Liu Jiansheng, Zhang Haihao, Zhao Yilin, Xia Longhui, Guo Chen, Yang Huai, Luo Na, He Zhanlong, Ma Shaohui
Institute of Medical Biology, Chinese Academy of Medical Sciences, and Peking Union Medical College (CAMS & PUMC), 935 Jiao Ling Road, Kunming, Yunnan Province, 650118, People's Republic of China.
Yunnan Key Laboratory of Vaccine Research Development on Severe Infectious Disease, Kunming, 650118, People's Republic of China.
Virol J. 2016 Sep 27;13(1):162. doi: 10.1186/s12985-016-0615-2.
Four vaccine-related polioviruses (VRPV) were isolated from aseptic encephalitis cases in Yunnan, China in 2010. The genomic sequences of these VRPVs were investigated to gain a better understanding of their molecular characteristics.
Molecular typing was performed by amplification and sequencing of the VP1 region. The genomic sequences of the four VRPV3 strains were compared to vaccine strain and wild strain sequences to study genetic drift and recombination.
All four isolates could be entirely neutralized by polyclonal poliovirus 3 (PV3) antisera but not by PV1 and PV2 antisera and displayed a temperature-sensitive phenotype. The genomic sequences of all four isolates contained two Sabin 3-specific attenuating mutations at nucleotides 472(C → T) and 2034(C → T), but a third Sabin 3-specific attenuating mutation at position 2493 (T → C) had reverted back to a T. Recombination analyses showed RF108/YN/CHN/2010 and RF134/YN/CHN/2010 strain recombined with Sabin 2 at the 3'-end of the 2C to 3'-untranslated region (3'-UTR) and at the 5'-end of the 3D to 3'-UTR, respectively.
Four VRPV3 strains including two type 3/type 2 intertypic recombinants were identified. The recombination of Sabin vaccine strains with other Sabin serotypes or human enterovirus C species could be a critical factor in the potential of emerging viruses and related disease outbreaks. Therefore, it is essential to be persistent in the surveillance of EVs (including PV).
2010年在中国云南，从无菌性脑炎病例中分离出4株疫苗相关脊髓灰质炎病毒（VRPV）。对这些VRPV的基因组序列进行了研究，以更好地了解其分子特征。
通过对VP1区域进行扩增和测序来进行分子分型。将4株VRPV3毒株的基因组序列与疫苗株和野生株序列进行比较，以研究基因漂移和重组情况。
所有4株分离株均能被脊髓灰质炎病毒3型（PV3）多克隆抗血清完全中和，但不能被PV1和PV2抗血清中和，且表现出温度敏感表型。所有4株分离株的基因组序列在核苷酸472（C→T）和2034（C→T）处含有两个Sabin 3特异性减毒突变，但在位置2493（T→C）处的第三个Sabin 3特异性减毒突变已回复为T。重组分析表明，RF108/YN/CHN/2010株和RF134/YN/CHN/2010株分别在2C的3'端至3'非翻译区（3'-UTR）以及3D的5'端至3'-UTR与Sabin 2发生了重组。
鉴定出4株VRPV3毒株，包括2株3型/2型的型间重组毒株。Sabin疫苗株与其他Sabin血清型或人肠道病毒C种之间的重组可能是新出现病毒及相关疾病暴发可能性的关键因素。因此，持续监测肠道病毒（包括脊髓灰质炎病毒）至关重要。
