Genome characterization, antigenicity and pathogenicity of a novel infectious bronchitis virus type isolated from south China.

ABSTRACT: In 2014, three infectious bronchitis virus (IBV) strains, designated as ?CoV/ck/China/I0111/14, ?CoV/ck/China/I0114/14 and ?CoV/ck/China/I0118/14, were isolated and identified from chickens suspected to be infected with IBV in Guangxi province, China. Based upon data arising from S1 sequence and phylogenetic analyses, the three IBV isolates were genetically different from other known IBV types, which represented a novel genotype (GI-29). Virus cross-neutralization tests, using ?CoV/ck/China/I0111/14 as a representative, showed that genotype GI-29 was antigenically different from all other known IBV types, thus representing a novel serotype. Complete genomic analysis showed that GI-29 type viruses were closely related to and might originate from a GX-YL5-like virus by accumulation of substitutions in multiple genes. These GI-29 viral genomes are still evolving and diverging, particularly in the 3' region, although we cannot rule out the possibility of recombination events occurring. For isolate ?CoV/ck/China/I0114/14, we found that recombination events had occurred between nsps 2 and 3 in gene 1 which led to the introduction of a 4/91 gene fragment into the ?CoV/ck/China/I0114/14 viral genome. In addition, we found that the GI-29 type ?CoV/ck/China/I0111/14 isolate was a nephropathogenic strain and high pathogenic to 1-day-old specific pathogen-free (SPF) chickens although cystic oviducts were not observed in the surviving layer chickens challenged with ?CoV/ck/China/I0111/14 isolate.

SUBMITTER: Jiang L 

PROVIDER: S-EPMC7106192 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature