猪伪狂犬病毒Bartha-K61疫苗株和变异株主要免疫原性基因分析

摘要

Swine pseudorabies has occurred in many provinces in China since the end of 2011 and PRV variant strains have been confirmed as the causative agents.In addition,some reports showed that the currently used vaccines did not provide complete protection.In the present study,the homology of gB,gC and gD genes and their deduced amino acid sequences of pseudorabies Bartha-K61 vaccine strain and variant strains were analyzed in order to compare the differences in these genes coding for major immunogenic proteins.As a result,the protein sequences of Bartha-K61 vaccine strains and variant strains was 96.3％ ～ 96.9％ identical but 23 differences in gB,92.7％ ～ 93.1％ identical but 25 differences in gC and 96.8％ ～ 97.3％ identical but 10 differences in gD,respectively.Phylogenetic analysis of deduced amino acid sequences ofgB,gC and gD genes showed that Bartha-K61 vaccine strains and variant PRV strains belonged to two different evolutionary branches.%自2011年底以来,我国多个省份暴发了猪伪狂犬病,一些研究院所证实当前猪伪狂犬病毒流行株发生了一定程度的变异,疫苗不能提供完全的保护.为了在分子生物学水平上比较不同厂家猪伪狂犬病毒Bartha-K61疫苗株,以及与当前流行的猪伪狂犬病病毒变异株,在主要免疫原性蛋白之间的差异,选取了4个厂家的活疫苗Bartha-K61株,通过二代测序方法进行测序,对Bartha-K61株gB、gC和gD这3种主要免疫原性基因以及推导出的氨基酸序列与变异株之间进行同源性分析.结果显示,Bartha-K61疫苗株与变异株gB蛋白序列中有23处特征性的差异,同源性为96.3％～96.9％;gC蛋白序列中有25处特征性的差异,同源性为92.7％～93.1％;gD蛋白序列中有10处特征性的差异,同源性为96.8％～97.3％;以gB、gC和gD氨基酸序列建立的进化分析结果显示,Bartha-K61疫苗株与变异株分属两个不同进化分支.