河南省部分地区猪流行性腹泻病毒ORF3和N基因的克隆及其遗传进化分析

为探究河南省猪流行性腹泻病毒部分毒株的遗传进化情况,采用RT-PCR对2017年2月至2018年1月在河南省部分地区猪场收集到的25份PEDV阳性病料进行ORF3和N基因的扩增,并对其进行克隆、序列比对及遗传进化分析。结果显示,PEDV毒株的ORF3基因序列是由675个核苷酸组成的,与经典毒株CV777之间核苷酸及氨基酸同源性分别为95.2%~97.5%和95.1%~96.9%。N基因之间的核苷酸与氨基酸同源性分别为96.2%~100%和93.8%~99.8%;与经典毒株CV777核苷酸与氨基酸的同源性分别为94.7%~95.8%和93.2%~96.8%。河南部分地区PEDV流行毒株与经典毒株CV777不在同一分支,说明猪场暴发猪流行性腹泻与免疫接种疫苗后依旧难以控制的原因,可能与大多数PEDV河南流行株发生变异有关。

Cloning and Phylogenetic Analysis of ORF3 and N Genes of Porcine Epidemic Diarrhea Virus (PEDV) in Some Regions of Henan

In order to explore the prevalence and mutation of porcine epidemic diarrhea virus(PEDV)in Henan Province,ORF3 and N genes were amplified from 25 PEDV field strains by RT-PCR,cloned,sequenced and compared with the other reference strains in GenBank,which were collected from different regions of Henan Province from February 2017 to January 2018.The results showed that the ORF3 genes of25 PEDV field strains are all 675 bp,These PEDV ORF3 have 95.2%-97.5%and 95.1%-96.9%similarities with CV777 at nucleotide and amino acid levels,respectively.The similarities of nucleotide and amino acid levels between N gene are 96.2%-100%and 93.8%-99.8%,respectively.These PEDV N gene have94.7%-95.8%and 93.2%-96.8%similarities with CV777 at nucleotide and amino acid levels,respectively.The PEDV epidemic strains in some parts of Henan are not in the same branch as the CV777,it showed that the reason why pig epidemic diarrhea and immunization vaccines were still difficult to control after pigs outbroke may be related to the variation of most PEDV Henan strains.