2017年江西部分地区PEDV分子流行病学调查

为了解江西地区猪流行性腹泻病毒(PEDV)的流行和变异情况,本研究利用RT-PCR方法对2017年采自江西省部分地区规模化猪场182份腹泻仔猪小肠组织和粪便样品进行检测,并设计了2对引物对37份阳性病料的S基因进行扩增、克隆及序列测定,以及与GenBank中登录的22株PEDV S基因参考序列进行遗传进化分析。结果显示,37株PEDV江西流行株的S基因序列长为4 158或4 161 bp,编码1 385或1 386个氨基酸,全部为Group 1型,与美国流行毒株较为接近,而与欧洲毒株(Br1/87)及疫苗株(CV777)亲缘关系较远;37株PEDV中有36株为G1-1亚群,1株为G1-2亚群;37株PEDV江西毒株间的S基因核苷酸序列同源性为96.9%～100.0%,氨基酸序列同源性为96.1%～100.0%,与22株参考毒株的核苷酸、氨基酸序列同源性分别为92.7%～100.0%和91.5%～100.0%;相较于CV777疫苗株,PEDV江西流行毒株的S基因存在碱基缺失、插入和位点突变现象。本研究从分子流行病学角度证实了2017年江西部分地区PEDV的流行与变异情况,为指导江西省PEDV的科学防控提供了参考依据。

Molecular Epidemiological Investigation of Porcine Epidemic Diarrhea Virus in Jiangxi Province in 2017

To investigate the epidemiological and genetic variation of porcine epidemic diarrhea virus (PEDV) in Jiangxi province,a total of 182 clinical porcine intestinal and fecal samples were collected from pig farms in some areas of Jiangxi province in 2017 and detected for PEDV by RT-PCR.Two pairs of primers were designed and the S gene from 37 PEDV positive samples were amplified,cloned and sequenced.Genetic evolution analysis of S gene was performed using bioinformatics software and referenced PEDV strains registered in GenBank.The results showed that the length of S gene genome of 37 Jiangxi PEDV strains was 4 158/4 161 bp,encoding 1 385/1 386 amino acids.All PEDV strains belong to Group 1 which had a close relationship with the United States strains,and differed genetically from European strains (Br1/87) and the vaccine strains (CV777).36 of 37 PEDV Jiangxi strains were G1-1 and 1 strain was G1-2.The nucleotides homology of S gene among 37 PEDV strains were 96.9% to 100.0%,and that of amino acids homology was 96.1% to 100.0%.The nucleotides and amino acids homology of S gene between PEDV strains and referenced PEDV strains were 92.7% to 100.0% and 91.5% to 100.0%,respectively.Compared with the vaccine strains (CV777),S gene of PEDV Jiangxi strains existed bases deletions,insertions and mutation.This study confirmed the prevalence and variation of PEDV in Jiangxi province from the perspective of molecular epidemiology,and provided references for guiding the scientific prevention and control of PEDV in Jiangxi province.