鸡传染性支气管炎病毒分离鉴定及S1基因遗传演化分析

为调查辽宁地区鸡传染性支气管炎病毒(IBV)的流行及遗传演化情况,从辽宁某鸡场疑似鸡传染性支气管炎病料中分离得到1株病毒,经分子生物学检测、鸡胚矮小化试验、新城疫病毒血凝特性干扰试验和动物回归试验,确定该毒株为IBV,并命名为CH/LN/2019。扩增该毒株S1基因并进行序列分析发现,分离株S1基因全长1 620 nt,编码540个氨基酸,S1蛋白裂解位点为HRRRR,属于基因Ⅰ型(QX型)毒株;同源性比对发现,分离株与基因Ⅰ型代表毒株QXIBV株的核苷酸和氨基酸序列同源性最高,分别为95.6%和94.8%;与国内常规型疫苗H52、H120和Ma5毒株的同源性较低,核苷酸和氨基酸序列同源性仅为77.2%~76.9%和75.4%~76.2%。本试验为辽宁地区鸡传染性支气管炎的流行病学调查及免疫防控提供了参考。

Isolation and identification of avian infectious bronchitis virus and genetic evolution analysis of its S1 gene

To investigate the prevalence and genetic evolution of the avian infectious bronchitis virus(IBV) in the Liaoning area, a strain of the virus was isolated from the suspected diseased chicken on a chicken farm in the area. By molecular biological detection, chicken embryo dwarfing test, Newcastle disease hemagglutination interference test, and animal regression test, the strain was identified as an avian infectious bronchitis virus and named CH/LN/2019. The research results showed that the S1 gene of the isolate was 1 620 nt in length and it encoded 540 aa. Its S1 protein cleavage site was HRRRR, which belonged to genotype I(the QX type), and the isolate had the highest nucleotide and amino acid sequence homology with the representative strain, the QX IBV strain, which was 95.6% and 94.8%, respectively, but low homology with the H52, H120 and Ma5 strains of the domestic conventional vaccine, with nucleotide and amino acid sequence homologies of 77.2%-76.9% and 75.4%-76.2%, respectively. This experiment provided a reference for epidemiological investigation and immune control of infectious bronchitis in the Liaoning area.