我国10株猪细小病毒7型全基因组遗传与重组分析

Molecular homology and recombinant analysis of 10 nearly full genomes of porcine parvovirus 7 in China

猪细小病毒7型(porcine parvovirus 7,PPV-7)是2016年首次从美国猪群发现和鉴定的新的猪细小病毒。为进一步了解PPV-7的分子流行病学特征,采用分段扩增的方法对来自我国不同省份的10份PPV-7阳性样品进行全基因组扩增和测序,并利用DNAStar、MEGA等软件对这10株PPV-7流行毒株进行分子遗传和重组分析。结果表明,10株PPV-7流行毒株与PPV-7参考毒株的核苷酸序列同源性为92.2%~95.9%,与其他同属的田鼠细小病毒2(KX272741)等参考毒株的同源性为46.1%~50.8%,与细小病毒亚科其他属参考毒株的同源性为29.4%~33.1%;因此作者建议重新将PPV-7归于一个新的病毒属。用RADP软件进一步分析PPV-7流行毒株重组时发现,不同流行毒株的重组位点和父系病毒的来源均不相同,表明这些流行毒株仍在不断发生变异和重组,且这种变异具有不确定性。这无疑增加了PPV-7致病性增强的风险,提示我们应持续重视和关注PPV-7的分子流行病学监测。

Porcine parvovirus 7(PPV-7) is a novel genus of porcine parvovirus which first identified in American pig swabs.To obtain the molecular epidemiological characteristics of PPV-7,the whole genomes of 10 PPV-7 positive samples from several provinces in China was amplified,sequenced and analyzed by DNAStar and MEGA.The results showed that the nucleic acid homology of these epidemic PPV-7 strains was 92.2%-95.9% with PPV-7 reference strains,46.1%-50.8% with other reference viruses in the same genus,and 29.4%-33.1% with other different genus in the same subfamily Parvovirinae.Thus,PPV-7 was proposed to create an additional new genus in the Parvovirinae.During the RADP analysis of PPV-7 viruses,recombinant sites and parental viruses were variable for different strains to reveal that the mutation and recombinant events among PPV-7 epidemic strains were still working uncertainly.These results would increase the risk of high pathogenicity of PPV-7,suggesting that the molecular epidemiological surveillance of PPV-7 should be paid more attention continually.