一株猪伪狂犬病病毒的主要毒力相关基因的变异分析及其对家兔的致病性

Analysis of Variation in Major Virulence-related Genes of a Strain of Pseudorabies Virus and Its Pathogenicity to Rabbits

旨在了解目前广东省伪狂犬病病毒(pseudorabies virus,PRV)流行变异情况,本研究采集了2020年广东省佛山市某规模化养猪场疑似PRV感染的病猪血液样本,接种PK-15细胞后,运用透射电镜和间接免疫荧光方法鉴定为PRV,并将其命名为GDFS2020株;分析主要毒力基因gB、gC、gD、gE和TK编码氨基酸序列进行分子特征及遗传进化分析,结果显示,该毒株为国内变异株,但有个别氨基酸位点发生了突变;家兔致病性试验结果表明,接种组家兔肝边缘有梗死,心、脾、肾及脑组织均有充血、肿大和淤血等病变;病理组织切片结果显示,脑组织神经元变性萎缩,核略微皱缩,空隙增多变大等明显的病理变化。以上结果表明,本试验成功分离了1株PRV变异株,并对家兔具有较强致病性,为广东省PRV流行病学研究及遗传进化提供了参考数据。

In order to investigate the current prevalence and variation of pseudorabies virus(PRV)in Guangdong Province,blood samples of diseased pigs with suspected PRV infection were collected from a large-scale pig farm in Foshan City,Guangdong Province in 2020.PRV was identified by transmission electron microscopy and indirect immunofluorescence,and which was named as GDFS2020 strain.Molecular characteristics and genetic evolution of gB,gC,gD,gE and TK deduced amino acid sequences were analyzed.The results indicated that GDFS2020 strain was a domestic variant,but there were individual amino acid mutations.The results of the pathogenicity test showed that there were infarcts at the edge of liver,hyperemia,swelling,and congestion in heart,kidney,spleen,and brain tissues.The results of the histopathological section showed obvious pathological changes such as degeneration and atrophy of neurons,nucleus slightly shrunken,and increase of voids in brain.Our results indicated that a mutant PRV strain was successfully isolated in this study and had high pathogenicity in rabbits,providing reference data for the epidemiological research and genetic evolution of PRV in Guangdong Province.