河北省猪场伪狂犬病病毒感染情况调查及gE基因遗传变异分析

Investigation of pseudorabies virus infection in Hebei Province and phylogenetic analysis of its gE gene

采用ELISA检测方法对2018年1月至2019年5月从河北省11个地市195个不同规模猪场采集的10479份血清进行gE抗体的检测,采用PCR方法对流产胎儿进行猪伪狂犬病病毒(pseudorabies virus,PRV)的抗原检测,并将部分阳性样本进行gE全基因的扩增和遗传变异分析。血清学检测结果显示,所检测的河北省11个地市均存在不同程度的PRV感染,血清样本gE抗体平均阳性率为50.05%;检测的195个猪场中,161个gE抗体为阳性,场群阳性率为82.56%,且存栏50~300头母猪的规模化猪场阳性率最高;不同阶段的猪群中,种猪群空怀母猪的阳性率最高,为73.75%。病原检测结果显示,204个流产胎儿中有54个为PRV阳性,阳性率为26.47%;对扩增的8株PRV进行遗传进化分析,结果显示河北省流行的毒株与2011年后的流行毒株亲缘关系较近,且均在第48位和第492位各存在1个天冬氨酸的插入,为变异毒株。以上结果提示,河北省猪场PRV的感染较为普遍。

To investigate the epidemic distribution of pseudorabies in Hebei Province,a total of 10479 pig sera derived from 195 large scale pig farms of 11 region between January 2018 and May 2019 were detected for the gE antibodies against pseudorabies virus(PRV)by ELISA test.Aborted fetuses were detected for PRV by PCR,and a portion of the positive samples were used for amplification of the complete gE gene,and the phylogenetic analysis was carried out.Serological test results showed that gE antibodies against PRV were found in all the 11 regions.The samples positive rate was 50.05%.Of the 195 farms tested,161 were positive for gE antibodies,the farm positive rate was 82.56%,and the highest positive rate was found in the large-scale farms with 50 to 300 sows.As for the different stages of the herd,sows in barren period showed the highest positive rate(73.75%).The detection results of the aborted fetuses showed that the infection rate of PRV was 26.47%.Eight of the complete gE genes were amplified and sequenced,phylogenetic analysis of the gE showed that the eight strains prevalent in Hebei Province closely related to the strains prevalent after 2011.The alignment results revealed that the eight prevalent strains together with other PRVs isolated since 2012 had the same sequence features with two Asp insertions at positions 48 and 492 of gE,indicating that they were variant PRVs.These results indicated that the prevalence of the PRV variants was high in Hebei Province.