猪流行性腹泻病毒广东分离株GD/JMEP的遗传演化分析

Analysis of genetic evolution of porcine epidemic diarrhea virus GD/JMEP isolated from Guangdong Province

为了解广东地区猪流行性腹泻病毒(PEDV)的流行现状,对广东地区猪场进行了PEDV流行株的分离,分离得到1株猪流行性腹泻病毒,对分离毒株的S、N、M及ORF3基因进行遗传演化分析。结果表明:检测的PEDV毒株GD/JMEP与经典的CV777毒株亲缘关系较远,与近几年广东地区流行的PEDV毒株处于一个群,亲缘关系较近;通过ORF3序列分析发现,未有核苷酸的缺失;N、M基因核苷酸和氨基酸同源性分析发现,GD/JMEP与EAS1等经典毒株的同源性相对较低,与2013—2015年中国、美国、韩国等流行毒株的同源性较高;相比于经典传统毒株CV777,GD/JMEP的N基因存在9个氨基酸的差异,M基因存在11个核苷酸位点的变异和3个氨基酸的改变S基因存在几个位点核苷酸的缺失或者插入;与目前流行毒株比较,M、N基因存在核苷酸位点的改变,S基因在406位点存在新的突变;通过氨基酸比对分析,GD/JMEP发生了6个新的氨基酸位点突变,表明本试验所检测的PEDV为目前广东流行毒株。

This study aimed to investigate the epidemic situation of porcine epidemic diarrhea virus（PEDV）. One PEDV strain namedGD/JMEP was isolated. The S, N, M and ORF3 genes of the isolate were cloned and sequenced as well as analyzed by bioinformatics. Theresults indicated that the tested PEDV strain GD/JMEP was far from CV777 strain but had closer relationship with the epidemic PEDV strainsin Guangdong, which were in the same branch. No deficiency of acid sequence was found in the ORF3 gene. Nucleotide and amino acid se-quence analysis of N or M gene indicated GD/JMEP exhibited fewer identities compared with classical strain such as EAS1, but a high iden-tity with the epidemic strains in China, American and Korea from 2013 to 2015 Nine amino acid mutation in N gene and 11 nucleotide and 3amino acid mutations in M gene were detected in GD/JMEP isolate compared with classical CV777 Nucleotides insertion or deletion of GD/JMEP were found in several sites of S gene compared with classical strains. New mutation at 406 nt of S gene compared with the latest epidem-ic strain was founded. Six new mutations of amino acid sites indicated GD/JMEP was a variant epidemic strain in Guangdong Province.