key: cord-0754509-7b7fqztd
authors: nan
title: Oral Sessions
date: 2017-11-30
journal: International Journal of Antimicrobial Agents
DOI: 10.1016/s0924-8579(17)30422-3
sha: 7f3ad16eb5c4a253b907c44b2aaf387b1bddaca3
doc_id: 754509
cord_uid: 7b7fqztd

nan

Epidemics of dengue involving severe dengue cases occur only in certain years or areas. Global epidemiology also shows that specific strains or genotypes of the same serotype of dengue viruses (DENVs) did increase in epidemic severity. Therefore, this study aimed at better defining the 'epidemic potential' of DENV through epidemiological, virological, and immunological characterization that will be worthwhile pursuing for future prediction of epidemic severity. We isolated the DENV-2 strains from patients presented as clinically mild dengue fever (DF) versus severe dengue hemorrhagic fever (DHF) cases with different epidemiological conditions (e.g. temporal and spatial attributes) during the same epidemic in the same city for better monitoring dynamics of viral genetic and phenotypic changes through an epidemic process. Additionally, different clades of DENV-2 with viral sequence variations isolated at various time points were used for spatial analyses on viral spreading and reproductive numbers of R0. DHF cases appeared mostly during climbing up and peaking time of dengue cases through temporal and spatial evolution of the epidemic in southern Taiwan. Interestingly, DENV-2 variations occurred at different days after the onset of dengue illness of the same patient at micro-level as well as in different time periods of the same epidemic at macro-level of population dynamics. Moreover, different DENV-2 isolates with viral sequence variations did have differences in viral growth kinetics, viral transmissibility and spatial spreading. The epidemiological conditions are more important than immune status of primary or secondary DENV infection as driving forces associated with viral changes and severe dengue cases, particularly in areas with low incidence of dengue in previous years. Taiwan has not been an area of dengue-endemicity, providing a very valuable opportunity to integrate clinical, epidemiological, viral and immunological findings from those time-dependent DENV isolates to generate causal inference to fully understanding the mechanism of increasing epidemic severity. It is particularly of importance to monitor DENV viral changes through international collaboration for those genotypes with greater inter-country spread.

mortality. In vitro antifungal susceptibility testing (AFST) should provide informative hints clinical drug use and predict the outcomes of treatment to a certain extent. The purpose of this study was to determine the antifungal susceptibility profiles of 384 clinical Aspergillus isolates from two centers in Taiwan and mainland China to the active antifungal drugs usually used and contribute to the knowledge of prevailing antifungal resistance patterns of Aspergillus at the two different centers. Methods: We have performed in vitro AFST of 384 genetically confirmed Aspergillus isolates representing of 23 different species collected from various clinical sources against the active antifungal drugs of amphotericin B, triazole and echinocandins using Sensititre YeastOne, a commercially available alternative to the Clinical and Laboratory Standards Institute microdilution method for Aspergillus, and analyzed the susceptibility profiles according to a general minimum inhibitory concentrations (MICs)/minimum effective concentrations (MECs) interpretation code. Difference in antifungal resistance patterns between the two centers Aspergillus isolates was also compared. Results: In total, 77.6% (298/384) of the tested Aspergillus isolates showed entirely susceptible profiles to all tested antifungals with fairly low MICs and MECs of ≤1 µg/mL, and 22.4% (86/384) isolates from different Aspergillus species showed resistance to one or two classes of antifungal drugs. Amphotericin B resistance was the predominant problem in those isolates showed reduced susceptibility, with a rate of 91.9% (79/86). Two A. fumigatus isolates resistant to triazole were discovered; one was resistant to voriconazole with a MIC >8 µg/mL and the other to itraconazole with a MIC of 16 µg/mL. No triazole cross-resistant isolates were found. Echinocandins were highly potent to the Aspergillus isolates tested. No distinct difference in the resistant profiles was observed between the two center isolates except for A. flavus from mailand China showed a higher resistance rate to amphotericin B of 53.8% (35/65) than those from Taiwan (25% (7/28)). Conclusion: We have identified the antifungal susceptibility profiles of clinical Aspergillus isolates from two centers in Taiwan and mainland China. Several resistance patterns were discovered among the different Aspergillus species. The potent in vitro activity of triazoles and echinocandins in this study indicates that these two classes of antifungal agents have a clinically important role in treatment of Aspergillus infections. Clinical use of amphotericin B should be done cautiously especially when A. flavus is encountered.

Background: Candidemia is the fourth most common bloodstream infection in hospitalized patients and mortality rate is as high as 40%. The Pitt bacteremia score (PBS) highly correlates with mortality in patients with bacteremia; however, there is no simplified and validated prediction rule for prognosis of candidemia. Our objective was to explore a better scoring system to predict prognosis.

Methods: We reviewed the medical records of patients with culture-proven candidemia diagnosed between 2009 and 2016 at Nagasaki university hospital in Japan. We used multivariable logistic regression models to identify prognostic factors. Results: A total of 146 patients were enrolled. The median age was 68 years old. Seven-day and thirty-day mortality rates were 13.7% and 30.8%, respectively. Factors associated with 7-and 30-day mortality in candidemia patients by univariate analysis were acute kidney injury including hemodialysis (AKI/HD), removal of central venous catheter (CVC) within 24 hours, PBS and patients back ground including diabetes mellitus, use of immunosuppressant and neutropenia. Based on these results, we formulated a modified PBS (mPBS) by replacing an evaluation item of body temperature in the PBS with AKI/HD. Factors associated with 7-and 30-day mortality by multivariate analysis are shown in Table. Background: Aspergillus terreus is a common soil saprophyte which is also clinically important, causing infections ranging from superficial infections, such as onychomycosis, to invasive aspergillosis (IA) in severe immunocompromised hosts. Endophthalmitis caused by A. terreus is rarely reported in the literature. We report a case of endogenous endophthalmitis caused by A. terreus in a nonimmunocompromised patient with hypertension, taking regular medications and blood pressure controlled in the normal range, but without prior intraocular eye surgery or history of immunosuppression.

Methods: A vitreous biopsy was taken for culture and direct smear microscopy and further identified the isolate from culture positive plates by phenotype observation and molecular methods. In vitro antifungal susceptibility test were done by Etest.

Results: Fungal spores and septate hyphae were found in vitreous direct smear ( Figure 1 ). Tiny hair-like colonies grew on SDA after 7 days" culture but the colony morphology is still atypical after 10 days" culture ( Figure 2 ). We found attached spores by using scotch tape to stick the colonies on the side to ( Figure 3 ). After 2 times generation (nearly a month), the strain showed typical colony ( Figure 4 ) and microscopic morphology ( Figure 5 ). The isolate was final identified as A. terreus according to morphology and the results of phenotypic and molecular identification. The isolate's MICs (µg/mL) to itraconazole, voriconazole, amphotericin B were 0.25, 0.125, and 2, respectively. Conclusion: Early diagnostic and therapeutic vitrectomy is useful for obtaining sufficient samples for organism identification and also to reduce organism load and inflammatory mediators in the eye. Timely reporting the results of direct smear to clinical physician is very meaningful for the initial selection of antimicrobial agents. For the phenotype atypical but clinical important filamentous fungi, using ITS sequence analysis and other molecular identification methods can help to identify the fungal pathogen promptly. Background: The increased incidence of invasive candidemia coincides with the increasing number of severe immunosuppressed patients. Even though new drugs have been presented, the development of resistance to antifungal drugs has become increasingly alarming, especially in patients who require longterm treatment or prophylaxis. A better understanding of awareness of shifts of flora to more-resistant species and clinical impact of anti-fungal drug resistance is essential for improving treatment outcomes. Through this study, we report resistance to the azoles and echinocandins among Candida species. Methods: We assessed the presence of 50 Candida isolates associated with bloodstream infections from January 2011 to December 2016. Resistance profiles were evaluated by measuring MICs for fluconazole, voriconazole, and micafungin. The interpretation of breakpoints was defined by guideline from Clinical and Laboratory Standard Institute (CLSI).

Results: A total of 50 episode of candidemia were recognized. Candida parapsilosis accounted for 36%, Candida albicans 32%, Candida tropicalis 14%, Candida glabrata 8%, Candida famata 6%, and 4% others. Gender disparity, male 62%, and female 38%. Most of patients 84% were admitted in the critical care with their age range ≤28 days and 14-65 year-old 27/50 (54%). All Candida strains had 100% susceptible against antifungal drug Micafungin. On the other hand, there were 4% isolates that have been resistant to voriconazole. Although in the azoles as well, fluconazole has the highest level (16%) of resistance and has an increasing tendency of their resistant level. Conclusion: The echinocandins, such as Micafungin exhibits excellent in vitro susceptibility to all Candida strains, thereby appropriate being used for critically ill patients, long-term treatment, and patients who require prophylactic antifungal drug. Differences in antifungal resistance among Candida strains isolated from hospitals emphasize the importance of local surveillance programs to influence the selection of therapeutic management for at-risk patients.

The impact of biofilm formation on breakthrough candidemia Li Wei-Sin 1 , Lee Chen-Hsiang 1,2 . 1 Division of Infectious Disease, Kaohsiung Chang Gung Memorial Hospital, 2 Chang Gung University, Kaohsiung

Background: Candidemia often contributes to poor prognosis of patients. Persistence and breakthrough is one of the common complications of candidemia. The occurrence of candidemia in patients receiving antifungal therapy at least 3-day (breakthrough candidemia, BrC) has been reported increasingly. Biofilm are mainly composed of sessile cells and extracellular matrix with initiation by the adherence of free-moving planktonic cells to surfaces of human endothelium or medical implants. This leads to difficulties in eradicating micro-organisms from the blood. We conduct this study to analyze the risk of BrC and emphases the impact of biofilm formation.

Methods: This retrospective study included adult patients with candidemia and received the repeat blood culture study at least once after the first episode of candidemia who admitted to Kaohsiung Chang Gung Memorial Hospital between January 2007 and December 2012. By matching with propensity score and Candida species, these enrolled patients were divided as two groups, with and without BrC, to evaluate the risk factors of BrC and clinical outcomes.

Results: A total of 238 patients were included in this study, of which 73 (30.7%) had BrC. Sixty-eight patients were matched on the basis of the propensity score and Candida spices in each group. The Candida strains with high biofilm former ( p < 0.001), treatment with azole ( p = 0.006), and inappropriate treatment within 48 h after blood culture collection ( p = 0.006), including resistance of initial antifungal agent ( p = 0.02) and suboptimal dose of initial antifungal agents ( p = 0.001) were significantly associated with BrC. In the multivariate analysis, patients with central venous catheter at diagnosis (OR, 3.77; CI, 1.1-80.7, p = 0.036), stains with higher biofilm former (OR, 8.03; 95% CI, 2.50-25.81; p < 0.0001), and patients receiving suboptimal dose of initial antifungal agents (OR, 5.54; 95% CI, 1.53-20.10; p = 0.009) were independently associated with BrC. Comparing with candidal strains in non-BrC group, biofilm former were significantly higher in Candida albicans, C. tropicalis, and C. glabrata in BrC group. No significant difference in overall mortality and duration of hospitalization between the 2 groups. Conclusion: High biofilm former, presence of central catheter, and suboptimal dose of initial antifungal agents were related to BrC. The biofilm formers of C. albicans, C. tropicalis, and C. glabrata were significantly higher in BrC group. These data suggest that biofilm plays a major role in the development of breakthrough candidemia.

Background: The antiherpetic drugs acyclovir (valaciclovir) and penciclovir (famciclovir) are phosphorylated by viral thymidine kinase and terminate DNA synthesis. ASP2151 (amenamevir) and foscavir directly inhibit viral helicase-primase and DNA polymerase, respectively, and inhibit replication of herpes simplex virus (HSV) and varicella-zoster virus. Acyclovir (ACV) and ASP2151 as well as foscavir have a different mode of action, and their inhibitory mode of viral replication is characterized by the appearance of their drug actions in the timing of drug addition and their maintenance of antiviral action. Methods: ASP2151 suppressed HSV replication more efficiently than ACV at 10 × 50% inhibitory concentration of plaque formation when treatments were started 0-24 h after infection and total incubation was 48 h. Results: When virus replication was monitored in the presence of drugs, ASP2151 and PFA inhibited replication of HSV to 1% of the inhibition by acyclovir from 0 to 3 h, and virus yields gradually increased to similar levels of inhibition with ACV. ASP2151 and PFA inhibited viral replication in their presence until 48 hours after infection but acyclovir allowed it, although the virus yield or viral DNA copy number was 0.01% of the control without the drug. The virus replicated in the presence of acyclovir had 3.00 ± 1.45 times less efficient infectivity per viral DNA copy than that in the absence of an antiviral agent, indicating virus with impaired DNA. Antiviral activity of ASP2151 was not influenced by any replication phase of infection, while that of ACV was much reduced by the late phase of infection.

Conclusion: Antiviral concentration is maintained by a sigle dose of ASP2151 and antiviral activity is not influenced by the replication cycle in contrast to valaciclovir. ASP2151, viral helicase-primase inhibitor, showed a preferable profile as an anti-herpetic agent with a better pharmacokinetic profile than acyclovir. Thus, the ideal profile of will open the new era of anti-herpetic therapy to herpes simplex virus infection and herpes zoster. Results: Physical examinations were normal except for disorientation and loss of vigor. Laboratory data exept for a low CD4 level at 44/µL and slight elevation of CRP were normal. Cryptococcal antigen was elevated while toxoplasma IgG and IgM were negative. Plain head CT scan and gadolinium-enhanced head MRI revealed brain edema and three masses in frontal and occipital lobes, which might have been induced by Cryptococcus spp. or other bacteria, or immune reconstitution inflammatory syndrome (IRIS). Lymphoma was not strongly suspected because multiple lesions should decrease its likelihood and gadolinium-enhanced MRI had not shown any lesion 3 months prior. We couldn't perform lumbar puncture because of the risk of brain herniation. We started amphotericin B and flucytosine for cryptococcal infection, and ceftriaxone, metronidazole and teicoplanin for possible bacterial abscesses. On hospital day (HD) 15, his consciousness deteriorated, and head CT showed worsening of the brain edema. Neurosurgeons performed a small craniotomy to decrease intracranial pressure, but were unable to sufficiently aspirate the abscesses. On HD 20, his fever increased to 39°C. Gram staining of the brain did not detect bacteria but dexamethasone 0.3 mg/kg/day p.o. was initiated for the case of IRIS. But, on HD30, the brain biopsy turned out to be DLBCL. Standard therapy for Intracranial DLBCL, radiation and high-dose methotrexate, was not possible given the patient's condition. Therefore, only whole brain radiation was performed. However, the patient's condition did not improve, and he died on HD 81. Conclusion: Among patients with chronic respiratory diseases, seropositive status directly translated into protection against influenza infection. However, higher rates of serum antibodies against influenza viruses in HCWs also indicate that this group is repeatedly exposed to these viruses suggesting a greater risk of acquiring the infection in case of an outbreak, and of graver concern, transmitting it to vulnerable patients. Background: Zika virus was discovered in 1947 and belongs to Flavivirus family. It was drawn much attention because of the world wide outbreak in 2015. It has been shown that this virus cause neurological disorders such as Guillain-Barré syndrome and acute myelitis in adults and microcephaly in the newborn children. Zika viral NS2B-NS3 protease is a two component serine protease required for maturation of viral proteins, which makes it an attractive target.

We have made three distinct Zika protease constructs (eZiPro, bZiPro, and gZiPro) for structural and functional studies. X-ray crystallography, thermal shift assay, and NMR spectroscopy are used to characterize the structures of the protease constructs, giving rise to insight into structure-based inhibitor design.

Results: Zika protease are demonstrated to be in the closed conformation regardless of inhibitor/substrate binding. The crystal structure of Zika protease in complex with Ac-KR-aldehyde (IC 50 208 nM) was also determined in which the N-terminal cap region and aldehyde are important for binding. Further NMR studies confirmed the binding mode in solution. Titration of peptide substrates with different lengths reveals that the N-terminal cap is also required for the binding because peptides without the aldehyde group do not bind to the protease. Conclusion: The protease construct (bZiPro) in which NS2B cofactor region and NS3 protease region are co-expressed is suitable for studying protease and inhibitor interactions. The artificial glycine linker used in conventional construct may affect protease dynamics in solution. The dipeptide inhibitor Ac-KRaldehyde is a potent protease inhibitor while challenges still remain to have clinical applications due to the charges. Fragmentbased drug discovery may provide a way for developing potent protease inhibitors. Background: Hepatitis B and C are seen higher than other population among hemodialysis patients. Parenteral transmission is common route. In hemodialysis units, nearly all of the patients screens for both of them. AntiHCV and HbsAg are oftenly used. Despite some prevention methods such as device separation; cross infections occurs. Occult infections of hepatitis B and C virus can not be diagnosed by standard laboratory screening tests. Detection of the HBV DNA in the absence of HBsAg antigen in the serum is called occult hepatitis B infection (OBI). Detection of the HCV-RNA in mononuclear cells from peripheral blood during the absence of anti-HCV and HCV RNA in the serum is called occult hepatitis C infection (OCI). We aimed to diagnose OBI and OCI rates at hemodialysis patients in province of Canakkale in Turkey. Methods: HbsAg and antiHCV negative, with normal Alanin Amino Transpherase (ALT) values were included in the study. Demographic datas, causes of renal failure, hemodialysis method and duration, ALT values and hepatitis markers were recorded from the previous patient files. Patient study group consisted of 100 objects. In the serum, anti-Hbc IgG values were investigated by Enzyme-Linked Immunosorbent Assay (ELISA) (Architecht Abbott, USA). HBV DNA in the serum and HCV RNA in the mononuclear cells were investigated by real time PCR method. Results: Mean age of the patients were between 63.5 ± 12.5 years old. Mean dialysis period was 67.6 ± 51.3 months. Nearly 85% of patients has arteriovenous fistula. Mean ALT level was 10.5 ± 7.2 IU/ mL (Normal range = 0-55 Iu/mL). Total Anti-Hbc positivity was found 27%. The number of HBV DNA positive with anti-Hbc Ig G negative patients were only four. Alone antiHBc positivity was not detected. In the serum, by detection of HBV DNA, OBI was observed at 4% of the patients. In all these patients anti-HBs was positive.

Mean antiHBs titer was 377.75 ± 12.55 mIU/mL. We could not detect HCV RNA in either serum or mononuclear cells. OCI rate was zero in study group. Conclusion: In Turkey HBsAg positivity was 4.01%, anti -HCV positivity was 6.94%, HBsAg and anti -HCV positivity were 0.70% and the rate of seronegative (HBsAg negative, anti -HCV negative) patient was reported as 88.35% when the viral serology profiles were examined in hemodialysis patients. Usually OCI rates are higher than OBI. Among the hemodialysis patients OBI may be detected even if it is rare. We think that, to prevent transmission of HBV infections, it is not enough to investigate the existence of the viruses by only routine serological tests.

OS 4-1 Urinary concentrations and bactericidal activity of tobramycin in healthy subjects receiving a single oral dose (600 milligrams) Maria Loose 1 , Kurt Naber 2 , Paul Shields 3 , Harald Reinhart 4 , Florian Wagenlehner 1 . 1 Justus-Liebig Univ. of Giessen, Giessen, Germany, 2 Technical Univ. of Munich, Straubing, Germany, 3 Enteris BioPharma, Inc., Boonton, NJ, 4 Allphase Pharma Consulting, LLC, Amman, Jordan

Background: A phase I clinical study was performed to assess pharmacokinetics and safety of an oral form of tobramycin after multiple ascending doses in healthy subjects. This ex vivo study presents urinary concentrations (UC) and bactericidal activity of tobramycin in a subset. Methods: Urine of 9 healthy subjects was collected before and 0-2, 2-4, 4-8, 4-12, 12-16, 16-24 hours (h) after oral administration of 600 mg Tobrate™ (tobramycin formulated for improved absorption). The UC were determined by a LC-MS/MS method. Urinary bactericidal titers (UBTs) were determined for five test strains. The minimal inhibitory and bactericidal concentrations (MIC/MBC) of the test strains were determined in cation-adjusted Mueller-Hinton Broth (CAMHB) and in pooled blank urine (MBC) of the subjects at different pH (5.5; 6.5; 7.5; 8.5). Results: The median UC of tobramycin were 0.3; 33.1; 25.7; 7.1; 3.3; and 1.3 mg/L. The individual urine pH ranged between 5.3 and 8.2. The MIC/MBC (mg/L) of tobramycin for the test strains: Escherichia coli ATCC 25922: 4/4 mg/L; E. coli 1949820: 2/2 mg/L; Klebsiella pneumoniae 595: 2/2 mg/L; Proteus mirabilis 414: 8/16 mg/L; Pseudomonas aeruginosa 586: 0.5/1 mg/L. In blank urine the MBC (mg/L) was 16 mg/L or more for all strains at pH 5.5, and at pH 6.5/ 7.5/8.5 for E. coli ATCC 25922: 2/1/1 mg/L; E. coli 1949820: 8/2/ 2 mg/L; K. pneumoniae 595: 4/2/2 mg/L; P. mirabilis 414: 8/4/ 8 mg/L; P. aeruginosa 586: 16/4/1 mg/L. The median UBT values during the collecting periods 2-4/4-8 h: E. coli ATCC 25922: 2/4; E. coli 1949820: 4/2; K. pneumoniae 595: 4/4; P. mirabilis 414: 4/2; P. aeruginosa 586: 2/1. For each strain at least a UBT of 2 was reached in all subjects, except an UBT of 1 in 2 subjects for the P. aeruginosa strain. Conclusion: The new Enteris formulation of oral tobramycin significantly improved the very poor absorption of standard tobramycin salt. After a single dose of 600 mg of oral tobramycin, positive UBTs could be reached against all strains, with highest titers observed during the collection period of 2-4 hours (in 1 subject of 4-8 hours) after administration. For all pathogens tested, concentrations of tobramycin in urine were at least two times above urinary MBC. On average urinary MBC was present up to 8 hours. Therefore a BID or TID dosage regimen may be suitable for testing treatment of urinary tract infection in clinical studies. Since activity of tobramycin is higher in alkaline than in acid urine, alkalizing co-medication could improve urinary bactericidal activity.

OS 4-2 Effect of toxin production by antibiotics in multidrug-resistant Streptococcus pyogenes Masaaki Minami 1 *, Ryoko Sakakibara 2 , Mika Watanabe 2 , Hideo Morita 2 , Naoto Kanemaki 3 . 1 Department of Bacteriology, Nagoya City University, 2 Department of Clinical Investigation, Daido Hospital, 3 Department of Gastroenterology, Daido Hospital Background: Streptococcus pyogenes causes several serious diseases such as cellulitis, sepsis, necrotizing fasciitis. Although it is relatively sensitive against most antibiotics, clindamycin, tetracycline, and levofloxacin-resistant Streptococcus pyogenes has emerged recently. Although many researchers pay attention to antimicrobial susceptibility patterns such as Antibiogram, few researchers concern how antibiotics affect the toxin-production of drug-resistant Streptococcus pyogenes. Now we focus on the antibiotic induced toxin-production from multidrug-resistant Streptococcus pyogenes. Methods: Multidrug-resistant (clindamycin-, tetracycline-, and levofloxacin-resistant) Streptococcus pyogenes was isolated from Daido Hospital in Japan. This clinical isolate was confirmed by VITEK II system. The antibiotic-resistant patterns such as MICs were determined by E-test according to CLSI recommendation. Bacteria was pre-incubated on sheep blood agar for 24 hours and adjusted to 1 × 10 8 CFU. Then, it incubated Todd Hewitt broth with 10 μg/mL clindamycin, tetracycline, and levofloxacin, respectively. At adequate time points, we measured the turbidity (O.D. 600 nm) of bacterial culture for growth analysis. After 12 hours, we analyzed the DNase activity and hemolysis assays by using bacterial culture. Results: The MICs of clindamycin, tetracycline, and levofloxacin on bacteria were >256 μg/mL, >256 μg/mL, and >16 μg/mL, respectively. There were no differences of growth between antibiotic treated and untreated bacteria. The DNase and hemolysis activities from levofloxacin-induced bacteria were significant greater than those from antibiotic-untreated bacteria. The DNase and hemolysis activities from clindamycin-induced bacteria were slightly greater than those from antibiotic-untreated bacterium. Tetracycline did not affect the DNase and hemolysis activities on this bacteria significantly. Conclusion: This study showed that there is a difference in toxin production even for the same antibiotic-resistant bacteria depending on the type of antibacterial agent. Our result also revealed that levofloxacin-induced the toxin production on drug-resistant Streptococcus pyogenes. Background: Pseudomonas aeruginosa is a Gram-negative bacterium commonly implicated in nosocomial infections; it is also associated with resistance to multiple first-line antimicrobial agents. Ceftolozane/tazobactam is a new antimicrobial combination approved by the FDA for the treatment of infections due to P. aeruginosa. We detected ceftolozane/tazobactam resistance in a clinical isolate and examined the possible underlying mechanism(s). Methods: Bloodstream isolates of P. aeruginosa from 2015 and 2016 were screened for multidrug resistance. Selected isolates were subjected to susceptibility testing of a secondary antimicrobial agent panel by Etests and clonal uniqueness was confirmed by pulsed-field gel electrophoresis (PFGE). Hydrolytic activity of crude cell lysate was assessed using a spectrophotometric assay with nitrocefin as the substrate, after normalizing for total protein content. P. aeruginosa ATCC 27853 and a clinical isolate known to harbor VIM-2 were used as controls. Single nucleotide polymorphism (SNPs) analysis from whole genome sequencing was undertaken to provide additional insights on resistance mechanism(s). Reads from selected isolates were mapped against the genome of the reference strain PAO1. Variants identified by GATK, SamTools and CLC Genomics Workbench 8.5 were selected and annotated with SnpEff. Results: Out of 81 bloodstream isolates screened, 5 were resistant to ceftolozane/tazobactam ( prevalence = 6.2%). Specifically, we identified a pair of isolates from the same patient. The index isolate was susceptible to ceftolozane/tazobactam (MIC = 1.5/4 mg/L), but another isolate recovered 24 days later (mutant) was resistant (MIC = 6/4 mg/L). Similar susceptibility profiles were also seen with ceftazidime/avibactam. Both isolates were clonally similar by PFGE. Normalized hydrolytic activity was found to be approximately 25% higher in the mutant isolate. Whole genome sequencing revealed mutations in genes predicted to encode a D-Ala-D-Ala carboxypeptidase DacB (G87D), AmpD (V10G), and AmpC βlactamase (V213A) in the resistant isolate. Conclusion: Ceftolozane/tazobactam resistance in P. aeruginosa could be mediated via overexpression of beta-lactamase (e.g., AmpC). Background: Antibiotic resistance has become a global health threat due to the rapid evolution of multi-drug resistance in pathogenic bacteria as well as the shortage of avaibile alternatives for treating bacterial infections, especially for Gram-negative bacteria. Robenidine (NCL812), a currently registered animal coccidiostat, has been shown to have bactericidal activity against Gram-positive organisms including methicillin-resistant Staphylococcus aureus. During analogue screening undertaken for NCL001 to NCL266, NCL259 and NCL265 showed the best activity in initial screening test agsint two MRSA and two E. coli isolates (MIC ranging 8-16 µg/mL). Meanwhile, these two compounds also demonstrated excellent bactericidal activity according to minimum bactericidal concentration testing against Gramnegative bacteria, achieving 100% reduction of colony forming units within 20 minutes at the MIC for a selected E. coli strain. Methods: Minimum inhibitory concentrations, Minimum bactericidal concentration and time-kill kinetic assays were used to evaluate efficacy and pharmacodynamics against 91 human pathogenic isolates (E. coli, Enterobacter aerogenes, Enterobacter cloacae, Klebsiella oxytoca, Klebsiella pneumoniae) and 134 animal pathogenic isolates (ExPEC, ETEC). In vitro toxicity profiles were created using cell cytotoxicity assays against a variety of eukaryotic cell lines. Synergistic or antagonistic effects of an efflux pump inhibitor in conjunction with the compounds were examined using the checkerboard method. Results: The compounds demonstrated antimicrobial activity against a range of human and veterinary pathogens at low concentrations (NCL259, MIC 50 < 64 µg/mL; NCL265, MIC 50 < 16 µg/ mL). This activity was bacteriostatic and was sustained overa 24 hour period. The compounds have a much lower MIC in E. coli lacking the drug efflux pump (AcrB) and the MICs against the wild type E. coli were significantly lower in the presence of an efflux pump inhibitor. SDS-PAGE also showed the resistant and sensitive Klebsiella isolates differed in cell membrane protein composition. Conclusion: NCL259 and NCL265 have powerful bactericidal activity against Gram-negative bacteria and they are efflux pump substrates. Therefore, the usage of efflux pump inhibitors in combination with NCL 259/265 may increase activity against Gramnegative bacteria. These results suggest that these compounds and further derivatives have the potential to be developed into novel antimicrobial therapies against human/veterinary Gram-negative pathogens.

OS 4-6 High in vitro activity of meropenem/RPX7009 against KPC-producing Enterobacteriaceae in China Qiwen Yang, Ge Zhang, Zhipeng Xu, Yingchun Xu. Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China

Background: The purpose of this study was to evaluate the activity of meropenem in combination with RPX7009, a novel betalactamase inhibitor, against Enterobacteriaceae isolates producing KPC serine-carbapenemases collected in Chinese hospitals. Methods: A total of 129 KPC-producing Enterobacteriaceae collected from 16 Chinese hospitals located in 12 provinces from the year of 2006 to 2012 were evaluated. Bacteria were identified in Peking Union Medical College Hospital by MALDI-TOF MS method. The combination meropenem/RPX7009 was tested in a checkerboard configuration in a 96 well panel according to the Moody procedures in Clinical Microbiology Procedures Handbook. Minimum inhibitory concentrations (MICs) of other antimicrobial agents were determined using brothmicrodilution method by following Clinical and Laboratory Standards Institute (CLSI) guidelines. Ambler A,B,C,D group β-lactamase encoding genes were screened by PCR and sequencing. Expression level of blaKPC-2, ompK35, ompK36 and acrB gene in K.pneumoniae strains were evaluated by Reverse-transcriptional Real-time PCR. rpoB gene was used as internal reference gene. The expression level of the ompK35, ompK36 and acrB genes of selected clinical isolates were compared with that of K.pneumoniae strain ATCC13883. While the expression level of blaKPC-2 gene of the clinical isolates were compared with that of K. pneumoniae strain BAA1705. Results: The panel of 129 KPC-producing strains was highly resistant to meropenem alone, with meropenem MIC varying from 4 µg/mL (2 strains, 1.6%) to >64 µg/mL (74 strains, 57%). Both MIC 50 and MIC 90 of meropenem alone were >64 µg/mL. Addition of RPX7009 resulted in a dose-depended reduction of meropenem MIC: MIC 50 decreased to 8 µg/mL and 0.5 µg/mL in the presence of 2 µg/mL and 8 µg/mL of RPX7009, respectively. Maximal reduction of MIC 50 (to 0.25 µg/mL) was observed at 16 µg/mL of RPX7009. MIC 90 decreased to 8 µg/mL and 1 µg/mL in the presence of 8 µg/mL or 16 µg/mL of RPX7009, respectively. Maximal reduction of MIC 90 (to 0.5 µg/mL) was observed at 32 µg/ mL of RPX7009. Thirteen K. pneumoniae isolates which belonged to 4 clones were selected to investigate the relationship between the resistance level of meropenem plus RPX7009(MEM + RPX) and the gene expression level of blaKPC-2, ompK35, ompK36 and acrB genes. In the 8 strains with Meropenem + RPX7009 (8ug/ml) MIC of >1 ug/mL, decreased expression was found in ompK35 gene (8/8) and ompK36 (3/8) compared to the strain ATCC13883. increased expression was found in blaKPC-2 (6/8) and acrB (5/8). We have not noticed the obvious correlation between MEM + RPX high MIC and any single gene expression. However, isolates with high MEM + RPX MIC tend to express more KPC-2 and/or have ompK35/ompK36 loss. Conclusion: Addition of RPX7009 resulted in a dose-depended reduction of meropenem MIC against KPC-producing carbapenemresistant Enterobacteriaceae. High KPC-2 expression and/or porin loss may be related to high MEM + RPX MICs, while it required more investigation.

OS 4-7 Molecular characterization of extended spectrum beta-lactamase-producing Gram-negative uropathogens at a specialist hospital in North Western Nigeria Tanko Nuhu 1 *, Bolaji Rebecca Olajumoke 2 , Olayinka Busayo Olalekan 2 . 1 Department of Pharmaceutics and Pharmaceutical Microbiology, Usmanu Danfodiyo University, Sokoto, Nigeria, 2 Department of Pharmaceutics and Pharmaceutical Microbiology, Ahmadu Bello University, Zaria, Nigeria

Background: Extended Spectrum Beta-Lactamase (ESBL)-producing enterobacteroaceae are fast becoming the leading aetiological agents of antibiotic resistant infections. The study determined the prevalence and genetic profiles of ESBL-producing uropathogens among members of the family enterobacteriaceae. Methods: A total of 365 mid-stream urine sample collected over a period of 4 months were studied. Isolates were identified using Microgen Identification Kit, GN-ID. Susceptibility testing was performed using the modified Kirby Bauer method, and results were interpreted according to Clinical Laboratory Standard Institute (CLSI). ESBL production was detected by Double Disc Synergy Test (DDST). Molecular characterization of the ESBL positive isolates were confirmed by PCR method. Results: A total of 64 Gram negative uropathogens were isolated from 365 urine samples. The isolates were made up of E. coli (29.7%), Salmonella arizonae (23.1%), Klebsiella oxytoca (10.9%), Enterobacter gergoviae (9.4%), Citrobacter freundii (6.3%), Serratia marscense (6.3%), Klebsiella pnuemoniae (4.7%), Proteus mirabilis (1.6%), Enterobacter aerogenes (1.6%), Edwardsiella tarda (1.6%), Acinetobacter lwoffi (1.6%), Burkholderia pseudomallei (1.6%), and Pseudomonas aeruginosa (1.6%). The antibiotic susceptibility profiles of the isolates for 7 commonly prescribed antibiotics used in the treatment of UTI-associated infections showed that the isolates were resistant to cotrimoxazole (71.9%), nalidixic acid (67.2%), ciprofloxacin (54.7%), norfloxacin (53.1%), gentamicin (50.0%), amoxicillin/clavulanate (48.4%), and nitrofurantoin (29.7%). Majoriy of the isolates were multidrug resistant (64.1%), 15.6% were extensively drug resistant (XDR), 4.7% were pandrug resistant (PDR), while 15.6% did not fall into any of the classification. The PCR genomic DNA of the 15 MDR-ESBL-producing isolates showed that 73.3% were blaCTX-M, while 26.7% were blaOXA. Conclusion: The prevalence of ESBL in this study was 23.4%. molecular characterization of the selected MDR-ESBL-producing isolates showed that they harbored the blaCTX-M gene (73.3%) and blaOXA gene (26.7%).

OS 5-1 Implementation of an antibiotic stewardship program in a Tunisian teaching hospital Adnene Toumi*, Ikbel Kooli, Abir Aouam, Hajer Ben Brahim, Chawki Loussaief, Mohamed Chakroun. Infectious Diseases Department, UR12SP41, Monastir University Hospital, Tunisia

Background: In the past decade, antimicrobial resistance has emerged as a major healthcare concern. The impact of an antimicrobial stewardship program (ASP) in reducing inappropriate antimicrobial use has been proved. Until 2014, no ASP has been implemented in Tunisia. One of the first ASP has been implemented in our hospital in 2014. Our objective is to describe and to take stock of our ASP. Methods: Observational study carried out at the Fattouma Bourguiba Hospital in Monastir, Tunisia, a university teaching hospital (850 beds), from July 2014 to March 2017. All antimicrobial stewardship requests received and responses were collected in a standardized record.

Results: We collected 2625 antimicrobial stewardship requests with an average of 71 requests per month. Requests came mainly from the emergency department (n = 439, 16.8%), the orthopedic department (n = 371, 14.1%) and the visceral surgery department (n = 252, 9.6%). Physicians who solicited the ASP team were seniors in 1148 cases (43.7%). Requests were about antibiotic therapy in 1931 cases (73.6%), need of hospitalization in 325 cases (12.5%) or diagnostic assistance in 251 cases (9.6%). It was need of modifying antibiotic therapy in 1940 (74%), initiating in 530 cases (20%) and stopping in 153 (5.8%) cases. The antimicrobial stewardship activity required displacement in 573 cases (21.8%). In 1956 cases (74.5%), requests were given from the medical record. The stewardship's action was to modify antibiotic therapy in 996 cases (37.9%) and to start antibiotics in 505 cases (19.2%). No action was taken in 854 cases (32.6%). Conclusion: Our results shows that there is a great request for antimicrobial stewardship. Our intervention made it possible to start or modify antibiotic therapy in more than half of the cases, confirming importance to reinforce the antimicrobial stewardship activity in our hospital.

OS 5-2 Impact of early antibiotic therapy (EAT) on outcome of patients with sepsis at the Emergency Room of National Kidney and Transplant Institute Irene Rosellen P. Tan*, Myrna T. Mendoza. National Kidney and Transplant Institute, East Avenue, Diliman, Quezon City, Philippines

Background: In the surviving sepsis campaign published last 2013, an Early Goal-Directed Therapy (EGDT) was recommended. This emphasized specific bundles of care including antibiotic administration within the first hour of sepsis recognition and collection of blood culture prior to antibiotic initiation. Through the years, several foreign multicenter trials challenged these recommendations with contrasting results. There is no local study determining compliance to the specific recommendations that are applicable in the local setting. For these reasons, this study was conceptualized.

Methods: This 2-year retrospective cohort study included patients at the ER diagnosed with sepsis, severe sepsis and septic shock based on standard definitions. Patients were grouped based on timing of antibiotic initiation from sepsis recognition into the following groups: (1) Early Antibiotic Therapy (EAT) group (within 3 hours) and (2) Control Group (>3 hours). Primary outcomes are in-hospital mortality, time-to-antibiotics and extraction of blood culture prior to antibiotics. Secondary outcomes include length of hospital stay, use of vasopressors and mechanical ventilation and development of sepsis-related complications. A p value of <0.05 was considered significant to detect differences between the groups. Results: Two-hundred sixty-one patients were included with 53.26% overall mortality rate. The overall mean time-to-antibiotics is 5.92 hours and time-to-blood culture is 7.24 hours. Average timeto-antibiotics were ∼1.92 and ∼9.26 hours in the EAT and Control group respectively. Mortality was significantly higher in the control group (43.7% vs. 61.3%, p = 0.006). For the sepsis-related complications, more patients in the EAT group developed acute kidney injury ( p = 0.033). Acute respiratory failure ( p = 0.009) was significantly increased in the control group. Conclusion: Early initiation of antibiotic therapy within 3 hours from sepsis recognition demonstrated decreased mortality risk. Timing of antibiotics and collection of blood cultures were delayed compared to current recommendations. Among the sepsis-related complications, prolonged time-to-antibiotics (>3 hours) is associated with development of acute respiratory failure and subsequent need for mechanical ventilation.

Compliance with guidelines and appropriateness of antimicrobial prescribing in Australian hospitals Rodney James*, Kirsty Buising, Karin Thursky. National Centre for Antimicrobial Stewardship, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC 3000

Background: The Hospital National Antimicrobial Prescribing Survey is an auditing platform that enables facilities to determine the compliance with guidelines and appropriateness of their antimicrobial prescribing. All Australian Hospitals participate and the survey has been collecting prescribing data since 2011. Methods: Data from 385 facilities and 562 surveys which were submitted between January 1st 2015 to December 31st 2016 were analysed. The top 10 indications for which antimicrobials were prescribed, whether they were compliant with guidelines and their appropriateness were determined. Australia has a national set of prescribing guidelines for the use of antimicrobials and prescriptions were assessed against these, or local guidelines if available, and the appropriateness determined with use of an assessment guideline. Results: A There were 36,502 antimicrobial prescriptions analysed and top indication for prescribing antimicrobials was community acquired pneumonia with 5,933 prescribed, representing 16% of the total antimicrobials prescribed. The majority of these were compliant with guidelines (63%) with 38% deemed inappropriate. The indications with the highest proportion of compliance with guidelines were oral-oesophageal candidiasis (78%), followed by aspiration pneumonia (66%). The indications with the highest proportion of inappropriate prescribing were infective exacerbation of chronic obstructive pulmonary disease (87%), followed by trauma (65%). were gram positives), anaerobics (n = 12), and fungi (n = 2). As the primary therapy, 72.7% used antibiotics and drainage, 13.1% underwent surgery, and 14.1% treated with only antibiotics. As the initial antimicrobial agents (within 5 days), carbapenems were the most frequently used (n = 44), followed by beta-lactamase inhibitor combined penicillins (n = 40). The 60-day mortality was 5.9% (n = 6), the median length of hospital stay was 26 days, and the median duration of intravenous antibiotics was 26 days. High CCI score was significantly associated with a poor 60-day mortality (p = 0.033). There was no significant advantage of carbapenems compared to other antibiotics, regarding the outcomes of empyema. The incidence of side effects related to antibiotics was 13.1%, where liver dysfunction was the most commonly seen (n = 10). The frequency of escalating antibiotics was significantly decreased ( p = 0.009) in empyema patients who were administered the appropriate dose of antibiotics (n = 62), and side effects were not increased in those patients. Conclusion: Carbapenems did not have the advantage in the treatments of empyemas regarding outcomes we have evaluated.

The appropriate dosage of antibiotics may reduce unnecessary escalation of antibiotics in treating empyema patients.

OS 5-5

The impact of an antimicrobial stewardship ward round in cardiovascular surgical intensive care unit Ling-Ju Huang 1,6 *, Fu-Der Wang 2,6 , Jo-Ing Ku 3 , Tung-Ying Li 4 , Yu-Jiun Chan 4,7 , Yueh-Ching Chou 5 , Ching-Hung Chen 5 . Background: Japanese government established national action plan on antimicrobial resistance (AMR plan) in 2016, which aimed to reduce drug-resistant microorganisms and specific antimicrobials. Main purpose of AMR plan is 50% reduction of third generation oral cephalosporins (3G-OC) and fluoroquinolones (FQs), compared to 2013. We have started face to face conference of surgical prophylaxis appropriateness with 10 departments since 2016, thus we evaluated the effectiveness of the intervention for reduction of antimicrobials.

Methods: We evaluated the total amount of 3GC-OC, and oral FQs in Nagoya University Hospital since 2013 to 2016. Total amount of in-hospital, out-patient, and total prescriptions by years were extracted from pharmaceutical department system. Results: Table 1 Recognizing the challenges faced by prescribers, the Antibiotic Stewardship Program (ASP) developed a Best Practice Advisory (BPA) based on institutional broad-spectrum antibiotic policy and international clinical practice guidelines. Incorporated within our electronic medical record system, the BPA consists of a set of indications for each broad-spectrum antibiotic, making information more accessible to prescribers. The BPA system should promote appropriate antibiotic utilization. By utilizing information from the BPA and ASP audit findings, we seek to evaluate prescribers" knowledge on the indication of antibiotics they have prescribed. Methods: When prescribers order a broad-spectrum antibiotic, a BPA displaying a list of indications appears. They would then have to select an indication to complete the order. Indications selected by the prescribers and appropriateness assessed by ASP were compared. Significance of proportions was calculated by hypergeometric probabilities and Z-scores as appropriate.

Results: Of the 1330 courses of the antibiotics audited, prescribers had selected an indication for 1052 (79.1%) orders. Allergy or intolerance to other β-lactam antibiotics was selected by the prescriber for 11 orders, but 5 of these were discordant with the assessment done by the ASP (hypergeometric p(x < 4) = 0.04912). Clinical failure of narrow-spectrum antibiotics was selected for 179 courses, but 54 [z-score = 3.40 p = 0.0007, 95% CI (23.54%, 37.46%)] of these courses were started empirically. To understand the resistance mechanism, risk of resistance dissemination, and to further prevent and control DAP-R S. aureus, DAP-R strains were generated in vitro, and their biological adaptations were studied. Methods: Three DAP susceptible S. aureus strains, Pre3 (MRSA, ST239-t037), Pre5 (MRSA, ST239-t037), and Pre14b (MSSA, ST188-t189), were isolated from patients with bloodstream infections, and serially passaged in MH broth with a gradient of DAP concentration to select for resistant mutants. We investigated the antimicrobial susceptibility profile, the growth kinetics, fitness measurements, serum tolerance and phenotypic of both wild-type and mutant strains. Differences in genomic background of wildtype and mutants were also analyzed using whole genome sequencing.

Results: Highly DAP-R mutants were obtained after screening for 34 passages. The DAP MICs increased from 0.5 μg/ml in the parent strains to 16 μg/ml in the mutants, which remained tolerant to 4 μg/ml of DAP for more than 160 generations. The growth of the three mutant strains was slower than that of the parent strains, with competitive index of 0.652, 0.808 and 0.850, respectively. Compared with parent strains, in vitro serum tolerance of the mutants significantly decreased, and the same trend was also observed in lethality and pathogenicity in mice (P<0.01). Transmission electron microscopy and flow cytometry demonstrated that the cell walls of the mutants were markedly thicker than those of the parent cells (38.6% vs. 75.4%). Furthermore, a striking decrease in cell membrane potentials was found in only one mutant (28.3%), but it increased in the other two, with 46.1% and 292.5%, respectively, compared with the parent strains. Mutations in mprF (L822F/T345A), walK (Y225N/F473I) and GraS (G155A) were found in mutants.

The DAP-R mutants were stably maintained with an adaptive fitness cost in this study, indicating its potential to become wide-spread. Moreover, a series of gene mutation may play a role in DAP-R, which should enhance our awareness.

Background: Clostridium difficile infection (CDI) has reached an epidemic state in many developed countries with high incidence and severe disease, in not only traditional healthcare settings but also in the community. The binary toxin positive epidemic strain PCR ribotype (RT)027 has caused many outbreaks and remains prevalent in North America. This strain has never established in Australia, however, recently there have been reports of an increase in frequency of CDI due to other strains that produce binary toxin. One such strain that has increased in prevalence Australia-wide is RT251. Herein, we phenotypically characterised RT251 strains isolated in Australia from 2010 until 2015. Further, high resolution comparative genomics was used to ascertain the evolutionary history and likely geographic origin of this lineage. Methods: C. difficile RT251 strains in Australia (n = 93) were isolated by toxigenic culture. American RT251 strains (n = 31) were supplied by TechLab ® Inc. Genetic characterisation was performed using techniques including; toxin gene profiling, whole genome sequencing (WGS), in silico multi-locus sequence typing (MLST) and core genome single nucleotide variant (SNVs) analyses. Antimicrobial resistance was determined using an agar incorporation method (n = 15), in vitro toxin production was confirmed by Vero cell cytotoxicity assay (n = 13) and pathogenicity was observed in a murine model (n = 1), on a selection of isolates.

Results: WGS and MLST clustered RT251 in the same evolutionary clade (clade 2) as RT027. Core genome analyses revealed a group of clinical RT251 strains from Australia (n = 5) to be highly clonal, separated by 0-5 SNVs. Notably, these strains also shared a recent evolutionary history (<9 SNVs, many indistinguishable 0 SNVs) with another cluster of Australian RT251 strains (n = 9) isolated between December 2011 and July 2012. Remarkably, all Australian strains shared a common ancestor with a strain from Virginia, USA, isolated in 2012 (2-7 SNVs), indicating this lineage was of North American origin. All isolates were susceptible to metronidazole and vancomycin; one showed clindamycin and erythromycin resistance (MIC 8 mg/L and ≥256 mg/L, respectively Background: Tuberculosis (TB) incidence in Osaka city is high and homeless people are at higher risk due to malnutrition and poor living conditions. Osaka city has been promoting priority measures in TB control, such as free TB examination in the public. Nevertheless, there are still homeless people who do not undergo TB examination. This study aims to explore knowledge, attitude, and behavior towards TB examination among various groups of homeless people in Osaka city, Japan, and to identify the barriers and facilitators to TB examination among them. Methods: It was an exploratory qualitative study using in-depth interviews (IDIs) guided by semi-structured questionnaire. Study was conducted during July-November 2016. We targeted current and previous homeless people, over the age of 18 in Osaka city. Recruitment was carried out through purposive sampling, theoretical sampling and snowball sampling. We used thematic analysis with investigator triangulation for data analysis. Results: We conducted 58 IDIs. Among the 47 currently homeless people, 21 (44.7%) had TB examinations within the past year. 36 codes within 10 "categories" have emerged.

Barriers for undertaking TB examination were due to "living with the highest priority for survival", "feel of guilty has demotivated them health seeking", "lack of information due to social isolation", "uncertain information from other homeless people", "lack of knowledge and low risk perception", and "poor TB examination accessibility". Facilitators for undertaking TB examination included "adaptation to homeless life", "information network access", and "use of homeless support services that obligated them to take TB examination". "Correct knowledge and high risk perception" may reinforce their intention to continue TB examination with "the experience of free and user-friendly TB examination". Conclusion: Expanding of incorporating TB examination into various homeless support services and educational intervention during TB examination may be an effective measure. In addition, improving of TB examination accessibility and the provision of information for isolated homeless people, which is based on current homeless support services, are recommended. Background: Colistin is considered as the last resort to treat carbapenem-resistant Enterobacteriaceae infections, and its increase in resistance is a global concern. Plasmid mediated colistin resistance gene, mcr-1, has been found in distinct bacterial species from human, animals and environment. Furthermore, mcr-1 has been reported in several animal-origin isolates. Methods: Samples were collected from swine farms, cattle farms and broiler farms in four provinces (Jilin, Shandong, Henan and Guangzhou) of China in September 2016. All isolates were investigated by antimicrobial susceptibility testing and polymerase chain reaction for resistance genes screening (bla NDM , bla KPC , bla IMP and mcr-1). S1-PFGE and Southern blotting hybridization were used to determine the plasmid location of resistance genes. We also performed conjugation assays to test transferability of mcr-1 or bla NDM -bearing plasmids and further assessed biological costs of plasmid carriage by growth curve assay. coli also demonstrated resistant to polymyxin B, in which mcr-1 and bla NDM were coexistence. Most of these resistant genes located on plasmids, with sizes ranging from 40 to 244kb. 76.9% of mcr-1 located on IncI2 plasmid of roughly 65kb. The mainly type of carbapenemase was bla NDM-9 (13/26), which located on a non-typeable plasmid of approximately104kb. Growth curves of transconjugants carrying mcr-1 or/and bla NDM-9 showed an advantaged fitness than recipient.

Conclusion: mcr-1 was widespread in E. coli and K. pneumoniae isolated from farms in China. Resistance rates of antimicrobial, especially polymyxins and carbapenem, showed an extremely higher in one area, indicating antimicrobial resistance bacteria can spread from an infected individual to the whole farm. Co-existence of mcr-1 and bla NDM-9 was identified in various sequence types of E. coli with low fitness cost, suggesting an urgent need to enhance clinical infection control for decreasing dissemination. Results: See Table. Intracellular infection: a static effect was obtained for extracellular concentrations close (ciprofloxacin) or 5-6 times higher (meropenem, amikacin) than the MIC. Ciprofloxacin was more effective than the other drugs (higher reduction in the intracellular inoculum). Biofilms: ciprofloxacin was less potent (no reduction in viability at its MIC) and barely more effective (higher reduction in fluorescence signal) than the other drugs. In both models, eradication of bacteria was incomplete. Conclusion: Globally, antibiotics were unable to eradicate infection in these models. Poor bacterial responsiveness may contribute to explain therapeutic failure and recurrence of infections.

In vitro activity of cefiderocol against Objectives: This study was aimed to investigate the in vitro activities of cefiderocol (S-649266), ceftazidime-avibactam, ceftolozane-tazobactam, and other comparative drugs against Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia isolates associated with bloodstream infections.

Methods: A total of 300 isolates of P. aeruginosa (n = 100), A. baumannii (n = 100) and S. maltophilia (n = 100) collected from 300 patients with bacteraemia were evaluated. Minimum inhibitory concentrations (MICs) of these isolates to 11 antimicrobial agents were determined by the broth microdilution methods.

Results: All A. baumannii and more than 60% of P. aeruginosa isolates were not susceptible to meropenem. The MIC (mg/L) ranges of cefiderocol, ceftazidime-avibactam, and ceftolozanetazobactam were ≤0.03-4, 1-64, and 0.25-8 respectively, for P. aeruginosa; 0.06->64, 16->64, and 1->64, respectively, for A. baumannii; and ≤0.03-0.5, 2->64, and 1->64, respectively, for S. maltophilia. The MIC 90 (mg/L) of cefiderocol, ceftazidimeavibactam, ceftolozane-tazobactam, tigecycline, and colistin were 1, 16, 2, >4, and 2, respectively, for P. aeruginosa; 64, >64, >64, 4, 4, respectively, for A. baumannii and 0.25, >64, >64, 2, >8, respectively, for S. maltophilia. Conclusion: Cefiderocol exhibited more active in vitro activities than ceftazidime-avibactam, ceftolozane-tazobactam, tigecycline, and colistin against S. maltophilia and P. aeruginosa isolates. Cefiderocol showed equivalent activities with ceftazidimeavibactam and ceftolozane-tazobactam against meropenemresistant A. baumannii isolates. Background: Oral candidiasis is an independent prognostic factor that can determine the progression of HIV infection. Widespread and repeated use of azole drugs has been implicated as the reason for the emerging fluconazole resistance in Candida strains. The K21 compound is an ethoxylated version of quaternary ammonium silane, with various antimicrobial properties which exhibits no toxicity on human cells. This study aimed to evaluate K21 as a possible antifungal agent against fluconazole-resistant Candida strains.

Methods: An in vitro study was conducted by testing K21 compound against 122 fluconazole-resistant oral Candida isolates collected from HIV+ patients which included C. albicans (n = 107), C. glabrata (n = 12), C. krusei (n = 2) and C. dubliniensis (n = 1). The antifungal susceptibility testing was done by broth microdilution assay in 96 well microtitre plates containing RPMI media. The compound concentration used in the study ranged from 0.98-249.9 µg/mL. The plates were incubated at 37°C for 24 hours and the MIC values were read using a spectrophotometer at 450 nm. 

Background: Neisseria gonorrhoeae (NG) is the principal pathogen for patients with male urethritis. The guidelines recommend ceftriaxone as the first-line treatment regimen against gonococcal urethritis. Currently, the antimicrobial resistance of NG is a problem not only for fluoroquinolones but also cephalosporines worldwide. Thus, we are only able to use a limited number of antimicrobial agents. To date, there have been few reports about Table: (abstract OS 7-5) MICs of FRPM and MEPM +: positive for colonies, none: negative for colonies. the antimicrobial susceptibility of NG to carbapenem and none for faropenem. Therefore, we tried to evaluate them. Methods: We used 23 strains of NG obtained from patients with male urethritis at surveillance in Japan. According to the guidelines of the CLSI, we evaluated the minimal inhibitory concentrations (MICs) of FRPM and MEPM for NG by agar plate dilution methods without cysteine. Results: The (MIC) of FRPM was 1 μg/mL for both the MIC50 and MIC90. The range of the MIC was from less than 0.25 μg/mL to 1 μg/ mL. The MIC50 and MIC90 of MEPM were both less than 0.25 μg/ mL. The MIC was less than 0.25 μg/mL. Conclusion: The breakpoint of FRPM or MEPM for NG has not been defined. Those of cefpodoxime, cefixime and ceftriaxone are 0.5, 0.25, 0.25 μg/mL, respectively. MICs of FRPM were slightly high and those of MEPM were relatively low. In the treatment of NG, because we need to use alternative regimens in the current situation, we have to look for potential therapeutic agents.

OS 7-6 A population-based cohort study on the drug specific effect of statins on sepsis outcome Meng-tse Gabriel Lee 1 , Tzu-Chun Hsu 1 , Lorenzo Porta 2 , Shy-Shin Chang 3 , Chia-Hung Yo 4 , Kuang-Chau Tsai 4 , Matthew Lee 5 , Chien-Chang Lee 1 *. Background: Whether statin treatment, proved by recent experimental studies to have an antimicrobial activity, exerts a drug or a class specific effect in sepsis remains unknown. Methods: Short-term mortality in sepsis patients was analyzed using data from the National Health Insurance Research Database. Use of statins was defined as the cumulative use of a specific statin (atorvastatin, simvastatin or rosuvastatin) for more than 30 days prior to the index sepsis admission. We determined the association between statin and sepsis outcome by multivariate-adjusted Cox models and propensity score (PS) matched analysis, using a 1 Background: Penicillinase-resistant penicillins (cloxacillin, oxacillin and nafcillin) are the first-line therapy for methicillinsusceptible Staphylococcus aureus (MSSA) infections. However, these antibiotics are not available in Japan for commercial reasons. This situation creates challenges in terms of selecting de-escalation antibiotics when treating patients with severe MSSA infections (e.g., infective arthritis or infective endocarditis). In our hospital, in MSSA cases with sensitivity to ampicillin, we usually select ampicillin after confirming a negative result of a β-lactamase test. We report two cases in which ampicillin was successfully used to treat severe MSSA infections. Case 1: The patient was an 85-year-old woman whose chief complaints were fever and right buttock pain. A blood culture test disclosed MSSA with sensitivity to ampicillin. Hip joint MRI revealed inflammatory changes at the right hip joint, which suggested septic arthritis of the iliosacral joint. β-lactamase examination was negative. We changed antibiotics from ampicillin/ sulbactam and vancomycin to ampicillin alone as de-escalation. The treatment course was uneventful. After 4 weeks, she was switched from ampicillin to oral amoxicillin. She was discharged. Case 2: The patient was an 83-year-old woman whose chief complaint was fever. A petechial hemorrhage was observed on the right palpebral conjunctiva. Roth spots were present on the fundus of the eyes. A pansystolic murmur with Levine III/VI on apex was noted. Blood culture test disclosed MSSA with sensitivity to ampicillin. An echocardiogram revealed a vegetation 5 mm in diameter on the center of the posterior leaflet of the mitral valve. Infective endocarditis was diagnosed. Infectious brain aneurysm of left cerebellum was suspected on MRI. β-lactamase examination was negative. We changed antibiotics from cefazolin to ampicillin as de-escalation considering the possibility of ampicillin transitioning to the central nervous system. The treatment has been uneventful thus far. Conclusion: In cases of MSSA with sensitivity to ampicillin, when penicillinase-resistant penicillins are unavailable, ampicillin may become a treatment option once negative β-lactamase test results are confirmed.

In vitro synergistic activities of rifabutin with clarithromycin, imipenem-cilastin and tigecycline against the Mycobacterium abscessus complex Aristine Cheng, Yi-Tzu Tsai, Chien Jung-Yien, Po-Ren Hsueh, Wang-Huei Sheng, Yee-Chun Chen, Shan-Chwen Chang. National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan Background: Mycobacterium abscessus is an intrinsically multidrug-resistant pathogen which has emerged as a global threat among lipotourists, chronic lung disease and auto-interferon gamma antibody producing patients. A recent study has shown that surprisingly, rifabutin, in contrast to rifampin, is active against the M. abscessus complex in vitro especially against clarithromycin resistant strains and may be considered for treatment of M. abscessus disease. Exploring synergy between active available drugs is rational given the lack of new active drugs. Methods: We tested for in vitro synergy between rifabutin and 11 antimicrobials that are often used in combinatorial therapy for rapidly growing mycobacteria in reference and clinical isolates that were molecularly identified as subspecies of the M. abscessus complex using the checkerboard method. of M. abscessus subsp. massiliense isolates, and for rifabutin and tigecycline in 100% of M. abscessus subsp. massiliense isolates, with fractional inhibitory concentrations of <0.5. The combinations of rifabutin with amoxicillin-clavulanic acid, doxycycline, moxifloxacin or clofazimine were neither synergistic nor additive whereas the combinations of rifabutin with amikacin, linezolid, cefoxitin or ceftibutem were synergistic in ≤33% M. abscessus subsp. massiliense isolates. No rifabutin based combinations demonstrated antagonism. Conclusion: The safety and tolerability of adding rifabutin to standard clarithromycin, or imipenem-cilastin or tigecyclinecontaining regimens should be tested in clinical trials, and the results of susceptibility tests for rifabutin and its combination merit clinical validation for treating M. abscessus disease.

OS 8-1 Capsular serotype and polysaccharide production in hypervirulent K. pneumoniae strains from bacteremia in Japan Michinobu Yoshimura 1,2 , Atsushi Togawa 1 *. Background: Hypervirulent (HV) K. pneumoniae strains are associated with invasive syndromes such as liver abscess. We assessed the effect of capsular serotypes on the induction of HV and mucoid phenotypes and the effect of these phenotypes on the production of capsular (lipo)polysaccharides. Methods: A retrospective study of K. pneumoniae bacteremia cases was conducted in a 900-bed tertiary-care university hospital in Japan. String test was performed on all isolates to find HV strains. Mucoid phenotype was determined by visual inspection of colonies. Expression of capsular serotypes K1/K2 and magA/rmpA genes were determined by PCR. Clinical manifestations were collected from medical records. Results: A total of 134 patients with K. pneumoniae bacteremia was identified during the study period. 8% of isolates were determined as HV strains, and serotype K1 was predominant in these strains ( p = 0.004). In serotype K1-positive strains, both HV and mucoid phenotypes were observed more often than K1-negative strains (p ≤ 0.0001). However, by logistic regression analysis, mucoid phenotype was independently associated with serotype K1 (odds ratio, 7.73; 95% confidence interval, 1.44-40.81) . MagA and rmpA gene expression was strongly associated with serotype K1 ( p < 0.0001). Both HV and mucoid phenotypes were associated with overproduction of capsular polysaccharides (Figure 1 ). Liver abscess formation was strongly associated with the mucoid phenotype (odds ratio, 41.15; 95% confidence interval, 5.85-835.41) but not with the HV phenotype. Serotype K2 was not associated with either bacterial phenotype or liver abscess formation. Conclusion: Serotype K1 was a significant virulence factor for invasive syndromes through the induction of the mucoid phenotype and overproduction of capsular polysaccharides in K. pneumoniae bloodstream infection. Background: Natural history studies of HIV infection in pregnancy show that, prior to antiretroviral therapy, 25% of infants born to HIV-infected mothers become infected with HIV of which 5% are in-utero infections. The macrophage -tropic viral strain of HIV-1 (R5 virus) is the most commonly vertically transmitted strain. There is evidence of strong HIV-1 specific T-cell responses in the cord and peripheral blood of exposed-uninfected neonates. However, the exact mechanism of prevention of mother-to-foetus transmission (MFT) and, in particular, the role of macrophages remains unknown. The aim of the study was to determine whether placental macrophage are affected by highly active anti-retroviral therapy (HAART) administered to HIV positive women during pregnancy. Methods: Placentas from seven HIV-infected women receiving HAARTand 3 non-infected women were obtained within two hours of delivery, fixed in formalin and embedded in paraffin. 5 μm representative tissue sections were cut from representative areas of the placenta including the maternal surface and chorionic plate. To characterize the placental cells of macrophage phenotype, tissue sections were stained with the CD68 pan-macrophage antibody marker (CD68+ cells), Figure 1 . A section of intestine from a patient with Crohn's disease was included as a positive control. This sample exhibited a large number of CD68 strongly positive cells. Coded placental slides were evaluated by a histolopathologist experienced in placental pathology (PB) without knowledge of the patient's HIV status or transmission outcome. Results: Compared to healthy HIV-negative controls, foetal capillaries from test cases showed significantly reduced numbers of CD68+ cells (mean + SD; 14.6 + 8.4; 34.5 + 17.2, respectively, p = 0.03), Figure 2 . There was no difference in the numerical density of macrophage/monocytes within the villous stroma, trophoblast, and maternal vascular compartments between the two groups. Conclusion: The reduced frequency of macrophage in foetal capillaries of HAART -exposed placentas suggests regional differences in local placental immune selection. Such foetal "immune escape" may provide a protective mechanism against in-utero HIV transmission. Background: Antibiotic resistance is a mounting challenge in the modern era for which holistic treatment modalities could serve a solution. Ultra-high diluted Homeopathic medicines selected on the basis of symptom similarity acts favorably in very many infectious conditions under clinical settings. This pilot study attempts to study the action of commonly prescribed homeopathic medicines directly on the cultured MRSA isolate and concurrently testing the efficiency of same medicines in the diseased individual. Methods: 48 MRSA positive isolates from different clinical samples were isolated from using blood culture method. Few homeopathic medicines which were commonly prescribed for various infections were selected and sensitivity discs with those medicines were prepared as follows, 0.1cc of GMP standard homoeopathic dilutions were applied on 5 mm diameter sterile whatman filter paper and allowed to dry up completely. Samples from infections were cultured and bacterial strains were identified individually. Under sterile conditions Homeopathic sensitivity discs were fixed on bacterial culture plates and visible zones of inhibitions measured around each disc after incubation for 24 hrs. Results: Culture result showed Gram positive MRSA isolates. Homeopathic remedies showed zone of inhibition around the sensitivity discs. There were multiple sensitive drugs for same isolate. Conclusion: This pilot study suggests homeopathic medicines acts on in-vitro as well as in-vivo conditions which warrants further study. Background: Toxigenic strains of Clostridium difficile cause disease through production of the large clostridial toxins A and/or B. Nontoxigenic C. difficile [NTCD] strains do not produce either of these toxins and thus are considered clinically irrelevant. However, some strains of C. difficile, including NTCD, produce an ADP-ribosylating toxin [CDT] , the significance of which is unknown. These strains have recently been isolated from patients with severe diarrhoea, suggesting possible symptomatic infection due to CDT-NTCD. However, there are limited studies investigating the function(s) of CDT and its role in C. difficile infection. We sought to investigate the differences in virulence traits in toxigenic and CDT-NTCD C. difficile strains known to be prevalent in both animals and humans. Methods: Molecular typing experiments using three methods (PCR ribotyping/PCR-RT, multi-locus sequence typing/MLST and pulsedfield gel electrophoresis/PFGE) were performed on a diverse collection of 149 CDT-NTCD strains [humans n = 29, bovine n = 54, porcine n = 39, food n = 1, environment n = 26] to identify the best approach for typing these strains. Other phenotypic experiments performed included germination and sporulation assays, motility tests, cell cytotoxicity assays and assessment of pathogenicity in a murine model of infection. A subset of the CDT-NTCD strains underwent whole genome sequencing to identify genetic elements associated with survival and pathogenicity. Results: The diversity of the CDT-NTCD strains was best illustrated by PFGE, revealing three discrete pulso-types within one ribotype, however this method was labor intensive and irreproducible. All our isolates belonged to MLST Clade 5, a characteristic they share with the "hypervirulent" C. difficile lineage UK078. Motility studies showed that 94% of the CDT-NTCD strains were phenotypically non-motile [UK033, UK288, UK238] and had deletions in F2 [glycosylation genes] and F3 [early-stage flagellar genes] regions of their flagellar operons. Seven ribotypes [UK585, UK586, QX143, QX260, QX360, QX444 and QX521] were slightly motile but significantly less so than the reference strain R20291 and lacked the three glycosyltransferase genes [CD0241, CD0242 and CD0243] essential for C. difficile flagellum assembly and full motility. The flagellin and flagella cap genes, fliC and fliD, involved in adherence and host colonisation were conserved in all strains including reference strains. Genetic variations in cell surface proteins, Cwp2, Cwp66, Cwp84, SecA2 and SlpA, were also noted across different ribotypes. We confirmed toxicity of the CDT-NTCD C. difficile strains in Vero cells, however, this was not demonstrated in a mouse model of disease. Mice infected with CDT-NTCD strains all survived the infection despite detection of high numbers of spores [10 7 CFU/g] in the faeces at either 24hr or 96hr post-infection. They showed no signs of diarrhoea with the exception of mice infected with QX146 that had soft faeces/diarrhoea at 24 hours postinfection and weight loss. It is possible that the mouse model does not adequately demonstrate disease due to CDT-NTCD C. difficile strains.

Conclusion: This study provides the first in-depth analysis of CDT-NTCD C. difficile strains and contributes to the currently limited knowledge of these strains and their potential role in C. difficile disease.

OS 8-5 Pathogenic role of stringent response in oxidative stress response and biofilm formation of Helicobacter pylori Shigeru Kamiya, Hideo Yonezawa, Takako Osaki, Tomoko Hanawa. Department of Infectious Diseases, Kyorin University School of Medicine, Mitaka, Tokyo, Japan

Background: It has been reported that stringent response is a global bacterial response to nutritional limitation that is mediated by the accumulation of cellular (p)ppGpp (guanosine tetra-and penta-phosphate). ( p)ppGpp is synthesized by RelA and/or SpoT, and hydrolyze by SpoT, bifunctional enzyme. In the case of, H. pylori, SpoT is the only enzyme involved in synthesis and hydrolysis of ( p)ppGpp. Methods: In the present study, spoT isogenic mutants (ΔspoT) of H. pylori strains (TK 1049 and TK1402) were generated: fragment containing spoT::cat allele was constructed by PCR overlap extension and was used to disrupt the target gene by homologous recombination.

Results: There was no significant difference in the growth rates under nutrient rich conditions between ΔspoT mutants and their parental strains. Oxidative stress responses of ΔspoT mutants and their parental strains were evaluated. Although there was no significant difference in the sensitivity to hydrogen peroxide between ΔspoT and parental strains, ΔspoT strains were much more sensitive to active oxygen than parental strains. Biofilm forming ability of ΔspoT and parental strains was evaluated by conventional Crystal violet procedure. Biofilm formation by ΔspoT stains, particularly TK1402 ΔspoT strain, was significantly decreased compared to that by its parental strain. Conclusion: These results imply that the stringent response is involved in pathogenesis in H. pylori infections.

Chimeric virulence and antimicrobial-resistant plasmid pOU7519 in Salmonella enterica serovar Choleraesuis Chyi-Liang Chen 1 , Rajendra Prasad Janapatla 1 , Cheng-Hsun Chiu 1,2 *. Background: Zoonotic Salmonella enterica serovar Choleraesuis (S. choleraesuis), causing paratyphoid in pigs as well as bacteremia and mycotic aneurysm in humans, may carry a virulence plasmid ( pSCV50) and sometimes an antimicrobial-resistant plasmid. The aim of this study is to decipher the likely mechanism of how a virulence-resistance chimera of plasmid pOU7519 forms in S. choleraesuis. Methods: Whole plasmid sequence of pOU7519 in S. Choleraesuis strain OU7519 was determined using shotgun cloning and sequencing. Sequence annotation and comparison were performed to determine the sequence responsible for the formation of a chimeric virulence-resistance pOU7519. Other chimeric plasmids in the clinical S. Choleraesuis isolates were also examined. Results: The sequence of pOU719, 127,212-bp long, was identified to be a chimera of virulence pSCV50 and multidrug-resistant pSC138, that are found in S. Choleraesuis strain SC-B67. The pOU7519 contains various mobile DNAs, including prophages, insertion sequences, integron and transposons, especially the complex Tn21-like transposon Tn6088. By dissecting the junction site of the pSCV50-pSC138 chimera in pOU7519, defective sequences at integrase gene scv50 (int) and its attachment site (att) were found, and that likely resulted in a stable chimera plasmid due to the failure of excision from the pSCV50-pSC138 chimera. Similar structure of chimera was also found in other large plasmids of S. Choleraesuis. Conclusion: The deletion of both the int and att sties appeared to block chimera excision, and thus to generate an irreversible, stable pSCV50-pSC138 chimera. The genetic variation of virulence and antimicrobial-resistant plasmids poses a health risk to general public.

OS 8-7 Solithromycin inhibits MUC5AC production induced by Streptococcus pneumoniae and Haemophilus influenzae in human airway epithelial cells Kenji Ota 1 , Norihito Kaku 1 , Kosuke Kosai 1 , Naoki Uno 1 , Hiroo Hasegawa 1 , Taiga Miyazaki 2 , Koichi Izumikawa 3 , Hiroshi Mukae 2 , Katsunori Yanagihara 1 . 1 Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan, 2 Department of Respiratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan, 3 Department of Infectious Diseases, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan

Background: Solithromycin (SOL) is a novel macrolide with broad spectrum and has potent anti-inflammatory effects, which might be beneficial in treatment of community-acquired bacterial pneumonia. Previous studies have elucidated that macrolides inhibit MUC5AC overexpression as its immunomodulatory effect. The purpose of this study is to reveal the anti-inflammatory effect of SOL by inhibition of bacteria-induced MUC5AC overproduction. Methods: We used Streptococcus pneumoniae (Sp) lysate and Haemophilus influenzae (Hi) lysate to induce MUC5AC hypersecretion. H292 and A549 cells were cultured in liquid medium and grown in an incubator. After overnight serum starvation, cells were stimulated with various concentrations of lysate for 24 hours. In inhibition study, the cells were treated with SOL simultaneously with stimulation. In each study, the MUC5AC protein levels were measured by the enzyme-linked immunosorbent assay (ELISA). Results: H292 and A549 cells were stimulated by 5, 10, 15, 20, and 25 μg/mL of Sp and Hi lysate, respectively. In H292 cells, Sp lysate induced MUC5AC production most significantly at 15 μg/mL (220.0 ± 54.1%; P < 0.001), and Hi at 15 μg/mL (170.8 ± 47.3%; P < 0.001). In A549 cells, Sp at 15 μg/mL (98.1 ± 35.7%; P < 0.001), and Hi at 15 μg/mL (184.6 ± 25.2%; P < 0.001). In inhibition studies (Figure 1) , SOL inhibited MUC5AC production in H292 cells induced by Sp and Hi most significantly at concentrations of 50 μg/mL (47.0 ± 13.9% versus 3.0 ± 13.5% [P < 0.01] and 32.8 ± 28.6% versus −10.9 ± 20.7% [P < 0.05], respectively). Similarly, SOL inhibited MUC5AC production in A549 cells induced by Sp and Hi most significantly at concentrations of 100 μg/mL (101.9 ± 85.7% versus −24.6 ± 22.4% [P < 0.01] and 115.2 ± 40.3% versus −14.3 ± 10.3% [P < 0.001], respectively). Conclusion: SOL showed anti-inflammatory effects by inhibition of MUC5AC production induced by Sp and Hi in H292 and A549 cells. This is the first study to reveal the immunomodulatory effect of SOL on human airway epithelial cells using bacterial stimulations. prophylaxis for colorectal surgery. However, there is little known about long-term effects of oral antibiotics on the bacterial flora in a surgical ward. Between Nov. 2007 and Dec. 2012 we have performed a randomized controlled trial to verify the efficacy of oral antibiotic prophylaxis in patients undergoing colorectal surgery (JMTO PREV 07-01). That trial concluded oral antibiotic prophylaxis reduced the risk of SSIs. Depending on the results, we have used oral antibiotic prophylaxis (kanamycin and metronidazole) to all patients undergoing colorectal surgery except patients with contraindication. In this study we investigated effects of oral antibiotic use for 10 years on the bacterial flora in our surgical ward. Methods: We retrospectively collected reports of all culturepositive specimen submitted from our surgical ward from Jan. 2012 to Dec. 2016. The frequencies and trends of bacteria were examined. Results: A total of 2281 organisms were identified. The top seven isolated organisms were E. coli (352/2281: 15.4%), Klebsiella pneumoniae (220/2281: 9.6%), Enterococcus faecalis (219/2281: 9.6%), Pseudomonas aeruginosa (193/2281: 8.4%), Enterobacter cloacae (167/2281: 7.3%), Staphylococcus aureus (118/2281: 5.1%), Enterococcus faecium (72/2281: 3.2%). Six species except E. faecium were consistent with the seven major species of bacteria reported in the national surveillance studies in Japan. These results seem that the oral antibiotic prophylaxis did not affect the bacterial flora isolated in our surgical ward. The annual trends in the proportion of isolated organisms were as follows: E. coli (2012: 14.1%, 2013: 16.6%, 2014: 16.2%, 2015: 14.9%, 2016: 15.5%), K. pneumoniae (7.3%, 9.1%, 9.9%, 16.0%, 10.4%), E. faecalis (11.4%, 7.5%, 7.7%, 13.2%, 8.3%), P. aeruginosa (7.3%, 6.0%, 13.1%, 10.8%, 7.8%), E. cloacae (6.9%, 4.8%, 10.2%, 6.3%, 13.0%), S. aureus (4.1%, 5.4%, 8.2%, 2.4%, 6.2%). These data did not show any significant changes of specific organisms over five years. Conclusion: Oral antibiotic prophylaxis use over years may not affect the bacterial flora in our surgical ward. Background: Cancer patients are often admitted to intensive care unit (ICU) due to vulnerable health condition and they are susceptible for colonization or infection. This study aims to address the long-term impact of having positive culture results during admission on one-year mortality among cancer patients who were admitted to ICU. Methods: We conducted this retrospective cohort study in Taichung Veterans General Hospital (VGHTC). Adult patients with a history of cancer who had at least one ICU admission during 2011 and 2016 in VGHTC after their cancer diagnosis were included. We included only the first ICU admission following cancer diagnosis (index ICU admission). Data regarding cancer diagnosis, location, and treatment were retrieved from cancer registry and data of demographic information, ICU admission, diagnoses, culture results, and medications were pulled from electronic medical records. The exposure is positive culture result during the index admission. The outcome is the mortality within one year after the index ICU admission. We assessed Kaplan-Meier survival curves and compared the mortality between patients with positive culture results and patients without positive culture results using log-rank test. We used a multivariable Cox proportional hazards regression model to adjust for confounders and to evaluate the influence of positive culture results on one-year mortality. Results: We included 1,260 cancer patients who had at least one ICU admission following cancer diagnoses. Of them, 525 (41.7%) Figure: (abstract OS 9-1) had positive culture results during admission and 461 (36.6%) died within one year after ICU admission. Compared with patients who survived within one year after ICU admission, patients who died were significantly more likely to have positive culture results (33.0% vs 56.6%), to have a higher APACHEII score (median 21 vs 24), to receive mechanical ventilation (69.5% vs 83.1%), or to receive renal replacement (1.6% vs 7.2%). Kaplan-Meier survival analysis indicated that positive culture in blood, respiratory, or urine was associated with significantly increased one-year mortality (log-rank test p < 0.0001; Figure) , while positive culture in skin and soft tissue or abdomen had no impact. Multivariable Cox proportional hazard regression analysis showed that having positive culture in blood, respiratory, or urine (adjusted hazard ratio = 1.30; 95% confidence interval = 1.07-1.59) were significantly associated with 30% increased hazard of death within one year after the ICU admission, after adjusting for other factors. Conclusion: Having positive culture results during ICU admission may be associated with a poor long-term survival among critically ill cancer patients.

OS 9-3 Strict glycemic control to prevent surgical site infections in gastroenterological surgery in patients with and without diabetes mellitus Toshie Tsuchida 1,2 , Yoshio Takesue 2 , Kaoru Ichiki 2 , Kazuhiko Nakajima 2 , Takashi Ueda 2 , Motoi Uchino 3 , Hiroki Ikeuchi 3 . Background: Perioperative hyperglycemia is a risk factor for surgical site infections (SSI). Meta-analysis confirmed benefits of intensive protocol targeting <150 mg/dL for reducing SSI. The aim of this study is to evaluate the benefits of a strict glycemic control for reducing SSI in gastroenterological surgery in patients with and without diabetes mellitus (DM). Methods: Patients who underwent esophagectomy, gastrectomy, colon and rectal surgery, and hepatobiliary-pancreatic surgery in Hyogo College of Medicine were entered into the study. The highest blood glucose level (BG) within 24 hours after gastroenterological surgery was evaluated.

Results: A total of 1,555 patients was analyzed, and 155 patients (10.0%) had DM. The incidence of BG of >200 mg/dL was 73.5% in DM patients, and 22.4% in non-DM patients (>150 mg/dL: 94.2% in DM and 68.0% in non-DM, respectively). SSI rate was significantly higher in DM patients compared with non-DM patients (22.6% vs. 16.2%; P = 0.047). Unexpectedly, hyperglycemia was not a significant risk factor for SSI among DM patients [OR = 1.48 (95% CI, 0.13-16.74, P = 0.752) for >150 mg/dL; OR = 1.74 (95% CI, 0.65-4.67, P = 0.275) for >200 mg/dL]. By contrast, non-DM patients with a BG of >150 mg/dL were found to have increased odds of SSI [OR = 1.75 (95% CI, 1.20-2.54, P = 0.004) for >150 mg/dL; OR = 1.32 (95% CI, 0.94-1.86, P = 0.111) for >200 mg/dL]. In addition, a significantly increased risk of SSI was demonstrated in patients with 151-200 mg/dL and >200 mg/dL compared with the reference group (≤150 mg/dL) in non-DM patients. Conclusion: A target BG of <150 mg/dL is recommended in patients without DM who undergo gastroenterological surgery. Additional study is required to determine an optimal target blood glucose level in DM patients. As limitation of this study, a single maximal postoperative elevated BG was evaluated, and corrected BG with insulin therapy was not taken into account. Background: Antibacterial linen has been studied and used widely in many hospitals in the world but not yet used in Vietnam. Many hospitals in Vietnam are challenging with the high incidence of hospital acquired infections (HAIs). This study was conducted to estimate the effectiveness of antibacterial linen in reducing the incidence of hospital acquired infections.

Methods: Experimental study, controlled before and after intervention, to estimated the effectiveness of using antibacterial linen named NMS, coated in antibacterial resin solution. Study was Figure: (abstract OS 9-2) One-year survival curves of patients with and without positive blood, respiratory, or urine cultulre restuls.

conducted at the intensive care unit of burn department and tropical diseases department in two periods, before interventionusing normal linenfrom January 2013 to May 2013 and after interventionusing antibacterial linenfrom June 2013 to December 2013. The purpose of this study was to estimate and compare the incidence of HAIs, the density of bacteria on linen and in the air of patient rooms in two periods.

Results: There were totally 190 patients in each period, there is no difference regarding clinical characteristics between 2 patient groups. In period after intervention, when using antibacterial linen, the incidence of HAIs decreased from 34.3% to 24.7%; the rate of positive culture on healthcare workers' uniforms decreased from 81.2% to 48.0%; the rate of positive culture on patients' uniforms and bed sheets decreased from 91.6% to 75.9%. Background: The population pyramid is shifting towards an increased elderly population. Elderly persons are facing underlying diseases and a decrease in their biological defense mechanism, bringing about the need to optimize anti-bacterial treatment for the elderly. We focused on very elderly patients, which has rarely ever been studied before.

Methods: 203 elderly patients over the age of 65 hospitalized with infectious diseases were retrospectively analyzed from June 2012 to May 2016. Elderly patients were divided into two groups. One is the elderly patients from 65 to 84 years. The other group is the very elderly patients over 85 years.

Results: Infectious focuses consisted of pneumonia, urinary tract infection, sepsis, and multiple infections. The effectiveness of the initial antibiotic effect was 76% for the elderly, the very elderly 72%. The numbers was very similar, however, overall survival rates of the elderly after 50 days were 87% for the elderly, and very elderly displaying a significantly lower survival rate of 55% ( p = 0.002) ( Figure 1 ). After multivariate analysis of risk factors affecting survival prognosis, it was found that the adverse prognostic risk factors for the elderly were malignancy, COPD and the initial antibiotic effect (Table 1(a)) . Whereas, for the very elderly, risk factors included performance status, and the initial antibiotic effect (Table 1(b) ). For both elderly and very elderly, the initial antibiotic effect was associated to creating better outcomes. Background: Campylobacter fetus is a part of the commensal flora found in the gastrointestinal tracts of cattle, and it rarely causes human infections. C. fetus-infected aneurysm (CFIA) is rare but fatal infection. The clinical epidemiology, risk factors, and optimal treatment of CFIA are still unclear. Methods: We present a 67-year-old man who was diagnosed with C. fetus bacteremia with infected left common iliac artery aneurysm and spondylodiscitis, successfully treated with antibiotics and surgery. We also reviewed the English and Japanese literature using PubMed, and ICHUSI (http://www.jamas.or.jp) by the Japanese Medical Abstract Society on CFIA. An episode of CFIA was defined as a patient having an aneurysm with at least 1 positive blood culture and/or positive arterial wall specimen culture yielding C. fetus. Results: We identified 46 cases in the English and Japanese literature from 1971 to 2016, and our case was also included. Apparently, CFIA was most frequently reported in France (36%), followed by Japan (28%). The median age of the patients was 70 years (range, 45-91 years), and 91% were men. The patients presented with fever (68%), abdominal pain (32%), and diarrhea (21%). Underlying diseases were cardiovascular disease (32%), hypertension (21%), alcoholism (13%), malignancy (11%), diabetes mellitus (4%), and exposure to raw meat (4%). Antimicrobial agents were initially administered as follows: penicillins in 7 (21%) of 33 (missing data for 14 cases), aminoglycosides in 7 (21%), carbapenems in 6 (18%), and fluoroquinolones in 6 (18%) cases. The median duration of the antimicrobial therapy was 42 days. The overall mortality rate was 19%; however, this rate increased to 47% (7/15) in cases of CFIA with rupture. Regardless of the type of initial antimicrobial agents used, all patients undergone surgery before their aneurysm ruptured had a favorable outcome. Conclusion: To our knowledge, this is the largest literature review of CFIA. Our results suggest that prompt surgical intervention is the most favorable outcome in CFIA. Furthermore, the frequent reporting of cases of this aneurysm in France and Japan might be due to the habitual consumption of raw meat. However, further clinical and epidemiological investigations of CFIA, including dietary history are needed.

OS 10-2 Staphylococcus argenteus, an emerging pathogen of community-onset bacteremia associated with high mortality Chien-Yu Chi 1 , Hao Lee 2 , Shin-Hei Du 2 , Xiao-Mei Wang 3 , Tai-Fen Lee 2 , Chun-Hsing Liao 4 , Shey-Ying Chen 1 , Lee-Jene Teng 2,6 , Po-Ren Hsueh 2,5 . Background: Enterococcus faecalis is an important pathogen in community-acquired and nosocomial infections worldwide, and it is common in urinary tract, endovascular, intra-abdominal and wound infections. Most E. faecalis isolates are susceptible to βlactams and glycopeptides, and both of them were commonly used in E. faecalis bacteremia. However, the use glycopeptide therapy may lead to unnecessary adverse effects, excessive cost and emergence of glycopeptide resistant pathogens. There were limited data about an association between the choice of antimicrobial agent for E. faecalis bacteremia and outcomes. The objective of this study was to assess the efficacies of β-lactam versus glycopeptide therapy in E. faecalis bacteremia.

Methods: This retrospective analysis was conducted at a medical center in Taiwan. Adult patients with E. faecalis isolated from blood sample between Jan 2013 and Dec 2014 and who were treated with appropriate antibiotics were analyzed. Patients were classified as glycopeptide group or β-lactam group according to the major therapy which was defined as the effective antibiotic used for more than 3 days and for the majority of the time during the antibiotic course. The clinical features were compared between the two groups, and the primary outcome was 28-day mortality. The Cox proportional regression model and propensity score-adjusted multivariate analyses were used to explore factors associated with the primary outcome.

Results: A total of 108 patients were enrolled in the final analysis. Thirty-eight patients received glycopeptide therapy and 70 patients received β-lactam therapy. In the glycopeptide group, ICU admission, septic shock and mechanical ventilation were observed more frequently, and patients were associated with a higher APACHE II score. A higher 28-day mortality was observed in glycopeptide group [15/38 (39.5%) Background: Cerebral gumma is a rare complication of syphilis, usually presenting at a very late stage. As non-invasive diagnosis of brain mass lesion is difficult, those can be resected before definitive diagnosis. We experienced a human immunodeficiency virus (HIV) positive case of cerebral syphilitic gumma arising shortly after amoxicillin therapy. Methods: We made an operation, and the resected brain tumor was used for additional examination. Treponema pallidum immunohistochemical stain using rabbit purified IgG fraction polyclonal antibody and T. pallidum specific PCR (targeting polA and TpN47) for homogenized brain specimens were done. Later, T. pallidum DNA was analyzed for subtyping.

A 44 year-old male with general fatigue was diagnosed to have syphilis. He also had HIV infection with a CD4 count of 349/μL. Oral high dose amoxicillin was administered for eight weeks, followed by combined antiretroviral therapy. Six months later, he visited emergency room with brain mass lesion in the right temporal lobe. Partial lobectomy was performed with tentative diagnosis of glioblastoma by the frozen section. Later, we detected T. pallidum in the resected tissue, by PCR, immunostaining. The final diagnosis was cerebral syphilitic gumma caused by Treponema pallidum strain type 14b/f, a rare subtype. After operation, the patient recovered without complication and received additional ceftriaxone. Background: Environmental reservoir is an important source of multidrug-resistant Acinetobacter baumannii (MRAB) outbreaks. The role of post-outbreak environmental surveillance for guiding sustained control effort has not been examined. Methods: Enhanced environmental disinfection and regular environmental surveillance of ward communal areas after an outbreak were performed in a University-affiliated hospital. To assess the usefulness of environmental culture in predicting patients with MRAB, weekly surveillance of communal areas was continued for 3 months after the outbreak in intervention wards. Results: Eight (57.1%) of 14 patients' immediate surroundings and 5 (31.3%) of 16 communal areas were contaminated with MRAB at the start of the outbreak. With enhanced environmental disinfection and isolation of MRAB patients, communal areas were rendered culture negative for MRAB. Post-outbreak weekly surveillance of communal areas showed that identification of newly diagnosed MRAB patients was significantly correlated with preceding environmental contamination with MRAB ( p = 0.001). The incidence of nosocomial MRAB infection was significantly lower in the intervention as compared with non-intervention wards (0.55 vs 2.28 per 1000 patient-days, p = 0.04). All MRAB isolated from the environmental and patients' samples belonged to MLST ST457 and were blaOXA23-like positive. Conclusion: Environmental surveillance may serve as a surrogate marker for the presence of MRAB carriers. Implementation of timely infection control measures should be guided by environmental culture for MRAB to minimize the risk of MRAB outbreak. Two clonally related and 3 diverse K. pneumoniae and the E. coli strain carried bla VIM-4 on conjugative, IncA/C plasmids exhibiting identical restriction patterns. The entire sequence of pKW4-VIM, derived from KKp4, was established. pKW4-VIM is a 162117 bp long IncA/C 2 plasmid harbouring three resistance islands: RI-1 with tet(A), strA, strB and sul2, RI-2 with ISEcp1, bla CMY-4 , blc and sugE and RI-3 with In416 containing the bla VIM-4 , Tn8802 with an arsenic resistance operon, an In-t4-like integron and a mercury resistance operon. Further to this uniform plasmid in six isolates, the remaining two isolate also harboured bla VIM-4 on the same In416 integron, although plasmids of these two isolates were not transferable.

Conclusion: Our findings confirmed that the high prevalence of VIM-producer Enterobacteriaceae in Mubarak Hospital in Kuwait was due to a plasmid outbreak of a conjugative IncA/C 2 episome harbouring In416, an integron also present in the remaining strains carrying non-conjugative VIM plasmids.

OS 11-2 Ampicillin plus ceftriaxone could treat safely infective endocarditis caused by Enterococcus faecalis Hanako Yoshihara, Takahiko Fukuchi, Hitoshi Sugawara. Jichi Medical University Saitama Medical Center

Background: Ampicillin plus gentamicin is the first-line therapy for treating infective endocarditis caused by Enterococcus faecalis.

In cases with renal dysfunction, ceftriaxone is seldom administered instead of gentamicin, and there are reports that ampicillin plus ceftriaxone is as effective as ampicillin plus gentamicin. We report a case in which ampicillin plus ceftriaxone was effective for treating infective endocarditis caused by E. faecalis. Case: The patient was a 74-year-old woman who underwent aortic valve replacement with a bioprosthetic valve 7 years prior to attending our hospital. Her stool was bloody, thus she underwent colonoscopy and biopsy, which revealed colonic adenoma. Two weeks later, she felt lower back pain, which worsened. She was admitted to our hospital and her blood culture tests disclosed E. faecalis. Lumbar vertebra MRI showed a high density area at the L4/L5 level on short tau inversion recovery. Therefore, we administered ampicillin for pyogenic spondylitis caused by E. faecalis, but bacillemia persisted. We diagnosed her as having possible infective endocarditis according to modified Duke Criteria. We added ceftriaxone instead of gentamicin because of her renal dysfunction (her serum creatinine level was 1.16 mg/dl). Nine days after adding ceftriaxone, E. faecalis was finally confirmed to be negative from blood culture. Therefore, we continued this treatment for another 6 weeks.

During follow up, infective endocarditis did not relapse. Conclusion: Although treatment of infective endocarditis caused by E. faecalis with ampicillin plus ceftriaxone is becoming widely known, it remains seldom used worldwide. In our case, concomitant use of β-lactams was effective, and the patient's renal function did not deteriorate. We hope this treatment might be adopted in broad cases. 64.4% of the strains were multi drug (MDR), 31.4% extreme (XDR), and 1.3% pan drug resistant (PDR). 83.8% produced carbapenemases, the most common ones being OXA-48-like (43.4%) and NDM enzymes (24.5%), the former one exceeding the latter one since 2013. Multiple carbapenemase producers (a total of 59 isolates (14.9%), 57 of them producing NDM and OXA type enzymes) appeared in 2012 and stabilised over 10% by 2013. No KPC producing strains were encountered. The overall rate of colistin resistance was 15.9%. It was first encountered in 2011 and 2012 (6.7 and 7.1%, respectively) reaching 20.4% by 2015. One mcr-1 positive isolate and no mcr-2 positive one was detected. Non-susceptibility to tigecycline varied between 46.7% and 64.3% during the study period. Among the 326 K. pneumoniae strains 4 major PFGE clusters representing 63.2% of all K. pneumoniae were identified: KP10 (6.1% of the strains with multiple MLST types), KP22 (33.7%, representing ST14), KP28 (12.3%, ST147) and KP32 (11.0% ST231). The increasing colistin and aminoglycoside resistance over time coincided with the spread of some of these clones: i.e. ST14 strains since 2013 and ST231 since 2014. 78.2% and 97.2% of ST14 and ST231 isolates carried at least one 16S modifying enzyme gene, the former one mostly armA, the latter one exclusively rmtF. Conclusion: Our data show that the burden of CRE in this region is a highly complex phenomenon considerably affected by the spread of a few highly resistant clones. Only close monitoring by molecular typing could offer a chance to understand, and hence limit the spread of CRE.

OS 11-4 Genome wide dissection of S. pneumoniae non-susceptible to a wide range of β-lactam antibiotics, circulating among preschool children in central Vietnam Hiroshi Fujii 1,2 , Koya Ariyoshi 2 . 1 Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan, 2 Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan

Background: Our previous population-based study revealed a high carriage rate of S. pneumoniae (SP) non-susceptible to a wide range of β-lactam antibiotics, including carbapenem (SP-NS), among preschool children (<5 yr) living in central Vietnam between 2008 and 2009 (331 healthy children in the community; 552 hospitalized children with acute respiratory infection). Approximately 80% of analyzed 50 SP-NS samples were related to globally circulating resistant SP clones with the most predominant clone of PMEN (Pneumococcal Molecular Epidemiology Network) 14 double loci variant (DLV) 19F/ST320 (40%), followed by PMEN1 23F/ST81 (14%). As well as PMEN strains, a new ST (ST13223), serogroup6/ST473 DLV, was identified (16%) in SP-NS. The objective of the study is to clarify how SP-NS in Vietnam has genetically evolved.

Methods: In this study, SP-NS was defined as MEPM MIC> = 1 μg/ ml and, PCG or CTX MIC> = 2 μg/ml. Whole genome sequencing (WGS) using Illumina Miseq platform was performed to search for recombination regions associated with high β-lactam antibiotics MICs and to create phylogeny of SP-NS. Putative recombination events were analyzed using Gubbins algorithm. Results: WGS was successfully done in total 45 SP isolates (SP-NS n = 23; other SP as controls n = 22; serogroup/serotype 6 (n = 20), 19F (n = 23), 11A (n = 1), 23F (n = 1)). This revealed that there were 8, 6 and 8 different alleles of pbp2x, pbp1a and pbp2b, respectively and that one of three pbp2x alleles in serogroup6/ST13223 (x1), which was identical to that of 19F/ST320, was associated with the high MIC pattern to both PCG and CTX. Further analysis revealed recombination event was rarely observed in 19F/ST320 (r/m ratio 0.096), probably due to the disruption of competence pilus (comGC) gene by the insertion of a prophage, whereas frequent recombination was seen in serogroup6/ST13223 (r/m ratio 0.44) and recombination events spanning pbp2x were associated with the high MIC pattern. It also indicated ST13223 was probably derived from an ancestor through a recombination event acquiring a genome region spanning both ddl and pbp2b (the potential donor is PMEN1 Background: Hypervirulent Klebsiella pneumoniae is a major cause of community-acquired pyogenic infections in Asian countries. Capsular type K1 K. pneumoniae strains were wellknown for their high virulence and associated invasive infections. They are usually susceptible to most antimicrobials, with the exception of ampicillin. Little is known regarding the clinical and molecular characteristics of antimicrobial-resistant K1 K. pneumoniae strains.

Methods: This retrospective study evaluated patients who were infected with capsular type K1 K. pneumoniae strains in a Taiwanese medical center between April 2013 and March 2016. Isolates from invasive diseases, such as bacteremia, pneumonia or pyogenic abscess, were included in this study. Antimicrobialresistant strains were defined as non-susceptibility to agents except ampicillin/amoxicillin. The clinical characteristics of these antimicrobial-resistant K1 K. pneumoniae infections were analyzed. These strains underwent analysis of pulse-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), resistance mechanisms, and in vivo virulence. The in vivo virulence and resistance mechanisms of two isogenic strains with different resistance phenotypes were compared. Results: Among 190 capsular type K1 K. pneumoniae strains, 18 antimicrobial-resistant strains were identified. The 14-day and 28day mortality rates of infections caused by antimicrobial-resistant strains were significantly higher than that caused by antimicrobialsensitive strains (33% vs. 10.5%, p = 0.005; 50% vs 12.2%, p < 0.001; respectively). Most antimicrobial-resistant strains were associated with nosocomial (n = 11) or healthcare-associated infections (n = 5). They were not clonally related by PFGE, and the sequencing type (ST) of these strains were ST23 (n = 16), ST260 (n = 1), and ST340 (n = 1). Half these strains exhibited high in vivo virulence in a mouse lethality experiment (the 50% lethal dose ≤ 10 4 /cfu). The major resistance mechanisms involved the presence of βlactamases (SHV-5, SHV-12, CTX-M3, DHA-1) and the overexpression of efflux pumps (AcrAB/OqxAB). One strain exhibited higher resistance level of cephalosporins compared with its isogenic counterpart due to overexpression of DHA-1 cephalosporinase, but retained its high in vivo virulence. Conclusion: Antimicrobial-resistant capsular type K1 strains infections were associated with a high mortality rate. These virulent K1 K. pneumoniae strains can evolve to harbor various resistance mechanisms, which may represent an emerging and severe threat to public health. Infectious diseases and resistance to antibiotics are believed to be a major public health concern worldwide. Effective empirical therapy is a key factor. An understanding of local antibiotic resistance epidemiology is critical to be able to adapt empirical therapeutic strategies, and improve diagnosis and prevention. The aim of our study was to identify current trends in antibiotic resistance by analyzing local epidemiology in a large hospital center in Marseille, France, over a three-year period (January 2014 to December 2016). All data on antibiotic susceptibility were collected from public laboratory hospitals in Marseille, and we focused on the top 15 most common bacteria isolated. Over the period, Antibiotic Susceptibility Testing (AST) was performed for 99,932 bacterial species isolated. The top 15 most frequent bacteria represent 82.9% of all AST performed (n = 82,829). Overall, we found that the level of resistance to antibiotics was not worrying for the most common bacteria, with a significant decrease of resistance for key antibiotics including aminoglycosides, penicillins and cephalosporins for E. coli, P. mirabilis, S. marcescens and K. oxytoca. We observed an increase in resistance to cephalosporins and carbapenems for K. pneumoniae. For P. aeruginosa and M. morganii, we obtained a decrease of wild-type strains corresponding to full susceptibility to a panel composed of 9-12 antibiotics tested. Moreover, we observed a low level of resistance to carbapenem in Gram-negative bacteria with less than 3.2% in positive blood culture and <5% for other samples for the bacteria of the top 15. Thus, our study demonstrates that the level of resistance to antibiotics of the most common bacteria involved in infections is for beyond the recent alarmist publications and prediction of mortality due to MDR in the media. We believe that such epidemiological data are useful for implementing therapeutic strategies and for the continued real-time surveillance of the evolution of resistance to antibiotics in common bacteria.

these patients were decolonized after rifampin usage. Two patients with MSSA colonization at enrollment showed evidence of recolonization with genetically-unrelated MSSA strains two months after discontinuation of treatment. There were five ST45-SCCmecV T -RIF-R strains from two patients isolated during rifampin exposure. Sequencing of the rpoB gene in RIF-R S. aureus isolates revealed different mutation sites between MSSA and MRSA isolates. Conclusion: RIF-R S. aureus nasal carriage isolates from patients receiving rifampin-containing regimens might acquire resistance from extrinsic sources rather than develop the mechanism during rifampin exposure. Background: The etiology of infections of the central nervous system (CNS) in Nepal often goes unrecognized due to underdeveloped laboratory facilities. This might lead to overtreatment with broad-spectrum antibiotics and possible side effects. In addition, the use of over the counter antibiotics before arrival to hospital is widespread in the area which complicates the diagnostic evaluation for the clinicians. The aim of this study was to investigate the microbial etiology of CNS infections at a hospital in Nepal.

Methods: From November 2014 to February 2016 cerebrospinal fluid (CSF) was collected, from 176 consecutive patients presenting at United Mission Hospital in Tansen, Nepal, with symptoms of possible CNS infection. Patient data was registered and analysis of blood cells in CSF including differential count was performed at the hospital. The samples were initially stored at −20°C and transported on dry ice to Örebro, Sweden, where multiplexed PCR was performed targeting six bacteria, seven viruses and two fungi (FilmArray ME panel, BioFire, BioMerieux). Results: 89% of the patients had CSF white cell count >3/μL suggesting CNS infection. Of the bacteria analyzed with the assay, H. influenzae was found in 46 samples, S. pneumoniae in 44, and N. meningitidis in 1 sample. Of these, 31 samples were positive for both H. influenzae and S. pneumoniae. Neither L. monocytogenes, E. coli K1 nor S. agalactiae were found. Cryptococcus neoformans/ gatti was found in four samples. The viruses detected included enterovirus (n = 8), varicella zoster virus (n = 5), herpes simplex virus 1 (n = 3) and human herpes virus 6 (n = 3). 59% of the samples were negative. 67% of the patients had taken antibiotics before lumbar puncture, mainly oral cephalosporins. Conclusion: By using the FilmArray multiplex PCR panel we detected important pathogens known to cause CNS infections. A relatively large proportion of the samples were positive for both H. influenzae and S. pneumoniae which was unexpected. The prevalence of DNA from these bacteria could in most cases be confirmed by other methods, but all are not considered to be clinically relevant. A relatively large proportion of the samples were tested negative for the pathogens included in the PCR assay, which indicates that CNS infections in the area often are caused by other important pathogens such as other viruses or mycobacteria. Interestingly a majority of the patients had taken broad-spectrum antibiotics before arrival to hospital which highlights the urgent need for improved routine diagnostics. Background: Numerous studies have indicated that appropriate empiric antibiotic therapy is associated with survival in adult patients with bloodstream infection. However, the utility of empiric antibiotic therapy for pediatric patients with bloodstream infection has not yet been well studied. The purpose of this study is to investigate the impact of an inappropriate empiric antibiotic therapy on mortality in pediatric patients with bloodstream infection. Methods: We retrospectively collected the data of pediatric patients (aged ≤15 years) with positive blood culture in the university hospital between 2007 and 2016. The association between the use of inappropriate empiric therapy and mortality was investigated. Inappropriate empiric antibiotic therapy was defined as the use of antibiotics within 48 hours of blood culture that is not suceptible in vitro to the bacteria detected in the blood culture.

Results: A total of 247 events of bacteremia in 223 pediatric patients were analyzed. There were 208 (84%) events of hospital acquired infection, and 16 (7%) pediatric patients died within 28 days. 150 (61%), 90 (36%) and 7 (3%) events were due to Grampositive bacteria, Gram-negative bacteria, and fungi, respectively. Inappropriate empiric antibiotic therapies were administered in 34 (16%) events. The Kaplan-Meier curve showed a significant difference between the patients with inappropriate empiric antibiotic therapy and those with appropriate therapy (log-rank test p = 0.004). Univariate analysis showed that inappropriate empiric antibiotic therapy (hazard ratio, 3.99; 95% confidence interval, 1.36-10.74; p = 0.01), age (hazard ratio, 0.86; 95% confidence interval, 0.70-1.00; p = 0.045), de-escalation therapy (hazard ratio, 0.14; 95% confidence interval, 0.008-0.69; p = 0.01), were the associated factors of 28-day mortality. Multivariate cox regression analysis showed that inappropriate empiric antibiotic therapy was the independent risk factor of 28-day mortality (hazard ratio, 4.39; 95% confidence interval, 1.48-11.9; p = 0.01) after adjustment for the McCabe severity assessment score. Conclusion: Inappropriate empiric antibiotic therapy was the independent risk factor of 28-day mortality in pediatric patients with bloodstream infection.

OS 13-2 Acute gastroenteritis in hospitalized children in southern Taiwan: emphasis on Clostridium difficile related acute gastroenteritis Fu-Chun Kuo 1,2 , Shih-Min Wang 1,2,3 , Ching-Fen Shen 1 , Ning Chung 1 , Tzong-Shiann Ho 1,2 , Ching-Chuan Liu 1,3 , TPIDA 4 .

a novel efficient disinfectant formulation against antibiotic-resistant microbial pathogens Chalermpong Saenjum 1,2 , Manu Deeudom 3

Most Imipenem resistance A. baumannii (IRAB) isolates (66.7%) belonged to ST684, a novel ST, were susceptible to tigecycline and colistin but 50% resistant to ampicillin-sulbactam and 100% resistant to all other antibiotics tested. The predominant mechanism of imipenem resistance from these neonate patients is ISAba1-bla OXA-80 , which has never been reported in Asia. Most infected newborns were premature (95%), with low birth body weight (70% <1500 g), prolonged intubation, usage of percutaneous central venous catheter (65%) and long-term usage of total parenteral nutrition or intrafat (95%). IRAB infection, inappropriate initial therapy, 1-minute Apgar score and early onset infection within the first 10 days of life were found correlated with mortality by log-rank test. Gestational age, C-reactive protein (CRP) level, and previous usage of imipenem were statistically significant risk factors for acquiring IRAB infections. Conclusion: For reducing mortality, it is crucial to consider giving colistin in 2 days for IRAB high risk neonates such as prematurity, high CRP level and previous imipenem usage. Restricting usage of predictor?

ESR 91 mm/hr (AUC, 0.571; sensitivity 0.714; specificity 0.6); and SFL 443 ng/mL (AUC

95% confidence interval (CI), 2.12-65.5, P = 0.0048) and female (OR, 22.2; 95% CI, 3.31-149, P = 0.0014) were significantly associated with CNSC. Conclusion: High levels of iron stored in the body can intensify neurological damage among patients with IE. OS 12-5 Characterization of rifampin-resistant Staphylococcus aureus nasal carriage in patients receiving rifampin-containing regimens for tuberculosis Yu-Tsung Huang 1,2,3 , Chun-Hsing Liao 1,4 , Shey-Ying Chen

In fifty-four C. difficile related AGE patients, the mean age was 1.8 ± 1.1 years old, and male to female ratio was 1:1. The most common symptom were fever (89%), followed by poor activity/appetite (87%), nausea/vomiting (57%), abdominal pain (46%) and bloody/ tarry stool (11%) in children with C. difficile related AGE. Twenty-eight C. difficile related AGE patients had co-detection of two pathogens (51.9%, 28/54). These patients were divided into two groups by single C. difficile detection and co-detection. The results showed that white blood cell (WBC) count and C-reactive protein (CRP) level were significant higher in single C. difficile related AGE group than co-detection group

Modified Duke's criteria was used to define IE, which was treated according to European Society of Cardiology (ESC) or Infectious Diseases Society of America (IDSA) guidelines. Patients with IE who had no IDC were excluded. Data included age, gender, habitus, underlying diseases, causative pathogens, quick Sepsis-Related Organ Failure Assessment (qSOFA) score, cardiovascular surgery during admission, length of in-hospital stay (days), and crude mortality in 180 days. We compared the period, in days, from admission to initial IDC for the early (≤10 days) group and the late (>10 days) group

The mean age was 66 years (range, 26-92) and 43 (71.6%) were men. The following conditions were noted: patients with a history of smoking (38.3%) and alcohol intake (45%), patients with cardiovascular disease (63.3%) and diabetes mellitus (13.3%)

There was no significant difference in age (P = 0.26), gender (P = 0.3), underlying disease (P = 0.25), cardiovascular surgery during admission (P = 1.00), qSOFA score (P = 0.52), distribution of causative pathogens, or crude mortality in 180 days (21.9 vs 38.8%, P = 0.21). However, the length of in-hospital stay was significantly shorter in the early group (49.9 vs 102.7 days, P < 0.001). Conclusion: IDC within 10 days from admission may provide the shorter length of in-hospital stay in patients with IE

Adenovirus detection in pediatric community acquired pneumonia in Taiwan during

11 Centers for Disease Control, Taiwan Background: Community acquired pneumonia (CAP) is one of the most common pediatric infectious disease worldwide. Both viruses and bacteria contribute to CAP, either alone or in combination. Human adenovirus (HAdV) infection is well known for its unique manifestation mimicking bacterial infection. In this study, we aim to explore the role and contribution of HAdV in pediatric CAP. Methods: The medical records of children enrolled by the Taiwan Pediatric Infectious Disease Alliance (TPIDA) project during 2010-2015 were reviewed. Hospitalized children with segmental or lobar pneumonia were included. The demographic, clinical, laboratory and radiographic data were analyzed. HAdV infection was defined as HAdV isolated or positive HAdV polymerase chain reaction (PCR) from clinical specimens. Results: Totally, seventy-two cases (5.6%) were identified from 1279 CAP patients. Among these cases, 51 had HAdV isolated, 49 had positive HAdV PCR detected, while 28 were positive for both results

9%), including bacteria in 54 cases, virus in 2 cases, and mixed pathogens in 8 cases. There is no significant difference in age, gender, underlying diseases, and the way of care between children with co-detection and those with only HAdV detection

There is no difference in the duration of hospitalization stay, total febrile days, the need for intensive care, the incidence of respiratory failure and parapneumonic effusion among two groups

5 Division of Infectious Diseases, Chiba Children's Hospital, Chiba, Japan Background: Tosufloxacin (TFLX) is a fluoroquinolone antimicrobial agent. TFLX granules for children were released in Japan in 2010 to treat otitis media and pneumonia caused by drug-resistant bacteria, e.g. penicillin-resistant Streptococcus pneumoniae and beta-lactamase-negative, ampicillin-resistant Haemophilus influenzae. Since its introduction, many pediatricians and otolaryngologists prescribe TFLX owing to its clinical effectiveness, good compliance based on a twice-daily dosage, and relatively pleasant taste. Frequent use of TFLX may lead to an increased risk of drugresistant bacteria. The aim of this study was to identify trends in TFLX susceptibility of S. pneumoniae isolated from communityacquired pneumococcal pneumonia in children <5 years of age, before and after the introduction of TFLX granules for children

Jiun-Ling Wang 6 . 1 Department of Pediatrics, Kaohsiung Veterans General Hospital

Background: To investigate molecular characteristics of rifampinresistant (RIF-R) Staphylococcus aureus isolated from patients receiving RIF-containing regimens as treatment for tuberculosis (TB). Methods: The subjects in this study comprised patients with TB who received RIF-containing regimens during the period November 2009 to May 2011 at a medical center in Taiwan. Nasal swabs were taken from anterior nares for S. aureus culture at enrollment and then every two months after treatment of TB had been discontinued. Identification and antimicrobial susceptibility testing of S. aureus were performed using the Phoenix automated microbiology system and the E-test, respectively. Genetic relatedness of the isolates was determined using pulsed-field gel electrophoresis, multilocus sequence typing (ST), spa typing, and typing of the SCCmec gene. The presence of rifampin resistance-associated mutations in the rpoB gene and the presence of fusidic acid resistance genes ( fusB and fusC) in S. aureus isolates were also analyzed. Results: Among the 200 patients enrolled in this study, 152 completed follow-up during treatment and 114 completed 2 months of follow-up after discontinuing rifampin. At enrollment, ten patients (5%) had nasal colonization with S. aureus, namely 8 with methicillin-susceptible S. aureus (MSSA) and 2 with methicillin-resistant S. aureus MRSA (ST59-SCCmecIV-RIF-S). All

Background: The prevalence of antibiotic resistance among the bacteria has been increasing worldwide. This study was carried out to develop a novel efficient disinfectant formulation against antibiotic-resistant microbial pathogens in order to prevent outbreaks of hospital-acquired infections. Methods: The novel efficient disinfectant formulation has been developed using quaternary ammonium compounds as a major active ingredient and synergistic with three minor cationic active ingredients. The antimicrobial activity against Acinetobacter baumannii, Pseudomonas aeruginosa ATCC 27853, Klebseilla pneumoniae, Proteus mirabilis, Salmonella enteritidis, Bacillus subtilis, Stenotrophomonas maltophilia, Cryptococcus neoformans, Clostridium perfringens, C. difficile, and Trichophyton rubrum were investigated. Moreover, the antimicrobial activity against several antibiotic-resistant microbial pathogens were studied, including methicillin-resistance S. aureus ATCC 25923, vancomycin-resistance enterococci, ESBL-producing E. coli, Multidrug-resistant M. tuberculosis (MDR-TB), M. tuberculosis H37Rv (reference strain), M. avium (Nontuberculous mycobacteria; NTM), E. coli CRE-01 (carbapenemase strain containing blaNDM and blaOXA-181 genes), and K. pneumoniae CRE-05 (carbapenemase strain containing blaNDM gene). Furthermore, the oral acute toxicity in Wistar rats was also evaluated. Results: The results indicated that the novel efficient disinfectant formulation at the concentration of 0.1% exhibited the antimicrobial activity against A. baumannii, P. aeruginosa ATCC 27853, K. pneumoniae, S. enteritidis, B. subtilis, S. maltophilia, C. neoformans, C. perfringens, T. rubrum, C. difficile, MRSA ATCC 25923, vancomycinresistance enterococci, ESBL-producing E. coli, E. coli CRE-01, and K. pneumoniae CRE-05 in 1 minute of exposure time and in 5 minutes of exposure time for P. mirabilis. Interestingly, the concentration of 0.5% exhibited the antimicrobial activity against multidrug-resistant M. tuberculosis (MDR-TB), M. tuberculosis H37Rv (reference strain), and M. avium (Nontuberculous mycobacteria; NTM) in 1 minute. Finally, the results revealed that the oral acute toxicity in Wistar rats of both sexes was greater than 5000 mg/kg body weight. Conclusion: It can be concluded here that the novel efficient disinfectant formulation exhibited the potent antimicrobial activity against antibiotic-resistant microbial pathogens and it was found to be safe in the toxicity test with animal.OS 12-2 Challenges and successes: TB infection control program implementation at Academic Medical Center in Saudi Arabia: A multidisciplinary process improvement project Ashraf Khan*, Hanan Balkhy, Fatimah Abdulkareem, Moaied Matalqah, Abrar Turkistani. King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia Background: King Abdulaziz Medical City is a 936 beds academic medical center in Riyadh, Saudi Arabia. In 2012, risk assessment of TB control program was conducted for the first times that identified deficiencies in the program. The multidisciplinary approached were adopted for series of multifaceted strategies. Methods: Determination of TB infection control efforts in the utilization of a hierarchy of measures as of Administrative, Respiratory and Environmental. Review of community TB disease profile, including the epidemiologic surveillance data Statistical review of number of patient admitted at medical center with suspected or confirmed TB disease. Determination if patient with unrecognized TB disease. Determination which HCW needed to be included in the respiratory protection program. Identification of areas in the KAMC with an increased risk for healthcare-associated transmission of Myobacterium tuberculosis, e.g. ER, critical care units. Assessment of the number of airborne infection isolation rooms (AIIR) or Portable HEPA filters needed for the medical center. Survey to determine Knowledge, Attitude and Practices (KAP) of HCW before and after Implementation of TB Program. Results: A total of 3200 N95 Respirator fit testing was conducted from October 2012 -July 2015. However due to MERSCoV outbreak extra workload was assigned to nursing education for N95 Respirator fit testing. From August 2015 till October 2016, a total of 8917 staff was fit tested. This accounted 80% of all direct patient care providers. A new program was established in 2017 with train-the-trainers approach including hiring of occupational safety officer and introduction of Powered Air Purifying Respirator (PAPR). A total of 250 PAPR are now in circulation in high-risk patient care areas of the hospital. ER patient care areas including waiting areas air handling system were upgraded with introduction of 50 more portable HEPA filter machines. Dedicated Infectious Disease physician conducted round on early discharge or transfer of unnecessary isolated TB patients in ER and proper isolation of highly suspected patients. Fast triaging and ID assessment reduced overstaying of patients in ER from 48 hours to 3 hours or less. In 2015 -A total of 1,629; nurses, physician and other HCW attended educational huddles at worksite and workstation related to airborne disease and importance of N95 respirators. 550 HCW, direct patient care providers participated in KAP survey study in the Emergency Room. Prior to implementation of TB process improvement plan, KAP correct response rate was 26%. After implementation of our approach and education, correct response rate improved to 95%. Conclusion: Due to success of program, hospital administration decided to open Infection Control N95 Respirator Fit Testing Clinic providing testing for all new employees and employees due for re testing every one or two years. Our successful implementation of TB control and prevention resulted in less exposure of staff with TB patients.Background: The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing worldwide. This study investigated the clinical features and bacteriology of pediatric patients with ESBL-producing E. coli bacteremia and compared their characteristics with those of adult patients. Methods: Clinical and laboratory data from all of the 41 patients aged ≤18 years diagnosed with E. coli bacteremia were collected over 5 years. Patients aged >18 years diagnosed with E. coli bacteremia, matched 1:1 for calendar time, were enrolled as the adult group. All E. coli isolates were tested for their blaCTX-M group and sequence type 131 (ST131). A novel seven-single nucleotide polymorphism-based clonotyping test was applied to detect the septatypes of each isolate. Results: In the adult group, patients with ESBL-producing E. coli bacteremia had more previous hospitalizations and antimicrobial agent use than did those with non-ESBL-producing E. coli bacteremia, but these differences were not found in pediatric group. In the pediatric group, the proportion of isolates producing CTX-M group 9 was higher than that in the adult group (85.7% vs. 42.9%; p < 0.05). Among both groups, there were more E. coli ST131 in ESBL isolates in than there were non-ESBL isolates. The distribution of septatypes was more homogenous in ESBLproducing E. coli among the pediatric patients than among the adult patients. Conclusion: ST131 was the major clone causing E. coli bacteriemia in both pediatric and adult populations. The pediatric population demonstrated a higher number of isolates producing CTX-M group 9 with more homogenous septatypes compared with the adult population.