一株肉鸡呼肠孤病毒变异株的分离鉴定

Isolation and Identification of a Variant Strain of Reovirus from Broilers

旨在研究肉鸡呼肠孤病毒分离株致病与基因组变异情况。2017年从山东潍坊地区跗关节肿胀、出血严重商品肉鸡中收集病料,进行病毒分离,通过RT-PCR检测、电镜观察对病毒进行鉴定;将分离到的病毒回归商品肉鸡;设计18对引物对分离株全基因组扩增测序,并进行了遗传进化分析;将分离毒株与经典毒株S1133进行血清交叉中和试验。结果表明分离到一株禽呼肠孤病毒(命名为WF17),回归商品肉鸡能完全复制出临床症状,并能从试验鸡中重新分离到该病毒。该分离株基因组完全符合禽呼肠孤病毒基因组结构特点,主要抗原σC蛋白基因与台湾918株最接近,相似性为92.7%,与S1133株的相似性只有55.9%。WF17株与S1133株的抗原相关指数(R值)只有0.19。目前以S1133株为主的商品化疫苗无法对禽呼肠孤病毒变异株产生有效保护。

This experiment was conducted to study the pathogenicity and genome variation of broiler reovirus isolates in Shandong Province.In 2017,a virus was isolated from commercial broilers with tarsal joint swelling and severe bleeding in Weifang,Shandong,and identified by RT-PCR and electron microscopy.And the virus was returned to commercial broilers.The whole genome of the isolated strain was amplified by using18 pairs of primers,then sequenced,and its genetic evolution was analyzed.Serum cross neutralization test was carried out between the isolated strain and the classical strain S1133.Our results showed that a strain of avian reovirus (named WF17) was isolated.The clinical symptoms could be completely replicated in commercial broilers and the virus could be re-isolated from experimental chickens.The genome of the isolate fully conformed to the genomic structure of avian reovirus.And the main antigen (σC protein) gene was closest to 918 strain from Taiwan Province,with 92.7% homology,and 55.9% homology with S1133 strain.The antigen-related index ( R value) between WF17 strain and S1133 strain was only 0.19.At present,commercialized vaccine based on S1133 strain can not effectively protect variant avian reovirus strains.