仔猪感染猪轮状病毒的鉴定及基因分析

GENETIC ANALYSIS OF PORCINE ROTAVIRUS INFECTION IN PIGLETS

为弄清2013年年初上海某猪场发生的仔猪腹泻疫情病因,本研究随机采集发病猪场的仔猪腹泻样品9份,利用RT-PCR方法对采集样品进行病原检测。结果显示,9份临床样品中有4份为猪轮状病毒阳性,而猪流行性腹泻病毒和猪传染性胃肠炎病毒均为阴性。根据GenBank公布的猪轮状病毒参考株序列设计两对引物,对其中阳性样品的VP6和VP7基因进行RT-PCR扩增、基因克隆和序列测定分析。结果显示,4份阳性样品的VP6基因大小为1356 bp,VP7基因大小为1100 bp;序列分析结果显示,VP6基因与A群代表株OSU的氨基酸同源性为64.1%~87.0%,与代表株Gottfriend的氨基酸同源性为26.3%~60.8%;VP7基因与不同G型代表株的氨基酸同源性为71.8%~97.3%。根据上述结果分析,我们推测引起此次仔猪腹泻疫情中的主要病原是由属于A群G9血清型的猪轮状病毒引起,本研究为此次仔猪腹泻疫情的诊断提供了依据。

Diarrhea outbreaks occurred in piglets in early 2013 in Shanghai. To identify the etiological agents, nine fecal samples were randomly collected from ill animals and tested in RT-PCR for the presence of rotaviruses, Transmissible gastroenteritis virus (TGEV)and Porcine epidmic diarrhea virus (PEDV). Four of 9 samples were rotavirus positive (44.4%). All samples were TGEV or PEDV negative. Based on sequences of VP6 and VP7 of reference strain in GenBank, two pairs of primers were designed for amplifying the target genes. The full-lengths of VP6 and VP7 were 1300 bp and 1100 bp. Sequence alignments showed that VP6 shared 64.1%-87.0%amino acid homology with OSU strain in group A and 26.3%-60.8%with Gottfriend strain. As for VP7, homology of amino acid sequences ranged from 71.8%to 97.3%with G type strains. Analysis of PoRV VP7 suggested that it belong to G9 genotype. These results established a reliable basis for prevention and control of piglet diarrhea.