2011年～2012年G9型猪轮状病毒流行病学调查及VP7基因遗传进化分析

Epidemiological survey of porcine rotavirus genotype G9 and the genetic variation analysis of VP7 gene

为分析G9型猪轮状病毒(RV)的遗传变异情况,本研究根据GenBank中VP7序列设计合成一对扩增VP7基因的引物,采用PCR方法对2011年～2012年分离的部分RV VP7基因进行扩增、克隆和序列测定,并进行比对和遗传进化分析。结果表明:531份病料中RV阳性份数为39,阳性率为7.34%;而在检测的121个猪场中,共有23个猪场显示阳性,猪场阳性率为19%。VP7基因全长1 062 bp,含有一个982 bp的开放阅读框,编码326个氨基酸。与参考病毒株VP7全长基因核苷酸比较,同源性为91.5%～99.3%。在31 nt、56 nt、75 nt、82 nt、191 nt、215 nt等位置均存在点突变,无插入和缺失。核苷酸系统发育进化树表明:黑龙江省哈尔滨市、桦南、绥化,辽宁省大连市、内蒙古自治区采集病料样品的基因间差异较小,与采集自中国广西、浙江、贵州、北京的病料样品基因相比差异性较大,这表明VP7基因存在地域差异。

To study the variation of porcine rotavirus （PoRV） genotype G9, the VP7 gene sequences of PoRV, which were isolated in different swine breeding farms in 2012, were amplified by RT-PCR technique, sequenced, and evolution analyzed. The results demonstrated that full-length VP7 gene was 1,062 bp, including a 982 bp ORF which encodes 326 amino acids. The VP7 gene shared 91.5% to 99.3% identities with PoRV reference strains. Compared with 99-SP1904, 99-SP1542, 99-TK.2091, 99-TK2082 and JP32-4 strain, point mutations were found at positions of 31 nt, 56 nt, 75 nt, 82 nt, 191 nt, 251 nt with no insertions or deletions. Phylogenetic analysis revealed that VP7 genes from Heilongjiang, Liaoning and Inner Mongolia were similar, but were significantly different fi＇om which of Guangxi, Zhejiang, Guizhou and Beijing. These results showed the VP7 gene variations were relevant to the difference of the regions.