15株猪流行性腹泻病毒河南株ORF3全基因的克隆与序列分析

为调查近年来河南省猪流行性腹泻病毒（PEDV）的遗传变异情况，从2015—2017年河南部分地区猪场患腹泻仔猪的小肠组织及内容物中克隆了15株PEDV ORF3基因，并对其进行了序列测定及分析。结果显示，15株PEDV河南株 ORF3 基因序列长度均为675 bp。15株PEDV分离株之间核苷酸同源性为94.4％～99.9％，与经典毒株CV777、弱毒株attenuated DR13核苷酸同源性分别为95.7％～97.0％和96.6％～98.1％。遗传进化分析显示，PEDV分为两大群，3株分离株属于G1群，单独成一个小的分支。其余12株分离株与往年河南流行株、大部分国内分离株、韩国、日本、美国及法国毒株位于G2群，亲缘关系较近，而与经典毒株CV777亲缘关系较远。表明河南省PEDV有变异和进化趋势，为河南省PED的防控和疫苗的研制提供技术支持。

Cloning and sequence analysis of the ORF3 gene of fifteen porcine epidemic diarrhea virus strains from Henan Province

In order to investigate recent genetic variations of porcine epidemic diarrhea virus (PEDV), ORF3 genes of 15 PEDV Henan strains were cloned and analyzed from intestinal tissues and contents of piglets with diarrhea from various areas in Henan Province from 2015 to 2017. The results showed that fifteen PEDV ORF3 sequences had 675 bp in length. The nucleotide homologies of the 15 isolates were 94.4%-99.9%, and they shared 95.7%-97.0% and 96.6%-98.1% nucleotide sequence identity to classical strain CV777 and attenuated strain DR13, respectively. Phylogenetic tree based on the ORF3 genes showed that PEDV strains could be divided into two groups, and three isolates identified in this study belonged to group 1, and formed a small branch. Other twelve PEDV isolates were located in group 2, and they seemed to be closely related to domestic strains, Korean strains, Japanese strains, American strains as well as France strains, whereas differed genetically from classical strain CV777. The results provided a new support of preventive and control and vaccine study of PEDV.