摘要
为了确诊一起绵羊伪狂犬病的发生,采集送检病羊的皮肤、脾脏、淋巴结、脑等组织器官进行实验室病毒分离和PCR检测。结果显示,病料中扩增出了伪狂犬病病毒的特异性g E基因片段。结合流行病学调查、病理剖检和实验室诊断,确定引起此次疫情的病原为伪狂犬病病毒。为了进一步了解此次疫情中PRV g E基因的分子特征,特对PCR扩增产物进行了连接、转化和测序分析。遗传进化分析表明,该分离株与亚洲各分离株处于同一分支,基因同源性高达98.4%-99.4%,与欧洲、美洲分离株同源性相对较远,分别为97.0%-97.2%、97.2%-97.3%;g E蛋白氨基酸序列分析显示,该分离株在g E蛋白的第48位和第492位各存在1个天冬氨酸的插入,与我国当前流行的伪狂犬变异株相同,同时在当前猪伪狂犬病病毒变异株基础上又出现了新氨基酸位点的变异,如L49P、P160T、V406G、G445R,其分子生物学特性有待进一步的研究。本文通过综合诊断确定该病由伪狂犬病病毒引起,为我国绵羊伪狂犬病的流行病学分析及防控提供了重要的理论依据。
To diagnose a suspected sheep pseudorabies case,pathologic autopsy was performed and tissues of the sheep werecollected for virus isolation and identification using PCR.PRV was amplified from the tissues and its infection was confirmed.In or-der to further understand the molecule characteristic of the g E gene,the 1740-bp DNA fragment of g E gene was amplified,clonedand sequenced. Phylogenetic analysis showed that the sheep PRV isolate shared 98.4% to 99.4% sequence identity with all kindsof isolates from Asia,and shared 97.0% to 97.2% and 97.2% to 97.3% sequence identity with Europe and American isolates,re-spectively. The alignment results revealed that the isolate had the same sequence features with two insertions of Asp at sites of 48 and 492 comparing with the PRVs isolated from the modern prevalent mutations. Besides,four new amino acid sites emerged,andthey were L49 P,P160T,V406 G and G445 R compared with the prevalent mutated strains of swine PR.This study provides an use-ful information for the molecular epidemiology,prevention and control of sheep PRV in China.
引文
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