2016年河南省猪流行性腹泻病毒S、M基因遗传变异分析

摘要

To investigate the genetic variation of S and M genes of porcine epidemic diarrhea virus (PEDV) in Henan province,a total of 67 clinical samples were collected from 16 large-scale pig farms in different regions of Henan province during 2016 Jan to 2017 Apr and detected for PEDV by RT-PCR.Then the S gene partial sequences and M gene sequences were cloned and sequenced from representative PEDV positive samples,and phylogenetic analysis was carried out using MEGA7.The results indicated that there were 43 samples of 13 large-scale pig farms showed PEDV positive,and the positive rate was 64.2％.Sequences analysis showed that the sequence homology of nucleotide and amino acids in partial S gene shared 97.0％-99.9％ and 95.9％-100.0％ among 13 PEDV strains,respectively.Compared with the classical strain CV777,the sequence homologies were 94.9％-96.0％ and 93.6％-95.3％,respectively.Compared with the reference strains of PEDV in GenBank,the sequence homologies were 92.0％-99.6％ and 89.8％-99.7％,respectively.In M genes,the sequence homology of nucleotide and amino acids shared 98.2％-99.9％ and 96.0％-99.6％ among 13 PEDV strains,respectively.Compared with the classical strain CV777,the sequence homologies were 97.2％-98.2％ and 96.0％-98.2％,respectively.Compared with the reference strains of PEDV in GenBank,the sequence homology were 93.5％-99.6％ and 91.2％-99.1％,respectively.Phylogenetic analysis showed that 13 PEDV strains had the same branch with the PEDV epidemic strain XM1-2 in Fujian province in 2016 but not Chinese vaccine CV777,which indicated that the epidemic strains in Henan province were not closely related to the Chinese vaccine strains.In this study,the genetic variation of PEDV in Henan province was determinated,which would lay the foundation for the diagnosis and prevention of PED in Henan province.%为了解目前河南省猪流行性腹泻病毒(PEDV)S、M基因的遗传变异情况,本研究于2016年1月～2017年4月从河南省不同地区的16个规模化养猪场采集到67份病死仔猪小肠病料,应用RT-PCR进行PEDV检测,选取部分PEDV阳性样品分别进行PEDV S基因部分序列和M基因全序列的扩增、克隆和序列测定,并对其进行序列和遗传进化分析.结果显示,16个规模化养猪场67份样品中共有13个猪场的43份病料显示PEDV阳性,阳性率为64.2％,选取的13株PEDV代表株间S基因的核苷酸序列和推导的氨基酸序列同源性分别为97.0％～99.9％和95.9 ％～100.0％,与经典株CV777同源性分别为94.9 ％～96.0％和93.6 ％～95.3％,与GenBank中登录的PEDV参考株同源性分别为92.0％～99.6％和89.8％～99.7％.13株PEDV间M基因核苷酸序列和推导的氨基酸序列的同源性为98.2 ％～99.9％和96.0％～99.6％,与经典株CV777同源性分别为97.2％～98.2％和96.0％～98.2％,与PEDV参考株同源性分别为93.5％～99.6％和91.2％～99.1％.遗传进化分析显示,13株PEDV与中国疫苗株CV777处在不同的分群,与2016年中国福建省PEDV流行株XM1-2处于同一分支,表明河南省PEDV流行株与中国疫苗株亲缘关系较远.本研究结果明确了目前河南省PEDV的遗传变异情况,为河南省PED的诊断和防控提供了参考依据.