id author title date pages extension mime words sentences flesch summary cache txt cord-286658-9kco7qad Jiang, Lei Characterization of the complete genome, antigenicity, pathogenicity, tissue tropism, and shedding of a recombinant avian infectious bronchitis virus with a ck/CH/LJL/140901-like backbone and an S2 fragment from a 4/91-like virus 2018-01-15 .txt text/plain 7003 302 54 Recently, numerous IBV strains have been identified and new genotypes/serotypes have emerged from existing viruses via point mutations, insertions, and deletions in the viral genome, especially in the S1 subunit of the spike protein gene. There have been several episodes of infectious bronchitis (IB) in Chinese chicken flocks, and the genotypes/serotypes of IBVs were previously classified based mainly on the nucleotide sequences of genes encoding the S1 subunit of the spike protein (Han et al., 2011) , and in some cases based on cross virus-neutralization Chen et al., 2017) in China. In addition, it is very interesting to note that the/I1101/16 isolate exhibited decreased replication levels in both the tracheal and kidney tissues (two target tissues for most IBVs) compared with one of its parental viruses (the ck/CH/LHLJ/140901 strain, which does not cause severe clinical disease in SPF chickens), but it exhibited prolonged replication and shedding post-challenge in a Table 3 Pairwise comparisons of the nucleotide sequences of the S2 subunit of the spike genes between the 4/91 vaccine strain, I1101/16 isolate, and pathogenic 4/91 strain a . ./cache/cord-286658-9kco7qad.txt ./txt/cord-286658-9kco7qad.txt