陕西省部分地区猪伪狂犬病病毒分离鉴定及其gE基因遗传变异分析

Isolation and Identification of Porcine Pseudorabies in Some Areas of Shaanxi Province and Analysis of Genetic Variation of gE Gene

为了解2015年陕西省猪伪狂犬病(PR)流行情况和病毒遗传变异特点,采集不同地区28份疑似PR发病猪场的病料进行PCR检测,采用鸡胚绒毛尿囊膜接种和BHK-21细胞培养分离PRV,应用生物信息学方法分析主要毒力基因gE遗传变异特征。结果显示,从28份PRV疑似病料中检测出7份PRV阳性样品,分离出7株PRV地方株。陕西分离毒株与目前国内的流行毒株同源性较高,且在同一进化分支内,与欧美分离株同源性较低,亲缘关系相对较远。其中4个分离毒株具有变异株的典型分子特征,即773bp^775bp CGA的特征性插入,另3个分离毒株则与经典参考毒株Ea株和GDSH株位于1个相对独立的分支;SX01株和SX03株抗原表位发生改变,SX03株O-GalNAc糖基化位点缺失,SX04株在1个抗原表位增加了1个潜在的O-GalNAc糖基化位点。表明陕西省PRV gE基因在分子水平上发生了变异,核酸演化上发生了相对独立的进化,氨基酸序列的突变对其抗原表位和糖基化位点产生了影响。

In order to investigate the prevalence and genetic variation of PRV in Shaanxi Province in 2015,28 diseased tissues of swine were collected and detected by PCR, and the PRV was isolated by inoculating chick embryo chorioallantoic membrane and BHK-21 cell.Meanwhile the main virulence gene gE was amplified and its genetic variation characteristics were analyzed by bioinformatics methods.The results showed that the isolated 7 PRV Shaanxi strains had higher homology and closer relationships with Chinese epidemic strains than foreign reference strains.Among them,4 strains had characteristic insert of CGA in 773 bp- 775 bp,which was the important marker for the PRV variant,and the other 3 strains had closer relationships with classical strains GDSH and Ea.The epitopes of strains SX01 and SX03 were changed,O-GalNAc glycosylation site of strain SX03 was deleted, a potential O-GalNAc glycosylation site was added in a epitope of strain SX04.The research indicated that PRV gE gene of Shaanxi had mutated in molecular level,and the mutant amino acids had an impact on its epitope and glycosylation sites.This study provided a theoretical basis for PRV monitoring and control.