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为了解云南省疫苗衍生脊髓灰质炎病毒(Vaccine-derived Poliovirus,VDPV)的基因组特征,对2010年及2012年监测到的4株VDPV进行全基因组序列测定。结果显示,2株Ⅱ型VDPV的基因组全长均为7439nt,与Sabin Ⅱ疫苗株全基因组核苷酸和氨基酸的序列同源性分别为95.4%和97.7%;2株I型VDPV基因组全长均为7441nt,与Sabin I疫苗株全基因组核苷酸和氨基酸序列的同源性分别为93.9%和97.9%。减毒位点分析发现II型和I型VDPV毒株分别有两个(nt 481和nt 2909)和三个减毒位点(nt 480、nt 2795和nt 6203)发生了回复突变。VP1序列分析显示II型和I型VDPV毒株与相应Sabin株的变异分别为1%和2.3%,重组分析显示II型和I型VDPV的基因组结构分别为S2/S3和S1/S2/S1/S3,后者的重组次数高达3次,显示了重组的普遍性和复杂性,也表明了病毒在人体内复制和传播的持久性与重组的多样性成正相关。因此,从分子水平分析VDPV的特性,可掌握病毒的变异动态,为制定科学可行的VDPV控制策略提供理论依据。
In order to understand the genomic characteristics of Vaccine-derived Poliovirus (VDPV) in Yunnan Province, genome-wide sequence analysis of 4 VDPV strains detected in 2010 and 2012 was performed. The results showed that the two genotypes of type Ⅱ VDPV were all 7439nt in length and shared 95.4% and 97.7% identity with the whole nucleotide and amino acid sequence of Sabin Ⅱ vaccine strain respectively. Was 7441nt, which shared 93.9% and 97.9% identity with the genome-wide nucleotide and amino acid sequence of Sabin I vaccine strain, respectively. Analysis of the attenuated sites revealed a back mutation in two (nt 481 and nt 2909) and three attenuated (nt 480, nt 2795 and nt 6203) strains of type V and type V VIVs, respectively. VP1 sequence analysis showed that the VDPV strains of type II and type I had 1% and 2.3% variation with the corresponding Sabin strains, respectively. Recombinant analysis revealed that the genomic structure of type VDPVs of type II and type I were S2 / S3 and S1 / S2 / S1 / S3, which is up to 3 times in number of recombinations, shows the universality and complexity of recombination and also shows that there is a positive correlation between the persistence of replication and spread of the virus in the human body and the diversity of recombination. Therefore, analyzing the characteristics of VDPV from the molecular level can grasp the variation of the virus and provide a theoretical basis for the development of a scientific and feasible VDPV control strategy.