Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Heilongjiang Hegang Center for Animal Disease Control and Prevention, Hegang 154106, China.
Infect Genet Evol. 2021 Oct;94:105006. doi: 10.1016/j.meegid.2021.105006. Epub 2021 Jul 20.
During 2016 to 2020, GVI-1 type infectious bronchitis virus (IBV) strains were sporadically reported across China, indicating a new epidemic trend of the virus. Here we investigated the molecular characteristics and pathogenicity of two newly isolated GVI-1 type IBV virus strains (CK/CH/TJ1904 and CK/CH/NP2011) from infected chicken farms in China. Genetic evolution analysis of the S1 gene showed the highest homology with the GVI-1 representative strain, TC07-2. Phylogenetic analysis and recombination analysis of the virus genomes indicated that newly isolated strains in China may be independently derived from recombination events that occurred between GI-19 and GI-22 strains and early GVI-1 viruses. Interestingly, unlike the deduced parental GI-19 or GI-22 strains, CK/CH/TJ1904 and CK/CH/NP2011 showed affinity for the trachea rather than the kidney and were less pathogenic. This difference may be because of recombination events that occurred during the long co-existence of the GVI-1 viruses with prevalent GI-19 and GI-22 strains. Considering the new trend, it is very important to permanently monitor circulating strains and to develop new vaccines to counteract emerging new-type IBVs.
2016 年至 2020 年期间，中国各地零星报告了 GVI-1 型传染性支气管炎病毒（IBV）株，表明该病毒出现了新的流行趋势。本研究调查了中国两个新分离的 GVI-1 型 IBV 病毒株（CK/CH/TJ1904 和 CK/CH/NP2011）的分子特征和致病性。S1 基因的遗传进化分析显示与 GVI-1 代表株 TC07-2 的同源性最高。病毒基因组的系统进化分析和重组分析表明，中国新分离株可能是由 GI-19 和 GI-22 株与早期 GVI-1 病毒之间的重组事件独立产生的。有趣的是，与推断的亲本 GI-19 或 GI-22 株不同，CK/CH/TJ1904 和 CK/CH/NP2011 对气管而不是肾脏具有亲和力，且致病性较低。这种差异可能是由于 GVI-1 病毒与流行的 GI-19 和 GI-22 株长期共存过程中发生了重组事件。鉴于这种新趋势，持续监测流行株并开发新疫苗以应对新兴的新型 IBV 非常重要。
