猪繁殖与呼吸综合征病毒R98弱毒株的分离鉴定与ORFs3～7基因特性研究

Isolation and genetic characterization of one attenuated strain R98 of porcine reproductive and respiratory syndrome virus

从江苏某种猪场自北美引进的猪繁殖与呼吸综合征病毒(PRRSV)抗体阳性临床健康仔猪血清中分离到1株病毒,经生物学特性测定、血清学试验、分子生物学鉴定、电镜观察及猪体致病性试验,鉴定为美洲型PRRSV类弱毒株。应用RT-PCR技术对该分离株ORFs3～7结构蛋白基因进行扩增、克隆与cDNA序列分析,结果表明该分离毒株的ORFs3～7基因序列与PRRSV-MLV弱毒株的相应基因同源性均达99.0%以上,属美洲型毒株。

A strain of virus was isolated from serum of health piglets with antibody to porcine reproductive and respiratory syndrome virus（PRRSV）, which were imported from North American. The isolated virus was identified as an attenuated American type virus of PRRSV through biological properties, serum assay, molecular biologic identification, electron microscopic appearance and pathogenicity for piglet. The structural protein genes ORFs3-7 were amplified by RT-PCR and sequenced. The results showed that the sequence of this isolate had high homology with that of PRRSV-MLV and which can amount to above 99% ,demonstrating that R98 may be evolved from attenuated strain of North American PRRSV.