摘要
为查明山东省某猪场流行性腹泻的病因，本研究对该猪场病死仔猪进行病理学检查，并对采集的7份仔猪腹泻样品进行猪流行性腹泻病毒（PEDV）的套式RT-PCR检测。病理学检查发现病猪的肠道肿胀、变薄、出血，肠绒毛皱缩、变短、边缘粗糙。套式RT～PCR结果显示，7份样品均为PEDV阳性；对其中两份PEDV阳性病料进行S基因扩增，分析其遗传变异，结果显示这两株PEDV野毒株的s基因与参考疫苗株CV777的同源性为92．3％～92．4％，与其他野毒株的同源性为96．6％～98．6％。PEDV的遗传进化树结果显示，PEDV分为两个进化分支G1和G2，G1包括CV777等疫苗株及中国和韩国早期的部分毒株，G2则是PEDV变异株为主的分支，包括本试验分离的野毒株及近年来美国、中国等国的野毒株，这些毒株都存在两个插入突变和1个缺失突变。结果表明，变异株已成为PEDV的流行优势毒株，且这些变异位点有可能成为鉴定PEDV变异株的分子特征。
To ascertain a diarrhea case in a pig farm in Shandong province,the pathological chan- ges of dead piglets were observed and nested RT-PCR test was carried out on 7 diarrhea samples for porcine epidemic diarrhea virus （PEDV）. Pathological examination revealed that intestine was detected as enlargement, hyperemia and edema. After histological examination, the typical micro- scopic lesions of intestine were disappearance of epithelial cells, villus shrinkage and shortening. The result of nested RT-PCR showed that all of the 7 samples could amplify a specific target band of PEDV. Molecular characteristics of two field strains showed that they had an amino acid ho- mology of 92.3% to 92.4% with vaccine CV777 and 96.6% to 98.6% with other previous field strains which sequences were downloaded from GenBank. Phylogenetic tree analysis further re- vealed that all of PEDV strains could be mainly divided into two clusters of G1 and G2. G2 con- sisted of the field strains of our study and other field strains from USA, China and so on, which had the same sequence characteristics of two insertions and one deletion,while G1 consisted of all vaccines of CV777 and several older field strains from China and Korea. These results indicated that our field strains were the dominant strains in recent epidemic diarrhea occurrence. Moreover, its molecular characteristics might be a characterization of differentiating the field and vaccine strains.
出处
《中国畜牧兽医》
CAS
北大核心
2015年第7期1654-1660,共7页
China Animal Husbandry & Veterinary Medicine
基金
青岛市民生计划项目(13-1-3-91-nsh)
关键词
猪流行性腹泻病毒
鉴定
分子特征
S基因
porcine epidemic diarrhea virus
identification
molecular characteristics ~ S gene
