Combination of intratypic and intertypic recombinant events in EV71: a novel evidence for the "triple-recombinant" strains of genotype A viruses in Mainland China from 2008 to 2010
Combination of intratypic and intertypic recombinant events in EV71: a novel evidence for the "triple-recombinant" strains of genotype A viruses in Mainland China from 2008 to 2010
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EV71型内和型间重组事件的组合：2008年至2010年中国大陆A基因型病毒“三重重组”株的新证据
DOI：
10.1007/s11262-015-1170-4
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发表时间：
2015-06-01
期刊：
影响因子：
1.6
通讯作者：
Liu, Wanhong
中科院分区：
文献类型：
--
作者：
Liu, Yongjuan;Zhang, Fengfeng;Liu, Wanhong
1969年首次分离出的肠病毒71型（EV71）被归类为A基因型。有趣的是，A基因型消失了近40年，直到2008-2010年才在中国大陆重新出现。关于重新出现的基因型A病毒的遗传特性的研究很少报道。本研究对中国a型病毒进行了分子流行病学和基因组重组分析。系统进化分析表明，1987-2011年中国大陆地区除报告的17株基因型为A型和3株孤儿株（C0、C3和B5）外，几乎所有的EV71株都属于C4亚基因型。将C4亚基因型进一步划分为C4a1、C4a2和C4b 3个支系。2008-2009年，基因型A病毒在中国东部和中部地区与优势进化支C4a2和重新出现的进化支C4b共同传播。综合重组分析表明，基因型A病毒是异型内重组和型间重组相结合的“三重重组”。在某些特定的C4a2毒株和重新出现的C4b毒株中，分别观察到最古老的C4b毒株（SHZH98）与柯萨奇病毒A5 （CVA5）之间的型间重组和在5'-UTR上有一个连接的C1毒株之间的非典型重组。在中国基因型A病毒中，重新出现的C4b毒株与特异性的C4a2毒株在5'-UTR上有一个连接，存在非典型重组。综上所述，这些结果为中国基因型A病毒的发生提供了可能的解释，对预防和控制疫情具有重要意义。
The first Enterovirus 71 (EV71) strain isolated in 1969 was classified as genotype A. It is interesting that the genotype A disappeared nearly 40 years until its re-emergence in mainland China in 2008-2010. Few studies on genetic characterization of the re-emerged genotype A viruses have been reported. In this study, a series of analyses were performed on molecular epidemiology and genome recombination of genotype A viruses in China. Phylogenetic analysis indicated that except for 17 reported genotype A strains and 3 orphan strains (C0, C3 and B5), almost all EV71 strains in mainland China were belonging to subgenotype C4 during 1987-2011. The subgenotype C4 was further divided into 3 clades C4a1, C4a2, and C4b. The genotype A viruses co-circulated with the predominant clade C4a2 and the re-emerged clade C4b both in eastern and central China in 2008-2009. Moreover, comprehensive recombination analysis showed that the genotype A viruses were "triple-recombinant" by combination of intratypic and intertypic recombination. Intertypic recombination between the oldest C4b strain (SHZH98) and Coxsackievirus A5 (CVA5) and intratypic recombination between the SHZH98 and C1 strains both with one junction in 5'-UTR were observed for some specific C4a2 strains and the re-emerged C4b strain, respectively. And intratypic recombination between the re-emerged C4b strain and the specific C4a2 strains with one junction in 5'-UTR was observed for the Chinese genotype A viruses. Taken together, these results provided potential explanations for the genesis of Chinese genotype A viruses which were significant for preventing and controlling outbreaks.