CON-PEDV. Furthermore, 155.5 μg 25(OH)D(3)/kg supplementation downregulated the mRNA abundance of inflammatory cytokines and interferon signal pathway-related genes (p < 0.05) compared with CON-PEDV. These results suggested that dietary supplementation of 155.5 μg 25(OH)D(3)/kg could alleviate intestinal damage and protect against PEDV-induced inflammatory status.


id: cord-003973-pnareltx
author: Hulst, M.M.
date: 2019-04-01
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6849764/
doi: 10.1111/jam.14235
title:
  Study on inactivation of porcine epidemic diarrhoea virus, porcine sapelovirus 1 and adenovirus in the production and storage of laboratory spray‐dried porcine plasma

abstract:
  AIM: Evaluation of the thermal and physical conditions for inactivation of adenovirus (AdV), porcine sapelovirus 1 (PSV1) and the economically important viruses porcine epidemic diarrhoea virus (PEDV) and porcine circovirus 2 (PCV2) in the production of spray‐dried porcine plasma (SDPP). METHODS AND RESULTS: Citrate‐treated porcine plasma of pH 7·5, 9·8 and 10·2 (8·5% dry‐matter) was spiked with PEDV, PSV1, PCV2 and AdV and incubated at 3°C for maximum 24 h, and at 44 or 48°C for maximum 10 min (Experiment 1). Spiked citrate‐treated concentrated plasma of pH 7·5 and 9·8 (24% dry‐matter) was spray dried in a laboratory scale apparatus (Experiment 2). Aliquots of SDPP were stored over a period of 0–10 weeks at 11 and 20°C (Experiment 3). Reverse transcription(RT)‐quantitative PCR detected no notable reduction in viral genomes in treated plasma and SDPP samples. No infectious PSV1 was re‐isolated from plasma and SDPP samples in cell culture. At pH 10·2 and 3°C, infectivity of PEDV in plasma was reduced with a reduction factor of 4·2 log 10 (LRF) at 10 h contact time, whereas heating to 44°C for at least 1 min at alkali pH was needed to achieve a LRF of 4·2 for AdV. Spray drying at an outlet temperature of 80°C reduced AdV infectivity effectively (LRF = 5·2) and PEDV infectivity for 95% (LRF = 1·4). After storage at 20°C for 2 weeks no infectious PEDV was re‐isolated from SDPP anymore (LRF ≥4·0). Due to growth of antibiotic‐resistant bacteria from plasma in cell cultures used for PCV2 isolation, no data regarding inactivation of PCV2 were obtained. CONCLUSIONS: Five percent of PEDV stayed infectious after our spray drying conditions. Spray drying in combination with storage for ≥2 weeks at 20°C eliminated infectivity of PEDV effectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The conditions for inactivation of virus in plasma and SDPP determined are important for producers to inactivate PEDV during production of SDPP.


id: cord-004713-gzts5h0y
title: Pathogenetic observations on pleural effusion disease in rabbits
author: Fennestad, K. L.
date: 1985
txt: ./txt/cord-004713-gzts5h0y.txt
cache: ./cache/cord-004713-gzts5h0y.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7086705/
doi: 10.1007/bf01378969
summary:
  A pathogenetic study of pleural effusion disease (PED) in rabbits was made, using the virulent PED agent or virus (PEDV) and an avirulent derivate of this isolate. Support for this contention is the enhancement of virulence of PED virus (PEDV) observed in the "natural" disease and --after its isolation --by continued serial propagation in rabbits at intervals of 3---10 days (Fig. 1) . However, there is also evidence which might suggest that increasing time of persistence of virulent virus in the individual rabbit host may operate in the reverse direction by selecting a population of predominantly avirulent PEDV particles, which appear to be unable to cause disease unless undergoing new rabbit passages at short intervals (t, 6). After infection with the avirulent derivate, the isolates from serum obtained during the entire period of viraemia were demonstrable in serum dilution 10 -1 to 10 -a, but the primary rabbit inoculation of these dilutions never resulted in clinical signs of PED.

abstract:
  A pathogenetic study of pleural effusion disease (PED) in rabbits was made, using the virulent PED agent or virus (PEDV) and an avirulent derivate of this isolate. Independent of infective dose within the range examined, the virulent isolate caused fatal clinical disease, whereas the avirulent isolate caused subclinical infection. The two isolates differed in rapidity of initial spread of infection and in the maximum virus titres in serum, but they both resulted in a similar low level persisting viraemia. Circulating virulent virus gradually became avirulent during the viraemia. Avirulent infection induced protective immunity to virulent challenge during the first week after primary infection, but full clinical protection was not established until after the fourth week. The findings, corrobated with other closely comparable observations, suggest that the emergence of PED as an intercurrent mortality problem during rabbit passage of pathogenicTreponema pallidum is the result of a specific selective pressure on a benign passenger virus. The expression of virulence of PEDV appears to be dependent on length of interval between passages.


id: cord-004727-9sniu39j
title: Pleural effusion disease in rabbits: Observations on viraemia, immunity and transmissibility
author: Fennestad, K. L.
date: 1981
txt: ./txt/cord-004727-9sniu39j.txt
cache: ./cache/cord-004727-9sniu39j.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7086771/
doi: 10.1007/bf01320789
summary:
  Baby rabbits surviving infection with pleural effusion disease virus (PEDV) developed viraemia persisting for at least six months. The demonstration of pleural effusion disease (PED) virus as passenger of rabbit testicular suspensions of Treponema pallidum in several laboratories shows that this virus can be transmitted from rabbit to rabbit by testicular fluids at intervals of 7--14 days, i.e. the customary time between intratesticular inoculation and harvest of treponemes from the testes (3, 6, 7) . Infected and uninfected rabbits remained together in the same cage for a period of 90--180 days, and their blood was examined for PEDV at 30-day intervals from time of inoculation. To observe if the virus present in blood would retain inability to provoke clinical disease, serial rabbit passages of infectious serum from p.i. days 90, t20, 150 and 180 were carried out at 7-day intervals.

abstract:
  Baby rabbits surviving infection with pleural effusion disease virus (PEDV) developed viraemia persisting for at least six months. Only the infectious serum samples collected during the first 2 months of disease could transfer the typical PED. Six months after neonatal infection, virus concentration in serum was 10(2) to 10(4) rabbit-infectious doses per ml, the level of IgG appeared elevated, and serum rendered non-infectious by ether-treatment had a protective effect in passive immunisation experiments. No evidence of glomerulonephritis or deposits of immunoglobulins could be demonstrated in the kidneys. During the nursing period PEDV was transmitted from infected baby rabbits to two out of four dams, but not to control litter-mates. After the nursing period control rabbits, caged together with the viraemic rabbits for 60 to 150 days, remained free from PEDV infection.


id: cord-009526-ghm1hvei
title: Genomic investigation of piglet resilience following porcine epidemic diarrhea outbreaks
author: Bertolini, F.
date: 2016-12-12
txt: ./txt/cord-009526-ghm1hvei.txt
cache: ./cache/cord-009526-ghm1hvei.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7159462/
doi: 10.1111/age.12522
summary:
  Porcine epidemic diarrhea virus (PEDV) belongs to the Coronaviridae family; this family includes a wide variety of viruses that affect humans and other animals, causing respiratory and gastroenteric diseases (Weiss & Navas-Martin 2005) . The degree to which the small percentage of na€ ıve suckling piglets recover during PED outbreaks in the wider industry is unknown, as is the biological mechanisms involved, but two main hypothesis can be suggested: (i) survival can be related to variation in the intestinal receptor used by PEDV to gain entry to intestinal epithelial cells (the ANPEP gene) or (ii) as summarized by Schneider & Ayres (2008) and Ayres & Schneider (2012) , survival and recovery can be related to particular host immune responses that enhance viral clearance, increase cell epithelial regeneration rate or reduce viral replication rate. In this study, our aim was to investigate genome-wide differences between dead and recovered suckling piglets from commercial farms during PED outbreaks. Table S1 Number of dead and recovered piglets from the PEDV outbreak in each considered farm.

abstract:
  Porcine epidemic diarrhea virus (PEDV) belongs to the Coronaviridae family and causes malabsorptive watery diarrhea, vomiting, dehydration and imbalanced blood electrolytes in pigs. Since the 1970s, PED outbreaks have become a source of problems in pig producing countries all over the world, causing large economic losses for pig producers. Although the infection in adults is not fatal, in naïve suckling piglets mortality is close to 100%. In this study, we investigated genome‐wide differences between dead and recovered suckling piglets from commercial farms after PED outbreaks. Samples from 262 animals (156 dead and 106 recovered) belonging to several commercial lines were collected from five different farms in three different countries (USA, Canada and Germany) and genotyped with the porcine 80K SNP chip. Mean F (st) value was calculated in 1‐Mb non‐overlapping windows between dead and recovered individuals, and the results were normalized to find differences within the comparison. Seven windows with high divergence between dead and recovered were detected—five on chromosome 2, one on chromosome 4 and one on chromosome 15—in total encompassing 152 genes. Several of these genes are either under‐ or overexpressed in many virus infections, including Coronaviridae (such as SARS‐CoV). A total of 32 genes are included in one or more Gene Ontology terms that can be related to PED development, such as Golgi apparatus, as well as mechanisms generally linked to resilience or diarrhea development (cell proliferation, ion transport, ATPase activity). Taken together this information provides a first genomic picture of PEDV resilience in suckling piglets.


id: cord-010053-kniq2mbw
author: Lee, Sunhee
date: 2019-05-20
txt: ./txt/cord-010053-kniq2mbw.txt
cache: ./cache/cord-010053-kniq2mbw.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7168548/
doi: 10.1111/tbed.13219
summary:
  title: Molecular characteristics and pathogenic assessment of porcine epidemic diarrhoea virus isolates from the 2018 endemic outbreaks on Jeju Island, South Korea Genetic and phylogenetic analyses revealed that the re-emergent Jeju Island PEDV isolates were most closely related to the pandemic genogroup 2b (G2b) strains that were responsible for the 2013-2014 global outbreaks, suggesting a direct introduction of the virus from the mainland of South Korea via unknown contaminating sources . In this study, we determined the complete genome sequences of field isolates on Jeju Island to investigate the diversity of the PEDVs responsible for the ongoing endemic outbreaks. Attenuation of an original US porcine epidemic diarrhea virus strain PC22A via serial cell culture passage Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene

title:
  Molecular characteristics and pathogenic assessment of porcine epidemic diarrhoea virus isolates from the 2018 endemic outbreaks on Jeju Island, South Korea

abstract:
  Since the 2013–2014 incursion of the virulent G2b porcine epidemic diarrhoea virus (PEDV) pandemic strains in South Korea, frequent moderate‐scale regional outbreaks have recurred. In particular, areas of Jeju Island with extensive swine production have faced repeated epidemics since the re‐emergence in 2014. The current study reports the complete genome sequences and molecular characterization of the representative PEDV strains responsible for the 2018 endemic outbreaks on Jeju Island. All isolates were determined to belong genetically to the highly pathogenic pandemic G2b group. Full‐length genome sizes of four isolates differed from that of the G2b epidemic field strain due to insertion or deletion (DEL) mutations in the non‐structural protein (nsp)‐ or spike (S) protein‐coding regions. The 2018 Jeju isolates shared 96.7%–98.7% and 98.5%–99.4% identity at the S gene and whole‐genome levels, respectively, compared to global G2b PEDV strains. Genetic and phylogenetic analyses indicated that the 2018 isolates were closest to the 2014 G2b re‐emergent Jeju strains, but appeared to have undergone substantial rapid independent evolution. Among the isolates, a notable nsp3 DEL variant strain, KOR/KNU‐1807/2018, was isolated and propagated by continuous passages in Vero cells, and displayed typical PEDV‐induced syncytia formation. Genomic sequencing identified a unique 8‐nt DEL in the extreme C‐terminal region of the S gene at the 4th passage (KNU‐1807‐P4) compared to its original sample. This DEL resulted in the premature termination of S by nine amino acid residues (EVFEKVHVQ), which contained a KxHxx motif that is a potential endoplasmic reticulum retrieval signal. In vivo animal studies showed that variant strain KNU‐1807 had decreased virulence in suckling piglets. These results advance our knowledge regarding the genetic variation and pathogenicity of the G2b PEDV endemic strains prevalent in Jeju swine herds in South Korea.


id: cord-014932-web2tdef
title: Cloning the structure genes and expression the N gene of porcine epidemic diarrhea virus DX
author: Li, Jian-qiang
date: 2009-05-28
txt: ./txt/cord-014932-web2tdef.txt
cache: ./cache/cord-014932-web2tdef.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7091100/
doi: 10.1007/s12250-009-2982-y
summary:
  The structure genes spike (S), nucleocapsid (N), membrane (M), small membrane (sM) of a porcine epidemic diarrhea virus (PEDV) strain DX isolated in Gansu province, North-west of China, were cloned, sequenced and compared with published sequences of PEDV strains. The N gene was cloned using two primers which contained Nco I and BamH I restriction enzyme sites and subcloned into expression vector pET30a. Cloning and sequence analysis of the N gene of porcine epidemic diarrhea virus LJB/03 Cloning and sequence analysis of the N gene of porcine epidemic diarrhea virus LJB/03 Cloning and sequence analysis of the Korean strain of spike gene of Porcine epidemic diarrhea virus and expression of its neutralizing epitope in plants Cloning and Sequence Analysis of the Nucleocapsid Gene of Porcine Epidemic Diarrhea Virus Chinju99 Cloning and sequence analysis of the spike gene of Porcine epidemic diarrhea virus Chiju99

abstract:
  The structure genes spike (S), nucleocapsid (N), membrane (M), small membrane (sM) of a porcine epidemic diarrhea virus (PEDV) strain DX isolated in Gansu province, North-west of China, were cloned, sequenced and compared with published sequences of PEDV strains. The nucleotide sequences encoding the entire S, sM, M and N genes open reading frame (ORF) of DX were 4 152, 231, 681 and 1 326 bases long respectively. There were transcription regulatory sequences (TRSs) upstream of the initiator ATG of the S, N and M genes. The amino acids sequences of S, M and N contained 30, 3 and 7 potential asparagine (N)-linked glycosylation sites. Homologous analysis and phylogenetic trees showed that DX had the closest relationship with strains LJB/06, JS-2004-2Z and CH/HLJH/06 that were also isolated from China and indicated the prevalence of some PEDV isolates in China were widespread since the JS-2004-2Z strain originated from the south of the China, and LJB/06 and CH/HLJH/06 were isolated from northeast China. The N gene was cloned using two primers which contained Nco I and BamH I restriction enzyme sites and subcloned into expression vector pET30a. The recombinant plasmid was then transformed into E.coli Rossta. SDS-PAGE showed there was a protein of about 55kDa as expected and Western blot indicated the N protein had biological activity.


id: cord-016858-pbjj50bx
title: Immunohistochemical Staining for Detection of Porcine Epidemic Diarrhea Virus in Tissues
author: Jung, Kwonil
date: 2015-09-10
txt: ./txt/cord-016858-pbjj50bx.txt
cache: ./cache/cord-016858-pbjj50bx.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7121281/
doi: 10.1007/978-1-4939-3414-0_2
summary:
  PEDV antigens in frozen tissues are visualized as green staining in the cytoplasm of infected cells by fluorescent dyes conjugated with antibodies when activated by exciting light of a specific wavelength under a fluorescence microscope. In FFPE tissues, PEDV antigens are visualized as red staining in the cytoplasm of infected cells by the deposition of the substrate chromogen, Fast Red. 2013 to present, has led to a substantial loss of piglets (more than 10 % of US swine population). Viral antigens in frozen, fi xed cells, or tissues can be detected by immunohistochemistry (IHC) (or immunohistochemical staining) using specifi c antibodies labeled with fl uorescent dyes, such as Alexa Fluor ® 488 and fl uorescein isothiocyanate (FITC), or enzymes, such as alkaline phosphatase (AP) and peroxidase. Monoclonal antibody-based immunohistochemical detection of porcine epidemic diarrhea virus antigen in formalin-fi xed, paraffi n-embedded intestinal tissues

abstract:
  Porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus, has resulted in significant economic losses in the European, Asian, and North American swine industries in previous years. PEDV infection causes acute diarrhea/vomiting, dehydration, and high morbidity and mortality in seronegative neonatal piglets. In this chapter, materials and methods for performing immunohistochemistry (IHC) for the detection of PEDV antigens in frozen or formalin-fixed, paraffin-embedded (FFPE) tissues are provided. In IHC of frozen tissues where viral antigens are well preserved, the use of specific antibodies labeled with fluorescence dyes provides excellent advantages and convenience, resulting in high sensitivity and specificity of IHC and reduction of operation time. In IHC of FFPE tissues where tissue or cell morphology is well preserved, the use of specific antibodies labeled with enzymes, such as alkaline phosphatase, also gives rise to significant advantages in defining the correlation of viral antigens with histopathologic lesions. PEDV antigens in frozen tissues are visualized as green staining in the cytoplasm of infected cells by fluorescent dyes conjugated with antibodies when activated by exciting light of a specific wavelength under a fluorescence microscope. In FFPE tissues, PEDV antigens are visualized as red staining in the cytoplasm of infected cells by the deposition of the substrate chromogen, Fast Red.


id: cord-033488-du8heorx
author: Ho, Thuong Thi
date: 2020-09-16
txt: ./txt/cord-033488-du8heorx.txt
cache: ./cache/cord-033488-du8heorx.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7524870/
doi: 10.3389/fimmu.2020.02152
summary:
  (A) Sera from five mice from each group immunized with a negative control (wild-type crude extract, G1) or a positive control (commercial vaccine, G2) or the crude extract containing COE-GCN4pII (G3) were mixed, diluted 200 times and used as a primary antibody for detecting 1 µg of purified PEDV antigen. Different levels of PEDV-specific IgG (B), IgA (C), and IgM (D) antibodies in each mouse sera group were calculated as the reciprocal of the geometric mean titer of the five mice of each group vaccinated with the negative control (wild-type crude extract, G1) or the positive control (commercial vaccine, G2) or the crude extract containing COE-GCN4pII (G3). Therefore, plant crude extract containing the trimeric COE protein had the level of IgG antibodies similar to that of commercial vaccines against the PEDV DR13 strain after the third injection. Therefore, we concluded that plant crude extract containing the trimeric COE protein had a strong immunogenicity and induced a neutralizing antibody titer similar to that of the commercial vaccine against the attenuated PEDV DR13 strain.

title:
  Plant-Derived Trimeric CO-26K-Equivalent Epitope Induced Neutralizing Antibodies Against Porcine Epidemic Diarrhea Virus

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a causative agent of a highly infectious disease with a high mortality rate, especially in newborn piglets in Asian countries resulting in serious economic loss. The development of a rapid, safe, effective and cost-efficient vaccine is crucial to protect pigs against PEDV infection. The COE antigen is regarded to be a major target for subunit vaccine development against PEDV infection. The naturally assembled COE protein forms a homotrimeric structure. In the present study, we successfully produced a trimeric COE protein as a native structure by fusion with the C-terminal isoleucine zipper trimerization (GCN4pII) motif in Nicotiana benthamiana, with a high expression level shown via semi-quantified Western blots. Trimeric COE protein was purified via immobilized metal affinity chromatography (IMAC), and its trimeric structure was successfully demonstrated by a cross-linking reaction, and a native PAGE gel. A crude extract containing the COE trimer was used for evaluating immunogenicity in mice. After 1 and 2 booster immunizations, the crude extract containing trimeric COE elicited elevated PEDV-specific humoral responses, as demonstrated by ELISA and Western blot analyses. Notably, a virus-neutralizing antibody assay indicated that the neutralization activities of sera of mice vaccinated with the crude extract containing COE-GCN4pII were similar to those of mice vaccinated with a commercial vaccine. These results suggest that crude extract containing trimeric COE is a promising plant-based subunit vaccine candidate for PEDV prevention.


id: cord-252121-s1zxu5vo
title: Role of Transportation in Spread of Porcine Epidemic Diarrhea Virus Infection, United States
author: Lowe, James
date: 2014-05-17
url: https://www.ncbi.nlm.nih.gov/pubmed/24750785/
doi: 10.3201/eid2005.131628
abstract:
  After porcine epidemic diarrhea virus (PEDV) was detected in the United States in 2013, we tested environmental samples from trailers in which pigs had been transported. PEDV was found in 5.2% of trailers not contaminated at arrival, , suggesting that the transport process is a source of transmission if adequate hygiene measures are not implemented.


id: cord-252772-f3fctcru
title: The Coronavirus PEDV Evades Type III Interferon Response Through the miR-30c-5p/SOCS1 Axis
author: Wang, Changlin
date: 2020-05-22
txt: ./txt/cord-252772-f3fctcru.txt
cache: ./cache/cord-252772-f3fctcru.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32574254/
doi: 10.3389/fmicb.2020.01180
summary:
  Moreover, we demonstrated that PEDV escaped IFN-λ responses by substantially upregulating the suppressor of cytokine signaling protein 1 (SOCS1) expression, which impaired the induction of IFN-stimulated genes (ISGs) and dampened the IFN-λ antiviral response and facilitated PEDV replication in Vero E6 cells. Compared with a mock uninfected control, PEDV did not increase the expression of IFNλ transcripts as observed until 12 hpi, and then gradually induced IFN-λ expression, indicating that PEDV infection elicits type III IFN expression at the late stage of infection instead of the early stage of infection in the Vero E6 cells (Figure 1A) , which was consistent with the results in porcine enteroids (Li et al., 2019) . In the current study, we observed that PEDV elicited substantially increased IFN-λ expression in Vero E6 cells only after 24 hpi (Figure 1A) , which is consistent with the results observed in porcine enteroids following PEDV infection (Li et al., 2019) , indicating that PEDV has evolved mechanisms to escape IFN-λ antiviral response instead of IFN-λ production at the late stage of infection.

abstract:
  Porcine epidemic diarrhea virus (PEDV) is an economically important pathogen that has evolved several mechanisms to evade type I IFN responses. Type III interferon (IFN-λ), an innate cytokine that primarily targets the mucosal epithelia, is critical in fighting mucosal infection in the host and has been reported to potently inhibit PEDV infection in vitro. However, how PEDV escapes IFN-λ antiviral response remains unclear. In this study, we found that PEDV infection induced significant IFN-λ expression in type I IFN-defective Vero E6 cells, but virus-induced endogenous IFN-λ did not reduce PEDV titers. Moreover, we demonstrated that PEDV escaped IFN-λ responses by substantially upregulating the suppressor of cytokine signaling protein 1 (SOCS1) expression, which impaired the induction of IFN-stimulated genes (ISGs) and dampened the IFN-λ antiviral response and facilitated PEDV replication in Vero E6 cells. We further showed that PEDV infection increased SOCS1 expression by decreasing host miR-30c-5p expression. MiR-30c-5p suppressed SOCS1 expression through targeting the 3′ untranslated region (UTR) of SOCS1. The inhibition of IFN-λ elicited ISGs expression by SOCS1 was specifically rescued by overexpression of miR-30c-5p. Collectively, our findings identify a new strategy by PEDV to escape IFN-λ-mediated antiviral immune responses by engaging the SOCS1/miR-30c axis, thus improving our understanding of its pathogenesis.


id: cord-254192-86ksgl5t
author: Li, Liang
date: 2019-10-17
txt: ./txt/cord-254192-86ksgl5t.txt
cache: ./cache/cord-254192-86ksgl5t.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3389/fimmu.2019.02394
doi: 10.3389/fimmu.2019.02394
summary:
  Here, to resolve the mechanism responsible for the disparity between IFN-λ3 and type I IFN in anti-mucosal virus infection, we compared the transcription profiles induced by the two IFNs in porcine intestinal epithelial (IPEC-J2) cells by RNA-Seq. Our results showed that the pretreatment of IPEC-J2 cells with IFN-λ3 resulted in the differential expression of 983 genes. Here, to resolve the mechanism responsible for the disparity between IFN-λ3 and type I IFN in anti-mucosal virus infection, we compared the transcription profiles induced by the two IFNs in porcine intestinal epithelial (IPEC-J2) cells by RNA-Seq. Our results showed that the pretreatment of IPEC-J2 cells with IFN-λ3 resulted in the differential expression of 983 genes. In this study, we comprehensively compared the transcriptional profiling of IFN-λ3-and IFN-α-induced genes in a porcine intestinal epithelial cell line (IPEC-J2) and verified the RNA-Seq results by reverse transcriptase quantitative PCR (RT-qPCR) in vitro, and further confirmed the transcriptional profile difference in crypt-derived porcine enteroids.

title:
  IFN-Lambda 3 Mediates Antiviral Protection Against Porcine Epidemic Diarrhea Virus by Inducing a Distinct Antiviral Transcript Profile in Porcine Intestinal Epithelia

abstract:
  Type III interferon-lambda (IFN-λ) plays a critical role against infection, particularly in mucosal infection in the respiratory and gastrointestinal tract. Our study and other previous studies have shown that porcine IFN-λ more efficiently curtails the infection of porcine epidemic diarrhea virus (PEDV) in the intestine epithelia than type I IFN, whereas IFN-λ3 exerts a more potent effect than IFN-λ1. However, the underlying mechanism remains elusive, and in particular, the transcriptional profile induced by IFN-λ3 has not been reported. Here, to resolve the mechanism responsible for the disparity between IFN-λ3 and type I IFN in anti-mucosal virus infection, we compared the transcription profiles induced by the two IFNs in porcine intestinal epithelial (IPEC-J2) cells by RNA-Seq. Our results showed that the pretreatment of IPEC-J2 cells with IFN-λ3 resulted in the differential expression of 983 genes. In contrast, IFN-α only modified the expression of 134 genes, and 110 of these genes were also observed in the response to IFN-λ3. A transcriptional enrichment analysis indicated that IFN-λ3 or IFN-α regulates multiple cellular processes and that IFN-λ3 activates more robust signaling pathways, particularly the antiviral Jak-STAT signaling pathway, than IFN-α. Furthermore, we verified the RNA-Seq results through an RT-qPCR analysis of IPEC-J2 cells and porcine enteroids. Moreover, transient expression of the porcine rsad2 and mx2 genes among the top 10 genes induced by IFN-λ3 significantly inhibited PEDV infection. Collectively, the data showed that IFN-λ3 induces a unique transcriptional profile that does not completely overlap with that induced by IFN-α and strongly elicits a set of genes responsible for the antiviral activity of IFN-λ3. These findings provide important knowledge regarding the elicited ISGs of type I and III IFNs in restricting porcine intestinal viral infection.


id: cord-254317-n2knqj4z
title: The enhanced replication of an S-intact PEDV during coinfection with an S1 NTD-del PEDV in piglets
author: Su, Yunfang
date: 2018-11-27
txt: ./txt/cord-254317-n2knqj4z.txt
cache: ./cache/cord-254317-n2knqj4z.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/30593369/
doi: 10.1016/j.vetmic.2018.11.025
summary:
  Porcine epidemic diarrhea virus (PEDV) variants having a large deletion in the N-terminal domain of the S1 subunit of spike (S) protein were designated as S1 NTD-del PEDVs. They replicate well in experimentally infected pigs. Effect of mucin, bile and bile acids on the infection of PEDV icPC22A and icPC22A-S1Δ197 in Vero and IPEC-DQ cells Viruses (icPC22A or icPC22A-S1Δ197) were mixed with different concentrations of BM (0, 0.1, 0.3, 0.5 mg/mL) or PGM (0, 0.5, 1.0, 2.5, 5.0 mg/mL). Compared with the peak fecal PEDV N gene shedding titer (11.6 ± 0.2 log 10 copies/mL) of piglets in the icPC22A group (1 dpi), pigs in the coinfection group had a significantly higher peak titer (13.6 ± 0.7 log 10 copies/mL) ( Fig. 1B and Table 2 ) at a delayed time point (1.5 dpi). S1 NTD-del PEDV replicated to a lower peak titer in coinfection than that in single virus infection in both Vero cells and IPEC-DQ cells.

abstract:
  Porcine epidemic diarrhea virus (PEDV) variants having a large deletion in the N-terminal domain of the S1 subunit of spike (S) protein were designated as S1 NTD-del PEDVs. They replicate well in experimentally infected pigs. However, on farms they often co-infect pigs with the PEDV containing an intact S protein (S-intact PEDV). We aimed to characterize viral replication and pathogenesis in neonatal gnotobiotic pigs infected simultaneously with the two types of PEDV using two recombinant PEDVs: icPC22A and its S1 NTD-del form icPC22A-S1Δ197. Additionally, viral replication was compared in Vero and IPEC-DQ cells at the presence of bovine mucin (BM), porcine gastric mucin (PGM), swine bile and bile acids during inoculation. In the pigs coinfected with icPC22A and icPC22A-S1Δ197, icPC22A replicated to a higher peak titer than its infection of pigs without the presence of icPC22A-S1Δ197. The severity of diarrhea and intestinal atrophy were similar between icPC22A and the coinfection groups, but were significantly higher than icPC22A-S1Δ197 group. In Vero and IPEC-DQ cells, certain concentrations of BM, PGM, bile and bile acids increased significantly the infectivity of icPC22A but had no or negative effects on icPC22A-S1Δ197. These results indicated that the replication of the S-intact PEDV was enhanced during coinfection in piglets. This observation may be explained partially by the fact that mucin, bile and bile acids in gastrointestinal tract had facilitating effects on the infection of S-intact PEDV, but no/inhibition effects on S1 NTD-del PEDV.


id: cord-254405-yc1q20fz
author: Jie, Tao
date: 2018-07-31
txt: ./txt/cord-254405-yc1q20fz.txt
cache: ./cache/cord-254405-yc1q20fz.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-018-3968-6
doi: 10.1007/s00705-018-3968-6
summary:
  Furthermore, we cultured the virus and screened for attenuated PEDV strains by analyzing the genovariations that occurred during passaging -confirming the results in animal experiments. [27] analyzed a cell culture-adapted PEDV (passage 100) strain with a smaller ORF3 gene and found it to have lower virulence relative to the wild-type virus. Molecular characterization of the ORF3 and S1 genes of porcine epidemic diarrhea virus non S-INDEL strains in seven regions of China Comparative genomic analysis of classical and variant virulent parental/attenuated strains of porcine epidemic diarrhea virus Isolation and identification of porcine epidemic diarrhea virus strain HBMC2012 and its pathogenicity in piglet Cloning and further sequence analysis of the spike gene of attenuated porcine epidemic diarrhea virus DR13 Genome sequencing and analysis of a novel recombinant porcine epidemic diarrhea virus strain from Henan, China Genome sequencing and analysis of a novel recombinant porcine epidemic diarrhea virus strain from Henan, China

title:
  Preparation and characterization of an attenuated porcine epidemic diarrhea virus strain by serial passaging

abstract:
  Porcine epidemic diarrhea virus (PEDV) is prevalent in most parts of the world. Owing to its antigenic variation, prevention of the diseases caused by this virus is difficult. In this study, two PEDV isolates with similar growth kinetics were successfully propagated in Vero cells. Complete genome sequence analysis showed that they have a 49nt deletion in the ORF3 gene and were classified into Group 1, the same group that includes the classical CV777 strain. Recombination analysis revealed that the event had occurred in the ORF1a gene, at 3596–6819 nt, among the two PEDV isolates and the CV777 and DR13 strains. During their continuous propagation, 14 nonsynonymous mutations occurred in the spike (S) gene of strain JS-2/2014 between generations G5 and G90, but there were no changes between G90 and G100. We assumed that strain JS-2/2014 might be attenuated by the 90th generation. Piglets orally fed with JS-2/2014 G90 showed no clinical symptoms, and no virus was detected in the feces and nasal fluid. In conclusion, JS-2/2014 was successfully identified by screening, was attenuated after propagation in Vero cells, and may serve as a candidate virus for vaccine preparations.


id: cord-255238-adpn5fb9
title: Discovery of a novel swine enteric alphacoronavirus (SeACoV) in southern China
author: Pan, Yongfei
date: 2017-09-28
txt: ./txt/cord-255238-adpn5fb9.txt
cache: ./cache/cord-255238-adpn5fb9.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.vetmic.2017.09.020
doi: 10.1016/j.vetmic.2017.09.020
summary:
  Isolation and propagation of the pathogen in cell culture resulted in discovery of a novel swine enteric alphacoronavirus (tentatively named SeACoV) related to the bat coronavirus HKU2 identified in the same region a decade ago. Most recently, several chimeric SeCoV strains with a TGEV genomic backbone replaced by a PEDV spike (S) gene were identified from swine fecal samples in Europe (Akimkin et al., 2016; Belsham et al., 2016; Boniotti et al., 2016) , implying that novel SeCoV pathogens could emerge by inter-CoV recombination under co-infection. In this study, we report the isolation and genetic characterization of a novel swine enteric alphacoronavirus (tentatively named SeACoV), related to a bat enteric coronavirus, from a pig farm that reported newborn-piglet diarrhea in southern China in 2017.

abstract:
  Outbreaks of diarrhea in newborn piglets without detection of transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV), have been recorded in a pig farm in southern China since February 2017. Isolation and propagation of the pathogen in cell culture resulted in discovery of a novel swine enteric alphacoronavirus (tentatively named SeACoV) related to the bat coronavirus HKU2 identified in the same region a decade ago. Specific fluorescence signal was detected in Vero cells infected with SeACoV by using a positive sow serum collected in the same farm, but not by using TGEV-, PEDV- or PDCoV-specific antibody. Electron microscopy observation demonstrated that the virus particle with surface projections was 100–120 nm in diameter. Complete genomic sequencing and analyses of SeACoV indicated that the extreme amino-terminal domain of the SeACoV spike (S) glycoprotein structurally similar to the domain 0 of the alphacoronavirus NL63, whereas the rest part of S structurally resembles domains B to D of the betacoronavirus. The SeACoV-S domain 0 associated with enteric tropism had an extremely high variability, harboring 75-amino-acid (aa) substitutions and a 2-aa insertion, compared to that of HKU2, which is likely responsible for the extended host range or cross-species transmission. The isolated virus was infectious in pigs when inoculated orally into 3-day-old newborn piglets, leading to clinical signs of diarrhea and fecal virus shedding. These results confirmed that it is a novel swine enteric coronavirus representing the fifth porcine coronavirus.


id: cord-255607-dbexsugq
author: Wu, Yang
date: 2020-05-31
txt: ./txt/cord-255607-dbexsugq.txt
cache: ./cache/cord-255607-dbexsugq.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3390/v12060599
doi: 10.3390/v12060599
summary:
  Our preliminary results revealed that endogenous TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), the key components in the IFN signaling pathway were downregulated in PEDV infected IPEC-J2 cells by iTRAQ analysis. Moreover, PEDV nsp15 can directly degrade the RNA levels of TBK1 and IRF3 dependent on its EndoU activity to suppress IFN production and constrain the induction of IFN stimulated genes (ISGs), by which PEDV antagonizes the host innate response to facilitate its replication. Previous studies suggest that PEDV can restrain host innate immune response by different strategies, such as by degradation or cleavage of key factors essential the IFN signaling pathway [25, 26] , competitive interaction between viral encoded proteins and modulators for IFN production [27, 28] , or localization changes of antiviral components [29] .

title:
  Porcine Epidemic Diarrhea Virus nsp15 Antagonizes Interferon Signaling by RNA Degradation of TBK1 and IRF3

abstract:
  Porcine epidemic diarrhea virus (PEDV) causes a porcine disease associated with swine epidemic diarrhea. The type I interferon (IFN-I or IFN α/β) is a key mediator of innate antiviral response during virus infection. Different antagonistic strategies have been identified and determined as to how PEDV infection inhibits the host’s IFN responses to escape the host innate immune pathway, but the pathogenic mechanisms of PEDV infection are not fully elucidated. Our preliminary results revealed that endogenous TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3), the key components in the IFN signaling pathway were downregulated in PEDV infected IPEC-J2 cells by iTRAQ analysis. In this study, we screened nsp15 as the most important viral encoded protein involved in TBK1 and IRF3 reduction. Endoribonuclease (EndoU) activity has been well determined for coronavirus nsp15. Three residues (H226, H241, and K282) of PEDV nsp15 were identified as critical amino acids for PEDV EndoU but not D265, which was not well correlated with published results of other coronaviruses, such as severe acute respiratory syndrome virus (SARS-CoV). Moreover, PEDV nsp15 can directly degrade the RNA levels of TBK1 and IRF3 dependent on its EndoU activity to suppress IFN production and constrain the induction of IFN stimulated genes (ISGs), by which PEDV antagonizes the host innate response to facilitate its replication. Collectively, these results have confirmed that PEDV nsp15 was capable of subverting the IFN response by the RNA degradation of TBK1 and IRF3.


id: cord-255773-b4re5bky
author: Zhang, Qingzhan
date: 2016-01-14
url: https://api.elsevier.com/content/article/pii/S0042682215005310
doi: 10.1016/j.virol.2015.12.010
title:
  Suppression of type I interferon production by porcine epidemic diarrhea virus and degradation of CREB-binding protein by nsp1

abstract:
  Type I interferons (IFN-α/β) are the major components of the innate immune response of hosts, and in turn many viruses have evolved to modulate the host response during infection. We found that the IFN-β production was significantly suppressed during PEDV infection in cells. To identify viral IFN antagonists and to study their suppressive function, viral coding sequences for the entire structural and nonstructural proteins were cloned and expressed. Of 16 PEDV nonstructural proteins (nsps), nsp1, nsp3, nsp7, nsp14, nsp15 and nsp16 were found to inhibit the IFN-β and IRF3 promoter activities. The sole accessory protein ORF3, structure protein envelope (E), membrane (M), and nucleocapsid (N) protein were also shown to inhibit such activities. PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP) by degrading CBP. A further study showed that the CBP degradation by nsp1 was proteasome-dependent. Our data demonstrate that PEDV modulates the host innate immune responses by degrading CBP and suppressing ISGs expression.


id: cord-255862-84u3c33m
title: Antiviral escin derivatives from the seeds of Aesculus turbinata Blume (Japanese horse chestnut)
author: Kim, Ji Won
date: 2017-07-01
txt: ./txt/cord-255862-84u3c33m.txt
cache: ./cache/cord-255862-84u3c33m.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.bmcl.2017.05.022
doi: 10.1016/j.bmcl.2017.05.022
summary:
  In this research, we investigated whether escin derivatives 1–7 (including new compounds 2, 3, 5 and 6), without the angeloyl or tigloyl groups and with modified glycosidic linkages by hydrolysis, have PEDV inhibitory effects with less cytotoxicity. Interestingly, compounds 1-7 isolated from the fraction with the two-step hydrolysis were evaluated to have much lower cytotoxic effects than compounds 8-10 from the n-BuOH part at concentration of 20 lM (Fig. S22) . As compounds 8-10 showed strong cytotoxic effects on Vero cells at 20 lM, their PEDV inhibitory activities were evaluated at a concentration of 2 lM. 33 To measure the expression level of viral RNA encoding nucleocapsid and spike proteins, compounds 4 and 6 were treated in Vero cells at a concentration of 40 lM and total RNA was extracted for reverse transcription followed by polymerase chain reaction using the primers for PEDV (STable 1 ).

abstract:
  Abstract Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high fatality of piglets, influencing the swine industry. Japanese horse chestnut (seed of Aesculus turbinata) contains many saponin mixtures, called escins, and has been used for a long time as a traditional medicinal plant. Structure-activity relationship (SAR) studies on escins have revealed that acylations at C-21 and C-22 with angeloyl or tigloyl groups were important for their cytotoxic effects. However, the strong cytotoxicity of escins makes them hard to utilize for other diseases and to develop as nutraceuticals. In this research, we investigated whether escin derivatives 1–7 (including new compounds 2, 3, 5 and 6), without the angeloyl or tigloyl groups and with modified glycosidic linkages by hydrolysis, have PEDV inhibitory effects with less cytotoxicity. Compounds 1–7 had no cytotoxicity at 20μM on VERO cells, while compounds 8–10 showed strong cytotoxicity at similar concentrations on PEDV. Our results suggest that escin derivatives showed strong inhibitory activities on PEDV replication with lowered cytotoxicity. These studies propose a method to utilize Japanese horse chestnut for treating PEDV and to increase the diversity of its bioactive compounds.


id: cord-257136-zpeh8pmc
author: Huang, Xin
date: 2019-04-26
txt: ./txt/cord-257136-zpeh8pmc.txt
cache: ./cache/cord-257136-zpeh8pmc.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/31025076/
doi: 10.1007/s00253-019-09835-7
summary:
  To develop a simple, rapid, accurate, and high-throughput detection method for diagnosis and differential diagnosis on swine enteric coronaviruses, specific primers and probes were designed based on the highly conserved regions of transmissible gastroenteritis virus (TGEV) N, porcine epidemic diarrhea virus (PEDV) M, porcine deltacoronavirus (PDCoV) M, and porcine enteric alphacoronavirus (PEAV) N genes respectively. To develop a simple, rapid, accurate, and high-throughput detection method for diagnosis and differential diagnosis on swine enteric coronaviruses, a TaqMan-probe-based multiplex real-time RT-qPCR assay was established to simultaneously detect TGEV, PEDV, PEAV, and PDCoV from the same reaction vial. To establish a high-specific multiplex real-time RT-qPCR for the detection and differential diagnosis of swine enteric coronaviruses, primer sets, and TaqMan probes were designed targeting the highly conserved regions of PEDV or PDCoV M genes and TGEV or PEAV N genes, based on bioinformatics analysis of each virus.

title:
  A TaqMan-probe-based multiplex real-time RT-qPCR for simultaneous detection of porcine enteric coronaviruses

abstract:
  Swine enteric coronaviruses are a group of most significant pathogens causing diarrhea in piglets with similar clinical symptoms and pathological changes. To develop a simple, rapid, accurate, and high-throughput detection method for diagnosis and differential diagnosis on swine enteric coronaviruses, specific primers and probes were designed based on the highly conserved regions of transmissible gastroenteritis virus (TGEV) N, porcine epidemic diarrhea virus (PEDV) M, porcine deltacoronavirus (PDCoV) M, and porcine enteric alphacoronavirus (PEAV) N genes respectively. A TaqMan-probe-based multiplex real-time RT-qPCR assay was developed and optimized to simultaneously detect these swine enteric coronaviruses. The results showed that the limit of detection can reach as low as 10 copies in singular real-time RT-qPCR assays and 100 copies in multiplex real-time RT-qPCR assay, with all correlation coefficients (R(2)) at above 0.99, and the amplification efficiency at between 90 and 120%. This multiplex real-time RT-qPCR assay demonstrated high sensitivity, extreme specificity, and excellent repeatability. The multiplex real-time RT-qPCR assay was then employed to detect the swine enteric coronavirus from 354 field diarrheal samples. The results manifested that TGEV and PDCoV were the main pathogens in these samples, accompanied by co-infections. This well-established multiplex real-time RT-qPCR assay provided a rapid, efficient, specific, and sensitive tool for detection of swine enteric coronaviruses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00253-019-09835-7) contains supplementary material, which is available to authorized users.


id: cord-258546-1tf5ggfo
title: New emergence pattern with variant porcine epidemic diarrhea viruses, South Korea, 2012–2015
author: Chung, Hee-Chun
date: 2016-12-02
txt: ./txt/cord-258546-1tf5ggfo.txt
cache: ./cache/cord-258546-1tf5ggfo.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.virusres.2016.06.013
doi: 10.1016/j.virusres.2016.06.013
summary:
  Since outbreaks of porcine epidemic diarrhea virus (PEDV) in the United States in 2013, explosive outbreaks of PED in South Korea have infected all age groups of pigs in 2014–2015 year. PED outbreaks re-occurred in Korea in 2013, however, it was demonstrated that the emerging PEDVs were not variants of old Korean isolates or attenuated vaccine strains (Chung et al., 2015) . This study tested whether PEDV isolated recently was crossed neutralized by serum of pigs which were vaccinated with Korean PED oral vaccine (Attenuated DR13 strain, Green Cross Veterinary Product Co., Ltd., Yong-In, Korea). Comparative genome analysis and molecular epidemiology of the reemerging porcine epidemic diarrhea virus strains isolated in Korea ISolation of porcine epidemic diarrhea virus during outbreaks in South Korea Isolation of porcine epidemic diarrhea virus (PEDV) in Korea Heterogeneity in spike protein genes of porcine epidemic diarrhea viruses isolated in Korea

abstract:
  Since outbreaks of porcine epidemic diarrhea virus (PEDV) in the United States in 2013, explosive outbreaks of PED in South Korea have infected all age groups of pigs in 2014–2015 year. This study analyzed a large collection of the Spike protein coding gene to infer the spatial-temporal diffusion history of PEDV. The studying results suggested that PEDVs in Korea belonged to different genogroups. While classical G1 was continuingly circulating between provinces of Korea, the pandemic G2a were recently introduced from China and USA. By the application of Bayesian phylogeographical analysis, this study demonstrated the spatial-temporal transmission of PEDVs within Korea. Of the recent emerged G2a viruses, J3142 strains showed potential recombination breakpoint (376–2,143nt) of S1 gene between KNU1303_Korea strain_G2a (KJ451046) and 45RWVCF0712_Thailand strain_G2b (KF724935). The pandemic G2a virus was partial neutralized by the antibodies invoked by the G1- based PED vaccine virus.


id: cord-259296-qsaewje2
title: Tomatidine inhibits porcine epidemic diarrhea virus replication by targeting 3CL protease
author: Wang, Pengcheng
date: 2020-11-11
url: https://doi.org/10.1186/s13567-020-00865-y
doi: 10.1186/s13567-020-00865-y
abstract:
  Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in suckling piglets, leading to severe economic losses worldwide. There is an urgent need to find new therapeutic methods to prevent and control PEDV. Not only is there a shortage of commercial anti-PEDV drugs, but available commercial vaccines fail to protect against highly virulent PEDV variants. We screened an FDA-approved library of 911 natural products and found that tomatidine, a steroidal alkaloid extracted from the skin and leaves of tomatoes, demonstrates significant inhibition of PEDV replication in Vero and IPEC-J2 cells in vitro. Molecular docking and molecular dynamics analysis predicted interactions between tomatidine and the active pocket of PEDV 3CL protease, which were confirmed by fluorescence spectroscopy and isothermal titration calorimetry (ITC). The inhibiting effect of tomatidine on 3CL protease was determined using cleavage visualization and FRET assay. Tomatidine-mediated blocking of 3CL protease activity in PEDV-infected cells was examined by western blot detection of the viral polyprotein in PEDV-infected cells. It indicates that tomatidine inhibits PEDV replication mainly by targeting 3CL protease. In addition, tomatidine also has antiviral activity against transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), encephalo myocarditis virus (EMCV) and seneca virus A (SVA) in vitro. These results may be helpful in developing a new prophylactic and therapeutic strategy against PEDV and other swine disease infections.


id: cord-259324-g8kv4pvq
title: Expression of the protective antigen for PEDV in transgenic duckweed, Lemna minor
author: Ko, Suk-Min
date: 2011-10-28
txt: ./txt/cord-259324-g8kv4pvq.txt
cache: ./cache/cord-259324-g8kv4pvq.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32226733/
doi: 10.1007/s13580-011-0007-x
summary:
  In this study, we assessed the feasibility of producing a protective antigen for the PEDV spike protein 1 using duckweed, Lemna minor. Transgene integration and expression of the PEDV spike protein 1 gene were confirmed by genomic PCR and RT-PCR and western blot analysis of transgenic Lemna, respectively. In this study, we report the stable transformation and expression of a protective antigen for PEDV in Lemna minor with potential for use as an effective complement to the diets of animals. Fronds were then blotted onto sterile filter paper, and co-cultivated with Agrobacterium tumefaciens strain EHA105 harboring the PEDV spike protein 1 gene fused to a c-myc tag for 72 h on antibiotic-free ½MS1BA medium. PCR products of the expected size (330 bp) corresponding to primers designed on the internal PEDV spike protein 1 gene were detected from kanamycin-resistant Lemna, whereas no DNA band corresponding to the target gene was detected in untransformed wild-type Lemna.

abstract:
  Duckweeds are small, floating aquatic plants with a number of useful characteristics, including edibility, fast-growing, and a clonal proliferation. Duckweed is also fed to animals as a diet complement because of its high nutritional value. Porcine epidemic diarrhea virus (PEDV) is a major causative agent of fatal diarrhea in piglets and is a serious problem in the hog-raising industry. In this study, we assessed the feasibility of producing a protective antigen for the PEDV spike protein 1 using duckweed, Lemna minor. Stably transformed Lemna were obtained by co-cultivation with A. tumefaciens EHA105 harboring the PEDV spike protein gene. Transgene integration and expression of the PEDV spike protein 1 gene were confirmed by genomic PCR and RT-PCR and western blot analysis of transgenic Lemna, respectively. This is the first report of the expression of a vaccine antigen against an animal infectious disease in duckweed.


id: cord-259794-6qoksn00
author: Shi, Da
date: 2017-01-03
txt: ./txt/cord-259794-6qoksn00.txt
cache: ./cache/cord-259794-6qoksn00.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28045037/
doi: 10.1038/srep39700
summary:
  Porcine epidemic diarrhea virus (PEDV) replicates in the cytoplasm of infected cells, but its nucleocapsid (N) protein localizes specifically to the nucleolus. The results suggest potential linkages among viral strategies for the regulation of cell survival activities, possibly through an interaction of N protein with NPM1 which prevents its proteolytic cleavage and enhances cell survival, thus ultimately promoting the replication of PEDV. In this study, to determine the intracellular distribution of N protein at the protein level, PEDV-infected Vero E6 cells were lysed, separated into nuclear and cytoplasmic fractions, and analyzed by western blotting. This study was based on different lines of evidence, reflecting both in vivo and in vitro situations, and demonstrated that PEDV N protein is able to associate with the major nucleolar protein NPM1 of Vero E6 cells (Fig. 2) ; we failed to detect an interaction with the fibrillarin or nucleolin (See Supplementary Fig. S2 ).

title:
  Nucleocapsid Interacts with NPM1 and Protects it from Proteolytic Cleavage, Enhancing Cell Survival, and is Involved in PEDV Growth

abstract:
  Porcine epidemic diarrhea virus (PEDV) replicates in the cytoplasm of infected cells, but its nucleocapsid (N) protein localizes specifically to the nucleolus. The mechanism of nuclear translocation, and whether N protein associates with particular nucleolar components, is unknown. In this study, we confirm that a nucleolar phosphoprotein nucleophosmin (NPM1) interacts and co-localizes with the N protein in the nucleolus. In vitro binding studies indicated that aa 148–294 of N and aa 118–188 of NPM1 were required for binding. Interestingly, N protein importation into the nucleolus is independent of the ability of NPM1 to shuttle between the nucleus and the cytoplasm. Furthermore, overexpression of NPM1 promoted PEDV growth, while knockdown of NPM1 suppressed PEDV growth. In addition, binding of N protein to NPM1 protects it from proteolytic degradation by caspase-3, leading to increased cell survival. Taken together, our studies demonstrate a specific interaction of the N protein with the host cell protein NPM1 in the nucleolus. The results suggest potential linkages among viral strategies for the regulation of cell survival activities, possibly through an interaction of N protein with NPM1 which prevents its proteolytic cleavage and enhances cell survival, thus ultimately promoting the replication of PEDV.


id: cord-260107-gqbtkf0x
title: Isolation and characterization of a Korean porcine epidemic diarrhea virus strain KNU-141112
author: Lee, Sunhee
date: 2015-10-02
txt: ./txt/cord-260107-gqbtkf0x.txt
cache: ./cache/cord-260107-gqbtkf0x.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0168170215300149
doi: 10.1016/j.virusres.2015.07.010
summary:
  In the present study, one Korean PEDV strain, KOR/KNU-141112/2014, was successfully isolated and serially propagated in Vero cells for over 30 passages. Our genomic analyses indicated that the Korean isolate KNU-141112 is genetically stable during the first 30 passages in cell culture and is grouped within subgroup G2b together with the recent re-emergent Korean strains. Our data indicated that KNU-141112 isolate is relatively stable during the first 30 passages in cell culture and is classified into subgroup G2b that includes PEDV strains responsible for recent severe outbreaks in Korea and the US. Although virus isolation in cell culture from clinical samples of naturally or experimentally infected pigs is fastidious, recent studies reported the successful isolation and propagation of several US original PEDV strains using Vero cells (Chen et al., 2014; Oka et al., 2014) . Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene

abstract:
  Severe outbreaks of porcine epidemic diarrhea virus (PEDV) have re-emerged in Korea and rapidly swept across the country, causing tremendous economic losses to producers and customers. Despite the availability of PEDV vaccines in the domestic market, the disease continues to plague the Korean pork industry, raising issues regarding their protective efficacy and new vaccine development. Therefore, PEDV isolation in cell culture is urgently needed to develop efficacious vaccines and diagnostic assays and to conduct further studies on the virus biology. In the present study, one Korean PEDV strain, KOR/KNU-141112/2014, was successfully isolated and serially propagated in Vero cells for over 30 passages. The in vitro and in vivo characteristics of the Korean PEDV isolate were investigated. Virus production in cell culture was confirmed by cytopathology, immunofluorescence, and real-time RT-PCR. The infectious virus titers of the viruses during the first 30 passages ranged from 10(5.1) to 10(8.2) TCID(50) per ml. The inactivated KNU-141112 virus was found to mediate potent neutralizing antibody responses in immunized guinea pigs. Animal studies showed that KNU-141112 virus causes severe diarrhea and vomiting, fecal shedding, and acute atrophic enteritis, indicating that strain KNU-141112 is highly enteropathogenic in the natural host. In addition, the entire genomes or complete S genes of KNU-141112 viruses at selected cell culture passages were sequenced to assess the genetic stability and relatedness. Our genomic analyses indicated that the Korean isolate KNU-141112 is genetically stable during the first 30 passages in cell culture and is grouped within subgroup G2b together with the recent re-emergent Korean strains.


id: cord-260835-ck9z5xsd
author: Kamau, Anthony Ndirangu
date: 2017-01-02
txt: ./txt/cord-260835-ck9z5xsd.txt
cache: ./cache/cord-260835-ck9z5xsd.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0168170216304725
doi: 10.1016/j.virusres.2016.10.004
summary:
  Results showed PEDV infection was restricted to pAPN and pAPN domain VII expressing NIH3T3 cells. Also, PEDV harvested from pAPN or domain VII expressing NIH3T3 cells was induced indirect plaques in Vero cells confirming successful entry and replication. In the current study, by constitutive expression of pAPN in non-susceptible NIH3T3 cells, we have sought to annotate the previous findings stipulating pAPN receptor function for PEDV. Susceptibility assays showed infection in pAPN domain-VII expressing cells but virus entry was abrogated in absence of seventh domain (pAPN DI-VI ) as shown in (Fig. 5A) . PEDV was also reported to interact with pAPN in porcine enterocytes (Li et al., 2009) , and is capable of infecting MDCK and ST cells expressing the pAPN receptor (Oh et al., 2003; Nam and Lee, 2010) . In our study, to determine the specific interactive point of pAPN wt with PEDV, domain mutants were expressed stably in NIH3T3 cells.

title:
  Porcine amino peptidase N domain VII has critical role in binding and entry of porcine epidemic diarrhea virus

abstract:
  Porcine epidemic diarrhea virus (PEDV) infects swine intestinal cells causing enteric disease. Research has shown that the entry into these cells is through porcine aminopeptidase N (pAPN) receptor. To gain insights into mechanisms of PEDV-pAPN interactions, the present study aimed at identifying the domain that is critical for PEDV binding. To this end, NIH3T3 cell lines constitutively expressing pAPN or pAPN mutants were generated. The mutants were; domain VII deletion mutant and domains IV–VI deletion mutant. In the latter, domain VII was linked to the transmembrane segment through domain III. Results showed PEDV infection was restricted to pAPN and pAPN domain VII expressing NIH3T3 cells. Further, reducing PEDV titre 10 fold resulted in 37.8% decrease in foci indicating positive correlation. A time course test at 12, 24, 36, 48 and 60 h showed that foci increased 6 fold in the overall time range. Also, PEDV harvested from pAPN or domain VII expressing NIH3T3 cells was induced indirect plaques in Vero cells confirming successful entry and replication. Collectively, our results demonstrate that PEDV recognizes pAPN and that the main interactive point is lodged within domain VII of the pAPN. These findings are important for therapeutic development as well as creating a platform for future studies on PEDV.


id: cord-261036-zdhg4axx
title: Enhanced cell fusion activity in porcine epidemic diarrhea virus adapted to suckling mice
author: Shirato, Kazuya
date: 2010-09-09
txt: ./txt/cord-261036-zdhg4axx.txt
cache: ./cache/cord-261036-zdhg4axx.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/20827493/
doi: 10.1007/s00705-010-0790-1
summary:
  PEDV obtained after ten passages through the brains (MK-p10) had increased virulence for mice, and its fusion activity in cultured cells exceeded that of the original strain. One of these (an H-to-R substitution at residue 1,381) was first detected in PEDV isolated after eight passages, and both this virus (MK-p8) and MK-p10 showed enhanced syncytium formation relative to the original MK strain and viruses isolated after two, four, and six passages, suggesting the possibility that the H-to-R mutation was responsible for this activity. Expression of the receptor protein for mouse hepatitis virus (MHV) and severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) in cultured cells confers susceptibility to each of these viruses [2, 4, 25] . In the present study, we isolated a strain of PEDV that was more virulent than the original tissue-culture-adapted virus after passage through mouse brain cells. To investigate viral virulence and replication in mouse brains, 0-day-old mice were infected i.c. with 5,000 PFU of PEDV and monitored daily for clinical features; they were also weighed daily.

abstract:
  Porcine epidemic diarrhea virus (PEDV) is the major causative agent of fatal diarrhea in piglets. To study the pathogenic features of PEDV using a mouse model, PEDV with virulence in mice is required. In pursuit of this, we adapted a tissue-culture-passed PEDV MK strain to suckling mouse brains. PEDV obtained after ten passages through the brains (MK-p10) had increased virulence for mice, and its fusion activity in cultured cells exceeded that of the original strain. However, the replication kinetics of MK and MK-p10 did not differ from each other in the brain and in cultured cells. The spike (S) protein of MK-p10 had four amino acid substitutions relative to the original strain. One of these (an H-to-R substitution at residue 1,381) was first detected in PEDV isolated after eight passages, and both this virus (MK-p8) and MK-p10 showed enhanced syncytium formation relative to the original MK strain and viruses isolated after two, four, and six passages, suggesting the possibility that the H-to-R mutation was responsible for this activity. This mutation could be also involved in the increased virulence of PEDV observed for MK-p10.


id: cord-261043-f9w310tp
title: Forecasting herd-level porcine epidemic diarrhea (PED) frequency trends in Ontario (Canada)
author: Ajayi, Toluwalope
date: 2019-03-01
txt: ./txt/cord-261043-f9w310tp.txt
cache: ./cache/cord-261043-f9w310tp.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.prevetmed.2019.01.005
doi: 10.1016/j.prevetmed.2019.01.005
summary:
  With recent advances in predictive analytics showing promise for health and disease forecasting, the primary objective of this study was to apply machine learning predictive methods (random forest, artificial neural networks, and classification and regression trees) to provincial PEDV incidence data, and in so doing determine their accuracy for predicting future PEDV trends. With 10-fold cross validation performed on the entire dataset, the overall accuracy was 0.68 (95% CI: 0.60 – 0.75), 0.57 (95% CI: 0.49 – 0.64), and 0.55 (0.47 – 0.63) for the random forest, artificial neural network, and classification and regression tree models, respectively. For the additional models constructed with random training and test sets (using 10-fold cross validation on the entire dataset), the summary confusion matrix in Table 3 indicates overall accuracy values of 68%, 57%, and 55% for random forest, neural nets, and classification trees respectively.

abstract:
  Porcine Epidemic Diarrhea Virus (PEDV) emerged in North America in 2013. The first case of PEDV in Canada was identified on an Ontario farm in January 2014. Surveillance was instrumental in identifying the initial case and in minimizing the spread of the virus to other farms. With recent advances in predictive analytics showing promise for health and disease forecasting, the primary objective of this study was to apply machine learning predictive methods (random forest, artificial neural networks, and classification and regression trees) to provincial PEDV incidence data, and in so doing determine their accuracy for predicting future PEDV trends. Trend was defined as the cumulative number of new cases over a four-week interval, and consisted of four levels (zero, low, medium and high). Provincial PEDV incidence and prevalence estimates from an industry database, as well as temperature, humidity, and precipitation data, were combined to create the forecast dataset. With 10-fold cross validation performed on the entire dataset, the overall accuracy was 0.68 (95% CI: 0.60 – 0.75), 0.57 (95% CI: 0.49 – 0.64), and 0.55 (0.47 – 0.63) for the random forest, artificial neural network, and classification and regression tree models, respectively. Based on the cross-validation approach to evaluating predictive accuracy, the random forest model provided the best prediction.


id: cord-261372-xjbs09gi
author: Sozzi, Enrica
date: 2010-02-28
txt: ./txt/cord-261372-xjbs09gi.txt
cache: ./cache/cord-261372-xjbs09gi.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0034528809001362
doi: 10.1016/j.rvsc.2009.05.009
summary:
  A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on the use of monoclonal antibodies was developed for the detection of porcine epidemic diarrhoea virus (PEDV). The objective of the present study was to develop a double antibody sandwich (DAS) ELISA, based on the use of monoclonal antibodies for PEDV detection in swine intestinal and faecal samples useful for routine examinations of field samples. It is already known that ELISA results depend on the clinical and pathological data: in intestinal contents and faecal specimens obtained from experimentally infected PEDV piglets, the virus shedding is detected with high consistency during the acute phase of disease, but much less frequently during the incubation period and the recovery phase (Callebaut et al., 1982) . Enzyme-linked immunosorbent assay for the detection of the coronavirus-like agent and its antibodies in pigs with porcine epidemic diarrhea

title:
  Comparison of enzyme-linked immunosorbent assay and RT-PCR for the detection of porcine epidemic diarrhoea virus

abstract:
  Abstract Porcine epidemic diarrhoea (PED) is a contagious enteric disease of pigs caused by a coronavirus. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) based on the use of monoclonal antibodies was developed for the detection of porcine epidemic diarrhoea virus (PEDV). The DAS-ELISA was compared with RT-PCR in the examination of 506 specimens collected during 2006–2007 from pigs originating from different farms located in the Po valley. Both faecal samples obtained directly from the rectum of live animals showing clinical signs and intestinal samples collected from the caecum of deceased pigs were included in the study. The correlation between the two methods was higher when testing faecal samples (K =0.97, 95% CI: 0.94–1.00) than testing intestinal samples (K =0.62, 95% CI: 0.35–0.89). The use of ELISA technology provided an efficient and effective mean of evaluating the presence of coronavirus PED antigen in field samples and indicates that this procedure is a very useful tool in epidemiological studies.


id: cord-261993-u2a26brw
title: Stability of Porcine Epidemic Diarrhea Virus on Fomite Materials at Different Temperatures
author: Kim, Yonghyan
date: 2018-02-13
txt: ./txt/cord-261993-u2a26brw.txt
cache: ./cache/cord-261993-u2a26brw.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/29438310/
doi: 10.3390/vetsci5010021
summary:
  A more sensitive immunoplaque assay was able to detect virus from Styrofoam, metal, and plastic at 20 days post application, representing a 3-log loss of input virus on fomite materials. Virus recovery from surfaces of Styrofoam, nitrile gloves, aluminum foil, Tyvek ® coverall, metal, rubber, plastic, cardboard, and cloth showed no significant differences between the materials at RT, suggesting that storage temperature had a substantial influence on virus survival. Quantifiable viral RNA was detected in Styrofoam, Tyvek, and cardboard materials, although infectious PEDV titer decreased by 3 to 4 logs at 4 °C after 20 days. Quantifiable viral RNA was detected in Styrofoam, Tyvek, and cardboard materials, although infectious PEDV titer decreased by 3 to 4 logs at 4 °C after 20 days. Survivability of porcine epidemic diarrhea virus (pedv) in bovine plasma submitted to spray drying processing and held at different time by temperature storage conditions

abstract:
  Indirect transmission of porcine epidemic diarrhea virus (PEDV) ensues when susceptible animals contact PEDV-contaminated fomite materials. Although the survival of PEDV under various pHs and temperatures has been studied, virus stability on different fomite surfaces under varying temperature conditions has not been explored. Hence, we evaluated the survival of PEDV on inanimate objects routinely used on swine farms such as styrofoam, rubber, plastic, coveralls, and other equipment. The titer of infectious PEDV at 4 °C decreased by only 1 to 2 log during the first 5 days, and the virus was recoverable for up to 15 days on Styrofoam, aluminum, Tyvek(®) coverall, cloth, and plastic. However, viral titers decreased precipitously when stored at room temperature; no virus was detectable after one day on all materials tested. A more sensitive immunoplaque assay was able to detect virus from Styrofoam, metal, and plastic at 20 days post application, representing a 3-log loss of input virus on fomite materials. Recovery of infectious PEDV from Tyvek(®) coverall and rubber was above detection limit at 20 days. Our findings indicate that the type of fomite material and temperatures impact PEDV stability, which is important in understanding the nuances of indirect transmission and epidemiology of PEDV.


id: cord-263439-oquk4t96
title: Clathrin- and serine proteases-dependent uptake of porcine epidemic diarrhea virus into Vero cells
author: Park, Jung-Eun
date: 2014-10-13
txt: ./txt/cord-263439-oquk4t96.txt
cache: ./cache/cord-263439-oquk4t96.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0168170214003001
doi: 10.1016/j.virusres.2014.07.022
summary:
  Similar to other coronaviruses, PEDV spike protein mediates its cell entry by binding to cellular receptors and inducing membrane fusion between viral envelopes and cellular membranes. Taken together, our findings reveal that PEDV enters Vero cells via clathrin-mediated endocytosis and requires serine proteolysis during infection. Based on these observations, we concluded that an exogenous protease, like trypsin, was necessary to induce cell-cell fusion in PEDV-infected Vero cells but not essentially required for virus-cell entry. So, we hypothesized that PEDV entry into Vero cells under the trypsin-free condition most likely occurred inside endosomal compartments where cellular proteases might operate similar to trypsin, facilitating S-mediated fusion of PEDV with the endosomal membrane. The infection inhibition assay using various substrates that interfere with endocytosis or lysosomotropic agents revealed that PEDV enters Vero cells via clathrin-mediated endocytic uptake and delivery of virus to an acidic intracellular compartment.

abstract:
  Porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus, is a causative agent of porcine enteric disease characterized by acute watery diarrhea and dehydration in sucking piglet. Similar to other coronaviruses, PEDV spike protein mediates its cell entry by binding to cellular receptors and inducing membrane fusion between viral envelopes and cellular membranes. However, the entry mechanism of PEDV is not studied. Here, we determined the entry mechanism of PEDV into Vero cells. Our data confirmed that PEDV entry followed clathrin-mediated endocytosis independence of caveolae-coated pit assembly. The internalized PEDV was co-localized with the clathrin-mediated endocytic marker, but not with the caveolae-mediated endocytic marker. In addition, cells treated with lysosomotropic agents and serine protease inhibitors were resistant to PEDV. Our data revealed that PEDV entry followed clathrin-mediated endocytosis and was dependent on a low pH and serine proteolysis for successful entry into cells.


id: cord-265679-7gzont7l
author: Guo, Nan
date: 2018-09-18
txt: ./txt/cord-265679-7gzont7l.txt
cache: ./cache/cord-265679-7gzont7l.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/30231560/
doi: 10.3390/v10090507
summary:
  In this study, the antiviral activity of a cationic amphibian antimicrobial peptide Caerin1.1 against porcine epidemic diarrhea virus (PEDV) was evaluated by an in vitro system using Vero cells. Vero cells cultured in 24-well plates were washed with PBS for 3 times and inoculated respectively with single medium, or single PEDV, or PEDV pre-incubated with different concentrations of Caerin1.1. PEDV suspensions containing different concentrations of Caerin1.1 were pre-incubated for 1 h at 37 • C, and were serially diluted before they were inoculated on the 80% confluent Vero cell monolayers grown in the 96-well plates, followed by washing 3 times with PBS. As shown in Figure 4 , Vero cells were infected with PEDV (200 pfu) pre-incubated with different concentrations of Caerin1.1. As shown in Figure 4 , Vero cells were infected with PEDV (200 pfu) pre-incubated with different concentrations of Caerin1.1.

title:
  Caerin1.1 Suppresses the Growth of Porcine Epidemic Diarrhea Virus In Vitro via Direct Binding to the Virus

abstract:
  Porcine epidemic diarrhea (PED) has re-emerged in recent years and has already caused huge economic losses to the porcine industry all over the world. Therefore, it is urgent for us to find out efficient ways to prevent and control this disease. In this study, the antiviral activity of a cationic amphibian antimicrobial peptide Caerin1.1 against porcine epidemic diarrhea virus (PEDV) was evaluated by an in vitro system using Vero cells. We found that even at a very low concentration, Caerin1.1 has the ability to destroy the integrity of the virus particles to block the release of the viruses, resulting in a considerable decrease in PEDV infections. In addition, Caerin1.1 showed powerful antiviral activity without interfering with the binding progress between PEDV and the receptor of the cells, therefore, it could be used as a potential antiviral drug or as a microbicide compound for prevention and control of PEDV.


id: cord-266571-qbskh1uu
author: de Arriba, M.L
date: 2002-06-04
txt: ./txt/cord-266571-qbskh1uu.txt
cache: ./cache/cord-266571-qbskh1uu.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0166093402000630
doi: 10.1016/s0166-0934(02)00063-0
summary:
  Lymphocyte proliferative responses were evaluated in mucosal (mesenteric lymph nodes) and systemic (spleen and blood) lymphoid tissues of conventional piglets inoculated with the virulent or attenuated isolates of porcine epidemic diarrhoea virus (PEDV) strain CV-777 and challenged 21 days later with the virulent isolate of the same virus. Virus-specific lymphoproliferative responses of systemic tissues (spleen and blood) and mesenteric lymph nodes were studied in conventional piglets after primary inoculation with the virulent, wild type, strain CV-777 of PEDV or its cell culture attenuated form and after challenge, 3 weeks later, with a high dose of the virulent virus. Correlations between lymphocyte proliferative responses in mononuclear cells collected from mesenteric lymph nodes, blood and spleen from pigs inoculated with virulent or attenuated PEDV or mock-inoculated and protection against challenge 21 days later with virulent PEDV.

title:
  Lymphoproliferative responses and protection in conventional piglets inoculated orally with virulent or attenuated porcine epidemic diarrhoea virus

abstract:
  Lymphocyte proliferative responses were evaluated in mucosal (mesenteric lymph nodes) and systemic (spleen and blood) lymphoid tissues of conventional piglets inoculated with the virulent or attenuated isolates of porcine epidemic diarrhoea virus (PEDV) strain CV-777 and challenged 21 days later with the virulent isolate of the same virus. A lymphoproliferative assay was developed in which mononuclear cells isolated from lymphoid tissues at different postinoculation and postchallenge days underwent a secondary in vitro stimulation with semipurified antigen obtained from PEDV-infected cell cultures. Vigorous lymphocyte proliferative responses were detected in the pigs inoculated with the virulent PEDV at postinoculation days 4–21, especially in the mesenteric lymph nodes and the blood; however, in the spleen this response was lower and less regular. The pigs inoculated with the attenuated virus showed a less intense response, the higher lymphocyte proliferation also corresponded to the mononuclear cells from mesenteric lymph nodes. Lymphocyte proliferation responses showed high correlations with protection against homologous challenge with virulent PEDV, and this correlation was higher in the gut associated lymphoid tissues (mesenteric lymph nodes). The cell proliferation response detected in blood mirrored that detected in the mesenteric lymph nodes, and showed also good correlation with protection. The results confirm that T-cell-helper function, assessed by lymphocyte proliferation responses, contributes to establishing a protective immune response against PEDV infections.


id: cord-266660-0wq77k6y
author: Choi, Jong-Chul
date: 2014-06-19
txt: ./txt/cord-266660-0wq77k6y.txt
cache: ./cache/cord-266660-0wq77k6y.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S1567134814002081
doi: 10.1016/j.meegid.2014.06.005
summary:
  title: Comparative genome analysis and molecular epidemiology of the reemerging porcine epidemic diarrhea virus strains isolated in Korea We detected three PEDV strains from ten small intestine samples from piglets with acute diarrhea and we determined the complete genome sequences of the reemerging Korean PEDV field isolates, except for the noncoding regions from both ends. This study aimed to determine the complete genome sequence of the reemerging Korean PEDV strain and to investigate their genetic relationship with other strains using comparative genome analysis and phylogenetic analysis. In addition, all available complete genome sequences of PEDV isolates from Korea were included in the alignment to compare the recent Korean strains with previous endemic Korean PEDV strains. Multiple alignment with other PEDV complete genomes indicated that the reemerging Korean strains possess genome sequences, which are distinct from those of previous Korean field strains (Fig. 1) .

title:
  Comparative genome analysis and molecular epidemiology of the reemerging porcine epidemic diarrhea virus strains isolated in Korea

abstract:
  Porcine epidemic diarrhea virus (PEDV), a member of the Coronaviridae family, is an enveloped, positive-sense, single-stranded RNA virus, which causes severe diarrhea and dehydration in suckling pigs. We detected three PEDV strains from ten small intestine samples from piglets with acute diarrhea and we determined the complete genome sequences of the reemerging Korean PEDV field isolates, except for the noncoding regions from both ends. The complete genome sequences of the strains were identical or almost identical (one synonymous single-nucleotide polymorphism (SNP) in the ORF1a/1b genomic sequence). Interestingly, comparative genome analysis of recent Korean PEDV isolates and other strains revealed that the complete genome sequences of recent Korean strains were almost identical (99.9%) to those of the US PEDV strains isolated in 2013. These results suggest that the three reemerging Korean strains are distinct from previous endemic Korean PEDV strains and has been recently introduced into Korea from oversea with high likelihood.


id: cord-267446-rpv19oy6
author: Park, Jung-Eun
date: 2011-06-12
url: https://www.ncbi.nlm.nih.gov/pubmed/21667287/
doi: 10.1007/s00705-011-1044-6
title:
  Receptor-bound porcine epidemic diarrhea virus spike protein cleaved by trypsin induces membrane fusion

abstract:
  Porcine epidemic diarrhea virus (PEDV) infection in Vero cells is facilitated by trypsin through an undefined mechanism. The present study describes the mode of action of trypsin in enhancing PEDV infection in Vero cells during different stage of the virus life cycle. During the viral entry stage, trypsin increased the penetration of Vero-cell-attached PEDV by approximately twofold. However, trypsin treatment of viruses before receptor binding did not enhance infectivity, indicating that receptor binding is essentially required for trypsin-mediated entry upon PEDV infection. Trypsin treatment during the budding stage of virus infection induces an obvious cytopathic effect in infected cells. Furthermore, we also show that the PEDV spike (S) glycoprotein is cleaved by trypsin in virions that are bound to the receptor, but not in free virions. These findings indicate that trypsin affects only cell-attached PEDV and increases infectivity and syncytium formation in PEDV-infected Vero cells by cleavage of the PEDV S protein. These findings strongly suggest that the PEDV S protein may undergo a conformational change after receptor binding and cleavage by exogenous trypsin, which induces membrane fusion.


id: cord-268010-1m5h3krw
author: Jung, Kwonil
date: 2016-12-02
url: https://www.ncbi.nlm.nih.gov/pubmed/27086031/
doi: 10.1016/j.virusres.2016.04.009
title:
  Porcine deltacoronavirus infection: Etiology, cell culture for virus isolation and propagation, molecular epidemiology and pathogenesis

abstract:
  Porcine deltacoronavirus (PDCoV) (family Coronaviridae, genus Deltacoronavirus) is a novel swine enteropathogenic coronavirus that causes acute diarrhea/vomiting, dehydration and mortality in seronegative neonatal piglets. PDCoV diarrhea was first reported in the US in early 2014, concurrently with co-circulation of porcine epidemic diarrhea virus (PEDV) (family Coronaviridae, genus Alphacoronavirus). The origin of PDCoV in pigs and also its sudden emergence or route of introduction into the US still remains unclear. In the US, since 2013–2014, the newly emerged PDCoV and PEDV have spread nationwide, causing a high number of pig deaths and significant economic impacts. The current US PDCoV strains are enteropathogenic and infect villous epithelial cells of the entire small and large intestines although the jejunum and ileum are the primary sites of infection. Similar to PEDV infections, PDCoV infections also cause acute, severe atrophic enteritis accompanied by transient viremia (viral RNA) that leads to severe diarrhea and/or vomiting, followed by dehydration as the potential cause of death in nursing piglets. At present, differential diagnosis of PDCoV, PEDV, and transmissible gastroenteritis virus (TGEV) is essential to control viral diarrheas in US swine. Cell culture-adapted US PDCoV (TC-PDCoV) strains have been isolated and propagated by us and in several other laboratories. TC-PDCoV strains will be useful to develop serologic assays and to evaluate if serial cell-culture passage attenuates TC-PDCoV as a potential vaccine candidate strain. A comprehensive understanding of the pathogenesis and epidemiology of epidemic PDCoV strains is currently needed to prevent and control the disease in affected regions and to develop an effective vaccine. This review focuses on the etiology, cell culture isolation and propagation, molecular epidemiology, disease mechanisms and pathogenesis of PDCoV infection.


id: cord-269013-ge7nmgsa
title: Complete Genome Sequence of Porcine Epidemic Diarrhea Virus in Vietnam
author: Vui, Dam Thi
date: 2014-08-14
txt: ./txt/cord-269013-ge7nmgsa.txt
cache: ./cache/cord-269013-ge7nmgsa.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1128/genomea.00753-14
doi: 10.1128/genomea.00753-14
summary:
  title: Complete Genome Sequence of Porcine Epidemic Diarrhea Virus in Vietnam Porcine epidemic diarrhea virus (PEDV) has emerged in Vietnam since 2009. Herein, full-length genome sequences are reported for three PEDV isolates from pigs displaying severe diarrhea from farms located in northern and southern provinces of Vietnam. The full-length genome sequence suggests that PEDV variants circulating in Vietnam swine farms are novel variants with changes in the spike structure. Completion of the porcine epidemic diarrhoea coronavirus (PEDV) genome sequence Sequence analysis of the partial spike glycoprotein gene of porcine epidemic diarrhea viruses isolated in Korea Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in south China Phylogenetic analysis of porcine epidemic diarrhea virus field strains prevailing recently in China Genetic diversity of ORF3 and spike genes of porcine epidemic diarrhea virus in Thailand

abstract:
  Porcine epidemic diarrhea virus (PEDV) has emerged in Vietnam since 2009. Herein, full-length genome sequences are reported for three PEDV isolates from pigs displaying severe diarrhea from farms located in northern and southern provinces of Vietnam. The results provide more understanding of the molecular characteristics of PEDV in Vietnam.


id: cord-272031-o2hx667i
title: Porcine epidemic diarrhoea: new insights into an old disease
author: Carvajal, Ana
date: 2015-09-29
txt: ./txt/cord-272031-o2hx667i.txt
cache: ./cache/cord-272031-o2hx667i.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s40813-015-0007-9
doi: 10.1186/s40813-015-0007-9
summary:
  Mortality in piglets less than two weeks old varied from 0 to 100 %, but it was usually lower than that described in outbreaks of diarrhoea caused by transmissible gastroenteritis virus (TGEV) which is another porcine coronavirus classically recognized as a cause of diarrhoea disease in swine. Although some reports have suggested that they could be associated with differences in the virulence of PEDV isolates, exhaustive challenge studies using pig adapted virus (not cell culture adapted isolates) in suckling piglets are needed to elucidate the role of the strain. The detection of PEDV specific antibodies is very useful, not for the investigation of diarrhoea outbreaks, but to determine whether an animal or a herd has previously been infected by this virus. Genetic characterization of porcine epidemic diarrhoea virus (PEDV) isolates from southern Vietnam during 2009-2010 outbreaks

abstract:
  Porcine epidemic diarrhea (PED) is an enteric disease in swine caused by an alphacoronavirus. It affects swine of all ages causing acute diarrhoea and can lead to severe dehydration and death in suckling piglets. Being recognized for the first time in Europe and Asia during the seventies and the eighties, respectively, it has remained a relevant cause of diarrhea outbreaks in Asia for years and to the present. It has become a major concern in swine production since 2013 when the virus was detected for first time in the USA and in other American countries causing a high number of pig deaths and significant economic losses. The present review aims at approaching the reader to the state of the art of PED giving answer to some of the most recent questions which have arisen related to this disease.


id: cord-272480-276r1lh7
author: Wang, Peng
date: 2019-02-09
txt: ./txt/cord-272480-276r1lh7.txt
cache: ./cache/cord-272480-276r1lh7.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/31179369/
doi: 10.1007/s13337-019-00513-w
summary:
  title: Isolation and recombinant analysis of variants of porcine epidemic diarrhea virus strains from Beijing, China The strains in this study are indicated by underline Isolation and recombinant analysis of variants of porcine epidemic diarrhea virus strains from… 297 Frequent mutation and recombination of genes may occur in epidemics of PEDV. The phylogenetic trees showed that, these PEDV isolates from the Beijing area belonged to group II, while the traditional vaccine strain, CV777, belonged to group I based on the comparison of several important genes in PEDV, such as ORF1a/1b, S, M, N, E, and ORF3. Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in south China Sequence and phylogenetic analysis of nucleocapsid genes of porcine epidemic diarrhea virus (PEDV) strains in China Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea

title:
  Isolation and recombinant analysis of variants of porcine epidemic diarrhea virus strains from Beijing, China

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a highly infectious virus infecting pigs with high morbidity, especially for newborn piglets. Several PEDV strains were isolated from the intestinal tracts of diarrheic piglets from the Beijing area, China. Sequencing of the whole-genome of the PEDV isolates (GenBank numbers MG546687-MG546690) yielded sequences of 28033–28038 nt. The phylogenetic tree revealed that these strains from the Beijing area belonged to group II, while the vaccine strain, CV777, belonged to group I. We also determined the genetic correlation between these strains and CV777 strain. However, it showed that these strains in the Beijing area had unique mutations. The sequence identity of PEDV strains showed that these strains are most similar to these strains LZW, CH/JX-1/2013, USAIllinois972013, USAKansas1252014, CH/GDZQ/2014, SHQPYM2013, AJ1102, CHZMDZY11, KoreaK14JB01, and CHYJ130330, respectively. The possible recombination events indicate that PEDV in this studies were possibly recombinant strain formed by parent strains USAIllinois972013, KoreaK14JB01, CHYJ130330, and CHZMDZY11. These PEDV strains has been genetic recombination and mutations. The variant strains characterized in this study help to the evolutionary analysis of PEDV.


id: cord-272728-inndwa61
author: Jung, Kwonil
date: 2018-08-31
txt: ./txt/cord-272728-inndwa61.txt
cache: ./cache/cord-272728-inndwa61.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.rvsc.2018.06.009
doi: 10.1016/j.rvsc.2018.06.009
summary:
  At PID 3 when vomiting had ceased, mean numbers of serotonin-positive EC cells per microscopic area (×250) were significantly (P < .05) increased in duodenum but reduced in ileum of the PEDV-inoculated pigs, compared with the corresponding negative controls, but they did not differ in mid-jejunum and colon (Table 1) . Histologic lesions and the distribution based on Table 1 Mean numbers ( ± SDM) of serotonin-positive enterochromaffin cells by immunohistochemistry in the crypt layers and entire or lower half of villi of duodenum, mid-jejunum, ileum, and colon per microscopic area, at ×250 magnification, of conventional 9-day-old nursing pigs inoculated with virulent US PEDV strain PC21A or mock at post-inoculation days (PIDs) 1, 3, and 5.

title:
  Immunohistochemical detection of the vomiting-inducing monoamine neurotransmitter serotonin and enterochromaffin cells in the intestines of conventional or gnotobiotic (Gn) pigs infected with porcine epidemic diarrhea virus (PEDV) and serum cytokine responses of Gn pigs to acute PEDV infection

abstract:
  Abstract Serotonin is a critical monoamine neurotransmitter molecule stored and released from enterochromaffin (EC) cells into the gut submucosa, transmitting the vomiting signal to the brain. We studied one mechanism by which vomiting is induced in pigs infected with porcine epidemic diarrhea virus (PEDV) by characterization of swine EC cells by immunohistochemistry. Conventional or gnotobiotic (Gn) 9-day-old pigs [PEDV-inoculated (n = 12); Mock (n = 14)] were inoculated orally (8.9–9.2 log10 genomic equivalents/pig) with PEDV PC21A strain or mock. This is the first identification of serotonin-positive EC cells in swine by immunohistochemistry and mainly in intestinal crypts, regardless of infection status. They were morphologically triangular-shaped or round cells with or without apical cytoplasmic extensions, respectively. At post-inoculation hour (PIH) 16 or 24, when vomiting was first or frequently observed, respectively, PEDV infection resulted in significantly reduced numbers of serotonin-positive EC cells in duodenum, mid-jejunum, ileum, or colon. However, two of three PEDV-inoculated Gn pigs that did not yet show vomiting at PIH 16 had numbers of serotonin-positive EC cells in duodenum, ileum and colon similar to those in the negative controls. These findings suggest that serotonin release from EC cells (increased serotonin levels) into the gut submucosa might occur early PEDV post-infection to stimulate the vagal afferent neurons, followed by vomiting. Serotonin might be involved in the mechanisms related to vomiting in PEDV-infected piglets. We also found that mid-jejunum was the primary site of acute PEDV infection, and that systemic innate and pro-inflammatory cytokine responses were induced during the acute stage of PEDV infection.


id: cord-272729-nbgdmavr
title: Ribavirin efficiently suppresses porcine nidovirus replication
author: Kim, Youngnam
date: 2012-10-27
url: https://www.sciencedirect.com/science/article/pii/S0168170212004078
doi: 10.1016/j.virusres.2012.10.018
abstract:
  Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine epidemic diarrhea virus (PEDV) are porcine nidoviruses that represent emerging viral pathogens causing heavy economic impacts on the swine industry. Although ribavirin is a well-known antiviral drug against a broad range of both DNA and RNA viruses in vitro, its inhibitory effect and mechanism of action on porcine nidovirus replication remains to be elucidated. Therefore, the present study was conducted to determine whether ribavirin suppresses porcine nidovirus infection. Our results demonstrated that ribavirin treatment dose-dependently inhibited the replication of both nidoviruses. The antiviral activity of ribavirin on porcine nidovirus replication was found to be primarily exerted at early times post-infection. Treatment with ribavirin resulted in marked reduction of viral genomic and subgenomic RNA synthesis, viral protein expression, and progeny virus production in a dose-dependent manner. Investigations into the mechanism of action of ribavirin against PRRSV and PEDV revealed that the addition of guanosine to the ribavirin treatment significantly reversed the antiviral effects, suggesting that depletion of the intracellular GTP pool by inhibiting IMP dehydrogenase may be essential for ribavirin activity. Further sequencing analysis showed that the mutation frequency in ribavirin-treated cells was similar to that in untreated cells, indicating that ribavirin did not induce error-prone replication. Taken together, our data indicate that ribavirin might not only be a good therapeutic agent against porcine nidovirus, but also a potential candidate to be evaluated against other human and animal coronaviruses.


id: cord-272973-kzaowysv
author: Joshi, Lok R.
date: 2018-05-03
url: https://doi.org/10.1007/s00705-018-3855-1
doi: 10.1007/s00705-018-3855-1
title:
  Passive immunity to porcine epidemic diarrhea virus following immunization of pregnant gilts with a recombinant orf virus vector expressing the spike protein

abstract:
  Passive immunity is critical for protection of neonatal piglets against porcine epidemic diarrhea virus (PEDV). Here, we investigated the immunogenicity of an orf virus (ORFV) vector expressing the full-length spike (S) protein of PEDV (ORFV-PEDV-S) in pregnant gilts and its ability to confer passive immunity and protection in piglets. Three doses of ORFV-PEDV-S were given to two groups of PEDV-negative pregnant gilts, with the last dose being administered two weeks prior to farrowing. One of the two groups immunized with the ORFV-PEDV-S recombinant virus was also exposed to live PEDV orally on day 31 post-immunization (pi). Antibody responses were assessed in serum, colostrum and milk of immunized gilts, and passive transfer of antibodies was evaluated in piglet sera. The protective efficacy of ORFV-PEDV-S was evaluated after challenge of the piglets with PEDV. PEDV-specific IgG, IgA and neutralizing antibody (NA) responses were detected in ORFV-PEDV-S-immunized and ORFV-PEDV-S-immunized/PEDV-exposed gilts. PEDV NA, IgG and IgA were detected in the serum of piglets born to immunized gilts, demonstrating the transfer of antibodies through colostrum and milk. Piglets born to immunized gilts showed reduced morbidity and a marked reduction in mortality after PEDV challenge in comparison to control piglets. Piglets born to gilts that received ORFV-PEDV-S and were exposed to live PEDV showed stronger NA responses and lower clinical scores when compared to piglets born to gilts immunized with ORFV-PEDV-S alone. These results demonstrate the potential of ORFV as a vaccine delivery platform capable of eliciting passive immunity against PEDV.


id: cord-273610-cfoq3r3i
title: Evidence of Recombinant Strains of Porcine Epidemic Diarrhea Virus, United States, 2013
author: Tian, Peng-Fei
date: 2014-10-17
txt: ./txt/cord-273610-cfoq3r3i.txt
cache: ./cache/cord-273610-cfoq3r3i.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3201/eid2010.140338
doi: 10.3201/eid2010.140338
summary:
  To investigate the evolutionary process by which porcine epidemic diarrhea virus (PEDV) in the United States hypothetically descended from strains in China, we analyzed PEDV-positive samples collected in China during January 2012–July 2013. To investigate the evolutionary process by which porcine epidemic diarrhea virus (PEDV) in the United States hypothetically descended from strains in China, we analyzed PEDV-positive samples collected in China during January 2012-July 2013. The exception is the N gene-based tree, in which the AH2012 was grouped more closely to the sublineage associated with the United States than the strains in the designated ZMDZY sublineage (online Technical Appendix Figure 1 ). It is possible that replacement of a region within the partial S-ORF3-E-M-partial N region of the AH2012 strain with a corresponding fragment close to the ZMDZY sublineage (including several newly identified strains) resulted in a recombinant strain related to emergence of this virus in swine in the United States. Complete genome sequence of porcine epidemic diarrhea virus strain USA/Colorado/2013 from the United States

abstract:
  To investigate the evolutionary process by which porcine epidemic diarrhea virus (PEDV) in the United States hypothetically descended from strains in China, we analyzed PEDV-positive samples collected in China during January 2012–July 2013. Recombination in 2 strain sublineages was likely associated with identification of PEDV in the United States in 2013.


id: cord-273705-0oyzg5tq
author: Duffy, Mark A
date: 2018-08-29
txt: ./txt/cord-273705-0oyzg5tq.txt
cache: ./cache/cord-273705-0oyzg5tq.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32289108/
doi: 10.1093/tas/txy088
summary:
  title: Impact of dietary spray-dried bovine plasma addition on pigs infected with porcine epidemic diarrhea virus Experimental data suggest that the addition of spray-dried plasma (SDP) to pig feed may enhance antibody responses against certain pathogens and negatively impact virus survival. The aim of this study was to determine the effect of bovine SDP (BovSDP) in the pig diet on acute porcine epidemic diarrhea virus (PEDV) infection. The results indicate that addition of BovSDP induced an earlier anti-PEDV antibody response in pigs experimentally infected with PEDV thereby reducing clinical disease and the amount and duration of viral shedding during acute PEDV infection. Starting with arrival in the research facility and for the duration of the study, all pigs were fed the same standard commercial corn-soybean meal-dried whey-based diet ( Table 2 ) except for the diet of the PEDV-BovSDP group, which was supplemented with 5% spray-dried commercial bovine plasma replacing soy protein concentrate on an equal total lysine basis ( Figure 1 ).

title:
  Impact of dietary spray-dried bovine plasma addition on pigs infected with porcine epidemic diarrhea virus

abstract:
  Experimental data suggest that the addition of spray-dried plasma (SDP) to pig feed may enhance antibody responses against certain pathogens and negatively impact virus survival. The benefit of SDP on Escherichia coli infection is well documented. The aim of this study was to determine the effect of bovine SDP (BovSDP) in the pig diet on acute porcine epidemic diarrhea virus (PEDV) infection. A total of 16 3-wk-old conventional crossbred pigs were used and divided into three groups. Treatments included 1) a negative control group fed a commercial diet and sham inoculated with commercial liquid porcine plasma (n = 3), 2) a positive control group fed a commercial diet and inoculated with PEDV-spiked porcine plasma (PEDV; n = 8), and 3) a third group of pigs fed the commercial diet with inclusion of 5% spray-dried bovine plasma and inoculated with PEDV-spiked porcine plasma (BovSDP; n = 5). Although clinical signs associated with PEDV infection were mild in the BovSDP group, two of eight pigs in the PEDV group developed moderate clinical disease and had to be euthanized. The PEDV IgG and IgA antibody levels and prevalence rates were significantly (P < 0.05) higher in the PEDV–BovSDP group compared with the PEDV group at 7 d postinoculation. The average fecal PEDV RNA shedding time was 7.2 ± 1.0 d for the PEDV–BovSDP group and 9.3 ± 1.1 d for the PEDV group with an overall time to clearance of PEDV shedding of 11 d for PEDV–BovSDP pigs and at least 14 d for PEDV pigs, which was not different (P = 0.215). The results indicate that addition of BovSDP induced an earlier anti-PEDV antibody response in pigs experimentally infected with PEDV thereby reducing clinical disease and the amount and duration of viral shedding during acute PEDV infection.


id: cord-273712-r2akpce8
author: Wang, Jingjing
date: 2016-02-19
txt: ./txt/cord-273712-r2akpce8.txt
cache: ./cache/cord-273712-r2akpce8.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/26908211/
doi: 10.1007/s12250-015-3690-4
summary:
  In the same beta group, the receptors for mouse hepatitis virus (MHV) and bovine coronavirus (BCoV) are carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) and a sugar, respectively, despite their high sequence homology Peng et al., 2012) . In our study, we compared the efficiency of pseudotyped viruses with S proteins from different groups of CoVs. Furthermore, the cell tropisms of TGEV and PEDV were characterized by live and pseudotyped viruses. Therefore, we compared the S protein amino acid sequences of CoVs from different groups, including SARS-CoV, MHV, HCoV-229E, TGEV, PEDV, HCoV-OC43, BCoV, and IBV (Gen-Bank accession numbers ABD72982.1, AAR92025.1, NP_073551.1, ABG89335.1, NP_598310.1, AAT84362.1, ABM66810.1, and NP_040831.1, respectively) using ClustalW ( Figure 1B ). Lentiviruses pseudotyped with SARS-CoV S protein could efficiently infect 293T cells expressing ACE2, and the pseudovirus level after entry reached 10 6 relative light units (RLU) ( Figure 2B ). To further study the cellular entry of CoVs, we used live PEDV and TGEV to infect different cell lines.

title:
  Comparison of lentiviruses pseudotyped with S proteins from coronaviruses and cell tropisms of porcine coronaviruses

abstract:
  The surface glycoproteins of coronaviruses play an important role in receptor binding and cell entry. Different coronaviruses interact with their specific receptors to enter host cells. Lentiviruses pseudotyped with their spike proteins (S) were compared to analyze the entry efficiency of various coronaviruses. Our results indicated that S proteins from different coronaviruses displayed varied abilities to mediate pseudotyped virus infection. Furthermore, the cell tropisms of porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) have been characterized by live and pseudotyped viruses. Both live and pseudoviruses could infected Vero- CCL-81 (monkey kidney), Huh-7 (human liver), and PK-15 (pig kidney) cells efficiently. CCL94 (cat kidney) cells could be infected efficiently by TGEV but not PEDV. Overall, our study provides new insights into the mechanisms of viral entry and forms a basis for antiviral drug screening. [Image: see text]


id: cord-273745-mwjh5se7
author: Meng, Fandan
date: 2014-03-25
txt: ./txt/cord-273745-mwjh5se7.txt
cache: ./cache/cord-273745-mwjh5se7.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0042682214000130
doi: 10.1016/j.virol.2014.01.010
summary:
  Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. When Vero cells were pre-treated with peptide (cell pretreatment assay) prior to virus infection (Fig. 1B) , little changes in virus titers were observed between the control and peptide treatment groups; some small effects were observed with the rabbit anti-PEDV neutralizing antibodies. Finally, in the virus pretreatment assays where PEDV was incubated with peptides prior to cell infection (Fig. 1C) , the results indicated that both peptides H and S inhibited PEDV infectivity where EC 50 values were approximately 1 μg/ml and 62.5 μg/ml, respectively. Results clearly show that peptide H had no demonstrable effects on TGEV or PrV even at very high peptide concentrations (1 mM/ml) (Fig. 3) suggesting that a non-specific reactivity with virus envelopes is unlikely to be the cause for attenuating PEDV infectivity.

title:
  A phage-displayed peptide recognizing porcine aminopeptidase N is a potent small molecule inhibitor of PEDV entry

abstract:
  Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. These same peptides had no inhibitory effects on infection of Vero cells by porcine epidemic diarrhea virus (PEDV). However, when PEDV, TGEV and porcine pseudorabies virus were incubated with peptide H (HVTTTFAPPPPR), only infection of Vero cells by PEDV was inhibited. Immunofluoresence assays indicated that inhibition of PEDV infection by peptide H was independent of pAPN. Western blots demonstrated that peptide H interacted with PEDV spike protein and that pre-treatment of PEDV with peptide H led to a higher inhibition than synchronous incubation with cells. These results indicate direct interaction with the virus is necessary to inhibit infectivity. Temperature shift assays demonstrated that peptide H inhibited pre-attachment of the virus to the cells.


id: cord-274765-3wzht843
title: Derivation of attenuated porcine epidemic diarrhea virus (PEDV) as vaccine candidate
author: Kweon, Chang-Hee
date: 1999-06-04
txt: ./txt/cord-274765-3wzht843.txt
cache: ./cache/cord-274765-3wzht843.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0264410X99000596
doi: 10.1016/s0264-410x(99)00059-6
summary:
  The field isolate of porcine epidemic diarrhea virus (PEDV) was serially passaged in Vero cells. The cell passaged PEDV, designated KPEDV-9, was tested for its pathogenicity in the neonatal pigs, immunogenicity and safety in the pregnant sows. The results of this study supported that the attenuated virus derived from serial passage could be applied as vaccine for protecting suckling piglets against PEDV infection. In this study, we investigated the attenuation of PEDV through serial passages in Vero cell cultures and its prophylactic eect in pregnant sows. Nevertheless, when compared with the wild PEDV, the animals inoculated with the high passage level of virus did not show any severe signs of diarrhea or death in piglets, supporting attenuation. Development of an Elispot for the detection of antibody secreting cells against the porcine epidemic diarrhea virus (PEDV) in dierent tissues

abstract:
  The field isolate of porcine epidemic diarrhea virus (PEDV) was serially passaged in Vero cells. The cell passaged PEDV, designated KPEDV-9, was tested for its pathogenicity in the neonatal pigs, immunogenicity and safety in the pregnant sows. The result indicated that KPEDV-9 at the 93rd passage revealed reduced pathogenicity in the neonatal pigs. Pregnant sows inoculated with the attenuated virus showed increased immune responses by ELISA. In addition, delivered piglets were protected from challenge of wild type PEDV. The safety test in pregnant sows indicated that all inoculated animals farrowed the average numbers of litters of piglets. The results of this study supported that the attenuated virus derived from serial passage could be applied as vaccine for protecting suckling piglets against PEDV infection.


id: cord-275499-25dp6u68
title: Porcine Epidemic Diarrhea Altered Colonic Microbiota Communities in Suckling Piglets
author: Tan, Zhen
date: 2019-12-30
txt: ./txt/cord-275499-25dp6u68.txt
cache: ./cache/cord-275499-25dp6u68.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3390/genes11010044
doi: 10.3390/genes11010044
summary:
  In this study, we successfully demonstrated that the microbial community structure of colonic mucosa and content differed significantly between healthy and PEDV-infected piglets. Likewise, previous research has shown that the proportions of Escherichia-Shigella, Enterococcus, Fusobacterium, and Veillonella increased significantly in PEDV-infected piglets, while those of short-chain fatty acid (SCFA)-producing bacteria (e.g., Rikenellaceae_RC9_gut_group, Butyricimonas, and Alistipes) underwent a decrease [21] . Some bacteria from Firmicutes and Bacteroidetes were enriched in healthy piglets, while some from Proteobacteria and Fusobacteria were more abundant in PEDV-infected groups. To better characterize the intestinal microbiomes of healthy versus PEDV-infected piglets, we recommend that future studies fully examine virome diversity using a larger sample size and metagenomic de novo sequencing of the gut microbial genome. Dynamic change of gut microbiota during porcine epidemic diarrhea virus infection in suckling piglets Changes in cecal microbiota community of suckling piglets infected with porcine epidemic diarrhea virus

abstract:
  Porcine epidemic diarrhea (PED) is a major gastrointestinal disease afflicting suckling pigs that causes huge industrial economic losses. In this study, we investigated microbiota from the colonic mucosa and content in healthy and PED piglets. High-throughput 16S rRNA gene sequencing was performed to identify inter-group differences. Firmicutes, Fusobacteria, Proteobacteria, and Bacteroidetes were the top four affected phyla. The proportion of Proteobacteria was higher in infected than in healthy piglets, and the opposite was observed for Bacteroidetes (more than four-fold higher in the healthy group). In the infected group, Fusobacterium accounted for 36.56% and 21.61% in the colonic mucosa and contents, respectively, while in the healthy group, they comprised 22.53% and 12.67%, respectively. The percentage of Lactobacillus in healthy colons (15.63%) was considerably higher than that in the disease group (<10%). In both the colonic mucosa and contents, functional enrichment differed significantly between healthy and diseased groups. Overall, infection with the PED virus increased the proportion of harmful bacteria and decreased the proportion of beneficial bacteria in the colons of piglets. Targeting intestinal microbiota could be a promising method for PED prevention, thus opening new avenues for future research.


id: cord-276542-lxwls664
author: Pan, Zhongzhou
date: 2020-06-03
url: https://www.ncbi.nlm.nih.gov/pubmed/32490723/
doi: 10.1080/21505594.2020.1771980
title:
  Development of a TaqMan-probe-based multiplex real-time PCR for the simultaneous detection of emerging and reemerging swine coronaviruses

abstract:
  With the outbreak of the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019, coronaviruses have become a global research hotspot in the field of virology. Coronaviruses mainly cause respiratory and digestive tract diseases, several coronaviruses are responsible for porcine diarrhea, such as porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and emerging swine acute diarrhea syndrome coronavirus (SADS-CoV). Those viruses have caused huge economic losses and are considered as potential public health threats. Porcine torovirus (PToV) and coronaviruses, sharing similar genomic structure and replication strategy, belong to the same order Nidovirales. Here, we developed a multiplex TaqMan-probe-based real-time PCR for the simultaneous detection of PEDV, PDCoV, PToV, and SADS-CoV for the first time. Specific primers and TaqMan fluorescent probes were designed targeting the ORF1a region of PDEV, PToV, and SADS-CoV and the ORF1b region of PDCoV. The method showed high sensitivity and specificity, with a detection limit of 1 × 10(2) copies/μL for each pathogen. A total of 101 clinical swine samples with signs of diarrhea were analyzed using this method, and the result showed good consistency with conventional reverse transcription PCR (RT-PCR). This method improves the efficiency for surveillance of these emerging and reemerging swine enteric viruses and can help reduce economic losses to the pig industry, which also benefits animal and public health.


id: cord-276989-441aclcc
author: Liu, Jianbo
date: 2020-03-12
txt: ./txt/cord-276989-441aclcc.txt
cache: ./cache/cord-276989-441aclcc.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0166093420301075
doi: 10.1016/j.jviromet.2020.113855
summary:
  title: Development of a rapid immunochromatographic strip test for the detection of porcine epidemic diarrhea virus specific SIgA in colostrum On the strip, a gold-labeled anti-SIgA SC mAb was applied to a conjugate pad; purified PEDV particles and goat anti-mouse antibodies were blotted onto a nitrocellulose membrane to form the test and control lines, respectively. Therefore, the aim of this study was to develop a simple and rapid immunochromatographic test strip incorporating a colloidal gold-labeled anti-SIgA SC mAb probe for the detection of anti-PEDV-specific SIgA in swine, and to compare its performance with an indirect SIgA ELISA based on the whole PEDV virus (Cong et al., 2019) . To test for colostrum, we diluted the samples 1: 20 in sample buffer and mixed thoroughly then, 100 μL of the solution was dispensed onto the sample pad well of the strip apparatus to determine the presence of PEDV specific SIgA, as described above.

title:
  Development of a rapid immunochromatographic strip test for the detection of porcine epidemic diarrhea virus specific SIgA in colostrum

abstract:
  Porcine epidemic diarrhea virus (PEDV) causes very high mortality in newborn piglets. The mucosal immune system in the gut must eliminate potential pathogens while maintaining a mutually beneficial relationship with the commensal microbiota. Antibodies derived from the secretory immunoglobulin A (SIgA) class, act as the first line of antigen-specific immunity in the gut by recognizing both pathogens and commensals. Therefore, the measurement of SIgA levels is an important index in evaluating PEDV infections and immune status. A simple and rapid method for the detection of PEDV-specific SIgA using an immunochromatographic test strip has been developed; incorporating a colloidal gold-labeled anti-SIgA secretory component (SC) mAb probe for the detection of anti-PEDV-specific SIgA in swine. On the strip, a gold-labeled anti-SIgA SC mAb was applied to a conjugate pad; purified PEDV particles and goat anti-mouse antibodies were blotted onto a nitrocellulose membrane to form the test and control lines, respectively. Results showed that the immunochromatographic test strip had high sensitivity and specificity. When compared with enzyme-linked immunosorbent assay, kappa value suggesting that the strip could be used to detect PEDV specific SIgA in colostrum samples. Furthermore, the strip assay is rapid and easy to perform with no requirement for professional-level skills or equipment. We found that the immunochromatographic test strip was a rapid, sensitive, and reliable method for the identification of PEDV specific SIgA, indicating its suitability for epidemiological surveillance as well as vaccine immunity when studying PEDV.


id: cord-277194-mj85mpo2
author: Perri, Amanda M.
date: 2019-05-08
txt: ./txt/cord-277194-mj85mpo2.txt
cache: ./cache/cord-277194-mj85mpo2.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3389/fvets.2019.00139
doi: 10.3389/fvets.2019.00139
summary:
  title: Factors Associated With Time to Elimination of Porcine Epidemic Diarrhea Virus in Individual Ontario Swine Herds Based on Surveillance Data Factors associated with time to elimination are likely reflective of the complexity of infection control practices applied in herds with different demographics and population structures, seasonal variability in the pathogen transmissibility, and the availability of resources to manage an emerging production-limiting disease. Therefore, the objective of this study was to determine time to PEDV elimination in Ontario swine herds infected between 2014 and 2017, on the basis of records from the DCP database; and to identify factors associated with the likelihood of elimination. A Cox''s proportional hazard model was constructed to investigate the effect of explanatory variables including herd type, season of diagnosis and year of diagnosis on the time to eliminate PEDV from the premises.

title:
  Factors Associated With Time to Elimination of Porcine Epidemic Diarrhea Virus in Individual Ontario Swine Herds Based on Surveillance Data

abstract:
  Porcine epidemic diarrhea virus (PEDV) emerged into Canada in January of 2014. The virus was considered to be of high importance and the number of new cases were tracked using different mechanisms by stakeholders such as veterinary services from the provincial government and the swine industry. In addition to the initial date of infection, veterinary organizations in the swine industry maintained a disease control program (DCP) database that contained the date of declaration of freedom from PEDV in individual herds. Such data allowed for the determination of the duration of PEDV infection in individual herds based on herd type, year and season of diagnosis. Therefore, the objective of this study was to determine time to PEDV elimination in Ontario swine herds infected between 2014 and 2017, on the basis of records from the DCP database; and to identify factors associated with the likelihood of elimination. Duration of time to eliminate PEDV was estimated using Kaplan-Meier survival curves. The final Cox's proportional hazard model included herd type, season and year of diagnosis. The hazard of PEDV elimination for premises that were farrow-to-wean was 3.36 times larger (P-value: 0.044, 95% CI: 1.03, 10.93) than for farrow-to-feeder herds. Herds diagnosed in the summer and fall had hazard ratios of 1.40 (P-value: 0.044, 95% CI: 1.03, 10.93) and 7.32 (P-value: <0.001, 95% CI: 3.12, 17.18), respectively compared to herds diagnosed in the winter months. The hazard ratio for herds diagnosed in 2015 was 0.54 (P-value: 0.015, 95% CI: 0.33, 0.89) compared to herds diagnosed in 2014. Factors associated with time to elimination are likely reflective of the complexity of infection control practices applied in herds with different demographics and population structures, seasonal variability in the pathogen transmissibility, and the availability of resources to manage an emerging production-limiting disease. The median times to elimination were relatively long, which could be due to how it was measured, decisions made at the level of individual herds or delays related to reporting PEDV elimination. Design of control measures for production-limiting diseases at the regional level should take these factors into consideration.


id: cord-278641-8lh5y7j0
title: Identification and characterization of PEDV infection in rat crypt epithelial cells
author: Chen, Jianing
date: 2020-09-17
url: https://www.ncbi.nlm.nih.gov/pubmed/32979749/
doi: 10.1016/j.vetmic.2020.108848
abstract:
  Porcine epidemic diarrhea (PED) is a devastating enteric disease to the world's swine production. Porcine epidemic diarrhea virus (PEDV), as the PED causative agent, has been commonly propagated and investigated in Vero cells, as well as in IPEC-J2, a porcine epithelial cell-jejunum 2. However, Vero cells, which are defective in interferon production, cannot represent the host response in enteric cells while PEDV replicates poorly in IPEC-J2 cells. In this study, we observed that rat crypt epithelial cells (IEC-6) were highly susceptible to different subtypes of PEDV. The replication kinetics of PEDV in IEC-6 cells is similar to that in Vero cells, but it is much higher than in IPEC-J2 cells. Besides that, PEDV infection in IEC-6 cells can induce the production of inflammatory cytokines and interferon, especially the type III IFNs. Collectively, our findings suggest that IEC-6 is an ideal cell line for PEDV replication and immune response studies.


id: cord-279598-xzionafe
author: Chang, Chia-Yu
date: 2019-02-21
txt: ./txt/cord-279598-xzionafe.txt
cache: ./cache/cord-279598-xzionafe.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1038/s41598-019-39844-5
doi: 10.1038/s41598-019-39844-5
summary:
  title: Identification of Neutralizing Monoclonal Antibodies Targeting Novel Conformational Epitopes of the Porcine Epidemic Diarrhoea Virus Spike Protein However, E10E-1-10, which targets a novel neutralizing epitope as shown with ICC staining, was also capable of binding to the full-length PEDV spike protein as well as truncated PEDV proteins, S 1-639 , S 1-575 , S 1-509 , S 1-501 , and S 1-485 with appropriate dilution effects. Similar to the results obtained by ICC staining, E10E-1-10 showed no binding ability www.nature.com/scientificreports www.nature.com/scientificreports/ toward PEDV S 1-435 by ELISA and therefore, an NmAb targeting a novel epitope of the new variant of PEDV specifically at a.a. 435-485 in the S1 region was confirmed. To further determine whether the binding of neutralizing epitopes require conformational integrity, immunodot blotting was performed by denaturing the various truncated PEDV spike proteins. Cell Attachment Domains of the Porcine Epidemic Diarrhea Virus Spike Protein Are Key Targets of Neutralizing Antibodies

title:
  Identification of Neutralizing Monoclonal Antibodies Targeting Novel Conformational Epitopes of the Porcine Epidemic Diarrhoea Virus Spike Protein

abstract:
  Since 2010, newly identified variants of porcine epidemic diarrhoea virus (PEDV) have caused high mortality in neonatal piglets which has devastated the swine industry. The spike (S) glycoprotein of PEDV contains multiple neutralizing epitopes and is a major target for PEDV neutralization and vaccine development. To understand the antigenicity of the new PEDV variant, we characterized the neutralizing epitopes of a new genotype 2b PEDV isolate from Taiwan, PEDV Pintung 52 (PEDV-PT), by the generation of neutralizing monoclonal antibodies (NmAbs). Two NmAbs, P4B-1, and E10E-1–10 that recognized the ectodomain of the full-length recombinant PEDV S protein and exhibited neutralizing ability against the PEDV-PT virus were selected. Recombinant truncated S proteins were used to identify the target sequences for the NmAbs and P4B-1 was shown to recognize the C-terminus of CO-26K equivalent epitope (COE) at amino acids (a.a.) 575–639 of the PEDV S. Interestingly, E10E-1–10 could recognize a novel neutralizing epitope at a.a. 435–485 within the S1(A) domain of the PEDV S protein, whose importance and function are yet to be determined. Moreover, both NmAbs could not bind to linearized S proteins, indicating that only conformational epitopes are recognized. This data could improve our understanding of the antigenic structures of the PEDV S protein and facilitate future development of novel epitope-based vaccines.


id: cord-279784-o80x8nj7
author: Wu, Yu
date: 2019-10-28
url: https://doi.org/10.1186/s12985-019-1232-7
doi: 10.1186/s12985-019-1232-7
title:
  Characterization and pathogenicity of Vero cell-attenuated porcine epidemic diarrhea virus CT strain

abstract:
  BACKGROUND: Porcine epidemic diarrhea virus (PEDV) has caused enormous economic losses to the global pig industry. Currently available PEDV vaccine strains have limited protective effects against PEDV variant strains. METHODS: In this study, the highly virulent epidemic virus strain CT was serially passaged in Vero cells for up to 120 generations (P120). Characterization of the different passages revealed that compared with P10 and P64, P120 had a higher viral titer and more obvious cytopathic effects, thereby demonstrating better cell adaptability. RESULTS: Pathogenicity experiments using P120 in piglets revealed significant reductions in clinical symptoms, histopathological lesions, and intestinal PEDV antigen distribution; the piglet survival rate in the P120 group was 100%. Furthermore, whole-genome sequencing identified 13 amino acid changes in P120, which might be responsible for the attenuated virulence of P120. CONCLUSIONS: Thus, an attenuated strain was obtained via cell passaging and that this strain could be used in preparing attenuated vaccines.


id: cord-279794-hn5vmic0
title: Evolutionary and genotypic analyses of global porcine epidemic diarrhea virus strains
author: Guo, Jiahui
date: 2018-08-27
txt: ./txt/cord-279794-hn5vmic0.txt
cache: ./cache/cord-279794-hn5vmic0.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1111/tbed.12991
doi: 10.1111/tbed.12991
summary:
  Molecular clock analysis showed that divergence of the GII‐c subgroup spike gene occurred in April 2010, suggesting that the subgroup originated from recombination events before the PEDV re‐emergence outbreaks. Consistent with our previous research (Wang, Fang, & Xiao, 2016a) , the phylogenetic tree indicated that the complete PEDV genomes evolved into two separate genogroups, GI (classical) and GII (variant), as presented in Figure 1a . Genetic variation of nucleocapsid genes of porcine epidemic diarrhea virus field strains in China Detection and molecular diversity of spike gene of porcine epidemic diarrhea virus in China Genome sequencing and analysis of a novel recombinant porcine epidemic diarrhea virus strain from Henan, China Complete genome sequence of a recombinant porcine epidemic diarrhea virus strain Evolutionary and epidemiological analyses based on spike genes of porcine epidemic diarrhea virus circulating in Thailand

abstract:
  Porcine epidemic diarrhea virus (PEDV), which re‐emerged in China in October 2010, has spread rapidly worldwide. Detailed analyses of the complete genomes of different PEDV strains are essential to understand the relationships among re‐emerging and historic strains worldwide. Here, we analysed the complete genomes of 409 strains from different countries, which were classified into five subgroup strains (i.e., GI‐a, GI‐b, GII‐a, GII‐b, and GII‐c). Phylogenetic study of different genes in the PEDV strains revealed that the newly discovered subgroup GII‐c exhibited inconsistent topologies between the spike gene and other genes. Furthermore, recombination analysis indicated that GII‐c viruses evolved from a recombinant virus that acquired the 5′ part of the spike gene from the GI‐a subgroup and the remaining genomic regions from the GII‐a subgroup. Molecular clock analysis showed that divergence of the GII‐c subgroup spike gene occurred in April 2010, suggesting that the subgroup originated from recombination events before the PEDV re‐emergence outbreaks. Interestingly, Ascaris suum, a large roundworm occurring in pigs, was found to be an unusual PEDV host, providing potential support for cross‐host transmission. This study has significant implications for understanding ongoing global PEDV outbreaks and will guide future efforts to develop effective preventative measures against PEDV.


id: cord-279813-mrei5kih
author: Temeeyasen, G.
date: 2017-12-14
url: https://www.ncbi.nlm.nih.gov/pubmed/29249266/
doi: 10.1016/j.virol.2017.11.024
title:
  Differential gene modulation of pattern-recognition receptor TLR and RIG-I-like and downstream mediators on intestinal mucosa of pigs infected with PEDV non S-INDEL and PEDV S-INDEL strains

abstract:
  Porcine epidemic diarrhea virus (PEDV) strains can be divided into non-S-INDEL and S-INDEL strains. PEDV pathogenesis is strain-specific, and studies in neonatal pigs have demonstrated that the PEDV non-S-INDEL strains are more pathogenic than the PEDV S-INDEL strains. RNA viruses, including PEDV, can interact with a large number of pattern recognition receptors (PRRs) in the intestinal mucosa, including toll-like receptors (TLRs) and RIG-I-like receptors (RLRs). We investigated the differential gene modulation of TLRs, RIG-I, and downstream mediators on the intestinal mucosa of neonatal pigs infected with PEDV S-INDEL and non-S-INDEL strains. Ten five-day-old piglets were inoculated orally with 10 ml of 10(4) TCDI(50)/ml of either PEDV non-S-INDEL or S-INDEL strains. PEDV S-INDEL infection induced pro-inflammatory cytokines through the non-canonical NF-κB signaling pathway by activating RIG-I. In contrast, PEDV non-S-INDEL infection suppressed the induction of pro-inflammatory cytokines and type 1 interferon production by down-regulation of TLRs and downstream signaling molecules.


id: cord-279903-z0wf1wli
author: Wang, Leyi
date: 2014-07-12
txt: ./txt/cord-279903-z0wf1wli.txt
cache: ./cache/cord-279903-z0wf1wli.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.jviromet.2014.07.005
doi: 10.1016/j.jviromet.2014.07.005
summary:
  title: Development and evaluation of a duplex real-time RT-PCR for detection and differentiation of virulent and variant strains of porcine epidemic diarrhea viruses from the United States In this study, the development and validation of a duplex real-time RT-PCR assay for detection and differentiation of the variant and the virulent strains of PEDV currently circulating in the US was reported. However, since the M gene is highly conserved between the virulent and the variant strains of PEDV in the US, this real-time RT-PCR assay cannot differentiate between the two strains of PEDV. Therefore, the aim of this study was to develop a duplex real-time RT-PCR which would detect and differentiate the virulent strain from the variant strain of PEDV. In conclusion, we have developed a duplex real-time RT-PCR assay that reliably detects and differentiates the virulent strain and variant strain of PEDV.

title:
  Development and evaluation of a duplex real-time RT-PCR for detection and differentiation of virulent and variant strains of porcine epidemic diarrhea viruses from the United States

abstract:
  Porcine epidemic diarrhea virus (PEDV) has caused significant economic losses in the US swine industry since May 2013. A new variant strain of PEDV emerged in the US in the late December, 2013. This variant strain of PEDV differs from the virulent strain of PEDV currently circulating in the US in 1170 nt of the 5’end of the S1 domain in the spike gene. Importantly, the variant PEDV caused significantly less mortality in piglets than the virulent PEDV, based on clinical observations. This suggests it may be a potential vaccine candidate for PED. Variant PEDV has been detected in samples from multiple states by our laboratory as well as other laboratories in the US. It is critical to detect and differentiate variant PEDV from the virulent PEDV during outbreaks to enhance control and to prevent PED associated disease. In this study, the development and validation of a duplex real-time RT-PCR assay for detection and differentiation of the variant and the virulent strains of PEDV currently circulating in the US was reported.


id: cord-280183-fxhkfjl6
author: Have, P.
date: 1992-04-30
url: https://www.sciencedirect.com/science/article/pii/037811359290135G
doi: 10.1016/0378-1135(92)90135-g
title:
  Coronavirus infection in mink (Mustela vision). Serological evidence of infection with a coronavirus related to transmissible gastroenteritis virus and porcine epidemic diarrhea virus

abstract:
  Abstract Antibodies to a transmissible gastroenteritis virus (TGEV)-related coronavirus have been demonstrated in mink sera by indirect immunofluorescence, peroxidase-linked antibody assays and immunoblotting. This is the first serological evidence of a specific coronavirus infection in mink. The putative mink coronavirus (MCV) seems to be widespread in the Danish mink population with a prevalence approaching 100%. Analysis by immunoblotting has shown that MCV is closely related to TGEV by the spike (S), matrix (M) and nucleoprotein (N) polypeptides. Furthermore, antibodies to MCV also cross-reacted with N and M polypeptides of porcine epidemic diarrhea virus (PEDV). Thus MCV may occupy an intermediate position between the TGEV group of coronaviruses and PEDV. The possibility that MCV may be associated with syndromes of acute enteritis in preweaning mink is discussed.


id: cord-280564-kgoczioe
author: Conceição-Neto, Nádia
date: 2017-09-08
txt: ./txt/cord-280564-kgoczioe.txt
cache: ./cache/cord-280564-kgoczioe.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1093/ve/vex024
doi: 10.1093/ve/vex024
summary:
  title: Identification of an enterovirus recombinant with a torovirus-like gene insertion during a diarrhea outbreak in fattening pigs In the sample, we observed the presence of a small Torovirus contig of 256 bp, which was included in the phylogenetic tree (Fig. 1A , Torovirus/BEL/2015), showing very low similarity with the gene insertion found in the recombinant virus. The enterovirus genome region before the torovirus insertion (VP1-VP4, 2 A, 2B, and 2 C) showed its highest similarity on the amino-acid level (94.5%) with EVG/Porcine/USA/Texas1/ 2014 (Fig. 1C) . In addition to confirming the presence of the enterovirus-torovirus recombinant using Sanger sequencing, we used proteomics to infer whether the protein of the insertion could be found in the sample. Taking the metagenomics data, the Sanger sequence confirmation and the proteomics results all together we can conclude that this recombinant virus is present in the sample and that the inserted protein is being expressed.

title:
  Identification of an enterovirus recombinant with a torovirus-like gene insertion during a diarrhea outbreak in fattening pigs

abstract:
  Diarrhea outbreaks in pig farms have raised major concerns in Europe and USA, as they can lead to dramatic pig losses. During a suspected outbreak in Belgium of porcine epidemic diarrhea virus (PEDV), we performed viral metagenomics to assess other potential viral pathogens. Although PEDV was detected, its low abundance indicated that other viruses were involved in the outbreak. Interestingly, a porcine bocavirus and several enteroviruses were most abundant in the sample. We also observed the presence of a porcine enterovirus genome with a gene insertion, resembling a C28 peptidase gene found in toroviruses, which was confirmed using re-sequencing, bioinformatics, and proteomics approaches. Moreover, the predicted cleavage sites for the insertion suggest that this gene was being expressed as a single protein, rather than a fused protein. Recombination in enteroviruses has been reported as a major mechanism to generate genetic diversity, but gene insertions across viral families are rather uncommon. Although such inter-family recombinations are rare, our finding suggests that these events may significantly contribute to viral evolution.


id: cord-282466-r2sjv9ih
title: Current Status of Porcine Epidemic Diarrhoea (PED) in European Pigs
author: Antas, Marta
date: 2019-10-24
txt: ./txt/cord-282466-r2sjv9ih.txt
cache: ./cache/cord-282466-r2sjv9ih.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.2478/jvetres-2019-0064
doi: 10.2478/jvetres-2019-0064
summary:
  Porcine epidemic diarrhoea (PED) is a highly contagious and devastating enteric disease of pigs caused by porcine epidemic diarrhoea virus (PEDV), an enveloped, single-stranded RNA virus belonging to the Alphacoronavirus genus of the Coronaviridae family. Heavy economic losses in the pig-farming industry were sustained in the USA between 2013 and 2015 when PEDV spread very quickly and resulted in epidemics. The purpose of this review is a description of the current status of porcine epidemic diarrhoea in European pigs and the risk presented by the introduction of PEDV to Poland in comparison to the epidemics in the USA. Pathogenesis comparison between the United States porcine epidemic diarrhoea virus prototype and S-INDEL-variant strains in conventional neonatal piglets Isolation and characterization of porcine epidemic diarrhea viruses associated with the 2013 disease outbreak among swine in the United States Characterizing the rapid spread of porcine epidemic diarrhea virus (PEDV) through an animal food manufacturing facility

abstract:
  Porcine epidemic diarrhoea (PED) is a highly contagious and devastating enteric disease of pigs caused by porcine epidemic diarrhoea virus (PEDV), an enveloped, single-stranded RNA virus belonging to the Alphacoronavirus genus of the Coronaviridae family. The disease is clinically similar to other forms of porcine gastroenteritis. Pigs are the only known host of the disease, and the occurrence of PED in wild boars is unknown. The virus causes acute diarrhoea, vomiting, dehydration, and high mortality in suckling piglets reaching 100%. Heavy economic losses in the pig-farming industry were sustained in the USA between 2013 and 2015 when PEDV spread very quickly and resulted in epidemics. The loss in the US pig industry has been estimated at almost seven million pigs. The purpose of this review is a description of the current status of porcine epidemic diarrhoea in European pigs and the risk presented by the introduction of PEDV to Poland in comparison to the epidemics in the USA.


id: cord-284322-synuzaxm
author: Borel, Nicole
date: 2010-07-27
txt: ./txt/cord-284322-synuzaxm.txt
cache: ./cache/cord-284322-synuzaxm.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/1471-2180-10-201
doi: 10.1186/1471-2180-10-201
summary:
  To confirm these initial observations, we established a cell culture model of mixed infections with Chlamydia and a cell culture-adapted porcine epidemic diarrhea virus (ca-PEDV) and hypothesized that this would result in the generation of persistent chlamydial forms. In contrast, dual infections with ca-PEDV and Chlamydia pecorum resulted in the exclusive production of aberrant inclusions containing between 2-50 ABs. Chlamydial inclusions in viral syncytia grew even larger than in non-viral infected Vero cells. The changes of chlamydial inclusion size by subsequent virus addition to Chlamydia abortus are different to those we observed in the Chlamydia pecorum dual infection experiments. TEM examinations of mixed infections (ca-PEDV and Chlamydia abortus or Chlamydia pecorum) revealed aberrant chlamydial inclusions containing fewer bacteria than typical inclusions and were located in viral syncytia or single cells without viral infection. Enlarged chlamydial inclusions were described in that study in the ca-PEDV co-infection model with Chlamydia abortus and Chlamydia pecorum but no further ultrastructural analysis has been subsequently performed.

title:
  Mixed infections with Chlamydia and porcine epidemic diarrhea virus - a new in vitro model of chlamydial persistence

abstract:
  BACKGROUND: Chlamydiae induce persistent infections, which have been associated with a wide range of chronic diseases in humans and animals. Mixed infections with Chlamydia and porcine epidemic diarrhea virus (PEDV) may result in generation of persistent chlamydial infections. To test this hypothesis, an in vitro model of dual infection with cell culture-adapted PEDV and Chlamydia abortus or Chlamydia pecorum in Vero cells was established. RESULTS: Infected cultures were investigated by immunofluorescence (IF), transmission electron microscopy (TEM) and re-infection experiments. By IF, Chlamydia-infected cells showed normal inclusions after 39 hpi. Dual infections with Chlamydia abortus revealed a heterogenous mix of inclusion types including small inclusions consisting of aberrant bodies (ABs), medium-sized inclusions consisting of ABs and reticulate bodies and normal inclusions. Only aberrant inclusions were observable in dual infection experiments with Chlamydia pecorum and PEDV. TEM examinations of mixed infections with Chlamydia abortus and Chlamydia pecorum revealed aberrant chlamydial inclusions containing reticulate-like, pleomorphic ABs, which were up to 2 μm in diameter. No re-differentiation into elementary bodies (EBs) was detected. In re-infection experiments, co-infected cells produced fewer EBs than monoinfected cells. CONCLUSIONS: In the present study we confirm that PEDV co-infection alters the developmental cycle of member species of the family Chlamydiaceae, in a similar manner to other well-described persistence induction methods. Interestingly, this effect appears to be partially species-specific as Chlamydia pecorum appears more sensitive to PEDV co-infection than Chlamydia abortus, as evidenced by TEM and IF observations of a homogenous population of aberrant inclusions in PEDV - Chlamydia pecorum co-infections.


id: cord-286831-ni7qfjk9
title: Antiviral activity of quercetin 7-rhamnoside against porcine epidemic diarrhea virus
author: Choi, Hwa-Jung
date: 2008-11-06
txt: ./txt/cord-286831-ni7qfjk9.txt
cache: ./cache/cord-286831-ni7qfjk9.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/18992773/
doi: 10.1016/j.antiviral.2008.10.002
summary:
  Following this, 0.09 mL of diluted virus suspension of PEDV containing CCID 50 (50% cell culture infective dose) of the virus stock to produce a appropriate cytopathic effects within 2 days after infection and 0.01 mL of medium supplemented with typsin-EDTA containing an appropriate concentration of the compounds were added. Current antiviral drugs, natural compounds and flavonoids were further studied for their inhibitory effects on replication of the PEDV and cytotoxicity in Vero cells, among which ribavirin, tannic acid, coumarin and interferon-␣ exhibited the activities with IC 50 of 4.1, 47.4, 9 g/mL and 0.52 unit, respectively. A similar result was obtained in control infections with treated ribavirin (Fig. 1 ), but antiviral activity was shown to be lower than that of Q7R. Trials of ribavirin in this study showed that the drug had favorable effects on antiviral activity in Vero cells infected with PEDV.

abstract:
  Porcine epidemic diarrhea virus (PEDV) is the predominant cause of severe entero-pathogenic diarrhea in swine. The lack of effective therapeutical treatment underlines the importance of research for new antivirals. In this study, we identified Q7R, which actively inhibited PEDV replication with a 50% inhibitory concentration (IC(50)) of 0.014 μg/mL. The 50% cytotoxicity concentration (CC(50)) of Q7R was over 100 μg/mL and the derived therapeutic index was 7142. Several structural analogues of Q7R, quercetin, apigenin, luteolin and catechin, also showed moderate anti-PEDV activity. Antiviral drugs and natural compounds revealed ribavirin, interferon-α, coumarin and tannic acid have relative weaker efficacy compared to Q7R. Q7R did not directly interact with or inactivate PEDV particles and affect the initial stage of PEDV infection by interfering of PEDV replication. Also, the effectiveness of Q7R against the other two viruses (TGEV, PRCV) was lower compared to PEDV. Q7R could be considered as a lead compound for development of anti-PEDV drugs to may be used to during the early stage of PEDV replication and the structure-activity data of Q7R may usefully guideline to design other related antiviral agents.


id: cord-287913-pe6ot11q
author: Jung, Kwonil
date: 2007-06-18
txt: ./txt/cord-287913-pe6ot11q.txt
cache: ./cache/cord-287913-pe6ot11q.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/17574457/
doi: 10.1016/j.tvjl.2007.04.018
summary:
  title: Effects of epidermal growth factor on atrophic enteritis in piglets induced by experimental porcine epidemic diarrhoea virus Epidermal growth factor (EGF) promotes gastrointestinal mucosal recovery by stimulating the mitogenic activity of intestinal crypt epithelial cells. The aim of this study was to determine the effects of EGF on atrophic enteritis induced in piglets by experimental infection with porcine epidemic diarrhoea virus (PEDV) strain Dr13. EGF stimulates proliferation of intestinal crypt epithelial cells and promotes recovery from atrophic enteritis in PEDV-infected piglets. Most PEDV + EGF piglets had moderate diarrhoea from 24 to 36 hpi and severe diarrhoea Table 1 Mean ratio of villous height to crypt depth (VH:CD) in piglets infected with porcine epidemic diarrhoea virus with (PEDV + EGF) or without (PEDV only) epidermal growth factor relative to uninfected piglets (control) This study has shown that EGF enhances proliferation of intestinal crypt epithelial cells and promotes the recovery of damaged villi in piglets infected with PEDV.

title:
  Effects of epidermal growth factor on atrophic enteritis in piglets induced by experimental porcine epidemic diarrhoea virus

abstract:
  Epidermal growth factor (EGF) promotes gastrointestinal mucosal recovery by stimulating the mitogenic activity of intestinal crypt epithelial cells. The aim of this study was to determine the effects of EGF on atrophic enteritis induced in piglets by experimental infection with porcine epidemic diarrhoea virus (PEDV) strain Dr13. Two groups of 12 conventional, colostrum-deprived, 1-day-old, large White-Duroc cross breed piglets were inoculated orally with PEDV (3 × 10(5) 50% tissue culture infective doses), with or without EGF (10 μg/kg/day, intraperitoneally once daily for 4 days after infection) and compared to 12 uninfected, untreated control piglets. PEDV + EGF piglets had less severe clinical signs than PEDV only piglets at 48 and 60 h post-infection (hpi). Histologically, the ratio of villous height:crypt depth of PEDV + EGF piglets was significantly higher than PEDV only piglets at 36 and 48 hpi. Immunohistochemistry for Ki67 demonstrated increased proliferation in intestinal crypt epithelial cells of PEDV + EGF piglets compared to PEDV only piglets at 36, 48 and 60 hpi. EGF stimulates proliferation of intestinal crypt epithelial cells and promotes recovery from atrophic enteritis in PEDV-infected piglets.


id: cord-287947-7kjxbd6t
author: Gao, Ruyi
date: 2020-04-23
txt: ./txt/cord-287947-7kjxbd6t.txt
cache: ./cache/cord-287947-7kjxbd6t.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32340172/
doi: 10.3390/ijms21082961
summary:
  Collectively, our data indicated that GLY inhibited PEDV infection and decreased proinflammatory cytokine secretion via the HMGB1/TLR4-mitogen-activated protein kinase (MAPK) p38 pathway. Western blotting showed that TAK induced moderately decreased porcine epidemic diarrhea virus nucleocapsid (PEDV-N) protein expression in a dose-dependent manner, and about 73% PEDV-N protein decreased when treating with 10 μM concentration of TAK (Figure 2A) , demonstrating the fact that TLR4 might regulate PEDV infection. Western blotting showed that TAK induced moderately decreased porcine epidemic diarrhea virus nucleocapsid (PEDV-N) protein expression in a dose-dependent manner, and about 73% PEDV-N protein decreased when treating with 10 μM concentration of TAK (Figure 2A) , demonstrating the fact that TLR4 might regulate PEDV infection. In this study, we explored GLY-inhibited PEDV infection and decreased proinflammatory cytokine production through effects on the HMGB1/TLR4-p38 pathway. In this study, we explored GLY-inhibited PEDV infection and decreased proinflammatory cytokine production through effects on the HMGB1/TLR4-p38 pathway.

title:
  Glycyrrhizin Inhibits PEDV Infection and Proinflammatory Cytokine Secretion via the HMGB1/TLR4-MAPK p38 Pathway

abstract:
  Our previous study showed that glycyrrhizin (GLY) inhibited porcine epidemic diarrhea virus (PEDV) infection, but the mechanisms of GLY anti-PEDV action remain unclear. In this study, we focused on the anti-PEDV and anti-proinflammatory cytokine secretion mechanisms of GLY. We found that PEDV infection had no effect on toll-like receptor 4 (TLR4) protein and mRNA levels, but that TLR4 regulated PEDV infection and the mRNA levels of proinflammatory cytokines. In addition, we demonstrated that TLR4 regulated p38 phosphorylation but not extracellular regulated protein kinases1/2 (Erk1/2) and c-Jun N-terminal kinases (JNK) phosphorylation, and that GLY inhibited p38 phosphorylation but not Erk1/2 and JNK phosphorylation. Therefore, we further explored the relationship between high mobility group box-1 (HMGB1) and p38. We demonstrated that inhibition of HMGB1 using an antibody, mutation, or knockdown decreased p38 phosphorylation. Thus, HMGB1 participated in activation of p38 through TLR4. Collectively, our data indicated that GLY inhibited PEDV infection and decreased proinflammatory cytokine secretion via the HMGB1/TLR4-mitogen-activated protein kinase (MAPK) p38 pathway.


id: cord-288058-oilurica
author: Cui, Tingting
date: 2020-04-05
txt: ./txt/cord-288058-oilurica.txt
cache: ./cache/cord-288058-oilurica.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32260595/
doi: 10.3390/v12040402
summary:
  To determine the effect of APN on coronavirus replication, the enterocytes were precultured with 1µg/mL hydrocortisone, 50 µM spermidine, 1 µg/mL insulin, 0.1 µM Wnt agonist, or 1% intestinal contents for 24 h prior to inoculation with PEDV CV777 Vero adapted strain, CV777 fecal suspension, and TGEV Miller. To determine the effect of APN on coronavirus replication, the enterocytes were precultured with 1µg/mL hydrocortisone, 50 µM spermidine, 1 µg/mL insulin, 0.1 µM Wnt agonist, or 1% intestinal contents for 24 h prior to inoculation with PEDV CV777 Vero adapted strain, CV777 fecal suspension, and TGEV Miller. The results show that pretreatment of primary enterocytes with hydrocortisone, spermidine, porcine insulin, Wnt agonist, and intestinal contents could stimulate the expression of APN and enhance the infection of PEDV CV777 Vero adapted and non-adapted strains and the TGEV Miller in the enterocytes.

title:
  Role of Porcine Aminopeptidase N and Sialic Acids in Porcine Coronavirus Infections in Primary Porcine Enterocytes

abstract:
  Porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV) have been reported to use aminopeptidase N (APN) as a cellular receptor. Recently, the role of APN as a receptor for PEDV has been questioned. In our study, the role of APN in PEDV and TGEV infections was studied in primary porcine enterocytes. After seven days of cultivation, 89% of enterocytes presented microvilli and showed a two- to five-fold higher susceptibility to PEDV and TGEV. A significant increase of PEDV and TGEV infection was correlated with a higher expression of APN, which was indicative that APN plays an important role in porcine coronavirus infections. However, PEDV and TGEV infected both APN positive and negative enterocytes. PEDV and TGEV Miller showed a higher infectivity in APN positive cells than in APN negative cells. In contrast, TGEV Purdue replicated better in APN negative cells. These results show that an additional receptor exists, different from APN for porcine coronaviruses. Subsequently, treatment of enterocytes with neuraminidase (NA) had no effect on infection efficiency of TGEV, implying that terminal cellular sialic acids (SAs) are no receptor determinants for TGEV. Treatment of TGEV with NA significantly enhanced the infection which shows that TGEV is masked by SAs.


id: cord-288253-wqrhiq08
author: Park, Jung-Eun
date: 2015-02-02
url: https://doi.org/10.1016/j.virusres.2014.12.024
doi: 10.1016/j.virusres.2014.12.024
title:
  Development of transgenic mouse model expressing porcine aminopeptidase N and its susceptibility to porcine epidemic diarrhea virus

abstract:
  Porcine coronavirus infections have known as they are specific to pigs with predominantly enteric or respiratory diseases. No laboratory animal model is yet been developed in porcine coronaviruses study. Here, we report that development of a transgenic mouse model expressing porcine APN which is susceptible to porcine coronavirus infection. The porcine APN transgene was constructed by fusing with mouse proximal APN promoter at 5′ terminus and bovine growth hormone polyadenylation site at its 3′ terminus. After screen on pubs from the microinjected mice, we confirmed two transgenic lines expressing porcine APN in various organs. We confirmed the susceptibility to porcine epidemic diarrhea virus, one of the porcine coronaviruses. These transgenic mice will be an important tool for research into the porcine coronaviruses.


id: cord-289026-v09m2fzw
author: Sun, Yan-gang
date: 2018-10-01
url: https://api.elsevier.com/content/article/pii/S0141813018305300
doi: 10.1016/j.ijbiomac.2018.05.167
title:
  Characterization of the interaction between recombinant porcine aminopeptidase N and spike glycoprotein of porcine epidemic diarrhea virus

abstract:
  Porcine epidemic diarrhea (PED) has caused huge economic losses to the global pork industry. Infection by its causative agent PED virus (PEDV), an Alpha-coronavirus, was previously proven to be mediated by its spike (S) glycoprotein and a cellular receptor porcine aminopeptidase N (pAPN). Interestingly, some recent studies have indicated that pAPN is not a functional receptor for PEDV. To date, there is a lack of a direct evidence for the interaction between pAPN and PEDV S protein in vitro. Here, we prepared pAPN ectodomain and the truncated variants of PEDV S protein in Drosophila S2 cells. These recombinant proteins were homogeneous after purification by metal-affinity and size-exclusion chromatography. We then assayed the purified target proteins through immunogenicity tests, PEDV binding interference assays, circular dichroism (CD) measurements, pAPN activity assay and structural determination, demonstrating that they were biologically functional. Finally, we characterized their interactions by gel filtration chromatography, native-polyacrylamide gel electrophoresis (PAGE) and surface plasmon resonance (SPR) analyses. The results showed that their affinities were too low to form complexes, which suggest that pAPN may be controversial as the genuine receptor for PEDV. Therefore, further research needs to be carried out to elucidate the interaction between PEDV and its genuine receptor.


id: cord-290819-zhywlf6r
author: Wu, Jiaqi
date: 2020-07-27
txt: ./txt/cord-290819-zhywlf6r.txt
cache: ./cache/cord-290819-zhywlf6r.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32719955/
doi: 10.1007/s00705-020-04747-8
summary:
  title: The antiviral protein viperin interacts with the viral N protein to inhibit proliferation of porcine epidemic diarrhea virus In the early stage of virus infection, the pattern recognition receptor (PRR) signaling pathway of the host cell is activated to induce interferon production, activating interferon-stimulated genes (ISGs) that encode antiviral proteins that exert antiviral effects. Increased expression of interferon and viperin and decreased replication of PEDV with a clear reduction in the viral load were observed in PEDV-infected IPEC-J2 cells. After virus infection, pattern recognition receptors recognize released viral nucleic acids and activate downstream signaling pathways to promote the production of specific transcription factors and type I interferons [25] . These results indicate that PEDV infection upregulates the expression of interferon and viperin in IPEC-J2 cells. This study showed that the expression of type I interferon increases and that of viperin is also upregulated in IPEC-J2 cells infected with PEDV.

title:
  The antiviral protein viperin interacts with the viral N protein to inhibit proliferation of porcine epidemic diarrhea virus

abstract:
  In the early stage of virus infection, the pattern recognition receptor (PRR) signaling pathway of the host cell is activated to induce interferon production, activating interferon-stimulated genes (ISGs) that encode antiviral proteins that exert antiviral effects. Viperin is one of the innate antiviral proteins that exert broad-spectrum antiviral effects by various mechanisms. Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes huge losses to the pig industry. Research on early antiviral responses in the gastrointestinal tract is essential for developing strategies to prevent the spread of PEDV. In this study, we investigated the mechanisms of viperin in PEDV-infected IPEJ-C2 cells. Increased expression of interferon and viperin and decreased replication of PEDV with a clear reduction in the viral load were observed in PEDV-infected IPEC-J2 cells. Amino acids 1–50 of porcine viperin contain an endoplasmic reticulum signal sequence that allows viperin to be anchored to the endoplasmic reticulum and are necessary for its function in inhibiting PEDV proliferation. The interaction of the viperin S-adenosylmethionine domain with the N protein of PEDV was confirmed via confocal laser scanning microscopy and co-immunoprecipitation. This interaction might interfere with viral replication or assembly to reduce virus proliferation. Our results highlight a potential mechanism whereby viperin is able to inhibit PEDV replication and play an antiviral role in innate immunity.


id: cord-290833-m0wodqr3
title: Synthetic surfactin analogues have improved anti-PEDV properties
author: Yuan, Lvfeng
date: 2019-04-11
txt: ./txt/cord-290833-m0wodqr3.txt
cache: ./cache/cord-290833-m0wodqr3.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pone.0215227
doi: 10.1371/journal.pone.0215227
summary:
  In this study, 10 surfactin analogues were obtained by chemical synthesis and evaluated to determine their anti-PEDV activities, hemolytic activities, and critical micelle concentrations. The production of designer surfactins, made by changing the number and composition of amino acids and fatty acids has proven to be an effective strategy for screening large numbers of lipopeptides for biological activity, but most current research focuses on their anticancer [4] , antimicrobial [5] and insulin delivery [6] properties but not on their antiviral potential. Time of addition assays were performed to determine whether the SLP5 exerts its anti-PEDV effect at the same stage during infection as surfactin. As expected for a normal component of the cell membrane, DEPE did not affect PEDV replication at any stage, while SLP5 and surfactin exhibited antiviral activity at specific stages. SLP5 also has two fewer hydrophobic amino acids than surfactin, this reduces the cost of synthesis while having little effect on antiviral activity.

abstract:
  Surfactin has antiviral activity against various enveloped viruses by inhibiting viral membrane fusion. However, the potential utility of surfactin as an antiviral drug is limited by its cytotoxicity. In this study, 10 surfactin analogues were obtained by chemical synthesis and evaluated to determine their anti-PEDV activities, hemolytic activities, and critical micelle concentrations. The main goal of our study was to develop a safer drug; a surfactin analogue with high anti-PEDV activity and low hemolytic activity. Compared with surfactin, one of the analogues we developed, SLP5, has lower hemolytic activity, with the same antiviral activity. The selectivity index of SLP5 is 52, while the SI for surfactin is 4, in other words, the safe and effective concentration range of SLP5 is 12 times greater than that of surfactin. Like surfactin, SLP5 has a direct antiviral effect on PEDV. Structurally, SLP5 is a linear lipopeptide with three carboxyl groups. Surfactin derivatives similar to SLP5 could be obtained by lactone bond hydrolyzation of surfactin, as well as total synthesis.


id: cord-292101-lnap47kp
author: Jung, Kwonil
date: 2015-06-12
url: https://doi.org/10.1016/j.vetmic.2015.03.022
doi: 10.1016/j.vetmic.2015.03.022
title:
  Structural alteration of tight and adherens junctions in villous and crypt epithelium of the small and large intestine of conventional nursing piglets infected with porcine epidemic diarrhea virus

abstract:
  Integrity of the intestinal epithelium is critical for proper functioning of the barrier that regulates absorption of water and restricts uptake of luminal bacteria. It is maintained mainly by tight junctions (TJs) and adherens junctions (AJs). We conducted immunofluorescence (IF) staining for in situ identification of zonula occludin (ZO)-1 proteins for TJ and E-Cadherin proteins for AJ in the small and large intestinal villous and crypt epithelium of nursing pigs infected with porcine epidemic diarrhea virus (PEDV). Twenty 9-day-old piglets [PEDV-infected (n = 9) and Mock (n = 11)] from PEDV seronegative sows, were orally inoculated [8.9 log(10) genomic equivalents/pig] with PEDV PC21A strain or mock. At post-inoculation days (PIDs) 1–5, infected pigs showed severe watery diarrhea and/or vomiting and severe atrophic enteritis. By immunohistochemistry, PEDV antigens were evident in enterocytes lining the villous epithelium. At PIDs 1–5, PEDV-infected pigs exhibited mildly to extensively disorganized, irregular distribution and reduced expression of ZO-1 or E-Cadherin in villous, but not crypt epithelial cells of the jejunum and ileum, but not in the large intestine, when compared to the negative controls. The structural destruction and disorganization of TJ and AJ were extensive in PEDV-infected pigs at PIDs 1–3, but then appeared to reversibly recover at PID 5, as evident by increased numbers of ZO-1-positive epithelial cells and markedly improved appearance of E-Cadherin-positive villous epithelium. Our results suggest a possible involvement of structurally impaired TJ and AJ in the pathogenesis of PEDV, potentially leading to secondary bacterial infections.


id: cord-292690-1p1gnpgf
author: Zang, Yue
date: 2020-08-16
txt: ./txt/cord-292690-1p1gnpgf.txt
cache: ./cache/cord-292690-1p1gnpgf.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32891955/
doi: 10.1016/j.vetmic.2020.108827
summary:
  title: Recombinant Lactobacillus acidophilus expressing S(1) and S(2) domains of porcine epidemic diarrhea virus could improve the humoral and mucosal immune levels in mice and sows inoculated orally In order to develop a new effective vaccine for the current PEDV, oral vaccines were generated by transferring eukaryotic expression recombinant plasmids carrying the S(1) and S(2) (antigenic sites of the S protein) epitopes of PEDV into a swine-origin Lactobacillus acidophilus (L. The results showed that oral administration of the VP1 gene of foot-and-mouth disease virus using Lactobacillus as a carrier could produce a higher antibody titer than injection, and induce humoral and cellular immunity (Li et al., 2007) . High-level mucosal and systemic immune responses induced by oral administration with Lactobacillus-expressed porcine J o u r n a l P r e -p r o o f epidemic diarrhea virus (PEDV)

title:
  Recombinant Lactobacillus acidophilus expressing S(1) and S(2) domains of porcine epidemic diarrhea virus could improve the humoral and mucosal immune levels in mice and sows inoculated orally

abstract:
  Porcine epidemic diarrhea (PED) is a highly contagious intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV), which is characterized by a high mortality rate in piglets. Since 2012, a remarkable growth in PED outbreaks occurred in many pig farms in China, landing a heavy blow on the pig industry. In order to develop a new effective vaccine for the current PEDV, oral vaccines were generated by transferring eukaryotic expression recombinant plasmids carrying the S(1) and S(2) (antigenic sites of the S protein) epitopes of PEDV into a swine-origin Lactobacillus acidophilus (L. acidophilus). After oral immunization of the BALB/c mice, higher levels of anti-PEDV specific IgG and SIgA antibodies and cellular immune responses were detected in mice orally administered with the recombinant L. acidophilus-S(1) compared to the L. acidophilus-S(2). Furthermore, L. acidophilus-S(1) was used to inoculate the pregnant sows orally and the results showed that the recombinant L. acidophilus-S(1) could elicit a specific systemic and mucosal immune response. In summary, our study demonstrated that oral immunization with L. acidophilus-S(1) could improve the humoral and mucosal immune levels in sows and would be a promising candidate vaccine against PEDV infection in piglets.


id: cord-292734-2g2ym81n
author: Jung, Kwonil
date: 2008-06-30
txt: ./txt/cord-292734-2g2ym81n.txt
cache: ./cache/cord-292734-2g2ym81n.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0034528807001828
doi: 10.1016/j.rvsc.2007.07.004
summary:
  The piglets were euthanized at 1, 2, or 3 days post-inoculation (DPI) to measure the villous height:crypt depth (VH:CD) ratio and to collect fecal samples for RT-PCR and virus isolation. No significant differences in mean VH:CD ratio and clinical symptoms (diarrhea, vomiting, dehydration, and anorexia) were observed between the PEDV/PGAR-infected and PEDV-infected groups of piglets at 1, 2 and 3 DPI; however, at 2 and 3 DPI, PGAR was detected in all fecal samples by RT-PCR and virus isolation. The aim of this study was to determine the impact of PGAR co-infection on PEDV pathogenicity by subjecting piglets experimentally co-infected by PEDV and PGAR to evaluation of clinical signs (severity in diarrhea, dehydration, and dehydration) and histological morphometric analysis (villous height: crypt depth) in mid-jejunum where PEDV lesions were evident.

title:
  Impact of porcine group A rotavirus co-infection on porcine epidemic diarrhea virus pathogenicity in piglets

abstract:
  Abstract Porcine epidemic diarrhea virus (PEDV) and porcine group A rotavirus (PGAR) are the main causative agents of acute diarrhea in piglets. In South Korea, PGAR is prevalent in piglets naturally infected with PEDV. Piglets naturally co-infected with PEDV and PGAR appeared to have severe and prolonged diarrhea that was distinct from that commonly observed. The aim of this study was to determine the impact of PGAR co-infection on PEDV pathogenicity in piglets. Thirty-six colostrum-deprived, one-day old, Large White-Duroc crossbred pigs were randomly divided into four equal groups: PEDV, PEDV/PGAR, PGAR, and control groups. The piglets were euthanized at 1, 2, or 3 days post-inoculation (DPI) to measure the villous height:crypt depth (VH:CD) ratio and to collect fecal samples for RT-PCR and virus isolation. No significant differences in mean VH:CD ratio and clinical symptoms (diarrhea, vomiting, dehydration, and anorexia) were observed between the PEDV/PGAR-infected and PEDV-infected groups of piglets at 1, 2 and 3 DPI; however, at 2 and 3 DPI, PGAR was detected in all fecal samples by RT-PCR and virus isolation. These findings failed to detect any interaction between PEDV and porcine rotavirus in the small intestines of piglets, suggesting that concurrent infection of PGAR may not synergistically enhance intestinal villous atrophy of piglets with PEDV disease. We propose that the severe diarrhea exhibited in PEDV and PGAR co-infected piglets may be more associated with the immunity level of the host rather than to any synergistic effect of PGAR on PEDV enteritis.


id: cord-292958-k5d5fo3i
title: Porcine epidemic diarrhea (PED) infection, diagnosis and vaccination: A mini review
author: Sekhon, Simranjeet Singh
date: 2017-01-04
url: https://www.ncbi.nlm.nih.gov/pubmed/32226596/
doi: 10.1007/s13530-016-0287-8
abstract:
  Porcine epidemic diarrhea virus (PEDV) is a main etiology causing severe enteric disease in piglets with clinical signs of anorexia, vomiting, diarrhea and dehydration resulting in loss of condition and death within a few days. Historically, PED is one of major causes of loss in swine and remains prevalent in some parts of the world. Even with increase in the available tests for PED diagnosis, which include histological diagnosis; virological diagnosis and serological diagnosis, there is no vaccine or specific treatment for this disease yet. In this mini review, the overview and current situation of PED is described with updated techniques, in an effort to comprehensively discuss and understand the disease characteristics.


id: cord-293458-jb7u9xn6
title: Vaccines for porcine epidemic diarrhea virus and other swine coronaviruses
author: Gerdts, Volker
date: 2016-12-02
url: https://doi.org/10.1016/j.vetmic.2016.11.029
doi: 10.1016/j.vetmic.2016.11.029
abstract:
  The recent introduction of the porcine epidemic diarrhea virus (PEDV) into the North American swine herd has highlighted again the need for effective vaccines for swine coronaviruses. While vaccines for transmissible gastroenteritis virus (TGEV) have been available to producers around the world for a long time, effective vaccines for PEDV and deltacoronaviruses were only recently developed or are still in development. Here, we review existing vaccine technologies for swine coronaviruses and highlight promising technologies which may help to control these important viruses in the future.


id: cord-293512-rcwwx7qw
author: Steinbach, Falko
date: 2016-10-27
url: https://www.ncbi.nlm.nih.gov/pubmed/27812401/
doi: 10.7717/peerj.2564
title:
  A retrospective study detects a novel variant of porcine epidemic diarrhea virus in England in archived material from the year 2000

abstract:
  Outbreaks of porcine epidemic diarrhea (PED) were first recorded in England in the 1970s and continued to be confirmed until 2002. Retrospective analysis of archived material from one of the last confirmed cases in England in the year 2000 demonstrates the previous existence of a very diverse PED virus strain. Following the outbreaks of PED in North America in 2013, there has been renewed interest in phylogenetic analysis of sequences from PEDV strains worldwide. There is a gap in the available sequence data between the mid 1980s and the mid 2000s. This work is an example of how this gap can be at least partially filled by the examination of archived material.


id: cord-294559-u0r7oh9z
author: Bian, Hongfen
date: 2019-01-18
txt: ./txt/cord-294559-u0r7oh9z.txt
cache: ./cache/cord-294559-u0r7oh9z.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s12917-019-1773-4
doi: 10.1186/s12917-019-1773-4
summary:
  title: A new immunochromatographic assay for on-site detection of porcine epidemic diarrhea virus based on monoclonal antibodies prepared by using cell surface fluorescence immunosorbent assay For rapid detection of PEDV, a new immunochromatographic assay (ICA) based on monoclonal antibodies (mAbs) was developed in this study. To compare its accuracy to other traditional detection methods, 27 swine stool samples from south of China were investigated with the new developed ICA, commercial strip and RT-PCR. Relying on signals emitted from gold nanoparticles labeled mAb (AuNPs-mAb), a new ICA was developed for sensitive, specific and on-site detection of PEDV in swine stool in China. They were capture and detection mAb, the size of gold nanoparticles, the type of sample pad, the type of conjugate pad, the type of Nitrocellulose membrane, the type of absorbent pad, the amount of tween-20 addition and the spray volume of AuNPs-mAb. The optimization methods are shown in the supplemental materials.

title:
  A new immunochromatographic assay for on-site detection of porcine epidemic diarrhea virus based on monoclonal antibodies prepared by using cell surface fluorescence immunosorbent assay

abstract:
  BACKGROUND: Porcine epidemic diarrhea virus (PEDV) is a highly effective pathogen that can cause death of new-born piglet, resulting in big economical loss in pig farming industry. For rapid detection of PEDV, a new immunochromatographic assay (ICA) based on monoclonal antibodies (mAbs) was developed in this study. RESULTS: The mAbs were prepared by using PEDV positive hybridoma cells that were selected by using cell surface fluorescence immunosorbent assay (CSFIA). Fourteen mAbs against PEDV strain isolated from south of China were prepared. The optimal mAb 4A11 was coated on NC membrane as the capturing reagent and the mAb A11H7 was coupled to gold nanoparticles (AuNPs) as detection reagent for the new ICA. The new ICA was used to measure PEDV in phosphate buffer containing tween-20. Results indicated that the limit of detection (LOD) of the new ICA was 0.47 μg/mL (5.9 × 10(3) TCID(50)/mL) and the liner detection range of the ICA was 0.625–10 μg/mL (7.8 × 10(3)–10(5) TCID(50)/mL). The specificity analysis results showed that this new ICA had no cross reaction in the presence of other porcine viruses. The ICA was also validated for the detection of PEDV in swine stool samples with little interference from swine stool. To compare its accuracy to other traditional detection methods, 27 swine stool samples from south of China were investigated with the new developed ICA, commercial strip and RT-PCR. Results showed that the new ICA was more comparable to RT-PCR than commercial test strip. CONCLUSIONS: A new ICA based on mAbs prepared by CSFIA was developed in this study. It was a sensitive, specific and rapid method that could be used for on-site detection of PEDV and therefore was useful for the diagnosis and prevention of PED. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12917-019-1773-4) contains supplementary material, which is available to authorized users.


id: cord-295534-bwa4wz94
author: Jung, Kwonil
date: 2015-02-26
url: https://www.ncbi.nlm.nih.gov/pubmed/25841898/
doi: 10.1016/j.tvjl.2015.02.017
title:
  Porcine epidemic diarrhea virus infection: Etiology, epidemiology, pathogenesis and immunoprophylaxis

abstract:
  Porcine epidemic diarrhea virus (PEDV), a member of the genera Alphacoronavirus in the family Coronaviridae, causes acute diarrhea/vomiting, dehydration and high mortality in seronegative neonatal piglets. For the last three decades, PEDV infection has resulted in significant economic losses in the European and Asian pig industries, but in 2013–2014 the disease was also reported in the US, Canada and Mexico. The PED epidemic in the US, from April 2013 to the present, has led to the loss of more than 10% of the US pig population. The disappearance and re-emergence of epidemic PED indicates that the virus is able to escape from current vaccination protocols, biosecurity and control systems. Endemic PED is a significant problem, which is exacerbated by the emergence (or potential importation) of multiple PEDV variants. Epidemic PEDV strains spread rapidly and cause a high number of pig deaths. These strains are highly enteropathogenic and acutely infect villous epithelial cells of the entire small and large intestines although the jejunum and ileum are the primary sites. PEDV infections cause acute, severe atrophic enteritis accompanied by viremia that leads to profound diarrhea and vomiting, followed by extensive dehydration, which is the major cause of death in nursing piglets. A comprehensive understanding of the pathogenic characteristics of epidemic or endemic PEDV strains is needed to prevent and control the disease in affected regions and to develop an effective vaccine. This review focuses on the etiology, epidemiology, disease mechanisms and pathogenesis as well as immunoprophylaxis against PEDV infection.


id: cord-296791-h8ftslps
title: Cloning and sequence analysis of the N gene of porcine epidemic diarrhea virus LJB/03
author: Junwei, Ge
date: 2006-10-01
url: https://www.ncbi.nlm.nih.gov/pubmed/16972037/
doi: 10.1007/s11262-005-0059-z
abstract:
  The nucleocapsid (N) gene of the porcine epidemic diarrhea virus (PEDV) strain LJB/03 which was previously isolated in Heilongjiang province, China, was cloned, sequenced and compared with published sequences of other avian and mammalian coronavirus. The nucleotide sequence encoding the entire N gene open reading frame (ORF) of LJB/03 was 1326 bases long and encoded a protein of 441 amino acids with predicted Mr of 49 kDa. It consisted of 405 adenines (30.5%), 294 cytosines (22.1%), 329 guanines (24.8%) and 298 thymines (22.5%) residues. Sequence comparison with other PEDV strains selected from GenBank revealed that the LJB/03 N gene has a high sequence homology to those of other PEDV isolates, 97.4% with JS2004, 95.6% with chinju99, 96.6% with Br1/87, and 96.8% with CV777. The encoded protein shared 96.4% amino acid identities compared with CV777, 96.1% with Brl/87, 98% with JS2004, 96.90% with chinju99, respectively. The amino acid sequence contained seven potential protein kinase C phosphorylation sites, nine Casein kinase II phosphorylation sites, one Tyrosine kinase phosphorylation site, two cAMP- and cGMP-dependent protein kinase phosphorylation sites.


id: cord-298401-4szmu1dh
author: Lyoo, Kwang-Soo
date: 2017-12-02
url: https://doi.org/10.1136/vr.103959
doi: 10.1136/vr.103959
title:
  Development of rapid immunochromatographic strip test for the detection of porcine epidemic diarrhoea virus

abstract:
  Porcine epidemic diarrhoea virus (PEDV) causes acute and severe watery diarrhoea and dehydration, as well as 50–100 per cent mortality in piglets. For the PEDV diagnosis, a rapid test kit that is specific and sensitive to PEDV is critical to monitor this disease at pig farms. The present study aimed to develop an immunochromatographic assay (ICA) strip test for detecting PEDV in faecal swabs. The newly developed diagnostic test showed a detection limit of 10(4.0) TCID(50)/ml of PEDV. Using faecal swab samples, the relative sensitivity and specificity of the ICA kit were 95.0 per cent and 98.6 per cent, respectively, compared with those of real-time RT-PCR. In samples from piglets experimentally infected with PEDV, the results showed 100 per cent agreement with those found by real-time RT-PCR. Our developed test strip will be useful for rapid diagnosis and can be used for epidemiological surveillance of PEDV infection.


id: cord-298685-qxkxjxsz
title: Porcine epidemic diarrhea: A retrospect from Europe and matters of debate
author: Pensaert, Maurice B.
date: 2016-12-02
txt: ./txt/cord-298685-qxkxjxsz.txt
cache: ./cache/cord-298685-qxkxjxsz.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.virusres.2016.05.030
doi: 10.1016/j.virusres.2016.05.030
summary:
  Pathogenesis studies with the prototype strain CV777 showed severe villous atrophy in neonatal pigs and the virus-animal interactions showed many similarities with transmissible gastro-enteritis virus (TGEV), another porcine coronavirus. Also, after a first epidemic phase of the new PEDV, the virus often persisted on breeding-finishing farms in weaned and feeder pigs (endemic PED). Results of pathogenesis studies obtained in caesarean derived, colostrum deprived neonatal pigs upon inoculation with the European prototype strain CV777 of the seventies, were practically identical to those observed more recently in Asia and in the USA epidemics with the so-called "original US PEDV strains" Stevenson et al., 2013; Kim and Chae, 2003) . In a serological study in Belgium in 1986, PEDV was associated with diarrhea in 13 out of 16 groups of feeder pigs after arrival in fattening farms (Callebaut et al., 1986) But, the virus remained prevalent in the swine populations of Western Europe during the eighties.

abstract:
  Abstract A retrospect is given on the emergence of porcine epidemic diarrhea (PED) during the early seventies in Europe. While, at first, it appeared as a disease affecting feeder pigs, fattening- and adult swine, it later also became pathogenic for neonatal and suckling pigs hereby drastically increasing its economic impact. Isolation of the causative virus revealed a new porcine coronavirus, the origin of which has never been clarified. Pathogenesis studies with the prototype strain CV777 showed severe villous atrophy in neonatal pigs and the virus-animal interactions showed many similarities with transmissible gastro-enteritis virus (TGEV), another porcine coronavirus. Disease patterns in field outbreaks showed muchvariation but, while farm related factors played a role, possible genetic variations of virus strains in Europe have not been examined and are thus unknown. CV777 in experimental pigs caused diarrheal disease and mortality rates similar to those later encountered in Asia and more recently with the “original” US strains even though genomic typing of the prototype European strain have shown that it belongs to the S-INDEL strains. In Europe, PED has become endemic during the eighties and nineties and subsequently regressed so that, after 2000, swine populations in many countries have largely become seronegative. Sporadic outbreaks have recently reappeared showing a large variety of clinical outcomes.


id: cord-298922-k568hlf4
author: Sun, Dongbo
date: 2015-06-15
txt: ./txt/cord-298922-k568hlf4.txt
cache: ./cache/cord-298922-k568hlf4.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0166093415000695
doi: 10.1016/j.jviromet.2015.03.002
summary:
  Among the disease-related functions, certain anti-viral pathways and proteins, such as the RIG-I-like receptor, Rap1, autophagy, mitogen-activated protein kinase, PI3K-Akt and Jak-STAT signaling pathways, and integrin β2/β3 and cystatin-C proteins, represented potential factors in PEDV infection. In our current study, we used a quantitative proteomics approach based on an iTRAQ tandem mass spectrometry (MS/MS) technique to identify proteins differentially expressed between PEDV-infected and mock-infected Vero E6 cells. To verify the differential expression of the selected DEPs, equivalent volumes of the cell lysate replicates from the PEDV-infected (V1-V3) and mock-infected (C1-C3) Vero E6 cells were pooled into the V and C samples, respectively, and western blotting was performed as described above, with the following exceptions: a 1:1000 dilution of the polyclonal antibodies anti-␤ tubulin, anti-integrin-␤3, anti-cystatin-C, anti-protein S100-A2, anti-apolipoprotein E4, and anti-centrin from rabbit (Beijing Biosynthesis Biotechnology, Beijing, China) was used as the primary antibody, and a 1:5000 dilution of the HRP-conjugated goat anti-rabbit IgG (Sigma-Aldrich, St. Louis, USA) was used as the secondary antibody.

title:
  Analysis of protein expression changes of the Vero E6 cells infected with classic PEDV strain CV777 by using quantitative proteomic technique

abstract:
  Recent outbreaks of porcine epidemic diarrhea virus (PEDV) have caused widespread concern. The identification of proteins associated with PEDV infection might provide insight into PEDV pathogenesis and facilitate the development of novel antiviral strategies. We analyzed the differential protein profile of PEDV-infected Vero E6 cells using mass spectrometry and an isobaric tag for relative and absolute quantification. A total of 126 proteins were identified that were differentially expressed between the PEDV-infected and mock-infected groups (P < 0.05, quantitative ratio ≥1.2), among which the expression of 58 proteins was up-regulated and that of 68 proteins was down-regulated in the PEDV-infected Vero E6 cells, involving in integrin β2/β3, cystatin-C. The Gene Ontology analysis indicated that the molecular function of the differentially expressed proteins (DEPs) was primarily related to binding and catalytic activity, and that the biological functions in which the DEPs are involved included metabolism, organismal systems, cellular processes, genetic information processing, environmental information processing, and diseases. Among the disease-related functions, certain anti-viral pathways and proteins, such as the RIG-I-like receptor, Rap1, autophagy, mitogen-activated protein kinase, PI3K-Akt and Jak-STAT signaling pathways, and integrin β2/β3 and cystatin-C proteins, represented potential factors in PEDV infection. Our findings provide valuable insight into PEDV-Vero E6 cell interactions.


id: cord-299345-2i48ld8d
title: Molecular characteristics of a novel recombinant of porcine epidemic diarrhea virus
author: Nefedeva, Mariia
date: 2019-02-06
txt: ./txt/cord-299345-2i48ld8d.txt
cache: ./cache/cord-299345-2i48ld8d.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/30725181/
doi: 10.1007/s00705-019-04166-4
summary:
  Pairwise identity analysis of the whole genome sequences revealed that PEDV/Belgorod/dom/2008 is an intermediate between PEDV and transmissible gastroenteritis virus (TGEV) strains. Based on the phylogenetic analysis of the M gene, the PEDV/Belgorod/ dom/2008 isolate belongs to the same clade as other virulent Russian PEDV strains, indicating a high degree of sequence homogeneity in the M gene (Fig. 3a) isolate is genetically distinct and does not belong to any group (Fig. 3b ). The identification of recombinant regions in PEDV/Belgorod/dom/2008 can be useful for further analysis of evolutionary variability, epidemiology, and development of a new diagnostic gene-based assay for porcine epidemic diarrhea virus. Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene Genome sequencing and analysis of a novel recombinant porcine epidemic diarrhea virus strain from Henan, China

abstract:
  Porcine epidemic diarrhea (PED) is a contagious viral disease in pigs, caused by the coronavirus porcine epidemic diarrhea virus (PEDV). PEDV infection results in significant mortality in piglets in unvaccinated herds. Like many others RNA viruses, PEDV has high evolutionary rate and is prone to genetic mutations. In this study, we analyzed the complete genome sequence of the recently sequenced isolate PEDV/Belgorod/dom/2008. A recombination event in S gene of PEDV/Belgorod/dom/2008 was detected. Pairwise identity analysis of the whole genome sequences revealed that PEDV/Belgorod/dom/2008 is an intermediate between PEDV and transmissible gastroenteritis virus (TGEV) strains. These results can be used for further analysis of the evolutionary variability, prevalence, and epidemiology of the porcine epidemic diarrhea virus.


id: cord-299988-jaekryq5
author: Karte, Claudia
date: 2020-09-10
txt: ./txt/cord-299988-jaekryq5.txt
cache: ./cache/cord-299988-jaekryq5.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s12917-020-02548-4
doi: 10.1186/s12917-020-02548-4
summary:
  title: Re-emergence of porcine epidemic diarrhea virus in a piglet-producing farm in northwestern Germany in 2019 After initial confirmation of PEDV by real-time RT-PCR, fecal material and small intestine samples from affected pigs were subjected to metagenomic analyses employing next-generation sequencing. Phylogenetic analyses showed high identities among the PEDV sequences obtained from samples of different animals and a close relation to recent strains from Hungary and France. After reports from Asia, that a new PEDV variant caused considerable losses [12, 13] , that highly virulent PEDV variant emerged also in the United States (US) in 2013, with swine farms experiencing explosive epidemics affecting all age classes of animals, with up to 95% mortality in suckling pigs [2, 14] . Emergence of porcine epidemic diarrhea virus in the United States: clinical signs, lesions, and viral genomic sequences

title:
  Re-emergence of porcine epidemic diarrhea virus in a piglet-producing farm in northwestern Germany in 2019

abstract:
  BACKGROUND: Porcine epidemic diarrhea (PED) is a viral enteric disease of pigs. It affects all age classes of animals but lethality is mainly seen in suckling piglets. After its first appearance in England in 1971, Porcine epidemic diarrhea virus (PEDV) has spread worldwide. While sporadic outbreaks prevailed in Europe, the disease had high impact in Asia. Following particularly severe outbreaks in 2011, high impact cases were also reported in the United States and neighboring countries in 2013. Subsequently, outbreaks were also reported in several European countries including Germany. These outbreaks were less severe. This case report describes a recent case of PED re-emergence in Germany and the sequence analyses of the causative PEDV. CASE PRESENTATION: In spring 2019 5 years after re-introduction of PED into Central Europe, a piglet-producer in northwestern Germany experienced an outbreak that affected sows, their suckling piglets, and weaners. After initial confirmation of PEDV by real-time RT-PCR, fecal material and small intestine samples from affected pigs were subjected to metagenomic analyses employing next-generation sequencing. Phylogenetic analyses showed high identities among the PEDV sequences obtained from samples of different animals and a close relation to recent strains from Hungary and France. Compared to the PEDV strains analyzed in 2014, genetic drift could be confirmed. Changes were mainly observed in the spike protein encoding S gene segment. In addition, metagenomic analyses showed multiple Picobirnavirus reads in all investigated samples. CONCLUSION: This case report shows that PEDV is still circulating in Europe. The causative strains are moderately virulent and are still closely related to the so-called INDEL strains reported previously in Europe, including Germany. However, a genetic drift has taken place that can be seen in a novel cluster comprising strains from Germany, Hungary and France in 2019. Relevance and impact of the detected Picobirna sequences need further investigations.


id: cord-301175-6alsigxk
author: Okda, Faten
date: 2015-08-01
url: https://doi.org/10.1186/s12917-015-0500-z
doi: 10.1186/s12917-015-0500-z
title:
  Development of an indirect ELISA, blocking ELISA, fluorescent microsphere immunoassay and fluorescent focus neutralization assay for serologic evaluation of exposure to North American strains of Porcine Epidemic Diarrhea Virus

abstract:
  BACKGROUND: Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlight the need for well-validated diagnostic tests for the identification of PEDV infected animals and evaluation of their immune status to this virus. PEDV was first detected in the U.S. in May 2013 and spread rapidly across the country. Some serological assays for PEDV have been previously described, but few were readily available in the U.S. Several U.S. laboratories quickly developed indirect fluorescent antibody (IFA) assays for the detection of antibodies to PEDV in swine serum, indicating prior exposure. However, the IFA has several disadvantages, including low throughput and relatively subjective interpretation. Different serologic test formats have advantages and disadvantages, depending on the questions being asked, so a full repertoire of tests is useful. Therefore, the objective of this study was to develop and validate multiple improved serological assays for PEDV, including an indirect ELISA (iELISA); a highly specific monoclonal antibody-based blocking ELISA (bELISA); fluorescent microsphere immunoassays (FMIA) that can be multiplexed to monitor exposure to multiple antigens and pathogens simultaneously; and a fluorescent focus neutralization assay (FFN) to measure functional virus neutralizing antibodies. RESULTS: A recombinant North American nucleoprotein (NP) based iELISA was developed and validated along with a bELISA using newly developed PEDV-NP specific biotinylated monoclonal antibodies (mAbs) and an FMIA using magnetic beads coupled with expressed NA PEDV-NP. Receiver operating characteristic (ROC) analysis was performed using swine serum samples (iELISA n = 1486, bELISA n = 1186, FMIA n = 1420). The ROC analysis for the FMIA showed estimated sensitivity and specificity of 98.2 and 99.2 %, respectively. The iELISA and bELISA showed a sensitivity and specificity of 97.9 and 97.6 %; and 98.2 and 98.9 %, respectively. Inter-rater (kappa) agreement was calculated to be 0.941 between iELISA and IFA, 0.945 between bELISA and IFA and 0.932 between FMIA and IFA. Similar comparative kappa values were observed between the iELISA, bELISA and FMIA, which demonstrated a significant level of testing agreement among the three assays. No cross-reactivity with the closely related coronaviruses, transmissible gastroenteritis virus (TGEV) or porcine respiratory coronavirus (PRCV) was noted with these assays. All three assays detected seroconversion of naïve animals within 6–9 days post exposure. The FFN assay allows relative quantitation of functional neutralizing antibodies in serum, milk or colostrum samples. CONCLUSION: Well-validated iELISA, bELISA and FMIA assays for the detection of PEDV antibodies were developed and showed good correlation with IFA and each other. Each assay format has advantages that dictate how they will be used in the field. Newly developed mAbs to the PEDV-NP were used in the bELISA and for expediting FFN testing in the detection and quantitation of neutralizing antibodies. In addition, these PEDV mAbs are useful for immunohistochemistry, fluorescent antibody staining and other antigen-based tests. Measurement of neutralizing antibody responses using the FFN assay may provide a valuable tool for assessment of vaccine candidates or protective immunity.


id: cord-301347-22lt6h40
author: Jarvis, Matthew C.
date: 2016-01-01
txt: ./txt/cord-301347-22lt6h40.txt
cache: ./cache/cord-301347-22lt6h40.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0167587715300416
doi: 10.1016/j.prevetmed.2015.10.020
summary:
  Phylogenetic analysis of the complete genome sequence data revealed high rates of recombination, resulting in differing evolutionary patterns in phylogenies inferred for the spike region versus whole genomes. Despite excising a large portion of the genome prior to analysis, the Bayesian trees illustrate two distinct entries of PEDV into the US and characterize the evolution of PEDV compared to other CoVs. Modeling of the pAPN RBD region has revealed that Asian strains have increasing diversity compared to previously developed vaccines, and the variability in both the American and Asian strains needs to be considered for future vaccine development. Phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in central China based on the ORF3 gene and the main neutralization epitopes Complete genome sequence of porcine epidemic diarrhea virus strain USA/Colorado/2013 from the United States Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene

title:
  Genomic and evolutionary inferences between American and global strains of porcine epidemic diarrhea virus

abstract:
  Porcine epidemic diarrhea virus (PEDV) has caused severe economic losses both recently in the United States (US) and historically throughout Europe and Asia. Traditionally, analysis of the spike gene has been used to determine phylogenetic relationships between PEDV strains. We determined the complete genomes of 93 PEDV field samples from US swine and analyzed the data in conjunction with complete genome sequences available from GenBank (n = 126) to determine the most variable genomic areas. Our results indicate high levels of variation within the ORF1 and spike regions while the C-terminal domains of structural genes were highly conserved. Analysis of the Receptor Binding Domains in the spike gene revealed a limited number of amino acid substitutions in US strains compared to Asian strains. Phylogenetic analysis of the complete genome sequence data revealed high rates of recombination, resulting in differing evolutionary patterns in phylogenies inferred for the spike region versus whole genomes. These finding suggest that significant genetic events outside of the spike region have contributed to the evolution of PEDV.


id: cord-301355-9lswjro2
author: Fan, Jing-Hui
date: 2015-12-01
txt: ./txt/cord-301355-9lswjro2.txt
cache: ./cache/cord-301355-9lswjro2.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0166093415002645
doi: 10.1016/j.jviromet.2015.07.021
summary:
  title: Development of an enzyme-linked immunosorbent assay for the monitoring and surveillance of antibodies to porcine epidemic diarrhea virus based on a recombinant membrane protein Therefore, the accurate diagnosis, serological monitoring, and surveillance of specific antibodies in pigs resulting from porcine epidemic diarrhea virus (PEDV) infection or vaccination would be essential in helping to control the spread of PED. To detect PEDV antibodies in eight herds, 382 serum samples were collected from sows that had been immunized with a PED vaccine, and screened using the developed ELISA in parallel with a serum neutralization (SN) assay. To determine the specificity of the developed ELISA, crossreactivity was assessed by determining the reactivity of the purified antigen with serum samples containing antibodies against TGEV, PRV, PRRSV, PCV2, CSFV and PEDV. Development and evaluation of enzyme-linked immunosorbent assay based on recombinant nucleocapsid protein for detection of porcine epidemic diarrhea (PEDV) antibodies

title:
  Development of an enzyme-linked immunosorbent assay for the monitoring and surveillance of antibodies to porcine epidemic diarrhea virus based on a recombinant membrane protein

abstract:
  The recent dramatic increase in reported cases of porcine epidemic diarrhea (PED) in pig farms is a potential threat to the global swine industry. Therefore, the accurate diagnosis, serological monitoring, and surveillance of specific antibodies in pigs resulting from porcine epidemic diarrhea virus (PEDV) infection or vaccination would be essential in helping to control the spread of PED. We developed and validated an indirect enzyme-linked immunosorbent assay (ELISA) based on the recombinant membrane (M) protein of PEDV. To detect PEDV antibodies in eight herds, 382 serum samples were collected from sows that had been immunized with a PED vaccine, and screened using the developed ELISA in parallel with a serum neutralization (SN) assay. Of the tested samples, 276 were positive for the presence of PEDV antibodies according to both assays, while 98 were negative. An excellent agreement between the ELISA and the SN assay was observed (kappa = 0.947; 95% confidence interval = 0.910–0.984; McNemar's test, P = 0.727). No cross-reaction was detected for the developed ELISA with other coronaviruses or other common pig pathogens. The developed ELISA could be used for serological evaluation and indirect diagnosis of PED infection.


id: cord-301655-6nxhvvm4
author: Lei, Xi-Mei
date: 2019-08-10
txt: ./txt/cord-301655-6nxhvvm4.txt
cache: ./cache/cord-301655-6nxhvvm4.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0378113519304365
doi: 10.1016/j.vetmic.2019.108387
summary:
  In order to determine and compare which of the viral proteins may be useful as diagnostic antigens, whole virus (WV) particles and a panel of structural and nonstructural PEDV proteins [spike subunit 1 (S1), the C-terminal part of ORF3 (ORF3C), envelope (E), nonstructural protein 1 (Nsp1), Nsp2, Ac (acidic domain of Nsp3), and ADRP (ADP-ribose-1-monophosphatase domain of Nsp3), expressed individually in bacterial and/or mammalian cells] were tested for reactivity with sera from PEDV-infected pigs by ELISA and/or western blot analysis. In this study, a panel of recombinant PEDV ORFs encoding structural and nonstructural proteins were expressed in mammalian and/or bacterial cells and screened for reactivity with porcine sera from seven provinces of China by ELISA and/or western blot analysis, in order to determine which antigen is most suitable as a diagnostic marker for PEDV infection.

title:
  Specific recombinant proteins of porcine epidemic diarrhea virus are immunogenic, revealing their potential use as diagnostic markers

abstract:
  Given the highly contagious and acute nature of porcine epidemic diarrhea (PED), especially in piglets, there is an urgent need for the development of rapid and sensitive diagnostic assays. The diagnostic potentials of specific porcine epidemic diarrhea virus (PEDV) accessory and nonstructural proteins, if any, have not yet been investigated. In order to determine and compare which of the viral proteins may be useful as diagnostic antigens, whole virus (WV) particles and a panel of structural and nonstructural PEDV proteins [spike subunit 1 (S1), the C-terminal part of ORF3 (ORF3C), envelope (E), nonstructural protein 1 (Nsp1), Nsp2, Ac (acidic domain of Nsp3), and ADRP (ADP-ribose-1-monophosphatase domain of Nsp3), expressed individually in bacterial and/or mammalian cells] were tested for reactivity with sera from PEDV-infected pigs by ELISA and/or western blot analysis. According to western blots, serum antibody interactions with the S1 protein were relatively more sensitive and specific than ORF3C, E and Ac. Furthermore, a total of 851 serum samples from diarrheal pigs of different ages were analyzed by ELISA, with most showing immune-reactivity towards the WV, S1, ORF3C, and E proteins. The earliest IgG antibody response was observed in the one-week-old piglets, with similar antibody ontogeny and patterns of seroconversion for S1, ORF3C, E, and WV antigens. In addition, the pattern of neutralizing antibody was more similar to that of IgA in weaning piglets after PEDV infection. Collectively, these data provide more reliable information on the host immune response to different viral proteins, which will be useful for development of novel serological assays and for design of vaccines that better stimulate protective immunity.


id: cord-302083-9q1i20o6
author: Jung, Kwonil
date: 2020-06-02
url: https://api.elsevier.com/content/article/pii/S0168170220301209
doi: 10.1016/j.virusres.2020.198045
title:
  Porcine epidemic diarrhea virus (PEDV): An update on etiology, transmission, pathogenesis, and prevention and control

abstract:
  Porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus in the family Coronaviridae, causes acute diarrhea and/or vomiting, dehydration and high mortality in neonatal piglets. Two different genogroups of PEDV, S INDEL [PEDV variant containing multiple deletions and insertions in the S1 subunit of the spike (S) protein, G1b] and non-S INDEL (G2b) strains were detected during the diarrheal disease outbreak in US swine in 2013-2014. Similar viruses are also circulating globally. Continuous improvement and update of biosecurity and vaccine strains and protocols are still needed to control and prevent PEDV infections worldwide. Although the non-S INDEL PEDV was highly virulent and the S INDEL PEDV caused milder disease, the latter has the capacity to cause illness in a high number of piglets on farms with low biosecurity and herd immunity. The main PEDV transmission route is fecal–oral, but airborne transmission via the fecal–nasal route may play a role in pig-to-pig and farm-to-farm spread. PEDV infection of neonatal pigs causes fecal virus shedding (alongside frequent detection of PEDV RNA in the nasal cavity), acute viremia, severe atrophic enteritis (mainly jejunum and ileum), and increased pro-inflammatory and innate immune responses. PEDV-specific IgA effector and memory B cells in orally primed sows play a critical role in sow lactogenic immunity and passive protection of piglets. This review focuses on the etiology, transmission, pathogenesis, and prevention and control of PEDV infection.


id: cord-302286-wu6csxve
title: Oral efficacy of Vero cell attenuated porcine epidemic diarrhea virus DR13 strain
author: Song, D. S.
date: 2007-02-28
url: https://www.ncbi.nlm.nih.gov/pubmed/16730762/
doi: 10.1016/j.rvsc.2006.03.007
abstract:
  Abstract A Vero cell attenuated porcine epidemic diarrhea virus (PEDV) strain, DR13, was distinguished from wild-type PEDV using restriction enzyme fragment length polymorphism (RFLP). Cell attenuated DR13 was orally or intramuscularly (IM) administered to late-term pregnant sows, and mortality resulting from the highly virulent PEDV challenge was investigated in passively immunized suckling piglets of the two different groups. The mortality rate of the oral group (13%) was lower than that of the IM group (60%). In particular, the concentration of IgA against PEDV was higher in piglets of sows in the oral group, compared to the IM group. The attenuated DR13 virus remained safe, even after three backpassages in piglets. The findings of this study support the theory that the Vero cell attenuated DR13 virus may be applied as an oral vaccine for inducing specific immunity in late-term pregnant sows with a high margin of protection against PEDV infection.


id: cord-302323-vvo8a4hp
author: Wang, Xiaobo
date: 2015-11-26
txt: ./txt/cord-302323-vvo8a4hp.txt
cache: ./cache/cord-302323-vvo8a4hp.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/26611909/
doi: 10.1007/s00705-015-2694-6
summary:
  To determine whether these mutations lead to changes in antigenicity, as suggested by the failure of PEDV vaccines in China, we first optimized the codons of typical S genes of the CV777 vaccine strain (G1 subtype) and LNCT2 strain (G2 subtype) and expressed the recombinant full-length sequence of the S protein in a eukaryotic expression system. The findings of this study confirmed that the recombinant S protein was highly immunogenic in Cross serum neutralization (SN) between the S proteins of the two PEDV subtypes and anti-S PAbs. Reciprocals of PEDV neutralizing antibody titers were expressed as the dilution inhibiting PEDV infection by 50 %, which was calculated as follows: Log50 % neutralizing titer = L-d (s-0.5), where L is the log of the lowest dilution factor, d is the difference between the dilution factors, and s is the sum of the ratios of positive wells Variation between porcine epidemic diarrhea virus subtypes 545 mice and could effectively induce production of antibodies, especially neutralizing antibodies.

title:
  Immunogenicity and antigenic relationships among spike proteins of porcine epidemic diarrhea virus subtypes G1 and G2

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a coronavirus that infects cells lining the small intestine of swine, resulting in vomiting, diarrhea, and dehydration. The amino acid sequence of the spike (S) protein, which is the principal target recognized by host immune cells, has multiple mutations that distinguish the two PEDV genotypes, G1 and G2. To determine whether these mutations lead to changes in antigenicity, as suggested by the failure of PEDV vaccines in China, we first optimized the codons of typical S genes of the CV777 vaccine strain (G1 subtype) and LNCT2 strain (G2 subtype) and expressed the recombinant full-length sequence of the S protein in a eukaryotic expression system. The IgG antibody levels of serum from mice immunized with purified S protein were markedly high. Antigenicity was compared by detection of polyclonal antibodies (PAbs) against the virus and S protein using an enzyme-linked immunosorbent assay (ELISA), an indirect immunofluorescence assay (IFA), and a serum cross-neutralization (SN) assay. Reactivity with the PAbs revealed significant cross-reactivity between the two PEDV subtypes, although there was a twofold difference in the antigenic responses based on PAb titers in the ELISA and IFA. Consistent with the variation in the S gene sequences, the SN titer suggested differences in the neutralization activity of the S protein between the two subtypes, which could explain the antigenic variation between the PEDV subtypes G1 and G2.


id: cord-302503-7s9f8wje
title: Rapid and efficient detection methods of pathogenic swine enteric coronaviruses
author: Fu, Yuguang
date: 2020-05-19
txt: ./txt/cord-302503-7s9f8wje.txt
cache: ./cache/cord-302503-7s9f8wje.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00253-020-10645-5
doi: 10.1007/s00253-020-10645-5
summary:
  In October 2010, a severe PED outbreak caused by a highly virulent PEDV variant emerged in southern China with high mortality ranging from 70 to 100%; the result was devastating damage to the pig farm industry and tremendous economic losses, and later, the PEDV variant spreads to other countries, e.g., USA, Canada, and Mexico ( For the early and rapid detection of PEDV, different types of PCR methods have been developed. A TaqMan probe-based real-time PCR to differentiate porcine epidemic diarrhea virus virulent strains from attenuated vaccine strains Development and evaluation of a duplex real-time RT-PCR for detection and differentiation of virulent and variant strains of porcine epidemic diarrhea viruses from the United States Development of a TaqMan-based real-time RT-PCR assay for the detection of SADS-CoV associated with severe diarrhea disease in pigs

abstract:
  ABSTRACT: Porcine enteric coronaviruses (CoVs) cause highly contagious enteric diarrhea in suckling piglets. These COV infections are characterized by clinical signs of vomiting, watery diarrhea, dehydration, and high morbidity and mortality, resulting in significant economic losses and tremendous threats to the pig farming industry worldwide. Because the clinical manifestations of pigs infected by different CoVs are similar, it is difficult to differentiate between the specific pathogens. Effective high-throughput detection methods are powerful tools used in the prevention and control of diseases. The immune system of piglets is not well developed, so serological methods to detect antibodies against these viruses are not suitable for rapid and early detection. This paper reviews various PCR-based methods used for the rapid and efficient detection of these pathogenic CoVs in swine intestines. KEY POINTS: 1. Swine enteric coronaviruses (CoVs) emerged and reemerged in past years. 2. Enteric CoVs infect pigs at all ages with high mortality rate in suckling pigs. 3. Rapid and efficient detection methods are needed and critical for diagnosis.


id: cord-302819-oj33i2ma
author: Pasick, J
date: 2014-08-07
txt: ./txt/cord-302819-oj33i2ma.txt
cache: ./cache/cord-302819-oj33i2ma.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/25098383/
doi: 10.1111/tbed.12269
summary:
  On the SDPP sample that was tested, the following N gene rRT-PCR results were observed: C t of 35.84 for PBS supernatant after 10 000 g, C t of 36.74 for the PBS pellet after 10 000 g, C t of 38.83 for the PBS + Nonidet P-40 Comparison of S protein gene sequences obtained from bioassay piglets versus those of field cases. No significant difference was observed in the kinetics of N gene rRT-PCR positivity in animals that were inoculated with the three SDPP samples that were tested, suggesting that each contained infectious virus. Negative contrast staining electron microscopy of fecal samples collected at 4 dpi from the SDPP-inoculated piglets and the positive control group piglets showed the presence of virus-like particles consistent with coronavirus virions. Similar virus-like particles were also found in the content of the small intestine of a SDPP-inoculated piglet at 7 dpi and a positive control group contact piglet at 5 days post-contact.

title:
  Investigation into the Role of Potentially Contaminated Feed as a Source of the First-Detected Outbreaks of Porcine Epidemic Diarrhea in Canada

abstract:
  SUMMARY: In January 2014, approximately 9 months following the initial detection of porcine epidemic diarrhea (PED) in the USA, the first case of PED was confirmed in a swine herd in south-western Ontario. A follow-up epidemiological investigation carried out on the initial and 10 subsequent Ontario PED cases pointed to feed as a common risk factor. As a result, several lots of feed and spray-dried porcine plasma (SDPP) used as a feed supplement were tested for the presence of PEDV genome by real-time RT-PCR assay. Several of these tested positive, supporting the notion that contaminated feed may have been responsible for the introduction of PEDV into Canada. These findings led us to conduct a bioassay experiment in which three PEDV-positive SDPP samples (from a single lot) and two PEDV-positive feed samples supplemented with this SDPP were used to orally inoculate 3-week-old piglets. Although the feed-inoculated piglets did not show any significant excretion of PEDV, the SDPP-inoculated piglets shed PEDV at a relatively high level for ≥9 days. Despite the fact that the tested PEDV genome positive feed did not result in obvious piglet infection in our bioassay experiment, contaminated feed cannot be ruled out as a likely source of this introduction in the field where many other variables may play a contributing role.


id: cord-302890-eenijt7f
author: Shi, Da
date: 2019-11-02
txt: ./txt/cord-302890-eenijt7f.txt
cache: ./cache/cord-302890-eenijt7f.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3390/vaccines7040173
doi: 10.3390/vaccines7040173
summary:
  To examine the inhibitory effects of shRNAs against N on target gene expression during PEDV replication, IEC cells were transfected with or without 1 µg, 2 µg, or 4 of µg shR-N307, shR-N463, and shR-N1071 or 4 µg of shR-NC for 24 h and infected with 100 TCID 50 /mL PEDV strain CV777 or LNCT2. To examine the inhibitory effects of shRNAs against N on target gene expression during CV777 and LNCT2 replication, IEC cells were transfected with indicated plasmids for 24 h and then infected with PEDV CV777 orLNCT2 strain (100 TCID 50 /mL). To examine the inhibitory effects of shRNAs against N on target gene expression during CV777 and LNCT2 replication, IEC cells were transfected with indicated plasmids for 24 h and then infected with PEDV CV777 orLNCT2 strain (100 TCID 50 /mL).

title:
  Significant Interference with Porcine Epidemic Diarrhea Virus Pandemic and Classical Strain Replication in Small-Intestine Epithelial Cells Using an shRNA Expression Vector

abstract:
  Porcine epidemic diarrhea (PED) re-emerged in China in 2010 and is now widespread. Evidence indicates that highly virulent porcine epidemic diarrhea virus (PEDV) strains belonging to genotype G2 caused a large-scale outbreak of diarrhea. Currently, vaccines derived from PEDV classical strains do not effectively prevent infection by virulent PEDV strains, and no specific drug is available to treat the disease. RNA interference (RNAi) is a novel and effective way to cure a wide range of viruses. We constructed three short hairpin RNA (shRNA)-expressing plasmids (shR-N307, shR-N463, and shR-N1071) directed against nucleocapsid (N) and determined their antiviral activities in intestine epithelial cells infected with a classical CV777 strain and LNCT2. We verified that shR-N307, shR-N463, and shR-N1071 effectively inhibited the expression of the transfected N gene in vitro, comparable to the control shRNA. We further demonstrated the shRNAs markedly reduced PEDV CV777 and LNCT2 replication upon downregulation of N production. Therefore, this study provides a new strategy for the design of antiviral methods against coronaviruses by targeting their processivity factors.


id: cord-303186-2hxlx1j2
author: Won, Hokeun
date: 2019-07-09
url: https://www.ncbi.nlm.nih.gov/pubmed/31364317/
doi: 10.4142/jvs.2019.20.e32
title:
  Generation and protective efficacy of a cold-adapted attenuated genotype 2b porcine epidemic diarrhea virus

abstract:
  The recent emergence and re-emergence of porcine epidemic diarrhea virus (PEDV) underscore the urgent need for the development of novel, safe, and effective vaccines against the prevailing strain. In this study, we generated a cold-adapted live attenuated vaccine candidate (Aram-P29-CA) by short-term passage of a virulent PEDV isolate at successively lower temperatures in Vero cells. Whole genome sequencing identified 12 amino acid changes in the cold-adapted strain with no insertions and deletions throughout the genome. Animal inoculation experiments confirmed the attenuated phenotype of Aram-P29-CA virus in the natural host. Pregnant sows were orally administered P29-CA live vaccines two doses at 2-week intervals prior to parturition, and the newborn piglets were challenged with the parental virus. The oral homologous prime-boost vaccination of P29-CA significantly improved the survival rate of the piglets and notably mitigated the severity of diarrhea and PEDV fecal shedding after the challenge. Furthermore, strong antibody responses to PEDV were detected in the sera and colostrum of immunized sows and in the sera of their offspring. These results demonstrated that the cold-adapted attenuated virus can be used as a live vaccine in maternal vaccination strategies to provide durable lactogenic immunity and confer passive protection to litters against PEDV.


id: cord-305156-w6iqeayr
author: Gallien, Sarah
date: 2018-10-11
url: https://www.sciencedirect.com/science/article/pii/S0378113518308964
doi: 10.1016/j.vetmic.2018.09.025
title:
  Limited shedding of an S-InDel strain of porcine epidemic diarrhea virus (PEDV) in semen and questions regarding the infectivity of the detected virus

abstract:
  PEDV is mainly transmitted by the oro-fecal route although PEDV shedding in semen has already been shown for an S-non-InDel PEDV strain infection. The aim of this study was to determine if PEDV can be shed in semen from SPF (specific pathogens free) boars infected by a French S-InDel PEDV strain (PEDV/FR/001/2014) and in case of positive semen to determine the infectivity of that semen. Both infected boars had diarrhea after inoculation and shed virus in feces. PEDV genome was also detected by RT-qPCR in the sperm-rich fraction of semen (6.94 × 10(3) and 4.73 × 10(3) genomic copies/mL) from the two boars infected with the S-InDel PEDV strain but only once at 7DPI. In addition, PEDV RNA in Peyer’s patches and in mesenteric lymph nodes was also present for the two inoculated boars. The PEDV positive semen (S-non-InDel and S-InDel) sampled during a previous trial and in this boar trial were inoculated to six SPF weaned pigs. The inoculated piglets did not seroconvert and did not shed virus throughout the duration of the study except for one pig at 18 DPI. But, PEDV could be detected in intestinal tissues such as duodenum, jejunum and jejunum Peyer’s patches by RT-qPCR except for one pig. Even if PEDV genome has been detected in semen, experimental infection of piglets with positive semen failed to conclude to the infectivity of the detected PEDV.


id: cord-305315-0qt7eth0
author: Cao, Liyan
date: 2015-08-18
url: https://doi.org/10.1186/s12985-015-0345-x
doi: 10.1186/s12985-015-0345-x
title:
  Porcine epidemic diarrhea virus inhibits dsRNA-induced interferon-β production in porcine intestinal epithelial cells by blockade of the RIG-I-mediated pathway

abstract:
  BACKGROUND: The lack of optimal porcine cell lines has severely impeded the study and progress in elucidation of porcine epidemic diarrhea virus (PEDV) pathogenesis. Vero cell, an African green monkey kidney cell line, was often used to isolate and propagate PEDV. Nonetheless, the target cells of PEDV in vivo are intestinal epithelial cells, during infection, intestinal epithelia would be damaged and resulted in digestive disorders. The immune functions of porcine epithelial cells and interactions with other immune cell populations display a number of differences compared to other species. Type I interferon (IFN) plays an important role in antiviral immune response. Limited reports showed that PEDV could inhibit type I interferon production. In this study, porcine small intestinal epithelial cells (IECs), the target cells of PEDV, were used as the infection model in vitro to identify the possible molecular mechanisms of PEDV-inhibition IFN-β production. RESULTS: PEDV not only failed to induce IFN-β expression, but also inhibited dsRNA-mediated IFN-β production in IECs. As the key IFN-β transcription factors, we found that dsRNA-induced activation of IFN regulatory factor 3 (IRF-3) was inhibited after PEDV infection, but not nuclear factor-kappaB (NF-κB). To identify the mechanism of PEDV intervention with dsRNA-mediated IFN-β expression more accurately, the role of individual molecules of RIG-I signaling pathway were investigated. In the upstream of IRF-3, TANK-binding kinase 1 (TBK1)-or inhibitor of κB kinase-ε (IKKε)-mediated IFN-β production was not blocked by PEDV, while RIG-I-and its adapter molecule IFN-β promoter stimulator 1 (IPS-1)-mediated IFN-β production were completely inhibited after PEDV infection. CONCLUSION: Taken together, our data demonstrated for the first time that PEDV infection of its target cell line, IECs, inhibited dsRNA-mediated IFN-β production by blocking the activation of IPS-1 in RIG-I-mediated pathway. Our studies offered new visions in understanding of the interaction between PEDV and host innate immune system.


id: cord-305859-vt8vwo3y
author: Jung, Kwonil
date: 2017-04-03
txt: ./txt/cord-305859-vt8vwo3y.txt
cache: ./cache/cord-305859-vt8vwo3y.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28374120/
doi: 10.1007/s00705-017-3351-z
summary:
  Fecal virus shedding, seroconversion and histopathology were evaluated in 3-7-year-old gnotobiotic calves orally inoculated with porcine deltacoronavirus (PDCoV) (9.0-9.6 log(10) genomic equivalents [GE] of OH-FD22-P5; n=4) or porcine epidemic diarrhea virus (PEDV) (10.2-12.5 log(10) GE of PC21A; n=3). In PDCoV-inoculated calves, an acute but persisting fecal viral RNA shedding and PDCoV-specific serum IgG antibody responses were observed, but without lesions or clinical disease. Our study demonstrated that Gn calves orally inoculated with the PDCoV strain OH-FD22 (ICs of cell-culture grown PDCoV from infected Gn pigs) develop an acute infection with persistent fecal PDCoV RNA shedding and PDCoVspecific serum IgG antibody responses, but show no signs of significant intestinal lesions or clinical disease [8] . In our study, there were no detectable fecal viral RNA shedding, virus-specific serum IgG antibody responses, histological lesions, and clinical disease in Gn calves orally inoculated with the PEDV strain PC21A (ICs of wild-type PEDV-infected Gn pigs) [6] .

title:
  Calves are susceptible to infection with the newly emerged porcine deltacoronavirus, but not with the swine enteric alphacoronavirus, porcine epidemic diarrhea virus

abstract:
  Fecal virus shedding, seroconversion and histopathology were evaluated in 3-7-year-old gnotobiotic calves orally inoculated with porcine deltacoronavirus (PDCoV) (9.0-9.6 log(10) genomic equivalents [GE] of OH-FD22-P5; n=4) or porcine epidemic diarrhea virus (PEDV) (10.2-12.5 log(10) GE of PC21A; n=3). In PDCoV-inoculated calves, an acute but persisting fecal viral RNA shedding and PDCoV-specific serum IgG antibody responses were observed, but without lesions or clinical disease. However, no fecal shedding, seroconversion, histological lesions, and clinical disease were detected in PEDV-inoculated calves. Our data indicate that calves are susceptible to infection by the newly emerged PDCoV, but not by the swine coronavirus, PEDV.


id: cord-306502-jkqg1qal
author: Dee, Scott
date: 2014-08-05
txt: ./txt/cord-306502-jkqg1qal.txt
cache: ./cache/cord-306502-jkqg1qal.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/25091641/
doi: 10.1186/s12917-014-0176-9
summary:
  title: An evaluation of contaminated complete feed as a vehicle for porcine epidemic diarrhea virus infection of naïve pigs following consumption via natural feeding behavior: proof of concept Here we provide proof of concept of this risk by describing a novel means for recovering PEDV-contaminated complete feed material from commercial swine sites and conducting an in vivo experiment to prove its infectivity. Clinical signs of PEDV infection (vomiting and diarrhea) and viral shedding were observed in both the Positive control and Treatment group'' post-consumption with virus and microscopic lesions detected in intestinal samples No evidence of infection was observed in the Negative controls. As more data regarding the risk of PEDV transmission via complete feed are needed, we conducted a study to test the risk of PEDV-contaminated complete feed using a novel on-farm sampling method for virus detection in feed along with an in vivo experiment (swine bioassay) using at-risk feed material.

title:
  An evaluation of contaminated complete feed as a vehicle for porcine epidemic diarrhea virus infection of naïve pigs following consumption via natural feeding behavior: proof of concept

abstract:
  BACKGROUND: Since its initial detection in May 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly throughout the US swine industry. Initially, contaminated feed was proposed as a risk factor for PEDV; however, data were not available to support this theory. Here we provide proof of concept of this risk by describing a novel means for recovering PEDV-contaminated complete feed material from commercial swine sites and conducting an in vivo experiment to prove its infectivity. RESULTS: For on-farm detection of PEDV RNA in feed, paint rollers were used to collect material from at-risk feed bins from 3 clinically affected breeding herds. This material was tested by PCR and determined to be positive for PEDV-RNA (Ct = 19.50-22.20 range). To test infectivity, this material was pooled (Ct = 20.65) and a Treatment group of 3-week old PEDV-naïve piglets were allowed to consume it via natural feeding behavior. For the purpose of a Positive control, piglets were allowed to ingest feed spiked with stock PEDV (Ct = 18.23) while the negative control group received PEDV-free feed. Clinical signs of PEDV infection (vomiting and diarrhea) and viral shedding were observed in both the Positive control and Treatment group’ post-consumption with virus and microscopic lesions detected in intestinal samples No evidence of infection was observed in the Negative controls. CONCLUSIONS: These data provide proof of concept that contaminated complete feed can serve as a vehicle for PEDV infection of naïve pigs using natural feeding behavior.


id: cord-306517-tls0849i
author: Leidenberger, S.
date: 2017-09-07
txt: ./txt/cord-306517-tls0849i.txt
cache: ./cache/cord-306517-tls0849i.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28883628/
doi: 10.1038/s41598-017-11160-w
summary:
  To characterize the Central European PEDV strains regarding their virulence in suckling piglets, and to assess the protective effect of maternally derived antibodies (MDA), four trial groups were randomly assigned, each consisting of two pregnant sows and their litter. To induce MDA in a subset of piglets, two sows received a cell culture-adapted PEDV strain, and another two sows were inoculated with field material from German PED outbreaks. Subsequently, all piglets were inoculated with the corresponding PEDV strains at an age of 3 to 6 days, and virus shedding, clinical signs and occurrence of specific antibodies were assessed. Piglets without MDA and inoculated with the cell culture-adapted virus (PEDV EU, group A2) started vomiting 24 hours post inoculation (hpi), and showed diarrhea from 36 hpi. All sows, which were inoculated with PEDV prior to farrowing (groups A1 and B1), showed IgG isotype antibodies in blood and colostrum samples at the day of farrowing using the ELISA assays mentioned above.

title:
  Virulence of current German PEDV strains in suckling pigs and investigation of protective effects of maternally derived antibodies

abstract:
  Porcine epidemic diarrhea (PED) has caused tremendous losses to the United States pig industry since 2013. From 2014, outbreaks were also reported from Central Europe. To characterize the Central European PEDV strains regarding their virulence in suckling piglets, and to assess the protective effect of maternally derived antibodies (MDA), four trial groups were randomly assigned, each consisting of two pregnant sows and their litter. To induce MDA in a subset of piglets, two sows received a cell culture-adapted PEDV strain, and another two sows were inoculated with field material from German PED outbreaks. Four sows stayed naïve. Subsequently, all piglets were inoculated with the corresponding PEDV strains at an age of 3 to 6 days, and virus shedding, clinical signs and occurrence of specific antibodies were assessed. Piglets without MDA showed a morbidity of 100% and low lethality, while almost all MDA-positive piglets stayed clinically healthy and showed considerably lower virus shedding. Taken together, the Central European PEDV strains showed rather low virulence under experimental conditions, and pre-inoculation of sows led to a solid protection of their offspring. The latter is the prerequisite for a sow vaccination concept that could help to prevent PED induced losses in the piglet sector.


id: cord-307110-eiobmxp2
title: Serological Screening for Coronavirus Infections in Cats
author: Zhao, Shan
date: 2019-08-13
txt: ./txt/cord-307110-eiobmxp2.txt
cache: ./cache/cord-307110-eiobmxp2.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/31412572/
doi: 10.3390/v11080743
summary:
  In total 137 cat serum samples and 25 FCoV type 1 or type 2-specific antisera were screened for the presence of antibodies against the S1 receptor binding subunit of the CoV spike protein, which is immunogenic and possesses low amino acid sequence identity among coronavirus species. Synthetic sequences of 12 coronavirus spike S1 subunits (HCoV-HKU1 (GB: YP_173238.1), MERS-CoV (GB:YP_009047204.1), SARS-CoV (GB: AAX16192.1), HCoV-OC43 (GB: AAR01015.1), HCoV-229E (GB: NP_073551.1), HCoV-NL63 (GB: YP_003767.1), TGEV (GB: ABG89325.1), PEDV (GB: AOG30832.1), BCoV (GB: P15777.1), PDCoV (GB: AML40825.1), FCoV type 1 (GB: FJ938060.1), FCoV type 2 (GB: AY994055.1)) and different domains of PEDV S1 subunit (S1 0 and S1 A-D , as identified and described in [40] ) were cloned into pCAGGS expression plasmids as described previously [41] .

abstract:
  Coronaviruses (CoVs) are widespread among mammals and birds and known for their potential for cross-species transmission. In cats, infections with feline coronaviruses (FCoVs) are common. Several non-feline coronaviruses have been reported to infect feline cells as well as cats after experimental infection, supported by their ability to engage the feline receptor ortholog for cell entry. However, whether cats might become naturally infected with CoVs of other species is unknown. We analyzed coronavirus infections in cats by serological monitoring. In total 137 cat serum samples and 25 FCoV type 1 or type 2-specific antisera were screened for the presence of antibodies against the S1 receptor binding subunit of the CoV spike protein, which is immunogenic and possesses low amino acid sequence identity among coronavirus species. Seventy-eight sera were positive for antibodies that recognized one or more coronavirus S1s whereas 1 serum exclusively reacted with human coronavirus 229E (HCoV-229E) and two sera exclusively reacted with porcine delta coronavirus (PDCoV). We observed antigenic cross-reactivity between S1s of type 1 and type 2 FCoVs, and between FCoV type 1 and porcine epidemic diarrhea virus (PEDV). Domain mapping of antibody epitopes indicated the presence of conserved epitope(s) particularly in the CD domains of S1. The cross-reactivity of FCoV type 1 and PEDV was also observed at the level of virus neutralization. To conclude, we provide the first evidence of antigenic cross-reactivity among S1 proteins of coronaviruses, which should be considered in the development of serological diagnoses. In addition, the potential role of cats in cross-species transmission of coronaviruses cannot be excluded.


id: cord-307408-6wfx0wey
author: Li, Renfeng
date: 2013-11-30
txt: ./txt/cord-307408-6wfx0wey.txt
cache: ./cache/cord-307408-6wfx0wey.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-013-1929-7
doi: 10.1007/s00705-013-1929-7
summary:
  title: Phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in central China based on the ORF3 gene and the main neutralization epitopes In this study, we aimed to investigate the molecular epidemiology and antigenic variability of PEDV field strains based on analysis of ORF3 and a portion of the S gene encoding three neutralizing epitopes (aa 499-638, 748-755, and 764-771) of the S protein. To further investigate the molecular epidemiology of this virus, we chose the ORF3 gene and a partial S gene encoding a region including three neutralization epitopes for studying the evolutionary characteristic and antigenic variation of PEDV. Based on the sequence analysis of ORF3 and partial S genes of PEDV, molecular epidemiology was conducted using 14 field strains from central China. Sequence and phylogenetic analysis of nucleocapsid genes of porcine epidemic diarrhea virus (PEDV) strains in China

title:
  Phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in central China based on the ORF3 gene and the main neutralization epitopes

abstract:
  Since 2010, porcine epidemic diarrhea has re-emerged with devastating impact on the swine-raising industry in central China. To investigate the epidemic characteristics of PEDV, the complete ORF3 genes of 14 PEDV field strains from central China during 2012 to 2013 were cloned, sequenced and compared with reference strains. Phylogenetic analysis based on the complete ORF3 gene showed that the PEDVs in central China and the reference strains could be divided into three groups: G1, G2, and G3. The 14 PEDV isolates were classified as G1 and showed a close relationship to some Chinese strains isolated previously in central China and differed genetically from recent isolates from southern China, Korean strains (SM98 and DB1865, 2012), the Chinese LZC strain (2007), and the vaccine strain (CV777) being used in China. Our findings suggested that the PEDVs circulating between 2012 and 2013 in central China might have evolved from earlier strains in the local region. To determine the reason for recent vaccination failures, we also studied variations in antigenicity of field strains by analyzing the three neutralizing epitope regions in the S gene. The results showed that the neutralizing epitopes at aa 245-252 were highly conserved, but most of the amino acid changes occurred in the epitope regions aa 7-146 and 271-278. We speculate that the amino acid mutations in the neutralizing epitope regions may be associated with changes in the antigenicity of PEDV and consequently result in vaccination failure. Together, these findings may be useful for understanding the epidemiology of PEDV and may be relevant for designing of new and more efficacious vaccines.


id: cord-308170-uqezwbzn
author: Dee, Scott
date: 2014-09-25
txt: ./txt/cord-308170-uqezwbzn.txt
cache: ./cache/cord-308170-uqezwbzn.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/25253192/
doi: 10.1186/s12917-014-0220-9
summary:
  title: An evaluation of a liquid antimicrobial (Sal CURB®) for reducing the risk of porcine epidemic diarrhea virus infection of naïve pigs during consumption of contaminated feed For the purpose of a positive control, a separate group of piglets was allowed to ingest non-treated (Sal CURB®-free) feed also spiked with stock PEDV (Ct = 25.22). Clinical signs of PEDV infection (vomiting and diarrhea) and viral shedding in feces were observed in the positive control group 2–3 days post-consumption of non-treated feed. Furthermore, the results from the positive control group provide additional proof of concept regarding the ability of contaminated feed to serve as a risk factor for PEDV infection of naïve piglets. The results of this study provide initial proof of concept that the application of a liquid antimicrobial product (Sal CURB®) reduced the risk of PEDV infection through contaminated feed.

title:
  An evaluation of a liquid antimicrobial (Sal CURB®) for reducing the risk of porcine epidemic diarrhea virus infection of naïve pigs during consumption of contaminated feed

abstract:
  BACKGROUND: Since its initial detection in May 2013, porcine epidemic diarrhea virus (PEDV) has spread rapidly throughout the US swine industry. Recently, contaminated feed was confirmed as a vehicle for PEDV infection of naïve piglets. This research provides in vivo data supporting the ability of a liquid antimicrobial product to reduce this risk. RESULTS: Sal CURB® (Kemin Industries, Des Moines, IA, USA) is a FDA-approved liquid antimicrobial used to control Salmonella contamination in poultry and swine diets. To test its effect against PEDV, Sal CURB®-treated feed was spiked with a stock isolate of PEDV (Ct = 25.22), which PEDV-naïve piglets were allowed to ingest via natural feeding behavior (ad libitum) for a 14-day period. For the purpose of a positive control, a separate group of piglets was allowed to ingest non-treated (Sal CURB®-free) feed also spiked with stock PEDV (Ct = 25.22). A negative control group received PEDV-free feed. Clinical signs of PEDV infection (vomiting and diarrhea) and viral shedding in feces were observed in the positive control group 2–3 days post-consumption of non-treated feed. In contrast, no evidence of infection was observed in pigs fed Sal CURB®-treated feed or in the negative controls throughout the 14-day study period. In addition, the Sal CURB®-treated feed samples had higher (p < 0.0001) mean PEDV Ct values than samples from the positive control group. CONCLUSIONS: These data provide proof of concept that feed treated with Sal CURB® can serve as a means to reduce the risk of PEDV infection through contaminated feed. Furthermore, the results from the positive control group provide additional proof of concept regarding the ability of contaminated feed to serve as a risk factor for PEDV infection of naïve piglets.


id: cord-308344-ao9z00t7
author: Diep, Nguyen Van
date: 2017-01-17
txt: ./txt/cord-308344-ao9z00t7.txt
cache: ./cache/cord-308344-ao9z00t7.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28095455/
doi: 10.1371/journal.pone.0170126
summary:
  title: Novel Porcine Epidemic Diarrhea Virus (PEDV) Variants with Large Deletions in the Spike (S) Gene Coexist with PEDV Strains Possessing an Intact S Gene in Domestic Pigs in Japan: A New Disease Situation Among 17 PEDV samples isolated from individual pigs, all of them contained at least two distinct genotypes with large genomic deletions, and 94.1% of them were found to consist of strains with an intact S gene. In this study, variants with large deletions in the S gene were found in eight primary and nine recurrent outbreaks from 16 pig farms, and they mostly (94.1%) coexisted with PEDV strains with an intact S gene. Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene New porcine epidemic diarrhoea virus variant with a large deletion in the spike gene identified in domestic pigs

title:
  Novel Porcine Epidemic Diarrhea Virus (PEDV) Variants with Large Deletions in the Spike (S) Gene Coexist with PEDV Strains Possessing an Intact S Gene in Domestic Pigs in Japan: A New Disease Situation

abstract:
  Since late 2013, after an absence of seven years, outbreaks of porcine epidemic diarrhea virus (PEDV) infection have reemerged and swept rapidly across Japan, resulting in significant economic losses. In this study, we report the emergence, mixed infection, and genetic characterization of 15 novel field PEDV variants with large genomic deletions. The sizes of deletion varied between 582 nt (194 aa) and 648 nt (216 aa) at positions 28–714 (10–238) on the S gene (protein). Among 17 PEDV samples isolated from individual pigs, all of them contained at least two distinct genotypes with large genomic deletions, and 94.1% of them were found to consist of strains with an intact S gene. These variants were found in eight primary and nine recurrent outbreaks, and they might be associated with persistent PEDV infection in the farms. Full-length S and ORF3 genes of eight variants derived from 2 samples were characterized. This is the first report of mixed infections caused by various genotypes of PEDV and would be important for the studies of viral isolation, pathogenesis, and molecular epidemiology of the disease.


id: cord-309359-85xiqz2w
title: Porcine epidemic diarrhea: a review of current epidemiology and available vaccines
author: Song, Daesub
date: 2015-07-29
txt: ./txt/cord-309359-85xiqz2w.txt
cache: ./cache/cord-309359-85xiqz2w.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/26273575/
doi: 10.7774/cevr.2015.4.2.166
summary:
  Continuous emergence of multiple mutant strains from several regions has aggravated porcine epidemic diarrhea endemic conditions and highlighted the need for new vaccines based on the current circulating PEDV. Genetic variabil ity and phylogeny of current Chinese porcine epidemic diarrhea virus strains based on spike, ORF3, and mem brane genes Molecular characteriza tion and phylogenetic analysis of membrane protein genes of porcine epidemic diarrhea virus isolates in China Isolation and characterization of porcine epidemic diarrhea viruses associated with the 2013 disease outbreak among swine in the United States Molecular epidemiology and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea Cell culture isolation and sequence analysis of genetically diverse US porcine epi demic diarrhea virus strains including a novel strain with a large deletion in the spike gene Genetic characterization of porcine epidemic diarrhea vi rus (PEDV) isolates from southern Vietnam during 2009 2010 outbreaks

abstract:
  Porcine epidemic diarrhea virus (PEDV), an Alphacoronavirus in the family Coronaviridae, causes acute diarrhea, vomiting, dehydration, and high mortality rates in neonatal piglets. PEDV can also cause diarrhea, agalactia, and abnormal reproductive cycles in pregnant sows. Although PEDV was first identified in Europe, it has resulted in significant economic losses in many Asian swine-raising countries, including Korea, China, Japan, Vietnam, and the Philippines. However, from April 2013 to the present, major outbreaks of PEDV have been reported in the United States, Canada, and Mexico. Moreover, intercontinental transmission of PEDV has increased mortality rates in seronegative neonatal piglets, resulting in 10% loss of the US pig population. The emergence and re-emergence of PEDV indicates that the virus is able to evade current vaccine strategies. Continuous emergence of multiple mutant strains from several regions has aggravated porcine epidemic diarrhea endemic conditions and highlighted the need for new vaccines based on the current circulating PEDV. Epidemic PEDV strains tend to be more pathogenic and cause increased death in pigs, thereby causing substantial financial losses for swine producers. In this review, we described the epidemiology of PEDV in several countries and present molecular characterization of current strains. We also discuss PEDV vaccines and related issues.


id: cord-309693-f2htekhz
author: Yu, Meiling
date: 2017-09-25
txt: ./txt/cord-309693-f2htekhz.txt
cache: ./cache/cord-309693-f2htekhz.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.3390/v9100274
doi: 10.3390/v9100274
summary:
  To develop an effective bivalent oral vaccine against TGEV and PEDV infection, the D antigenic site of the TGEV spike (S) protein and the major antigen site (core neutralizing epitope—COE) of the PEDV S protein were used as immunogens, and the enhanced green fluorescent protein (eGFP) gene was used as a reporter to construct genetically engineered Lactobacillus casei rLpPG(F)-T7g10-eGFP-6D-COE. The results showed that levels of anti-PEDV and anti-TGEV serum immunoglobulin G (IgG) and mucosal secreted immunoglobulin A (sIgA) antibodies obtained from the mice immunized with rLpPG(F)-T7g10-eGFP-6D-COE, as well as the proliferation levels of lymphocytes, were significantly higher than those in mice orally administered phosphate-buffered saline (PBS) or rLpPG-T7g10. This was evidenced by significantly higher levels of virus-neutralizing antibodies, anti-PEDV/TGEV serum IgG, and mucosal sIgA in mice orally immunized with rLpPG F -T7g10-eGFP-6D-COE, compared to the levels for the rLpPG-T7g10 or PBS groups.

title:
  Immunogenicity of eGFP-Marked Recombinant Lactobacillus casei against Transmissible Gastroenteritis Virus and Porcine Epidemic Diarrhea Virus

abstract:
  Porcine transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) are the causative agents of highly fatal acute diarrhea in pigs, resulting in enormous losses in the pig industry worldwide. To develop an effective bivalent oral vaccine against TGEV and PEDV infection, the D antigenic site of the TGEV spike (S) protein and the major antigen site (core neutralizing epitope—COE) of the PEDV S protein were used as immunogens, and the enhanced green fluorescent protein (eGFP) gene was used as a reporter to construct genetically engineered Lactobacillus casei rLpPG(F)-T7g10-eGFP-6D-COE. The expression of proteins of interest by the recombinant L. casei was confirmed by confocal laser scanning microscopy and a Western blot assay, and the immunogenicity of rLpPG(F)-T7g10-eGFP-6D-COE in orally immunized mice was evaluated. The results showed that levels of anti-PEDV and anti-TGEV serum immunoglobulin G (IgG) and mucosal secreted immunoglobulin A (sIgA) antibodies obtained from the mice immunized with rLpPG(F)-T7g10-eGFP-6D-COE, as well as the proliferation levels of lymphocytes, were significantly higher than those in mice orally administered phosphate-buffered saline (PBS) or rLpPG-T7g10. Moreover, the serum IgG antibodies showed neutralizing effects against PEDV and TGEV. Our data suggest that the antibiotic resistance-free genetically engineered L. casei bivalent oral vaccine provides a safe and promising strategy for vaccine development against PEDV and TGEV.


id: cord-310579-tnxokfwu
author: Kim, Sung-Jae
date: 2020-07-23
txt: ./txt/cord-310579-tnxokfwu.txt
cache: ./cache/cord-310579-tnxokfwu.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32717934/
doi: 10.3390/v12080790
summary:
  title: Molecular Characterization of Porcine Epidemic Diarrhea Virus and Its New Genetic Classification Based on the Nucleocapsid Gene In the phylogenetic trees inferred from the D1-D2 datasets of the S gene ( Figure 2 , Supplementary Figures S1 and S2) , the PEDV strains were classified into five sub-genogroups (G1a, G1b, G2a, G2b, and G2c), which were previously designated [8] . In the phylogenetic trees inferred from the D1-D2 datasets of the S gene ( Figure 2 , Supplementary Figures S1 and S2) , the PEDV strains were classified into five sub-genogroups (G1a, G1b, G2a, G2b, and G2c), which were previously designated [8] . Supported by high posterior probability values (0.90-1), the phylogenetic trees inferred from the D3-D4 datasets of the N gene (Figure 3, Supplementary Figures S3 and S4) suggested that the classification of PEDV strains into four S gene-based sub-genogroups G1a, G1b, G2b, G2a/G2c was more reliable. Sequence and phylogenetic analysis of nucleocapsid genes of porcine epidemic diarrhea virus (PEDV) strains in China

title:
  Molecular Characterization of Porcine Epidemic Diarrhea Virus and Its New Genetic Classification Based on the Nucleocapsid Gene

abstract:
  Porcine epidemic diarrhea virus (PEDV) causes continuous, significant damage to the swine industry worldwide. By RT-PCR-based methods, this study demonstrated the ongoing presence of PEDV in pigs of all ages in Korea at the average detection rate of 9.92%. By the application of Bayesian phylogenetic analysis, it was found that the nucleocapsid (N) gene of PEDV could evolve at similar rates to the spike (S) gene at the order of 10(−4) substitutions/site/year. Based on branching patterns of PEDV strains, three main N gene-base genogroups (N1, N2, and N3) and two sub-genogroups (N3a, N3b) were proposed in this study. By analyzing the antigenic index, possible antigenic differences also emerged in both the spike and nucleocapsid proteins between the three genogroups. The antigenic indexes of genogroup N3 strains were significantly lower compared with those of genogroups N1 and N2 strains in the B-cell epitope of the nucleocapsid protein. Similarly, significantly lower antigenic indexes in some parts of the B-cell epitope sequences of the spike protein (COE, S1D, and 2C10) were also identified. PEDV mutants derived from genetic mutations of the S and N genes may cause severe damage to swine farms by evading established host immunities.


id: cord-311255-zaa8i9vh
author: Kim, Youngnam
date: 2014-07-31
txt: ./txt/cord-311255-zaa8i9vh.txt
cache: ./cache/cord-311255-zaa8i9vh.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1016/j.virol.2014.04.040
doi: 10.1016/j.virol.2014.04.040
summary:
  Abstract The present study sought to investigate whether porcine epidemic diarrhea virus (PEDV) induces apoptosis and to elucidate the mechanisms associated with apoptotic cell death after PEDV infection. Interestingly, mitochondrial apoptosis-inducing factor (AIF) was found to translocate to the nucleus during PEDV infection, and AIF relocalization was completely abrogated by the presence of cyclosporin A (CsA), an inhibitor of cyclophilin D (CypD) that is an essential component of the mitochondrial permeabilization transition pore (mPTP) complex. Altogether, our results indicate that a caspase-independent mitochondrial AIF-mediated pathway plays a central role in PEDV-induced apoptosis to facilitate viral replication and pathogenesis. Therefore, in this study, we aimed to determine if PEDV induces apoptosis following infection in vitro and in vivo and to define the specific pathways involved in apoptotic death of virus-infected cells.

title:
  Porcine epidemic diarrhea virus induces caspase-independent apoptosis through activation of mitochondrial apoptosis-inducing factor

abstract:
  Abstract The present study sought to investigate whether porcine epidemic diarrhea virus (PEDV) induces apoptosis and to elucidate the mechanisms associated with apoptotic cell death after PEDV infection. PEDV-infected cells showed evidence of apoptosis in vitro and in vivo. However, experimental data indicated that the caspase cascade is not involved in PEDV-induced apoptotic cell death. Interestingly, mitochondrial apoptosis-inducing factor (AIF) was found to translocate to the nucleus during PEDV infection, and AIF relocalization was completely abrogated by the presence of cyclosporin A (CsA), an inhibitor of cyclophilin D (CypD) that is an essential component of the mitochondrial permeabilization transition pore (mPTP) complex. CsA treatment resulted in significant inhibition of PEDV-triggered apoptosis and suppressed PEDV replication. Furthermore, direct inhibition of AIF strongly impaired PEDV infection and virus-induced apoptosis. Altogether, our results indicate that a caspase-independent mitochondrial AIF-mediated pathway plays a central role in PEDV-induced apoptosis to facilitate viral replication and pathogenesis.


id: cord-311561-eiys4mbf
author: Song, Deping
date: 2014-12-04
txt: ./txt/cord-311561-eiys4mbf.txt
cache: ./cache/cord-311561-eiys4mbf.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/25477403/
doi: 10.1128/genomea.01239-14
summary:
  title: Full-Length Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain, CH/GDZQ/2014, Responsible for a Severe Outbreak of Diarrhea in Piglets in Guangdong, China, 2014 The full-length genome sequence of a variant porcine epidemic diarrhea virus (PEDV) strain, CH/GDZQ/2014, was determined. Here, we report the full-length genome sequence of a variant PEDV isolate, CH/GDZQ/2014, which is responsible for a severe outbreak of diarrhea in Guangdong, southern China, in March 2014. CH/GDZQ/2014 was a very virulent field PEDV strain isolated from Guangdong Province in southern China. Complete genome sequence of porcine epidemic diarrhea virus strain AJ1102 isolated from a suckling piglet with acute diarrhea in China Complete genome sequence of a Chinese virulent porcine epidemic diarrhea virus strain Complete genome sequence of a very virulent porcine epidemic diarrhea virus strain, CH/ GDGZ/2012, isolated in Southern China Complete genome sequence of novel porcine epidemic diarrhea virus strain GD-1 in China

title:
  Full-Length Genome Sequence of a Variant Porcine Epidemic Diarrhea Virus Strain, CH/GDZQ/2014, Responsible for a Severe Outbreak of Diarrhea in Piglets in Guangdong, China, 2014

abstract:
  The full-length genome sequence of a variant porcine epidemic diarrhea virus (PEDV) strain, CH/GDZQ/2014, was determined. The isolate was a variant strain with a relatively far relationship with the PEDV strains previously identified in the same area between 2011 and 2012 and was genetically distinct from the CV777-based vaccine strain currently being used in China.


id: cord-313126-7hrjzapj
author: Chen, Fangzhou
date: 2019-03-08
txt: ./txt/cord-313126-7hrjzapj.txt
cache: ./cache/cord-313126-7hrjzapj.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/30850666/
doi: 10.1038/s41598-019-40564-z
summary:
  Nineteen complete TGEV genomes and a single strain of porcine respiratory coronavirus (PRCV) from the US were generated and compared to historical strains to investigate the evolution of these endemic coronaviruses. The "variant" genotype shared similar unique deletions and amino acid changes with the recent PRCV strain identified in this study, suggesting a recombination event occurred between the ''''variant'''' TGEV and PRCV. Complete genomic sequences, a key residue in the spike protein and deletions in nonstructural protein 3b of US strains of the virulent and attenuated coronaviruses, transmissible gastroenteritis virus and porcine respiratory coronavirus

title:
  Decline of transmissible gastroenteritis virus and its complex evolutionary relationship with porcine respiratory coronavirus in the United States

abstract:
  The epidemiology and genetic diversity of transmissible gastroenteritis virus (TGEV) in the United States (US) was investigated by testing clinical cases for TGEV by real time RT-PCR between January 2008 and November 2016. Prevalence of TGEV ranged between 3.8–6.8% and peaked during cold months until March 2013, in which prevalence decreased to < 0.1%. Nineteen complete TGEV genomes and a single strain of porcine respiratory coronavirus (PRCV) from the US were generated and compared to historical strains to investigate the evolution of these endemic coronaviruses. Sixteen of our TGEV strains share 8 unique deletions and 119 distinct amino acid changes, which might greatly affect the biological characteristics of the variant TGEV, and resulted in a “variant” genotype of TGEV. The “variant” genotype shared similar unique deletions and amino acid changes with the recent PRCV strain identified in this study, suggesting a recombination event occurred between the ‘‘variant’’ TGEV and PRCV. Moreover, the results indicate the “variant” genotype is the dominant genotype circulating in the US. Therefore, this study provides insight into the occurrence, origin, genetic characteristics, and evolution of TGEV and PRCV circulating in the US.


id: cord-313691-6wq64h2b
author: Zhang, Yuhan
date: 2020-09-17
txt: ./txt/cord-313691-6wq64h2b.txt
cache: ./cache/cord-313691-6wq64h2b.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32957461/
doi: 10.3390/ani10091674
summary:
  This study aimed to observe the comparative pathogenicity and cross-protection between G1a and G2a PEDVs, and thus find a new insight into the antigenicity and immunogenicity of PEDVs. The results of the present study demonstrated that the G2a-based inactivated vaccine could provide sterilizing immunity against both highly virulent homologous and heterologous PEDV challenges. The findings of this study might explain the underlying mechanism that severe PED and deaths still occurred among the neonatal piglets of which CV777-based PEDV vaccine were administered in China, and imply G2a-based PEDV vaccine used in this study might be a good vaccine candidate for PEDV which may provide solid protection against circulating highly virulent PEDVs. ABSTRACT: To date, two genotypes, i.e., genotype 1 (G1) and genotype 2 (G2), of porcine epidemic diarrhea virus (PEDV) have been identified in swine, while the cross protection between the G2a and G1a subgenotypes is undetermined.

title:
  Evaluation of Cross-Protection between G1a- and G2a-Genotype Porcine Epidemic Diarrhea Viruses in Suckling Piglets

abstract:
  SIMPLE SUMMARY: Porcine epidemic diarrhea (PED), caused by PED virus (PEDV), is a devastating enteric disease in pigs worldwide. At least two genotypes (G1 and G2) and five subgenotypes (G1a, G1b, G2a, G2b, andG2c) of PEDV strains have been identified. To date, the reports on the antigenicity and immunogenicity of those viruses are limited and the results documented on cross-neutralization among different genotypes and/or subgenotypes of PEDV were inconsistent. This study aimed to observe the comparative pathogenicity and cross-protection between G1a and G2a PEDVs, and thus find a new insight into the antigenicity and immunogenicity of PEDVs. The results of the present study demonstrated that the G2a-based inactivated vaccine could provide sterilizing immunity against both highly virulent homologous and heterologous PEDV challenges. In contrast, the G1a-based inactivated vaccine could induce a sterilizing immune response against challenge of homologous strain CV777 and only provide partial protection for the challenge of a heterologous G2a PEDV CH/JX/01. The findings of this study might explain the underlying mechanism that severe PED and deaths still occurred among the neonatal piglets of which CV777-based PEDV vaccine were administered in China, and imply G2a-based PEDV vaccine used in this study might be a good vaccine candidate for PEDV which may provide solid protection against circulating highly virulent PEDVs. ABSTRACT: To date, two genotypes, i.e., genotype 1 (G1) and genotype 2 (G2), of porcine epidemic diarrhea virus (PEDV) have been identified in swine, while the cross protection between the G2a and G1a subgenotypes is undetermined. Hence, in the present study, we attempted to observe a comparative pathogenicity and cross protection of G1a (CV777) and G2a (CH/JX/01) PEDVs. Initially pregnant sows were vaccinated twice with the two kinds of inactivated G1a- and G2a-based PEDV vaccines, respectively and the delivered neonatal piglets were challenged with prototype isolates of G1a and G2a PEDVs, and then the pathogenicity and cross-protection in neonatal piglets were observed. The results showed that CH/JX/01, a highly virulent and dominant G2a PEDV strain currently circulating in China had more severe pathogenicity in vitro and in vivo, and induced more strong immune responses, including higher titers of sIgA in maternal milk than that induced by CV777 PEDV, a prototype of G1a PEDV strain. All piglets from the sows immunized with CH/JX/01 could not only survive when challenged with the homologous PEDV, but also be fully protected when challenged with heterogenous G1a PEDV. In contrast, the piglets from the sows immunized with CV777 could be protected when challenged with homologous PEDV and only partially protected when challenged with heterologous G2a strain of PEDV (CH/JX/01). The findings of this study provide new insights into the pathogenicity, antigenicity, and immunogenicity of currently circulating wild type G2a PEDV, which might be valuable for the development of novel PEDV vaccine candidates with improved efficacy.


id: cord-314751-i9rxesrg
author: Oh, Jongsuk
date: 2014-07-10
txt: ./txt/cord-314751-i9rxesrg.txt
cache: ./cache/cord-314751-i9rxesrg.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/25008896/
doi: 10.1007/s00705-014-2163-7
summary:
  In this study, a codon-optimized PEDV S1 gene containing amino acid residues 25–738 was synthesized based on a multiple alignment of the S amino acid sequences of PEDV field isolates and used to establish a stable porcine cell line constitutively expressing the PEDV S1 protein. In the present study, therefore, we first synthesized a full-length, codon-optimized PEDV S1 gene and then generated a stable porcine-origin cell line constitutively expressing the recombinant S1 protein. These results were coincident with the rabbit study described above, since the rabbit antisera generated by immunization with the recombinant S1 protein also contained low levels of neutralizing antibodies to the heterologous PEDV vaccine strain. In the present study, the first aim was to stably express the full-length, codon-optimized S1 gene of PEDV in porcine-origin cells and to evaluate the immunogenicity and efficacy of the recombinant S1 protein.

title:
  Immunogenicity and protective efficacy of recombinant S1 domain of the porcine epidemic diarrhea virus spike protein

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric pathogen of swine. Acute PEDV outbreaks have continually emerged in most swine-producing Asian countries and, recently, in the United States, causing significant economic losses in the pig industry. The spike (S) protein of PEDV is a type 1 transmembrane envelope glycoprotein and consists of the S1 and S2 domains, which are responsible for virus binding and fusion, respectively. Since the S1 domain is involved in a specific high-affinity interaction with the cellular receptor and induction of neutralizing antibody in the natural host, it is a primary target for the development of effective vaccines against PEDV. In this study, a codon-optimized PEDV S1 gene containing amino acid residues 25–738 was synthesized based on a multiple alignment of the S amino acid sequences of PEDV field isolates and used to establish a stable porcine cell line constitutively expressing the PEDV S1 protein. The purified recombinant S1 protein was found to mediate highly potent antibody responses in immunized rabbits. The antibodies strongly recognized the recombinant S1 protein from cell lysates and supernatants of S1-expressing cells, whereas they bound weakly to the authentic S protein of PEDV vaccine strain SM98-1. Furthermore, a serum neutralization test revealed that the rabbit antisera completely inhibit infection of the PEDV vaccine strain at a serum dilution of 1:16. We then tested the ability of vaccination with the recombinant S1 protein to protect piglets against PEDV. Late-term pregnant sows were inoculated intramuscularly with the purified S1 protein, and the outcome was investigated in passively immunized suckling piglets after a virulent PEDV challenge. The results showed that vaccination with S1 protein efficiently protected neonatal piglets against PEDV. Our data suggest that the recombinant S1 protein shows potential as an effective and safe subunit vaccine for PED prevention.


id: cord-315885-iu5wg5ik
author: Hoang, Hai
date: 2013-12-19
txt: ./txt/cord-315885-iu5wg5ik.txt
cache: ./cache/cord-315885-iu5wg5ik.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/24356830/
doi: 10.1128/genomea.01049-13
summary:
  title: Full-Length Genome Sequence of a Plaque-Cloned Virulent Porcine Epidemic Diarrhea Virus Isolate (USA/Iowa/18984/2013) from a Midwestern U.S. Swine Herd The complete genome sequence of PEDV strain USA/Iowa/18984/2013 was submitted to GenBank under the accession no. Complete genome sequence of porcine epidemic diarrhea virus strain USA/Colorado/2013 from the United States Complete genome sequence of porcine epidemic diarrhea virus strain AJ1102 isolated from a suckling piglet with acute diarrhea in China Complete genome sequence of a Chinese virulent porcine epidemic diarrhea virus strain Complete genome sequence of a recombinant porcine epidemic diarrhea virus strain from eastern China Complete genome sequence of a highly prevalent isolate of porcine epidemic diarrhea virus in south China Complete genome sequence of a variant porcine epidemic diarrhea virus strain isolated in central China Complete genome sequence of novel porcine epidemic diarrhea virus strain GD-1 in China

title:
  Full-Length Genome Sequence of a Plaque-Cloned Virulent Porcine Epidemic Diarrhea Virus Isolate (USA/Iowa/18984/2013) from a Midwestern U.S. Swine Herd

abstract:
  Porcine epidemic diarrhea (PED) was recognized in U.S. swine for the first time in early 2013. A plaque-purified PED virus (PEDV) isolate (USA/Iowa/18984/2013) was obtained from a diarrheic piglet. The isolate is genetically close to other previously reported U.S. PEDVs and recent Chinese PEDVs and was virulent when inoculated into neonatal pigs.


id: cord-316134-lkd2mj27
author: Sungsuwan, Suttipun
date: 2020-01-15
txt: ./txt/cord-316134-lkd2mj27.txt
cache: ./cache/cord-316134-lkd2mj27.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0042682219303150
doi: 10.1016/j.virol.2019.11.007
summary:
  Investigation of possible molecular interactions between components of PEDV, PDCoV and TGEV and their influence on replication of each virus would provide a crucial insight into comprehensive understanding of these CoVs. Of all viral proteins, we have chosen to start with the N protein, as it is among the most abundant and ubiquitous structural proteins in infected cells. For viral infection in the transient CoV N expression experiment, VeroE6 cells were transfected with 1 or 2 μg of pCAGGS-PEDV N-Myc, pCAGGS-PDCoV N-HA, pCAGGS-TGEV N-FLAG, or the empty pCAGGS vector and were incubated for 24 h to allow for protein expression. To investigate how this protein-protein interaction might affect PEDV replication, we transiently transfected VeroE6 cells with varying amounts of the pCAGGS plasmid expressing N proteins from either PDCoV or TGEV for 24 h before infection with PEDV-mCherry (MOI = 0.0001) and followed the course of viral replication for each condition.

title:
  Nucleocapsid proteins from other swine enteric coronaviruses differentially modulate PEDV replication

abstract:
  Porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV) and porcine deltacoronavirus (PDCoV) share tropism for swine intestinal epithelial cells. Whether mixing of viral components during co-infection alters pathogenic outcomes or viral replication is not known. In this study, we investigated how different coronavirus nucleocapsid (CoV N) proteins interact and affect PEDV replication. We found that PDCoV N and TGEV N can competitively interact with PEDV N. However, the presence of PDCoV or TGEV N led to very different outcomes on PEDV replication. While PDCoV N significantly suppresses PEDV replication, overexpression of TGEV N, like that of PEDV N, increases production of PEDV RNA and virions. Despite partial interchangeability in nucleocapsid oligomerization and viral RNA synthesis, endogenous PEDV N cannot be replaced in the production of infectious PEDV particles. Results from this study give insights into functional compatibilities and evolutionary relationship between CoV viral proteins during viral co-infection and co-evolution.


id: cord-316908-8ti75mru
author: Wei, Xiaona
date: 2020-02-10
txt: ./txt/cord-316908-8ti75mru.txt
cache: ./cache/cord-316908-8ti75mru.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32041637/
doi: 10.1186/s13567-020-0739-7
summary:
  Given that the differences in gene sequences and pathogenicity between classical and mutant strains of PEDV may lead to diverse invasion mechanisms, this study focused on the cellular entry pathways and cellular transport of the PEDV GI and GII subtype strains in Vero cells and IPEC-J2 cells. To clarify the specific endocytic pathways, systematic research methods were used and showed that PEDV enters cells via the clathrinand caveolae-mediated endocytosis pathways, in which dynamin II, clathrin heavy chain, Eps15, cholesterol, and caveolin-1 were indispensably involved. Our results showed that two the subtypes of PEDV utilized clathrin-, caveolae-, and lipid raft-mediated endocytosis to enter the Vero and IPEC-J2 cells, but the utilization efficiency of each endocytic pathway varied depending on the different genotypes and types of cells. We demonstrated that PEDV GI subtype GDS09 and GII subtype GDS01 strains could enter Vero and IPEC-J2 cells via the clathrin-, caveolae-, and lipid raft-mediated endocytosis pathways.

title:
  PEDV enters cells through clathrin-, caveolae-, and lipid raft-mediated endocytosis and traffics via the endo-/lysosome pathway

abstract:
  With the emergence of highly pathogenic variant strains, porcine epidemic diarrhea virus (PEDV) has led to significant economic loss in the global swine industry. Many studies have described how coronaviruses enter cells, but information on PEDV invasion strategies remains insufficient. Given that the differences in gene sequences and pathogenicity between classical and mutant strains of PEDV may lead to diverse invasion mechanisms, this study focused on the cellular entry pathways and cellular transport of the PEDV GI and GII subtype strains in Vero cells and IPEC-J2 cells. We first characterized the kinetics of PEDV entry into cells and found that the highest invasion rate of PEDV was approximately 33% in the IPEC-J2 cells and approximately 100% in the Vero cells. To clarify the specific endocytic pathways, systematic research methods were used and showed that PEDV enters cells via the clathrin- and caveolae-mediated endocytosis pathways, in which dynamin II, clathrin heavy chain, Eps15, cholesterol, and caveolin-1 were indispensably involved. In addition, lipid raft extraction assay showed that PEDV can also enter cells through lipid raft-mediated endocytosis. To investigate the trafficking of internalized PEDV, we found that PEDV entry into cells relied on low pH and internalized virions reached lysosomes through the early endosome–late endosome–lysosome pathway. The results concretely revealed the entry mechanisms of PEDV and provided an insightful theoretical basis for the further understanding of PEDV pathogenesis and guidance for new targets of antiviral drugs.


id: cord-317496-6o2upns3
author: Pascual-Iglesias, Alejandro
date: 2019-07-25
txt: ./txt/cord-317496-6o2upns3.txt
cache: ./cache/cord-317496-6o2upns3.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/31349683/
doi: 10.3390/v11080682
summary:
  In this line, we engineered an attenuated virus based on the transmissible gastroenteritis virus (TGEV) genome, expressing a chimeric spike protein from a virulent United States (US) PEDV strain. The rTGEV-RS-SPEDV vaccine candidate was also attenuated in three-week-old animals that were used to evaluate the protection conferred by this virus, compared with the protection induced by infection with a virulent PEDV US strain (PEDV-NVSL). Interestingly, Viruses 2019, 11, 682 9 of 18 when viral RNA was isolated from feces of 21-day-old piglets at seven days post-vaccination (see below) and rTGEV-RS-SPEDV virus was sequenced, the same modifications were observed. An attenuated chimeric rTGEV virus expressing the ectodomain of a virulent US PEDV S protein (rTGEV-RS-SPEDV) was engineered as vaccine candidate for PEDV and evaluated in a young piglet model system. An attenuated chimeric rTGEV virus expressing the ectodomain of a virulent US PEDV S protein (rTGEV-RS-SPEDV) was engineered as vaccine candidate for PEDV and evaluated in a young piglet model system.

title:
  Recombinant Chimeric Transmissible Gastroenteritis Virus (TGEV)—Porcine Epidemic Diarrhea Virus (PEDV) Virus Provides Protection against Virulent PEDV

abstract:
  Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus causing high morbidity and mortality in porcine herds worldwide. Although both inactivated and live attenuated vaccines have been extensively used, the emergence of highly virulent strains and the recurrent outbreaks even in vaccinated farms highlight the need of effective vaccines. Engineering of genetically defined live attenuated vaccines is a rational approach for novel vaccine development. In this line, we engineered an attenuated virus based on the transmissible gastroenteritis virus (TGEV) genome, expressing a chimeric spike protein from a virulent United States (US) PEDV strain. This virus (rTGEV-RS-SPEDV) was attenuated in highly-sensitive five-day-old piglets, as infected animals did not lose weight and none of them died. In addition, the virus caused very minor tissue damage compared with a virulent virus. The rTGEV-RS-SPEDV vaccine candidate was also attenuated in three-week-old animals that were used to evaluate the protection conferred by this virus, compared with the protection induced by infection with a virulent PEDV US strain (PEDV-NVSL). The rTGEV-RS-SPEDV virus protected against challenge with a virulent PEDV strain, reducing challenge virus titers in jejunum and leading to undetectable challenge virus RNA levels in feces. The rTGEV-RS-SPEDV virus induced a humoral immune response specific for PEDV, including neutralizing antibodies. Altogether, the data indicated that rTGEV-RS-SPEDV is a promising vaccine candidate against virulent PEDV infection.


id: cord-319460-n4ezxnjc
title: Porcine Epidemic Diarrhea Virus Shedding and Antibody Response in Swine Farms: A Longitudinal Study
author: Bertasio, Cristina
date: 2016-12-15
txt: ./txt/cord-319460-n4ezxnjc.txt
cache: ./cache/cord-319460-n4ezxnjc.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/28018330/
doi: 10.3389/fmicb.2016.02009
summary:
  During summer 2014, animals on two farms displaying mild clinical signs were detected as positive for PEDV by PCR (Boniotti et al., 2016) , and at the beginning of 2015 a new severe epidemic wave occurred (Efsa Ahaw Panel, 2014) . We conducted a longitudinal study by sampling the feces and blood of piglet groups from each farm at fixed intervals during a 2-5 months period, and then we determined PEDV shedding and the antibody presence. The highest fecal PEDV RNA shedding titer was observed in 3-6 day-old piglets with mean values (among shedding animals) of 5.9, 5.6, 5.6, and 6.2 log 10 copies/mL on F1, F2, F3, and F4, respectively ( Figure 1B; Supplementary Table 3 ). Determining the viral loads and shedding rates of PEDV in real field situations during outbreaks is important in evaluating the virulence of a strain and in predicting the susceptibility of infected animals, at different ages and in the various farm units, within a herd.

abstract:
  The porcine epidemic diarrhea virus (PEDV) causes an acute and highly contagious enteric disease characterized by severe enteritis, vomiting, watery diarrhea, and a high mortality rate in seronegative neonatal piglets. In the last few years, PED had a large economic impact on the swine industries in Asia and the US, and in 2014, the PEDV also re-emerged in Europe. Two main PEDV variants circulate worldwide but only the S INDEL variant, considered a mild strain, is spreading in Europe. To gain insights into the pathogenicity of this variant, its viral load and temporal shedding pattern were evaluated in piglets from infected farms. Quantitative real-time PCR (qPCR) targeting the spike gene, was validated according to the minimum information for quantitative real-time PCR experiments guidelines. The qPCR was applied to longitudinal studies conducted in four swine farms naturally infected with the PEDV S INDEL variant. Clinical data, fecal swabs, and blood samples were collected from 103 piglets at 15–30-day intervals for 2–5 months. On all four farms, diarrhea was observed in sows during gestation and in farrowing units, and the mortality rates of piglets were 18, 25, 30, and 35%. Different clinical pictures (0-50% of diarrhea positivity), viral titer levels (mean 5.3-7.2 log(10) genome copies/mL), and antibody conditions (30-80% of positivity) were registered among sows on the four farms. The percentage of qPCR positive piglets varied greatly from the beginning (63–100%) to the end (0%) of the infection course. Clinical signs were present in 96% of the qPCR positive animals. Viral loads ranged from 8.5 log(10) to 4 log(10) genome copies/mL in suckling pigs at 3–6 days of age and were not statistically different among farms, despite the different patterns observed in sows. After 2–3 weeks, only a few piglets still showed detectable viral levels and clinical signs, and they developed antibody responses. Moreover, co-infections with other pathogens and biosecurity procedures limiting the circulation of the virus could have influenced the severity of PED infection. QPCR and clinical data were useful in understanding the dynamics of PEDV infections and, therefore, in implementing appropriate control measures.


id: cord-319712-3dikelw6
author: Pujols, Joan
date: 2014-12-05
txt: ./txt/cord-319712-3dikelw6.txt
cache: ./cache/cord-319712-3dikelw6.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0378113514004994
doi: 10.1016/j.vetmic.2014.10.021
summary:
  title: Survivability of porcine epidemic diarrhea virus (PEDV) in bovine plasma submitted to spray drying processing and held at different time by temperature storage conditions Bovine plasma was inoculated with porcine epidemic diarrhea virus (PEDV) at an average final titer of 4.2 log10 TCID(50)/mL to determine the effect of spray drying on viral inactivation. Furthermore, and since April 2013, very similar PEDV strains to the Chinese variants have been Veterinary Microbiology 174 (2014) [427] [428] [429] [430] [431] [432] Bovine plasma was inoculated with porcine epidemic diarrhea virus (PEDV) at an average final titer of 4.2 log10 TCID 50 /mL to determine the effect of spray drying on viral inactivation. A second objective was to determine survival time of PEDV inoculated on spray-dried bovine plasma when stored under different temperatures (4, 12 and 22 8C) for different periods of time (0, 7, 14 and 21 days).

title:
  Survivability of porcine epidemic diarrhea virus (PEDV) in bovine plasma submitted to spray drying processing and held at different time by temperature storage conditions

abstract:
  Bovine plasma was inoculated with porcine epidemic diarrhea virus (PEDV) at an average final titer of 4.2 log10 TCID(50)/mL to determine the effect of spray drying on viral inactivation. Using a laboratory scale drier, inoculated plasma was spray dried at 200 °C inlet temperature and either 70 or 80 °C throughout substance. Both liquid and dried samples were subjected to three passages on VERO cell monolayers to determine PEDV infectivity. Results indicated liquid samples contained infective virus, but none of the spray dried samples were infectious. Also, survivability of PEDV inoculated on spray dried bovine plasma (SDBP) and stored at 4, 12 or 22 °C was determined for 7, 14 and 21 days. Commercial SDBP powder was inoculated with PEDV to an average final titer of 2.8 log10 TCID(50)/g. Five samples per time and temperature conditions were subjected to three passages on VERO cell monolayers to determine PEDV infectivity. The virus was non-infectious for all samples stored at 22 °C at 7, 14 and 21 days. PEDV was infective in 1 out of 5 samples stored at 12 °C at 7 days, but none of the samples stored for 14 and 21 days were infectious in cell culture. For samples stored at 4 °C, 4 out of 5 samples were infectious at 7 days, 1 out of 5 samples were infectious at 14 days, but none were infectious at 21 days. In summary, PEDV was not infectious on cell culture within 7 days when stored at room temperature and within 21 days when stored at refrigerated temperature.


id: cord-320559-up1q3k6q
title: Porcine epidemic diarrhea virus (PEDV) introduction into a naive Dutch pig population in 2014
author: Dortmans, J.C.F.M.
date: 2018-05-24
txt: ./txt/cord-320559-up1q3k6q.txt
cache: ./cache/cord-320559-up1q3k6q.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/29981699/
doi: 10.1016/j.vetmic.2018.05.014
summary:
  Porcine epidemic diarrhea virus (PEDV) is the highly contagious, causative agent of an economically important acute enteric disease in pigs of all ages. In total, 838 blood samples from sows from 267 farms and 101 samples from wild boars were collected from May till November 2014 and tested for antibodies against PEDV by ELISA. The number of required blood samples from animals and farms to estimate the seroprevalence of PEDV in Dutch sow herds was calculated based on the following assumptions: PEDV is highly contagious and no vaccination against this virus was carried out in the Netherlands. For the detection of PEDV antibodies in serum samples an in-house indirect ELISA based on the viral spike (S) protein S1-part of the G2b strain GDU (Non-S-INDEL, GenBank KU985230.1) was used, similar as the ELISA previously described (Gerber et al., 2014) .

abstract:
  Porcine epidemic diarrhea virus (PEDV) is the highly contagious, causative agent of an economically important acute enteric disease in pigs of all ages. The disease is characterized by diarrhea and dehydration causing mortality and growth retardation. In the last few decades, only classical PEDV was reported sporadically in Europe, but in 2014 outbreaks of PEDV were described in Germany. Phylogenetic analysis showed a very high nucleotide similarity with a variant of PEDV that was isolated in the US in January 2014. The epidemiological situation of PEDV infections in the Netherlands in 2014 was unknown and a seroprevalence study in swine was performed. In total, 838 blood samples from sows from 267 farms and 101 samples from wild boars were collected from May till November 2014 and tested for antibodies against PEDV by ELISA. The apparent herd prevalence of 0.75% suggests that PEDV was not circulating on a large scale in the Netherlands at this time. However, in November 2014 a clinical outbreak of PEDV was diagnosed in a fattener farm by PCR testing. This was the first confirmed PEDV outbreak since the early nineties. Sequence analyses showed that the viruses isolated in 2014 and 2015 in the Netherlands cluster with recently found European G1b strains. This suggests a one event introduction of PEDV G1b strains in Europe in 2014, which made the Netherlands and other European countries endemic for this type of strains since then.


id: cord-321739-dnuu6jok
title: Investigating the introduction of porcine epidemic diarrhea virus into an Ohio swine operation
author: Bowman, Andrew S
date: 2015-02-15
txt: ./txt/cord-321739-dnuu6jok.txt
cache: ./cache/cord-321739-dnuu6jok.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s12917-015-0348-2
doi: 10.1186/s12917-015-0348-2
summary:
  The Ohio swine operation (Figure 1 ), consisting of 3 multi-site, farrow-to-finish production flows (referred to as flows A-C, each having two breed-wean sites) and a multiplier herd (referred to as D, with a single breedwean site) had no prior cases of PEDV and was determined to have effective biosecurity measures in place evidenced by the absence of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) during more than the prior seven years. Beyond the sow unit, a wean-to-finish barn in flow A that received pigs on January 10 th from both flow A breed-wean units (A1 and A2) reported loose stools on January 12 th and had confirmation of PEDV with RT-PCR positive fecal samples collected the same day. On that same day, an oral fluid sample from one of the nurseries in flow B that received pigs from both flow B breed-wean units (B1 and B2) on January 15 th , 17 th , and 20 th , 2014 tested PEDV PCR positive ( Figure 1B ).

abstract:
  BACKGROUND: Porcine Epidemic Diarrhea virus (PEDV) is a highly transmissible coronavirus that causes a severe enteric disease that is particularly deadly for neonatal piglets. Since its introduction to the United States in 2013, PEDV has spread quickly across the country and has caused significant financial losses to pork producers. With no fully licensed vaccines currently available in the United States, prevention and control of PEDV disease is heavily reliant on biosecurity measures. Despite proven, effective biosecurity practices, multiple sites and production stages, within and across designated production flows in an Ohio swine operation broke with confirmed PEDV in January 2014, leading the producer and attending veterinarian to investigate the route of introduction. CASE PRESENTATION: On January 12, 2014, several sows within a production flow were noted with signs of enteric illness. Within a few days, illness had spread to most of the sows in the facility and was confirmed by RT-PCR to be PEDV. Within a short time period, confirmed disease was present on multiple sites within and across breeding and post weaning production flows of the operation and mortality approached 100% in neonatal piglets. After an epidemiologic investigation, an outsourced, pelleted piglet diet was identified for assessment, and a bioassay, where naïve piglets were fed the suspected feed pellets, was initiated to test the pellets for infectious PEDV. CONCLUSIONS: The epidemiological investigation provided strong evidence for contaminated feed as the source of the outbreak. In addition, feed pellets collected from unopened bags at the affected sites tested positive for PEDV using RT-PCR. However, the bioassay study was not able to show infectivity when feeding the suspected feed pellets to a small number of naïve piglets. The results highlight the critical need for surveillance of feed and feed components to further define transmission avenues in an effort to limit the spread of PEDV throughout the U.S. swine industry.


id: cord-321814-vt6yio6x
title: Isolation and characterization of a variant porcine epidemic diarrhea virus in China
author: Pan, Yongfei
date: 2012-09-12
txt: ./txt/cord-321814-vt6yio6x.txt
cache: ./cache/cord-321814-vt6yio6x.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/1743-422x-9-195
doi: 10.1186/1743-422x-9-195
summary:
  In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Phylogenetic analyses of the S protein amino acid sequences revealed that all PEDV strains in this study could be separated into two groups: CHGD-01 belonged to Group 2, which also contained the two Japanese isolates Kawahira and NK, eight Korean field strains (Chinju99, KNU-0801, KNU-0802, and KNU-0901-KNU-0905) and two Chinese strains (BJ-2011-1 and CH/FJND-3/2011), which were deposited in GenBank in 2011 ( Figure 3b ). Molecular characterization and phylogenetic analysis of membrane protein genes of porcine epidemic diarrhea virus isolates in China

abstract:
  An outbreak of diarrhea in pigs started in Guangdong, South China in January 2011. Cases were characterized by watery diarrhea, dehydration and vomiting, with 80–100% morbidity and 50–90% mortality in suckling piglets. The causative agent of the diarrhea was ultimately identified as porcine epidemic diarrhea virus (PEDV). In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. The complete genome of CHGD-01 was shown to be 28,035 nucleotides in length, with a similar structure to that of PEDV reference strains. Phylogenetic analyses based on the whole genome revealed that CHGD-01 shared nucleotide sequence identities of 98.2–98.4% with two other Chinese isolates reported in the same year, thus constituting a new cluster. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Its ORF3 and nucleoprotein genes, however, were divergent from all other sequenced PEDV isolate clusters and therefore formed a new group, suggesting a new variant PEDV isolate in China. Further studies will be required to determine the immunogenicity and pathogenicity of this new variant.


id: cord-321953-yql6gpd3
author: Barrera, Maritza
date: 2017-12-12
txt: ./txt/cord-321953-yql6gpd3.txt
cache: ./cache/cord-321953-yql6gpd3.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/29379796/
doi: 10.1155/2017/2978718
summary:
  Therefore, this report was conducted using the complete sequence of the S gene and powerful Bayesian phylogeographic reconstructions to clarify the putative origin of PEDV in Ecuador, revealing the wide expansion of the emergent PEDV strains, which caused the first PEDV outbreak in this country. To perform sequence comparison analyses and to establish the phylogenetic relationships of PEDV sequence from Ecuador, alignments using the consensus sequence of complete S gene available at GenBank database (Supplementary Information Table S1 ) were conducted by the algorithm ClustalW included in the program BioEdit Sequence Alignment Editor [33] . The phylogeographic study revealed the emergence of the Chinese PEDV strains followed by spreading to US in 2013 (Figures 3(a) and 3(b), Supplementary Material Video S1). Complete genome sequence of a porcine epidemic diarrhea S gene indel strain isolated in France in

title:
  Tracking the Origin and Deciphering the Phylogenetic Relationship of Porcine Epidemic Diarrhea Virus in Ecuador

abstract:
  In 2010, new Chinese strains of porcine epidemic diarrhea virus (PEDV), clinically more severe than the classical strains, emerged. These strains were spread to United States in 2013 through an intercontinental transmission from China with further spreading across the world, evidencing the emergent nature of these strains. In the present study, an analysis of PEDV field sequences from Ecuador was conducted by comparing all the PEDV S gene sequences available in the GenBank database. Phylogenetic comparisons and Bayesian phylogeographic inference based on complete S gene sequences were also conducted to track the origin and putative route of PEDV. The sequence from the PED-outbreak in Ecuador was grouped into the clade II of PEDV genogroup 2a together with other sequences of isolates from Mexico, Canada, and United States. The phylogeographic study revealed the emergence of the Chinese PEDV strains, followed by spreading to US in 2013, from US to Korea, and later the introduction of PEDV to Canada, Mexico, and Ecuador directly from the US. The sources of imports of live swine in Ecuador in 2014 were mainly from Chile and US. Thus, this movement of pigs is suggested as the main way for introducing PEDV to Ecuador.


id: cord-321992-lk2ao6m8
author: Annamalai, Thavamathi
date: 2015-12-15
txt: ./txt/cord-321992-lk2ao6m8.txt
cache: ./cache/cord-321992-lk2ao6m8.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0165242715002032
doi: 10.1016/j.vetimm.2015.09.006
summary:
  In the present study, we investigated the innate immune responses such as cytokine and NK cell activity as well as changes in frequencies of T cells to examine if differences coincide with the higher disease severity of suckling versus weaned pigs. The infected weaned pigs also had significantly higher NK cell frequencies in blood and ileum at PID 5 (P < 0.05) compared to infected suckling pigs ( Fig. 2A and B) . In infected suckling and weaned groups, peak IFN␣, IL-12 and TNF␣ levels coincided with onset of diarrhea and fecal PEDV RNA shedding and peak serum PEDV RNA titers (PIDs 1 and 3, respectively); and (4) Frequencies of CD3+CD4+ T cells were significantly higher in ileum of suckling pigs than in weaned pigs, whereas there was no difference in frequency of CD3+CD8+ T cells.

title:
  Age-dependent variation in innate immune responses to porcine epidemic diarrhea virus infection in suckling versus weaned pigs

abstract:
  Porcine epidemic diarrhea (PED) is an enteric coronaviral infection that causes severe morbidity and mortality in suckling pigs, but less severe disease in older pigs. Consequently, it causes significant economic losses to the pork industry. There are limited studies on the innate immune responses to PED virus (PEDV) in pigs. The aims of our study were to investigate differences in innate immune responses to PEDV infection in suckling and weaned pigs and to examine if disease severity coincides with reduced innate immune responses. Weaned 26-day-old pigs (n = 20) and 9-day-old nursing pigs (n = 20) were assigned to PEDV inoculated or uninoculated control groups. The pigs were observed daily for clinical signs, virus shedding and were euthanized at post-inoculation days (PIDs) 1 and 5 to assay immune responses. Blood samples were collected at PIDs 1, 3 and 5. The natural killer (NK) cell frequencies, NK cell activities (lysis of target K562 tumor cells in vitro), CD3+CD4+ T cell and CD3+CD8+ T cell frequencies were measured in blood and ileum at PIDs 1 and 5. The PEDV infected suckling pigs showed severe diarrhea and vomiting at PID 1, whereas the PEDV infected weaned pigs showed milder clinical signs starting at PID 3. PEDV infected suckling pigs had significantly higher diarrhea scores, earlier fecal PEDV RNA shedding and significantly higher viremia (viral RNA in serum) compared to weaned pigs. There was no mortality in either infected suckling or infected weaned pigs. The control pigs not inoculated with PEDV did not show any clinical signs and no detectable fecal or serum PEDV RNA. Strikingly, PEDV infected suckling pigs had significantly lower NK cell frequencies, undetectable NK cell activity and lower IFNγ producing NK cells in blood and ileum compared to PEDV infected weaned pigs. Pro-inflammatory cytokine profiles of PEDV infected suckling pigs differed from those of PEDV infected weaned pigs and coincided with onset of fecal PEDV RNA shedding and serum PEDV RNA titers. The infected suckling pigs have higher and earlier increases in serum IFNα, but lower serum IL-8 and TNFα levels compared to infected weaned pigs. CD3+CD4+ T cell frequencies were significantly higher in ileum of suckling pigs than in weaned pigs, whereas there was no difference in CD3+CD8+ T cell frequencies. In conclusion, the observations of impaired lytic activity and IFN-γ production by NK cells in suckling pigs coincided with the increased severity of PEDV infection in the suckling pigs compared with the weaned pigs.


id: cord-322475-i29t7ce8
author: Chen, Xi
date: 2012-07-29
txt: ./txt/cord-322475-i29t7ce8.txt
cache: ./cache/cord-322475-i29t7ce8.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s11262-012-0794-x
doi: 10.1007/s11262-012-0794-x
summary:
  title: Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) samples from field cases in Fujian, China In this study, we investigated molecular diversity, phylogenetic relationships, and protein characterization of Fujian field samples with other PEDV reference strains. Phylogenetic analysis based on S1 or sM gene, which have high levels of variations, indicated that each sample was related to the specific reference strain, and this finding was consistent with the protein characterization prediction analysis. In order to analyze the phylogenetic relationships between the 3 Fujian samples and other PEDV strains isolated in various regions worldwide, we constructed 2 phylogenetic trees using the deduced amino acid sequences of S1 and sM, respectively (Fig. 3) . Molecular characterization and phylogenetic analysis of membrane protein genes of porcine epidemic diarrhea virus isolates in China Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea

title:
  Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) samples from field cases in Fujian, China

abstract:
  The outbreak of porcine epidemic diarrhea virus (PEDV) has been a big problem of swine industry in China in recent years. In this study, we investigated molecular diversity, phylogenetic relationships, and protein characterization of Fujian field samples with other PEDV reference strains. Sequence analysis of the S1 and sM genes showed that each sample had unique characteristics, and the sample P55 may be differentiated from the others by the unique deletions and insertions of sM gene. Phylogenetic analysis based on S1 or sM gene, which have high levels of variations, indicated that each sample was related to the specific reference strain, and this finding was consistent with the protein characterization prediction analysis. The study is useful to better understand the prevalence of PEDV and its prevention and control in Fujian.


id: cord-322683-wkrj6n1d
author: Zhang, Pengfei
date: 2020-07-13
txt: ./txt/cord-322683-wkrj6n1d.txt
cache: ./cache/cord-322683-wkrj6n1d.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0378113520302698
doi: 10.1016/j.vetmic.2020.108793
summary:
  title: Cellular Poly(C) Binding Protein 2 Interacts with porcine epidemic diarrhea virus Papain-Like Protease 1 and Supports Viral Replication Taken together, these data demonstrated that PLP1 negatively regulated the production of type 1 interferon by interacting with PCBP2 and promoted PEDV replication. The PEDV N protein interacts with the TANK-binding kinase, blocking its association with interferon regulatory factor 3 (IRF3) and thus inhibiting IRF3 activation and type I IFN production (Ding et al., 2014; Hu et al., 2018) . PCBP2 expression is induced following viral infection and acts as a negative regulator of mitochondrial antiviral signaling protein (MAVS), triggering its degradation (You et al., 2009) . Although significant progress has been made in understanding PEDV evasion of innate immune responses, the mechanism of interaction between viral and host cell proteins remains unclear. In the present study, we demonstrated that PLP1 interacted with PCBP2 to inhibit IFN-β production and promote PEDV replication.

title:
  Cellular Poly(C) Binding Protein 2 Interacts with porcine epidemic diarrhea virus Papain-Like Protease 1 and Supports Viral Replication

abstract:
  Porcine epidemic diarrhea virus (PEDV) belongs to the Alphacoronavirus genus in the Coronaviridae family. Similar to other coronaviruses, PEDV encodes two papain-like proteases. Papain-like protease (PLP)2 has been proposed to play a key role in antagonizing host innate immunity. However, the function of PLP1 remains unclear. In this study, we found that overexpression of PLP1 significantly promoted PEDV replication and inhibited production of interferon-β. Immunoprecipitation and mass spectrometry were used to identify cellular interaction partners of PLP1. Host cell poly(C) binding protein 2 (PCBP2) was determined to bind and interact with PLP1. Both endogenous and overexpressed PCBP2 co-localized with PLP1 in the cytoplasm. Overexpression of PLP1 upregulated expression of PCBP2. Furthermore, overexpression of PCBP2 promoted PEDV replication. Silencing of endogenous PCBP2 using small interfering RNAs attenuated PEDV replication. Taken together, these data demonstrated that PLP1 negatively regulated the production of type 1 interferon by interacting with PCBP2 and promoted PEDV replication.


id: cord-327000-oyg3oyx1
title: Porcine Epidemic Diarrhea Virus and the Host Innate Immune Response
author: Li, Shasha
date: 2020-05-11
url: https://doi.org/10.3390/pathogens9050367
doi: 10.3390/pathogens9050367
abstract:
  Porcine epidemic diarrhea virus (PEDV), a swine enteropathogenic coronavirus (CoV), is the causative agent of porcine epidemic diarrhea (PED). PED causes lethal watery diarrhea in piglets, which has led to substantial economic losses in many countries and is a great threat to the global swine industry. Interferons (IFNs) are major cytokines involved in host innate immune defense, which induce the expression of a broad range of antiviral effectors that help host to control and antagonize viral infections. PEDV infection does not elicit a robust IFN response, and some of the mechanisms used by the virus to counteract the host innate immune response have been unraveled. PEDV evades the host innate immune response by two main strategies including: 1) encoding IFN antagonists to disrupt innate immune pathway, and 2) hiding its viral RNA to avoid the exposure of viral RNA to immune sensors. This review highlights the immune evasion mechanisms employed by PEDV, which provides insights for the better understanding of PEDV-host interactions and developing effective vaccines and antivirals against CoVs.


id: cord-329227-sqetz7h6
author: Hou, Yixuan
date: 2018-11-07
txt: ./txt/cord-329227-sqetz7h6.txt
cache: ./cache/cord-329227-sqetz7h6.txt
extension: .txt
mime: text/plain
url: https://jvi.asm.org/content/jvi/93/2/e01758-18.full.pdf
doi: 10.1128/jvi.01758-18
summary:
  The amounts of PEDV S proteins in the ERGIC, in other organelles, or on the cell surface are likely regulated by two nearby motifs in its cytoplasmic tail (CT): a tyrosine-based motif, Yxx⌽ (x is any residue and ⌽ is a bulky hydrophobic residue: F, M, I, L, or V), and an ER retrieval signal (ERRS), KVHVQ (10) (11) (12) (13) , as well as other viral and cellular proteins. One study demonstrated that a single amino acid substitution in this motif (KVHVQ to KVRVQ) weakens the intracellular retention function of the S proteins of the 10th passage of a murine-adapted PEDV variant, MK-P10 (18) , resulting in enhanced syncytium formation in Vero cells. In this study, we evaluated the phenotypes of transiently expressed S mutants containing mutations or deletions in these two motifs in mammalian cells and the virulence of three representative recombinant PEDVs in gnotobiotic piglets.

title:
  Deletion of both the Tyrosine-Based Endocytosis Signal and the Endoplasmic Reticulum Retrieval Signal in the Cytoplasmic Tail of Spike Protein Attenuates Porcine Epidemic Diarrhea Virus in Pigs

abstract:
  Porcine epidemic diarrhea virus (PEDV) causes high mortality in neonatal piglets. The PEDV spike (S) protein contains two intracellular sorting motifs, YxxΦ (tyrosine-based motif YEVF or YEAF) and KVHVQ at the cytoplasmic tail, yet their functions have not been fully elucidated. Some Vero cell-adapted and/or attenuated PEDV variants contain ablations in these two motifs. We hypothesized that these motifs contribute to viral pathogenicity. By transiently expressing PEDV S proteins with mutations in the motifs, we confirmed that the motif KVHVQ is involved in retention of the S proteins in the endoplasmic reticulum (ER)-Golgi intermediate compartment (ERGIC). In addition, we showed that the YxxΦ motif triggers endocytosis of S proteins. These two motifs synergistically regulate the level of S expressed on the cell surface. To investigate their role in viral pathogenicity, we generated three recombinant PEDVs by introducing deletions or a mutation in the two motifs of the infectious clone of PEDV PC22A strain (icPC22A): (i) icΔ10aa (ΔYxxΦEKVHVQ), (ii) icΔ5aa (ΔKVHVQ), and (iii) icYA (Y1378A, to an inactivated motif, AEVF). Infection of Vero cells with icΔ10aa resulted in larger syncytia and more virions, with reduced numbers of S protein projections on the surface compared with icPC22A. Furthermore, we orally inoculated five groups of 5-day-old gnotobiotic piglets with the three mutants, icPC22A, or a mock treatment. Mutant icΔ10aa caused less severe diarrhea rate and significantly milder intestinal lesions than icPC22A, icΔ5aa, and icYA. These data suggest that the deletion of both motifs can reduce the virulence of PEDV in piglets. IMPORTANCE Many coronaviruses (CoVs) possess conserved motifs YxxΦ and/or KxHxx/KKxx in the cytoplasmic tail of the S protein. The KxHxx/KKxx motif has been identified as the ER retrieval signal, but the function of the YxxΦ motif in the intracellular sorting of CoV S proteins remains controversial. In this study, we showed that the YxxΦ of PEDV S protein is an endocytosis signal. Furthermore, using reverse genetics technology, we evaluated its role in PEDV pathogenicity in neonatal piglets. Our results explain one attenuation mechanism of Vero cell-adapted PEDV variants lacking functional YxxΦ and KVHVQ motifs. Knowledge from this study may aid in the design of efficacious live attenuated vaccines against PEDV, as well as other CoVs bearing the same motif in their S protein.


id: cord-330035-0d6w8xyd
title: Cellular cholesterol is required for porcine nidovirus infection
author: Jeon, Ji Hyun
date: 2017-09-07
txt: ./txt/cord-330035-0d6w8xyd.txt
cache: ./cache/cord-330035-0d6w8xyd.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-017-3545-4
doi: 10.1007/s00705-017-3545-4
summary:
  The addition of exogenous cholesterol to MβCD-treated cells moderately restored the infectivity of porcine nidoviruses, indicating that the presence of cholesterol in the target cell membrane is critical for viral replication. The addition of exogenous cholesterol to MβCD-treated cells moderately restored the infectivity of porcine nidoviruses, indicating that the presence of cholesterol in the target cell membrane is critical for viral replication. Furthermore, pharmacological sequestration of cellular cholesterol efficiently blocked both virus attachment and internalization and, accordingly, markedly affected subsequent post-entry steps of the replication cycle, including viral RNA and protein biosynthesis and progeny virus production. Further experiments revealed that pharmacological depletion of cellular cholesterol primarily interferes with virus binding and penetration and subsequently influences post-entry stages of the PRRSV and PEDV replication cycle, including viral genomic and sg RNA synthesis, viral protein expression, and virus production.

abstract:
  Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine epidemic diarrhea virus (PEDV) are porcine nidoviruses that are considered emerging and re-emerging viral pathogens of pigs that pose a significant economic threat to the global pork industry. Although cholesterol is known to affect the replication of a broad range of viruses in vitro, its significance and role in porcine nidovirus infection remains to be elucidated. Therefore, the present study was conducted to determine whether cellular or/and viral cholesterol levels play a role in porcine nidovirus infection. Our results showed that depletion of cellular cholesterol by treating cells with methyl-β-cyclodextrin (MβCD) dose-dependently suppressed the replication of both nidoviruses. Conversely, cholesterol depletion from the viral envelope had no inhibitory effect on porcine nidovirus production. The addition of exogenous cholesterol to MβCD-treated cells moderately restored the infectivity of porcine nidoviruses, indicating that the presence of cholesterol in the target cell membrane is critical for viral replication. The antiviral activity of MβCD on porcine nidovirus infection was found to be predominantly exerted when used as a treatment pre-infection or prior to the viral entry process. Furthermore, pharmacological sequestration of cellular cholesterol efficiently blocked both virus attachment and internalization and, accordingly, markedly affected subsequent post-entry steps of the replication cycle, including viral RNA and protein biosynthesis and progeny virus production. Taken together, our data indicate that cell membrane cholesterol is required for porcine nidovirus entry into cells, and pharmacological drugs that hamper cholesterol-dependent virus entry may have antiviral potential against porcine nidoviruses.


id: cord-330475-mameyzih
author: Shi, Da
date: 2014-03-13
txt: ./txt/cord-330475-mameyzih.txt
cache: ./cache/cord-330475-mameyzih.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/24632575/
doi: 10.3390/v6031253
summary:
  Furthermore, by utilizing fusion proteins with green fluorescent protein (GFP), deletion mutations or site-directed mutagenesis of PEDV N protein, coupled with live cell imaging and confocal microscopy, it was revealed that, a region spanning amino acids (aa), 71–90 in region 1 of the N protein was sufficient for nucleolar localization and R87 and R89 were critical for its function. The B23.1-DsRed fusion protein was used to tag the nucleolus, so we could analyze nucleolar localization properties and colocalization in cotransfected cells by live cell imaging (direct fluorescence) or confocal microscopy. These expression plasmids were transfected into Vero E6 cells, the nuclear was stained with DAPI at 24 h post-transfection indicated that amino acids 148-220 directed AcGFP to the cytoplasm and nucleus and had a subcellular localization similar to AcGFP.

title:
  Molecular Characterizations of Subcellular Localization Signals in the Nucleocapsid Protein of Porcine Epidemic Diarrhea Virus

abstract:
  The nucleolus is a dynamic subnuclear structure, which is crucial to the normal operation of the eukaryotic cell. The porcine epidemic diarrhea virus (PEDV), coronavirus nucleocapsid (N) protein, plays important roles in the process of virus replication and cellular infection. Virus infection and transfection showed that N protein was predominately localized in the cytoplasm, but also found in the nucleolus in Vero E6 cells. Furthermore, by utilizing fusion proteins with green fluorescent protein (GFP), deletion mutations or site-directed mutagenesis of PEDV N protein, coupled with live cell imaging and confocal microscopy, it was revealed that, a region spanning amino acids (aa), 71–90 in region 1 of the N protein was sufficient for nucleolar localization and R87 and R89 were critical for its function. We also identified two nuclear export signals (NES, aa221–236, and 325–364), however, only the nuclear export signal (aa325–364) was found to be functional in the context of the full-length N protein. Finally, the activity of this nuclear export signal (NES) was inhibited by the antibiotic Lepomycin B, suggesting that N is exported by a chromosome region maintenance 1-related export pathway.


id: cord-330772-i7cfmw9x
author: Peng, Ju-Yi
date: 2019-12-03
txt: ./txt/cord-330772-i7cfmw9x.txt
cache: ./cache/cord-330772-i7cfmw9x.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/31797149/
doi: 10.1186/s13568-019-0916-0
summary:
  The in vitro toxicity and antiviral ability of the surfactin-like peptide in the BLFP crude extract against PEDV were evaluated using the Vero cells. To study the antiviral activity of BLFP crude extract against PEDV, the biosurfactants were added at different time points during the viral infection. No statically significant difference in the average daily gain was noted among all groups each week BLFP crude extract with PEDV-infected cells during the whole study. Similarly, extracellular viral RNA levels in PEDV-infected cells cultured with biosurfactants were significantly lower than those without BLFP crude extract 24 and 48 HPI (Fig. 8b) . b Extracellular viral RNA levels in the supernatants of PEDV-infected Vero cells treated with or without BLFP crude extract were determined by real-time reverse transcription (RT)-PCR. d Intracellular viral RNA levels in the supernatants of PEDV-infected Vero cells treated with or without BLFP crude extract were determined by real-time RT-PCR.

title:
  Evaluation of antiviral activity of Bacillus licheniformis-fermented products against porcine epidemic diarrhea virus

abstract:
  Bacillus licheniformis (B. licheniformis) is commonly used as probiotic and its secondary metabolites are attractive anti-microbial candidate. In the present study, we aimed to evaluate the antiviral activity of crude extracts from B. licheniformis against porcine epidemic diarrhea virus (PEDV), a highly contagious enveloped porcine virus that has caused great economic loss in pigs. In vivo, PEDV-infected piglets supplemented with air-dried solid state fermentative cultivate containing B. licheniformis-fermented products (BLFP) showed milder clinical symptoms and decreased viral shedding. Importantly, no significant systemic pathological lesions and no reduction in average daily gain were noted in pigs supplemented with the BLFP, which suggests that it is safe for use in pigs. In vitro experiments revealed that while B. licheniformis crude extracts exhibited no toxicity in Vero cells, co-cultivation of B. licheniformis crude extracts with PEDV significantly reduced viral infection and replication. Summarized current results suggest that the B. licheniformis-fermented products could be a novel candidate food additive for reducing the impact of PED on the swine industry.


id: cord-330825-apfcql4m
title: Phylogenetic tracking of current porcine epidemic diarrhea virus (PEDV) strains in the Philippines
author: Paraguison-Alili, Rubigilda
date: 2016-06-28
txt: ./txt/cord-330825-apfcql4m.txt
cache: ./cache/cord-330825-apfcql4m.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-016-2938-0
doi: 10.1007/s00705-016-2938-0
summary:
  title: Phylogenetic tracking of current porcine epidemic diarrhea virus (PEDV) strains in the Philippines Since the receptor-binding sites and majority of the neutralization epitopes are located in the S1 portion, this region has been subjected to sequencing and molecular analysis to determine the genetic relatedness of different PEDV viruses [1] [2] [3] . Using data from swine farms in these provinces and diagnosis data from the College of Veterinary Science and Medicine in Central Luzon State University, the incidence is 67 % in Pampanga, 79 % in Tarlac, 61 % in Batangas, and 90 to 100 % in Agusan. This is the first report of PEDV S1 gene sequences from the provincial PEDV hotspots of the Philippines, which include Batangas, Pampanga, Tarlac and Agusan. Phylogenetic analysis of the spike (S) gene of the new variants of porcine epidemic diarrhoea virus in Taiwan Molecular characterization of the spike and ORF3 genes of porcine epidemic diarrhea virus in the Philippines

abstract:
  To trace the possible route of introduction of porcine epidemic diarrhea virus (PEDV), the phylogenetic relationships of PEDV strains in the regions of epidemicity in the Philippines to PEDV strains that are endemic in other countries were investigated. Partial nucleotide sequences of the S1 spike gene was determined from the PEDV-positive samples and compared with S1 sequences from other countries. Phylogenetic analysis indicated that PEDV strains in the Philippines segregate into two groups. Members of group 1 are related to strains from the USA, Taiwan, Japan and Canada, while those in group 2 are related to strains from China and Vietnam.


id: cord-331509-p19dg1jw
author: Bigault, Lionel
date: 2020-05-31
txt: ./txt/cord-331509-p19dg1jw.txt
cache: ./cache/cord-331509-p19dg1jw.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0166093420301580?v=s5
doi: 10.1016/j.jviromet.2020.113906
summary:
  title: Porcine epidemic diarrhea virus: Viral RNA detection and quantification using a validated one-step real time RT-PCR In this study we described the development and validation of a SYBR™ Green one-step RT-qPCR according to the French norm NF U47-600, for the detection and quantification of PEDV viral RNA. Specificity and sensitivity, limit of detection (LoD), limit of quantification (LQ), linearity, intra and inter assay variability were evaluated using transcribed RNA and fecal and jejunum matrices spiked with virus. For a rapid, accurate and reliable diagnosis of PED in the veterinary laboratory, a method for the detection of PEDV viral RNA has been developed and more importantly validated according to the "Association Francaise de NORmalisation" (AFNOR) French NF U47-600 norm entitled "requirement and recommendation for the implementation, development and validation of PCR in animal health" (AFNOR, 2015a; AFNOR, 2015b) . This method should help harmonize detection and quantification of viral RNA from PEDV belonging to both S-non-INDEL and S-INDEL strains in both field and experimental settings.

title:
  Porcine epidemic diarrhea virus: Viral RNA detection and quantification using a validated one-step real time RT-PCR

abstract:
  Since 2014, porcine epidemic diarrhea virus (PEDV) has reemerged in Europe. RT-PCR methods have been described for the detection of PEDV, but none have been validated according to a norm. In this study we described the development and validation of a SYBR™ Green one-step RT-qPCR according to the French norm NF U47-600, for the detection and quantification of PEDV viral RNA. The method was validated from sample preparation (feces or jejunum) through to nucleic acid extraction and RT-qPCR detection. Specificity and sensitivity, limit of detection (LoD), limit of quantification (LQ), linearity, intra and inter assay variability were evaluated using transcribed RNA and fecal and jejunum matrices spiked with virus. The analytical and diagnostic specificities and sensitivities of this RT-qPCR were 100% in this study. A LoD of 50 genome copies/5 µl of extract from fecal matrices spiked with virus or RNA transcript and 100 genome copies/5 µl of extract from jejunum matrices spiked with virus were obtained. The Lower LQ (LLQ) was 100 genome copies/5 µl and the Upper LQ (ULQ) 10(8) copies/5 µl. This method is the first, validated according a norm for PEDV and may serve as a global reference method to harmonize detection and quantification of PEDV viral RNA in both field and experimental settings.


id: cord-331542-wy068c6o
title: Identification of a novel B-cell epitope in the spike protein of porcine epidemic diarrhea virus
author: Kong, Ning
date: 2020-04-03
txt: ./txt/cord-331542-wy068c6o.txt
cache: ./cache/cord-331542-wy068c6o.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s12985-020-01305-1
doi: 10.1186/s12985-020-01305-1
summary:
  The antisera titers were determined by indirect ELISA, western blot and IFA after four immunizations to find the important immunodominant region of S1, and then purified the immunodominant region of S1 protein and immunized mice to generate the special antibodies, and then used recombinant peptides to determine the B-cell epitopes of monoclonal antibodies. To accurately identify the immunodominant region of S1, the purified truncated S1 proteins (SA, SB, SC, SD and SE) were used to immunize BALB/c mice to prepare Fig. 1 Detection of recombinant proteins'' antigenicity for polyclonal antisera (PcAbs) by indirect ELISA, western blot and IFA. The indirect ELISA and western blot analysis showed that the SE polyclonal antisera had the highest antibody titers against PEDV S1 protein ( Fig. 1a and b) , suggesting that SE protein was the important immunodominant region of S1.

abstract:
  BACKGROUND: Porcine epidemic diarrhea virus (PEDV) infection causes an acute enteric tract infectious disease characterized by vomiting, anorexia, dehydration, weight loss and high mortality in neonatal piglets. During PEDV infection, the spike protein (S) is a major virion structural protein interacting with receptors and inducing neutralizing antibodies. However, the neutralizing B-cell epitopes within PEDV S protein have not been well studied. METHODS: To accurately identify the important immunodominant region of S1, the purified truncated S1 proteins (SA, SB, SC, SD and SE) were used to immunize BALB/c mice to prepare polyclonal antibodies. The antisera titers were determined by indirect ELISA, western blot and IFA after four immunizations to find the important immunodominant region of S1, and then purified the immunodominant region of S1 protein and immunized mice to generate the special antibodies, and then used recombinant peptides to determine the B-cell epitopes of monoclonal antibodies. RESULTS: Five antisera of recombinant proteins of the spike protein region of PEDV were generated and we found that only the polyclonal antibody against part of the S1 region (signed as SE protein, residues 666–789) could recognize the native PEDV. Purified SE protein was used to immunize BALB/c mice and generate mAb 2E10. Pepscan of the SE protein demonstrated that SE16 ((722)SSTFNSTREL(731)) is the minimal linear epitope required for reactivity with the mAb 2E10. Further investigation indicated that the epitope SE16 was localized on the surface of PEDV S protein in the 3D structure. CONCLUSIONS: A mAb 2E10 that is specifically bound to PEDV was generated and identified a specific linear B-cell epitope (SE16, (722)SSTFNSTREL(731)) of the mAb. The epitope region of PEDV S1 localized in the different regions in comparison with the earlier identified epitopes. These findings enhance the understanding of the PEDV spike protein structure for vaccine design and provide a potential use for developing diagnostic methods to detect PEDV.


id: cord-331652-oc5s1if2
author: Trudeau, Michaela P.
date: 2016-06-24
url: https://www.ncbi.nlm.nih.gov/pubmed/27341670/
doi: 10.1371/journal.pone.0158128
title:
  Comparison of Thermal and Non-Thermal Processing of Swine Feed and the Use of Selected Feed Additives on Inactivation of Porcine Epidemic Diarrhea Virus (PEDV)

abstract:
  Infection with porcine epidemic diarrhea virus (PEDV) causes diarrhea, vomiting, and high mortality in suckling pigs. Contaminated feed has been suggested as a vehicle of transmission for PEDV. The objective of this study was to compare thermal and electron beam processing, and the inclusion of feed additives on the inactivation of PEDV in feed. Feed samples were spiked with PEDV and then heated to 120–145°C for up to 30 min or irradiated at 0–50 kGy. Another set of feed samples spiked with PEDV and mixed with Ultracid P (Nutriad), Activate DA (Novus International), KEM-GEST (Kemin Agrifood), Acid Booster (Agri-Nutrition), sugar or salt was incubated at room temperature (~25°C) for up to 21 days. At the end of incubation, the virus titers were determined by inoculation of Vero-81 cells and the virus inactivation kinetics were modeled using the Weibull distribution model. The Weibull kinetic parameter delta represented the time or eBeam dose required to reduce virus concentration by 1 log. For thermal processing, delta values ranged from 16.52 min at 120°C to 1.30 min at 145°C. For eBeam processing, a target dose of 50 kGy reduced PEDV concentration by 3 log. All additives tested were effective in reducing the survival of PEDV when compared with the control sample (delta = 17.23 days). Activate DA (0.81) and KEM-GEST (3.28) produced the fastest inactivation. In conclusion, heating swine feed at temperatures over 130°C or eBeam processing of feed with a dose over 50 kGy are effective processing steps to reduce PEDV survival. Additionally, the inclusion of selected additives can decrease PEDV survivability.


id: cord-331919-6kistim2
author: Song, Daesub
date: 2012-01-22
txt: ./txt/cord-331919-6kistim2.txt
cache: ./cache/cord-331919-6kistim2.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/22270324/
doi: 10.1007/s11262-012-0713-1
summary:
  Another report revealed that PEDV has caused enteric disease with devastating impact since the first identification of PEDV in 1992 in Korea, and recent, prevalent Korean PEDV field isolates are closely related to Chinese field strains but differ genetically from European strains and vaccine strains [45] . For instance, it is possible to estimate the potential transmission of PEDV by comparing viral shedding load with a standard internal control DNA curve [72] , as well as to perform multiplex RT-PCR to detect PEDV in the presence of various viruses [73] -a technique that is particularly useful for rapid, sensitive, and cost-effective diagnosis of acute swine viral gastroenteritis). Shorter periods of virus shedding, as well as reduced severity and duration of diarrhoea in piglets, result from higher titres of serum antibodies; complete protection from PEDV infection prevents shedding after exposure to viral challenge [90] . Development of an ELISA for the detection fo antibody isotypes against porcine epidemic diarrhoea virus (PEDV) in sow''s milk

title:
  Porcine epidemic diarrhoea virus: a comprehensive review of molecular epidemiology, diagnosis, and vaccines

abstract:
  The porcine epidemic diarrhoea virus (PEDV), a member of the Coronaviridae family, causes acute diarrhoea and dehydration in pigs. Although it was first identified in Europe, it has become increasingly problematic in many Asian countries, including Korea, China, Japan, the Philippines, and Thailand. The economic impacts of the PEDV are substantial, given that it results in significant morbidity and mortality in neonatal piglets and is associated with increased costs related to vaccination and disinfection. Recently, progress has been made in understanding the molecular epidemiology of PEDV, thereby leading to the development of new vaccines. In the current review, we first describe the molecular and genetic characteristics of the PEDV. Then we discuss its molecular epidemiology and diagnosis, what vaccines are available, and how PEDV can be treated.


id: cord-332811-kjgah8ts
author: Lee, Do Hyun
date: 2015-06-23
txt: ./txt/cord-332811-kjgah8ts.txt
cache: ./cache/cord-332811-kjgah8ts.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-015-2494-z
doi: 10.1007/s00705-015-2494-z
summary:
  title: Immunoprophylactic effect of chicken egg yolk antibody (IgY) against a recombinant S1 domain of the porcine epidemic diarrhea virus spike protein in piglets A codon-optimized PEDV S1 gene consisting of amino acid residues 25–749 was synthesized and used to establish a stable porcine cell line constitutively expressing a recombinant PEDV S1 protein containing the chicken immunoglobulin Fc fragment at its C-terminus. Moreover, oral passive immunization using chicken IgY raised against the PEDV S1 protein was found to control and prevent PED post-challenge in suckling piglets. All neonatal piglets except for animals in the control group were inoculated orally with 1 ml of the small-intestine homogenate containing 10 4 TCID 50 /ml PEDV field virus determined using real-time RT-PCR as described previously [10] . Immunoprophylactic effect of chicken egg yolk immunoglobulin (IgY) against porcine epidemic diarrhea virus (PEDV) in piglets

title:
  Immunoprophylactic effect of chicken egg yolk antibody (IgY) against a recombinant S1 domain of the porcine epidemic diarrhea virus spike protein in piglets

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric pathogen of swine causing high mortality rates in piglets. PEDV outbreaks have occurred continuously in most swine-producing Asian countries and have recently emerged in the United States, leading to large economic losses for both the Asian and US pig industries. The spike (S) protein of PEDV consists of the S1 and S2 domains, responsible for virus binding and fusion, respectively. The involvement of the S1 domain in specific high-affinity interactions with the cellular receptor and induction of neutralizing antibodies in the natural host makes it a logical target for the development of effective vaccines and therapeutics against PEDV. Passive immunization by oral administration of egg yolk antibodies (IgY) obtained from immunized chickens provides an alternative source of specific antibodies for the prevention and treatment of PEDV in newborn piglets. In this study, we produced an IgY against the PEDV S1 protein and investigated its immunoprophylactic effect in neonatal piglets. A codon-optimized PEDV S1 gene consisting of amino acid residues 25–749 was synthesized and used to establish a stable porcine cell line constitutively expressing a recombinant PEDV S1 protein containing the chicken immunoglobulin Fc fragment at its C-terminus. The purified recombinant S1 protein was found to mediate potent immune responses in immunized hens. We next tested the ability of oral passive immunization with anti-PEDV S1 IgY to protect piglets against PEDV. Specific chicken IgY against the S1 protein was orally administered to neonatal piglets, and their responses subsequent to a virulent PEDV challenge were monitored. The results showed that oral administration of anti-PEDV S1 IgY efficiently protects neonatal piglets against PEDV, suggesting its potential as a prophylactic or therapeutic agent against acute PEDV infection.


id: cord-334218-bkjfy66e
author: Lin, Jung-Da
date: 2016-01-15
txt: ./txt/cord-334218-bkjfy66e.txt
cache: ./cache/cord-334218-bkjfy66e.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1371/journal.pone.0147316
doi: 10.1371/journal.pone.0147316
summary:
  title: Impact of Mated Female Nonproductive Days in Breeding Herd after Porcine Epidemic Diarrhea Virus Outbreak The objectives of the present study were to investigate the effects between a 1-year period before and after PEDV outbreak on a sow''s reproductive traits on a commercial pig farm in Taiwan. The average number of mated females, average parity of farrowed sows, number of matings, number of farrowings, FR, RR, number of abortions, LMFY, percentage of sows mated by 7 days after weaning, WFSI, FI, NPDs, replacement rates of sows and sow culling rates of preand post-PEDV outbreak periods were compared using a Mann-Whitney test. In the present study, we compared the productivity index of gilts and sows between 1 year pre-and post-PEDV outbreak in a Taiwanese breeding herd. Impact of porcine epidemic diarrhea virus infection at different periods of pregnancy on subsequent reproductive performance in gilts and sows

title:
  Impact of Mated Female Nonproductive Days in Breeding Herd after Porcine Epidemic Diarrhea Virus Outbreak

abstract:
  Porcine epidemic diarrhea virus (PEDV) is an important pathogen that has a significant economic impact on the swine industry by imposing a high rate of mortality in suckling piglets. However, limited information on the productivity values of gilts and sows infected with PEDV is available. Here, we evaluate the productivity index in gilts and sows during the 1-year period before (19 January 2013 to 18 January 2014) and after (19 January 2014 to 18 January 2015) a PEDV outbreak from a 2000-sow breeding herd in Taiwan. The farrowing rate (FR), return rate (RR), total pigs born per litter (TB), pigs born alive per litter (BA), weaning pigs per litter (WPL), pre-weaning mortality, percentage of sows mated by 7 days after weaning, weaning to first service interval (WFSI), mated female nonproductive days (NPDs), replacement rate of sows and sow culling rate were compared using productive records. The FR (-9.6%), RR (+9.8%), TB (-1.6), BA (-1.1), WPL (-1.1), sows mated by 7 days after weaning (-6.9%), WFSI (+0.8 days), NPDs (+6.9 days) and sow culling rate (+7.2%) were significantly different between the 1-year pre-PEDV outbreak period and the post-PEDV outbreak period. Impacts of the PEDV infection on the reproductive performance were more severe in pregnant gilts than in sows. In conclusion, these findings indicate that the outbreak of PEDV caused an increase in the rate of NPDs in breeding herds.


id: cord-336517-v7z62tld
author: Chu, Hsu-Feng
date: 2018-08-20
txt: ./txt/cord-336517-v7z62tld.txt
cache: ./cache/cord-336517-v7z62tld.txt
extension: .txt
mime: text/plain
url: https://www.sciencedirect.com/science/article/pii/S0166354218302183
doi: 10.1016/j.antiviral.2018.08.011
summary:
  Further studies suggest that PEDV PL2 pro exhibits much higher DUB activity than that of SARS-and MERS-CoV PL pro s and can be inhibited by the anti-leukemia drug 6-thioguanine (6TG). Previous studies suggested that the Ubl domain was not involved in the catalytic activity of SARS-and MERS-CoV PL pro s (Chou et al., 2012; Clasman et al., 2017) . Overall, the secondary, tertiary and quaternary structures of the PEDV PL2 pro catalytic core are similar to those of SARS-and MERS-CoV PL pro s, even though their sequence identity is only 22-25% (Fig. S1 ). In contrast, previous studies suggested that the binding site of 6TG for SARS-and MERS-CoV PL pro s may be near the catalytic triad''s cysteine residue due to its competitive pattern of inhibition Chou et al., 2008) . Structural and mutational analysis of the interaction between the Middle-East respiratory syndrome coronavirus (MERS-CoV) papain-like protease and human ubiquitin

title:
  Porcine epidemic diarrhea virus papain-like protease 2 can be noncompetitively inhibited by 6-thioguanine

abstract:
  Porcine epidemic diarrhea virus (PEDV) is a coronavirus (CoV) discovered in the 1970s that infects the intestinal tract of pigs, resulting in diarrhea and vomiting. It can cause extreme dehydration and death in neonatal piglets. In Asia, modified live attenuated vaccines have been used to control PEDV infection in recent years. However, a new strain of PEDV that belongs to genogroup 2a appeared in the USA in 2013 and then quickly spread to Canada and Mexico as well as Asian and European countries. Due to the less effective protective immunity provided by the vaccines against this new strain, it has caused considerable agricultural and economic loss worldwide. The emergence of this new strain increases the importance of understanding PEDV as well as strategies for inhibiting it. Coronaviral proteases, including main proteases and papain-like proteases, are ideal antiviral targets because of their essential roles in viral maturation. Here we provide a first description of the expression, purification and structural characteristics of recombinant PEDV papain-like protease 2, moreover present our finding that 6-thioguanine, a chemotherapeutic drug, in contrast to its competitive inhibition on SARS- and MERS-CoV papain-like proteases, is a noncompetitive inhibitor of PEDV papain-like protease 2.


id: cord-339012-4juhmjaj
author: Hou, Wei
date: 2020-07-28
txt: ./txt/cord-339012-4juhmjaj.txt
cache: ./cache/cord-339012-4juhmjaj.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1101/2020.07.28.224576
doi: 10.1101/2020.07.28.224576
summary:
  Instead, PEDV down-regulated the expression of a set of zinc finger proteins with putative antiviral activity and enhanced the expression of the transmembrane serine protease gene TMPRSS13 (alias MSPL) to support its own infection by virus-cell membrane fusion (Shi et al, 2017, Viruses, 9(5):114). Furthermore, by comprehensive datamining in biological and chemical databases and consulting related literature we identified sets of PEDV-response genes with potential to influence i) the metabolism of biogenic amines (e.g. histamine), ii) the formation of cilia and "synaptic clefts" between cells, iii) epithelial mucus production, iv) platelets activation, and v) physiological processes in the body regulated by androgenic hormones (like blood pressure, salt/water balance and energy homeostasis). The detected sets of differential expressed genes (DEGs) for PEDV and MRV were analyzed by gene set enrichment analysis (GSEA) using functional bioinformatic programs to retrieve biological processes (pathways and Gene Ontology terms [GO-term]) and associations with chemical compounds, including drugs.

title:
  Rapid host response to an infection with Coronavirus. Study of transcriptional responses with Porcine Epidemic Diarrhea Virus

abstract:
  The transcriptional response in Vero cells (ATCC® CCL-81) infected with the coronavirus Porcine Epidemic Diarrhea Virus (PEDV) was measured by RNAseq analysis 4 and 6 hours after infection. Differential expressed genes (DEGs) in PEDV infected cells were compared to DEGs responding in Vero cells infected with Mammalian Orthoreovirus (MRV). Functional analysis of MRV and PEDV DEGs showed that MRV increased the expression level of several cytokines and chemokines (e.g. IL6, CXCL10, IL1A, CXCL8 [alias IL8]) and antiviral genes (e.g. IFI44, IFIT1, MX1, OASL), whereas for PEDV no enhanced expression was observed for these “hallmark” antiviral and immune effector genes. Pathway and Gene Ontology “enrichment analysis” revealed that PEDV infection did not stimulate expression of genes able to activate an acquired immune response, whereas MRV did so within 6h. Instead, PEDV down-regulated the expression of a set of zinc finger proteins with putative antiviral activity and enhanced the expression of the transmembrane serine protease gene TMPRSS13 (alias MSPL) to support its own infection by virus-cell membrane fusion (Shi et al, 2017, Viruses, 9(5):114). PEDV also down-regulated expression of Ectodysplasin A, a cytokine of the TNF-family able to activate the canonical NFKB-pathway responsible for transcription of inflammatory genes like IL1B, TNF, CXCL8 and PTGS2. The only 2 cytokine genes found up-regulated by PEDV were Cardiotrophin-1, an IL6-type cytokine with pleiotropic functions on different tissues and types of cells, and Endothelin 2, a neuroactive peptide with vasoconstrictive properties. Furthermore, by comprehensive datamining in biological and chemical databases and consulting related literature we identified sets of PEDV-response genes with potential to influence i) the metabolism of biogenic amines (e.g. histamine), ii) the formation of cilia and “synaptic clefts” between cells, iii) epithelial mucus production, iv) platelets activation, and v) physiological processes in the body regulated by androgenic hormones (like blood pressure, salt/water balance and energy homeostasis). The information in this study describing a “very early” response of epithelial cells to an infection with a coronavirus may provide pharmacologists, immunological and medical specialists additional insights in the underlying mechanisms of coronavirus associated severe clinical symptoms including those induced by SARS-CoV-2. This may help them to fine-tune therapeutic treatments and apply specific approved drugs to treat COVID-19 patients.


id: cord-339546-m7rqr886
author: de Arriba, M.L
date: 2002-01-01
txt: ./txt/cord-339546-m7rqr886.txt
cache: ./cache/cord-339546-m7rqr886.txt
extension: .txt
mime: text/plain
url: https://api.elsevier.com/content/article/pii/S0165242701003865
doi: 10.1016/s0165-2427(01)00386-5
summary:
  An enzyme-linked immunospot (ELISPOT) has been developed to detect porcine epidemic diarrhea virus (PEDV)-specific antibody secreting cells (ASC) in gut associated lymphoid tissues (duodenum and ileum lamina propria and mesenteric lymph nodes) and systemic locations (spleen and blood) of conventional pigs so as to characterise the mucosal and systemic antibody response generated by the infection with PEDV. Memory antibody response to the PEDV was also studied by secondary in vitro stimulation of the mononuclear cells (MNC) isolated from mesenteric lymph nodes, spleen and blood. In order to evaluate the distribution of PEDV-speci®c ASC, MNC from mesenteric lymph nodes, lamina propria of duodenum and ileum, spleen and blood were recovered at various PID from PEDV exposed pigs and tested for antibody production by ELISPOT. Table 1 Numbers of isotype-specific ASC to PEDV (per 5 Â 10 5 MNC) in duodenum and ileum lamina propria, mesenteric lymph nodes (MLN), spleen and blood from pigs experimentally exposed to the virulent isolate of the PEDV strain CV-777 and sacrificed on PID 4, 7, 14, 21, 25 

title:
  Isotype-specific antibody-secreting cells in systemic and mucosal associated lymphoid tissues and antibody responses in serum of conventional pigs inoculated with PEDV

abstract:
  An enzyme-linked immunospot (ELISPOT) has been developed to detect porcine epidemic diarrhea virus (PEDV)-specific antibody secreting cells (ASC) in gut associated lymphoid tissues (duodenum and ileum lamina propria and mesenteric lymph nodes) and systemic locations (spleen and blood) of conventional pigs so as to characterise the mucosal and systemic antibody response generated by the infection with PEDV. A total number of 28 eleven-day-old conventional pigs were orally inoculated with the field isolate of the PEDV strain CV-777. Diarrhea was observed in 32% of the pigs and virus shedding was demonstrated in 100% between postinoculation day (PID) 1 and 8. Serum IgG and IgA antibodies to PEDV were detected by isotype ELISA from PID 12 and 15, respectively, reaching maximum values at PID 32 (IgG) and 21 (IgA). PEDV specific IgM ASC occurred in all the tissues between PID 4 and 7, with the strongest response in the intestinal lamina propria. IgA and IgG ASC responses were evident in the intestinal lymphoid tissues from PID 21, the highest number of specific ASC corresponded to the duodenum lamina propria. In the systemic lymphoid tissues the number of IgG and IgA ASC detected were lower than in the mucosal tissues, however, in the blood, presence of IgA ASC was constantly detected from PID 14 until the end of the experiment. Memory antibody response to the PEDV was also studied by secondary in vitro stimulation of the mononuclear cells (MNC) isolated from mesenteric lymph nodes, spleen and blood. The memory B cell response was prominent at PID 21 and 25 and consisted in IgG and IgA ASC. To our knowledge, this is the first report to research into the presence and distribution of specific ASC in different locations of the systemic and the gut associated lymphoid tissues after a PEDV infection as well as the presence of memory B cells.


id: cord-339871-jso21mbx
author: Lee, Sunhee
date: 2018-05-16
txt: ./txt/cord-339871-jso21mbx.txt
cache: ./cache/cord-339871-jso21mbx.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1111/tbed.12904
doi: 10.1111/tbed.12904
summary:
  To investigate the diversity of PEDVs responsible for the ongoing outbreaks in South Korea, in this study, we determined the full-length sequences of the S proteins of field isolates and complete genome sequences of representative strains identified throughout 2017. Based on the S gene sequences, therefore, PEDV can be genetically separated into two genogroup clusters, genogroup 1 (G1, classical and recombinant: low-pathogenic) and genogroup 2 (G2, field epizootic or panzootic: high-pathogenic), which are further divided into subgroups 1a and F I G U R E 1 Phylogenetic analysis based on nucleotide sequences of the spike genes (a) and full-length genomes (b) of porcine epidemic diarrhoea virus strains. Molecular characterization and phylogenetic analysis of membrane protein genes of porcine epidemic diarrhea virus isolates in China Full-genome sequence analysis of a variant strain of porcine epidemic diarrhea virus in South Korea Genomic and antigenic characterization of Porcine epidemic diarrhoea virus strains isolated from South Korea

title:
  Genomic and antigenic characterization of porcine epidemic diarrhoea virus strains isolated from South Korea, 2017

abstract:
  Porcine epidemic diarrhoea virus (PEDV) is a globally emerging and re‐emerging enteric coronavirus in pigs causing serious economic threats to the world swine industry. Since the re‐emergence of massive PEDV outbreaks in South Korea in 2013−2014, domestic pig farms have continued to experience PED epidemics or endemics. This study represents the molecular characterization of PEDV isolates identified in diarrhoeic animals collected across the country in 2017. Initial sequencing analysis of the full‐length S genes revealed that 70% of the 2017 isolates (7/10) belong to the G2b subgroup, while the remaining isolates were classified as G1b. The data indicated that both variant G1b and global epidemic G2b strains were responsible for current PED outbreaks in South Korea. The 2017 G1b and G2b isolates shared 98.7%–99.4% and 98.1%–99.2% amino acid sequence identity at the S gene level and 99.3% and 99.0%–99.6% nucleotide sequence homology at the genome level compared to the corresponding Korean prototype G1b and G2b strains, respectively. In an interesting manner, one G2b‐like KNU‐1705 strain was found to possess a large 39‐nucleotide deletion in the ORF1a region theoretically encoding nonstructural protein 3. Phylogenetic analysis based on the entire genome and spike protein sequences indicated that the 2017 isolates were most closely related to other global G1b or G2b strains but formed different branches within the same genogroup. These results indicate that PEDVs undergo continuous evolution in the field. In addition, one 2017 PEDV strain, KOR/KNU‐1705/2017, was successfully isolated and propagated in Vero cells. The antisera raised against the Korean prototype 2014 G2b strain efficiently neutralized KNU‐1705 virus infection, suggesting antigenic homology between the 2014 and 2017 PEDV strains. Our data advance the understanding of the molecular epidemiology and antigenicity of PEDV circulating in South Korea.


id: cord-339924-tsmnkuhw
title: Pathology of US Porcine Epidemic Diarrhea Virus Strain PC21A in Gnotobiotic Pigs
author: Jung, Kwonil
date: 2014-04-17
txt: ./txt/cord-339924-tsmnkuhw.txt
cache: ./cache/cord-339924-tsmnkuhw.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/24795932/
doi: 10.3201/eid2004.131685
summary:
  title: Pathology of US Porcine Epidemic Diarrhea Virus Strain PC21A in Gnotobiotic Pigs To understand the progression of porcine epidemic diarrhea virus infection, we inoculated gnotobiotic pigs with a newly emerged US strain, PC21A, of the virus. For the pig-passaged PC21A strain, RT-PCR/PCR results were negative for transmissible gastroenteritis virus/porcine respiratory coronavirus (7), rotavirus groups A-C (8), caliciviruses (13, 14) , astroviruses (15) , circoviruses, enterovirus, kobuvirus, and bocavirus. Electron micrograph of a US porcine epidemic diarrhea virus (PEDV) particle detected in a field fecal sample collected during a 2013 outbreak of PED on a farm in Ohio, USA; the fecal sample from which PEDV strain PC21A in this study was obtained was from a pig on the same farm during the same outbreak. Emergence of Porcine epidemic diarrhea virus in the United States: clinical signs, lesions, and viral genomic sequences

abstract:
  To understand the progression of porcine epidemic diarrhea virus infection, we inoculated gnotobiotic pigs with a newly emerged US strain, PC21A, of the virus. At 24–48 hours postinoculation, the pigs exhibited severe diarrhea and vomiting, fecal shedding, viremia, and severe atrophic enteritis. These findings confirm that strain PC21A is highly enteropathogenic.


id: cord-340202-ikptxviu
title: US-like isolates of porcine epidemic diarrhea virus from Japanese outbreaks between 2013 and 2014
author: Van Diep, Nguyen
date: 2015-12-02
txt: ./txt/cord-340202-ikptxviu.txt
cache: ./cache/cord-340202-ikptxviu.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1186/s40064-015-1552-z
doi: 10.1186/s40064-015-1552-z
summary:
  Sequencing and phylogenic analyses of the partial spike gene and ORF3 of PEDV demonstrated that all prevailing Japanese PEDV isolates belonged to novel genotypes that differed from previously reported strains and the two PEDV vaccine strains currently being used in Japan. Unlike vaccine strains, all prevailing field PEDV isolates in Japan were found to have a number of amino acid differences in the neutralizing epitope domain, COE, which may affect antigenicity and vaccine efficacy. This study aimed to evaluate the genetic characteristics and molecular epidemiology of the emergent Japanese PEDV isolates using genome analysis and phylogenetic analysis of the partial S gene and ORF3. To investigate the heterogeneity of the recent Japanese isolates and their genetic relationship with modified live vaccines, in addition to 2 PEDV vaccine strains (P5-V and 96-P4C6) used in Japan, representative isolates were selected for sequencing of the partial S gene and full ORF3 gene.

abstract:
  Since late 2013, outbreaks of porcine epidemic diarrhea virus (PEDV) have reemerged in Japan. In the present study, we observed a high detection rate of PEDV, with 72.5 % (148/204) of diarrhea samples (suckling, weaned, and sows) and 88.5 % (77/87) of farms experiencing acute diarrhea found to be positive for PEDV by reverse transcription PCR. Sequencing and phylogenic analyses of the partial spike gene and ORF3 of PEDV demonstrated that all prevailing Japanese PEDV isolates belonged to novel genotypes that differed from previously reported strains and the two PEDV vaccine strains currently being used in Japan. Sequence and phylogenetic analysis revealed prevailing PEDV isolates in Japan had the greatest genetic similarity to US isolates and were not vaccine-related. Unlike vaccine strains, all prevailing field PEDV isolates in Japan were found to have a number of amino acid differences in the neutralizing epitope domain, COE, which may affect antigenicity and vaccine efficacy. The present study indicates recent PEDV isolates may have been introduced into Japan from overseas and highlights the urgent requirement of novel vaccines for controlling PEDV outbreaks in Japan.


id: cord-340438-9q3ic0ye
author: Zhang, Jianqiang
date: 2018-02-21
url: https://www.ncbi.nlm.nih.gov/pubmed/29468451/
doi: 10.1007/s11262-018-1542-7
title:
  Identification of porcine epidemic diarrhea virus variant with a large spike gene deletion from a clinical swine sample in the United States

abstract:
  Two genetically different porcine epidemic diarrhea virus (PEDV) strains have been identified in the USA: US prototype (also called non-S INDEL) and S INDEL PEDVs. In February 2017, a PEDV variant (USA/OK10240-8/2017) was identified in a rectal swab from a sow farm in Oklahoma, USA. Complete genome sequence analyses indicated this PEDV variant was genetically similar to US non-S INDEL strain but had a continuous 600-nt (200-aa) deletion in the N-terminal domain of the spike gene compared to non-S INDEL PEDVs. This is the first report of detecting PEDV bearing large spike gene deletion in clinical swine samples in the USA.


id: cord-341469-7guojyay
author: Park, Seong-Jun
date: 2011-01-06
txt: ./txt/cord-341469-7guojyay.txt
cache: ./cache/cord-341469-7guojyay.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-010-0892-9
doi: 10.1007/s00705-010-0892-9
summary:
  Especially, ORF3 gene analysis can be used for discrimination between vaccine and wild-type PEDVs. Sequence and phylogenetic analysis showed that recent, prevalent Korean PEDV field isolates have close relationships to Chinese field strains and differ genetically from European strains and vaccine strains used in Korea. Sequence analysis of the complete ORF3 genes showed that all PEDVs, including the Korean field isolates, fell into three groups, and group 3 had two subgroups (3-1 and 3-2), as can be seen in the phylogenetic tree (Fig. 2) . Genetic analysis based on complete M and ORF3 genes showed that each PEDV group had several unique characteristics, and these results indicated that specific groups of PEDVs may be differentiated from other PEDVs, including Korean field isolates, by specific nucleotide differences, but more PEDVs need to be analyzed for more accurate analysis.

title:
  Molecular characterization and phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field isolates in Korea

abstract:
  Porcine epidemic diarrhea virus (PEDV) has caused enteric disease with devastating impact since the first identification of PEDV in 1992 in Korea. In this study, we investigated molecular epidemiology, showed genetic diversity, and analyzed phylogenetic relationships of Korean PEDV field isolates with other PEDV reference strains. Genetic analysis of the complete M and ORF3 genes showed that each PEDV group had several unique characteristics, and this indicated that specific groups of PEDVs may be differentiated from the other PEDVs by specific nucleotide differences. Especially, ORF3 gene analysis can be used for discrimination between vaccine and wild-type PEDVs. Sequence and phylogenetic analysis showed that recent, prevalent Korean PEDV field isolates have close relationships to Chinese field strains and differ genetically from European strains and vaccine strains used in Korea. These results raise questions as to whether a new type of PEDV vaccine may be necessary for preventing PEDV infection more effectively in Korea.


id: cord-341521-dntkdwkj
author: Luo, Yi-Ran
date: 2020-03-24
txt: ./txt/cord-341521-dntkdwkj.txt
cache: ./cache/cord-341521-dntkdwkj.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.2478/jvetres-2020-0024
doi: 10.2478/jvetres-2020-0024
summary:
  MATERIAL AND METHODS: We observed the effect of the PEDV SHpd/2012 strain on an infected Vero cell cycle through flow cytometry and Western blot, investigating the interrelationships of cell-cycle arrest, the DNA damage–signalling pathway caused by PEDV and the phosphorylation levels of the key molecules Chk.2 and H2A.X involved upstream and downstream in this pathway. We used inhibitors of ATM and Chk.2 to block the DNA damage-signalling pathway and to confirm whether PEDV infection can lead to cell-cycle arrest. We also treated cells with chemical inhibitors of ATM and Chk.2 to determine if cell-cycle arrest after PEDV infection was linked with activation of the DNA damage-signalling pathway. These results revealed that cell-cycle arrest after infection of Vero cells with PEDV was caused by activation of the DNA damage-signalling pathway.

title:
  Porcine Epidemic Diarrhoea Virus Induces Cell-cycle Arrest through the DNA Damage-signalling Pathway

abstract:
  INTRODUCTION: Porcine epidemic diarrhoea virus (PEDV) infection causes watery diarrhoea, vomiting, anorexia, and weight loss, especially among neonatal piglets, inflicting on them morbidity and mortality potentially reaching 90%–100%. Despite it being known that certain mammalian cell phases are arrested by PEDV, the mechanisms have not been elucidated, and PEDV pathogenesis is poorly understood. This study determined the effect of an epidemic PEDV strain on cell cycle progression. MATERIAL AND METHODS: We observed the effect of the PEDV SHpd/2012 strain on an infected Vero cell cycle through flow cytometry and Western blot, investigating the interrelationships of cell-cycle arrest, the DNA damage–signalling pathway caused by PEDV and the phosphorylation levels of the key molecules Chk.2 and H2A.X involved upstream and downstream in this pathway. RESULTS: PEDV induced Vero cell-cycle arrest at the G1/G0 phase. The phosphorylation levels of Chk.2 and H2A.X increased with the prolongation of PEDV infection, and no significant cell-cycle arrest was observed after treatment with ATM or Chk.2 inhibitors. The proliferation of PEDV was also inhibited by treatment with ATM or Chk.2 inhibitors. CONCLUSION: PEDV-induced cell-cycle arrest is associated with activation of DNA damage–signalling pathways. Our findings elucidate the molecular basis of PEDV replication and provide evidence to support further evaluation of PEDV pathogenesis.


id: cord-342923-prgorr3d
author: Li, Zhonghua
date: 2018-03-13
txt: ./txt/cord-342923-prgorr3d.txt
cache: ./cache/cord-342923-prgorr3d.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/29534017/
doi: 10.3390/v10030127
summary:
  title: Cellular hnRNP A1 Interacts with Nucleocapsid Protein of Porcine Epidemic Diarrhea Virus and Impairs Viral Replication Replication of PEDV was inhibited by silencing the expression of hnRNP A1 in CCL-81 cells, suggesting the positive effect of hnRNP A1 on PEDV infection. Previous studies have demonstrated hnRNP A1 could interact with N proteins of SARS Coronavirus and mouse hepatitis virus (MHV) [14, 19] . Our previous work has proved that hnRNP A1 underwent different regulations in jejunum tissues of piglets infected with PEDV virulent strain and its attenuated strain [20] . The beads were then washed with IP lysis buffer five times and boiled in sample buffer, and the proteins were subjected to SDS-PAGE, followed by immunoblotting analysis with anti-Flag PAb or anti-hnRNP A1 PAb. CCL-81 cells grown on coverslips were infected with PEDV YN144 strain, YN13 strain and CV777 strain, respectively, at a multiplicity of infection (MOI) 0.001.

title:
  Cellular hnRNP A1 Interacts with Nucleocapsid Protein of Porcine Epidemic Diarrhea Virus and Impairs Viral Replication

abstract:
  The nucleocapsid (N) protein is a major structural component of porcine epidemic diarrhea virus (PEDV), which is predicted to be a multifunctional protein in viral replication. Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a cellular protein participating in the splicing of pre-mRNA in the nucleus and translation regulation in the cytoplasm. According to our previous proteomic study about PEDV infection in vivo, hnRNP A1 was thought to be a cellular factor influencing PEDV replication. In this report, PEDV N protein was discovered to colocalize with cellular hnRNP A1 in perinuclear region of PEDV infected cells. Co-immunoprecipitation (CO-IP) results clearly demonstrated that PEDV N protein could bind to human hnRNP A1. Replication of PEDV was inhibited by silencing the expression of hnRNP A1 in CCL-81 cells, suggesting the positive effect of hnRNP A1 on PEDV infection.


id: cord-343132-qqhivgkq
author: Chang-Liao, Wan-Ping
date: 2020-07-15
txt: ./txt/cord-343132-qqhivgkq.txt
cache: ./cache/cord-343132-qqhivgkq.txt
extension: .txt
mime: text/plain
url: https://www.ncbi.nlm.nih.gov/pubmed/32760370/
doi: 10.3389/fmicb.2020.01578
summary:
  The results showed that the intracellular extracts of Ln. mesenteroides YPK30 possessed in vitro prophylactic, therapeutic, and direct-inhibitory effects against PEDV in the Vero cell model. As shown in Figure 3 , the metabolic activity of Vero cells pretreated with the intracellular extracts of Ln. mesenteroides, regardless of which strain, were similar to those pretreated with IFN-α2b (p > 0.05) but were significantly higher than the un-pretreated cells (p < 0.05), indicating that all the Ln. mesenteroides strains isolated from kefir grains possessed in vitro prophylactic effects against PEDV. durans, Lb. kefiri, Lc. lactis, and Ln. mesenteroides , were isolated from kefir grains, and the in vitro prophylactic effects of the intracellular extracts of these four species against PEDV infection in Vero cells were compared. Therefore, the in vitro prophylactic and therapeutic effects of the intracellular extracts of Ln. mesenteroides YPK30 against PEDV in Vero cells seem not be attributed to the direct interaction of bacterial components or metabolites with virus.

title:
  Isolation of a Leuconostoc mesenteroides Strain With Anti-Porcine Epidemic Diarrhea Virus Activities From Kefir Grains

abstract:
  Swine grown under commercial conditions are vulnerable to environmental exposure to several viruses, which may cause infectious diseases and spread easily and rapidly, resulting in significant economic losses in animal husbandry. Previous studies have suggested that probiotics seem to be a new and promising alternative to vaccinations to protect animals against potential viral infections. In this study, we used the Vero cell culture model of infection to study porcine epidemic diarrhea virus (PEDV). We screened lactic acid bacteria (LAB) with anti-PEDV potential from kefir grains, which are starter cultures used to ferment milk into kefir. Twenty-nine LAB strains were isolated and identified as Enterococcus durans, Lactobacillus kefiri, Lactococcus lactis, and Leuconostoc mesenteroides, according to 16S ribosomal RNA (rRNA) and rpoA gene sequence analyses. The anti-PEDV activities of the LAB intracellular extracts were compared, and the intracellular extracts of Ln. mesenteroides showed higher anti-PEDV activities than that of the other species. Among the Ln. mesenteroides strains, a strain designated YPK30 showed a higher growth rate than that of the other strains and was further evaluated for its anti-PEDV activity. The results showed that the intracellular extracts of Ln. mesenteroides YPK30 possessed in vitro prophylactic, therapeutic, and direct-inhibitory effects against PEDV in the Vero cell model. The expression levels of Type 1 interferon (IFN)-dependent genes, including Myxovirus resistance 1 (MX1) and interferon-stimulated gene 15 (ISG15), were significantly increased after treatment with intracellular extracts of Ln. mesenteroides YPK30 for 24 h. Such expression suggests that the anti-PEDV activity of Ln. mesenteroides YPK30 could be attributed to its up-regulatory effect on the expression of MX1 and ISG15 genes. These results suggested that Ln. mesenteroides YPK30 has the potential to provide some levels of host protection against PEDV infections.


id: cord-343780-084lq92r
title: Detection, sequence analysis, and antibody prevalence of porcine deltacoronavirus in Taiwan
author: Hsu, Tien-Huan
date: 2018-07-26
txt: ./txt/cord-343780-084lq92r.txt
cache: ./cache/cord-343780-084lq92r.txt
extension: .txt
mime: text/plain
url: https://doi.org/10.1007/s00705-018-3964-x
doi: 10.1007/s00705-018-3964-x
summary:
  title: Detection, sequence analysis, and antibody prevalence of porcine deltacoronavirus in Taiwan To investigate if PDCoV is also present in Taiwan, three swine coronaviruses—PDCoV, porcine epidemic diarrhea virus (PEDV), and transmissible gastroenteritis coronavirus (TGEV)—were tested using real-time reverse transcription polymerase chain reaction (rRT-PCR) in 172 rectal swab samples from piglets exhibiting diarrhea between January 2016 and May 2017 on 68 pig farms in Taiwan. Currently, there are at least three members of the family Coronaviridae that can cause diarrhea in pigs: transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), and porcine deltacoronavirus (PDCoV) [8] . Based on the real-time RT-PCR (rRT-PCR) detection results, the percentage of pig farms that were positive for at least of one of the coronaviruses was 25% for PDCoV (17/68), 22.1% for PEDV (15/68), and 2.9% for TGEV (2/68). Phylogeny analysis of PDCoV-N genes showed that PDCoVs found in Taiwan were highly similar in their nucleotide sequences to isolates from the United States, mainland China, and other countries (Fig. 1) .

abstract:
  Porcine deltacoronavirus (PDCoV) was initially documented in Hong Kong and later in the United States, South Korea, and Thailand. To investigate if PDCoV is also present in Taiwan, three swine coronaviruses—PDCoV, porcine epidemic diarrhea virus (PEDV), and transmissible gastroenteritis coronavirus (TGEV)—were tested using real-time reverse transcription polymerase chain reaction (rRT-PCR) in 172 rectal swab samples from piglets exhibiting diarrhea between January 2016 and May 2017 on 68 pig farms in Taiwan. The rRT-PCR results were positive for PDCoV (29/172, 16.9%), PEDV (36/172, 20.9%), TGEV (2/172, 1.2%), and coinfections (16/172, 9.3%). After cloning and sequencing, PDCoV nucleocapsid genes were analyzed. Phylogeny results indicated that the nucleotide sequences of all isolates were like those reported in other countries. To further trace PDCoV in the period of 2011 to 2015, an enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against PDCoV. The results showed that 279 of 1,039 (26.9%) sera were positive for the PDCoV nucleocapsid protein, implying that PDCoV might have existed in Taiwan before 2011.


