猪繁殖与呼吸综合征病毒的分离及其基因组变异特征的研究

Isolation of porcine reproductive and respiratory syndrome virus of XX2015 strain and study on genetic diversity of the strain

为了解猪繁殖与呼吸综合征病毒（PRRSV）在河南省新乡地区猪体内的进化情况,笔者对河南省新乡地区某猪场送检的疑似猪繁殖与呼吸综合征的病料进行了病毒的分离鉴定,并采用PCR扩增得到了该病毒的全基因组序列,同时对分离病毒株的GP5和NSP2序列进行了比对分析。结果显示：成功分离并鉴定出1株美洲型PRRSV（XX2015）,与中国代表毒株CH-1a中的核苷酸同源性是92.8%,与高致病性（HP）-PRRS病毒代表株Hu N4、Hu B1、He Nan-1、He NAN-A14株的核苷酸同源性则分别为97.2%、97.0%、97.2%、94.4%。对基因组的进一步分析表明,该毒株GP5蛋白非中和性表位处存在氨基酸变异,NSP2蛋白在第481位、第485-488位、第533-561位共缺失34个氨基酸。XX2015分离株是HP-PRRSV的一个代表株,该病毒株在NSP2蛋白中存在跳跃性突变,为进一步研究猪繁殖与呼吸综合征病毒的分子进化提供了分子证据。

This study aimed at investigating the genetic variation of porcine reproductive and respiratory syndrome（PRRS） in Xinxiang Prefecture,Henan Province. The porcine reproductive and respiratory syndrome virus（PRRSV） was isolated from samples suspected PRRSV infection. The full-length genomic sequence of the virus was amplified by PCR,and the GP5 and NSP2 gene were analyzed,respectively. Results showed that one filed strain PRRSV named as XX2015 strain was isolated,and it shared 92.8% nucleotide similarity of complete sequence with CH-1a strain,97.2%,97%,97.2% and 94.4% compared with Hu N4,Hu B1,He Nan-1,He NAN-A14 strains,respectively,which belongs to North American genotype PRRSV.The GP5 protein sequence was variable in the sites of none neutralizing epitope.In addition,the full-length genomic sequence of the virus revealed one distinct deletion in NSP2 which had significant difference with the 30 amino acid of HP-PRRSV. XX2015 strain was a representative strain of HP-PRRSV emerged in China,and the jumping deletion mutation in the NSP2 would provide the molecular evidence to research the molecular evolution of PRRSV.