一株基因V型禽呼肠孤病毒的分离鉴定与致病性研究

Isolation,identification and pathogenicity of a genotype-V avian reovirus

为了了解禽呼肠孤病毒(ARV)在我国的流行情况及其生物学特性和致病特点,通过细胞传代、RT-PCR检测及序列分析,从山东省送检的病鸡关节组织中成功分离到1株病毒,将其命名为ARV-SD20-3203,样品中未检测到其他常见外源禽类病毒的核酸。禽呼肠孤病毒主要保护性抗原σC基因的遗传进化分析结果表明,ARV-SD20-3203属于ARV基因V型,与基因Ⅴ型参考毒株918和1017-1的遗传距离较近,其氨基酸序列同源性分别为93.0%和92.4%,而与其他基因型毒株的遗传距离较远。ARV-SD20-3203毒株在LMH细胞上增殖良好;对鸡胚和雏鸡均具有明显的致病性,接种鸡胚可引起100%死亡,接种1日龄SPF雏鸡可引起75%死亡,其中SPF雏鸡接种病毒后第5天为死亡高峰期,第8天之后,不再出现SPF雏鸡死亡。该研究分离到1株基因V型ARV毒株,这为了解我国ARV变异株的流行及遗传进化特征提供了重要的材料。

This study aimed to understand the prevalence of avian reovirus(ARV)variants in our country,and their biological and pathogenic characteristics.A virus was isolated with the joint tissues of the infected chickens from Shandong Province,through cell passaging,RT-PCR and sequence analysis.The virus was named as ARV-SD20-3203,and no other common avian viral nucleic acids were detected from the sample.The results of genetic evolution analysis of the major protective antigenσC gene of ARV showed that the ARV-SD20-3203 was located in the V-genotype branch of the ARVs,and had a close genetic distance to the genotype V reference strains 918 and 1017-1.The amino acid sequence homology between them was 93.0%and 92.4%,respectively.However,the virus showed less close evolutionary relationships with other genotype strains.The isolated strain proliferated well on LMH cells,and had obvious pathogenicity to chicken embryos and chicks,which caused 100%mortality of inoculated chicken embryos,and 75%mortality of inoculated 1-day-old SPF chicks.The death peak point of SPF chicks was on the 5th day post-infection,and no chicks died after the 8th day.In this study,a genotype-V strain was isolated,which provided the important material for understanding the prevalence and genetic evolution characeristics of ARV variant strains in our country.