Mengting Ren,  Jie Sheng,  Tianxin Ma,  Liwen Xu,  Zongxi Han,  Huixin Li,  Yan Zhao,  Junfeng Sun,  Shengwang Liu

Infect Genet Evol. 2019 Jun 27:103942. doi: 10.1016/j.meegid.2019.103942

Abstract

In the present study, a thorough comparison of the infectious bronchitis virus (IBV) TC07-2/GVI-1 linage was conducted by comparing the S1 gene sequences of GVI-1 viruses with those of viruses representing the established genotypes and lineages. IBV GVI-1 strains were found to be closely genetically related to each other, irrespective of where the viruses were isolated, and differed from other known IBV genotypes and lineages; thus, it was confirmed that GVI represents a novel genotype. However, the GVI-1 viruses exhibited variable antigenicity when compared to each other. Further analysis found that strains CO8089L and CO8091L, which were isolated in Colombia in 2003, were closely related to GVI-1 viruses, suggesting that GVI-1 viruses likely originated from Colombia and are prevalent in at least five countries (Colombia, China, the Republic of Korea, Japan, and Vietnam). Analysis of the complete GVI-1 virus genomes suggested that the GVI-1 strains in China may be independently derived from recombination events that occurred between GI-19 strains and CO8089L/CO8091L-like viruses following the introduction of the viruses from Colombia. Similar to the viruses isolated in the Republic of Korea, GVI-1 viruses isolated in China also showed an affinity for the respiratory tract of chickens, which differed from one of the deduced parental viruses, the GI-19 strain. This difference may be due to recombination events that occurred in the genomes of the GVI-1 viruses, resulting in the replacement of the spike gene sequences in an YX10-like strain of GI-19 lineage.

Copyright © 2018. Published by Elsevier B.V.

KEYWORDS:

Antigenicity; Complete genome; Infectious bronchitis virus; Pathogenicity; TC07–2/GVI-1 lineage; Tissue tropism