2012―2013年猪繁殖与呼吸综合征病毒河南流行株的分离鉴定及分子流行病学调查

Identification and molecular epidemiology of porcine reproductive and respiratory syndrome virus prevailing in Henan province from 2012 to 2013

为了解河南地区猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus,PRRSV)流行毒株的遗传变异情况和发展趋势。通过RT-PCR方法,对2012―2013年采自河南省各地疑似病料进行PRRSV检测,并对阳性病料进行病毒分离鉴定及分子流行病学分析。结果显示:54份疑似病料中17份检测为阳性,阳性率为31.5%,并分离出3株PRRSV;通过完整的ORF5基因和部分NSP2基因序列遗传进化分析表明,河南地区流行毒株主要为美洲型PRRSV,且17份阳性样品中10份与高致病性猪繁殖与呼吸综合征病毒(HP-PRRSV)高度同源、2份与经典PRRSV高度同源、另外5份与美洲流行毒株NADC30高度同源,该类毒株的NSP2基因在不同部位存在393个核苷酸缺失,国内尚未见相关报道。结果表明,2012―2013年河南地区PRRSV主要流行毒株为HP-PRRSV,同时出现了新的变异毒株,使河南地区乃至我国PRRSV变异种类更加多样化,提示加强PRRSV流行及变异的监测十分必要。

This study aimed at analyzing the genetic variation and the development trend of PRR- SV in Henan province from 2012 to 2013. We tested 54 PRRSV samples collected from 2012 to 2013 in different districts of Henan province by RT-PCR, to isolate virus, analyze molecular epidemiology. The result showed that 17 samples of them were positive, the percentage of PRRSV positive specimens was 31. 50/0, and acquired 3 PRRSV field isolates; sequenced complete GP5 gene and partial NSP2 gene and phylogenetic analysis revealed that most of pandemic strains were the North American prototype,and in the 17 positive specimens,10 samples were highly homologous with the highly pathogenic PRRSV（HP-PRRSV）,2 samples were highly homologous with classic PRRSV, 5 samples were highly homologous with North American pandemic strain NADC30 which contained a discontinxtous deletion equivalent to 393 nucleotides, without related description in our country. The study indicated that HP-PRRSV was the popular strain in Henan province during 2012--2013,the novel variant emerged make the category of PRRSV variant more diverse, pointing that it is important to pay more attention to monitor prevalent and genetic variation of PRRSV.