肠道病毒71型宁波株分子流行病学研究

Study on the genome feature and molecular epidemiology of Enterovirus 71 isolated in Ningbo,Zhejiang province,China

目的:分析肠道病毒71型2010年宁波分离株的分子流行病学特征。方法:收集2010年宁波市手足口病患者临床标本177份,进行EV71荧光定量RT-PCR鉴定和病毒分离,采用RT-PCR对38株分离到的EV71进行VP1编码区基因扩增,并对扩增产物进行核苷酸序列测序和分析。根据VP1测序结果与国内外报道的各基因型和基因亚型EV71VP1序列进行同源性和亲缘进化分析。结果:88份鉴定为EV71的临床标本中共分离到38株病毒,分离株的VP1区核苷酸和氨基酸同源性分别是97.1%～100%和99.3%～100%。与C4a亚型的核苷酸和氨基酸同源性分别为93.2%～99.3%和98.3%～100%。亲缘进化树显示,宁波分离株全部属于C4基因亚型的C4a进化分支,并存在多个传播链。结论:宁波地区分离的EV71与近几年国内其他地区EV71分离株亲缘关系很近,有共同进化的趋势,属于C4基因亚型的C4a进化分支,并存在多个传播链。

Objective：To analyze the genome characterization and molecular epidemiology of EV71 strain isolated from clinical specimens of HFMD patient in Ningbo.Methods：Specimens were collected from clinically diagnosed cases with hand,foot and mouth disease in Ningbo in 2010,real-time quantitative RT-PCR were carried out to identify and isolate EV71.All isolated EV71 strains were performed for amplification and sequencing in entire VP1 coding region.Subsequently homology and phylogenetic analysis based on VP1 and others have published in GenBank were conducted.Results：38 Ningbo EV71 strains were isolated from HFMD patients in Ningbo in 2010 and the homology of nucleotide and amimo acid were 97.1%～100% and 99.3%～100%.The Ningbo strain shared the highest similarity with the type C4a were 93.2%～99.3% and 98.3%～100%.Phylogenetic analysis revealed that Ningbo strains clusterd within the C4a evolution branch of C4 subgenotype.Conclusion：The results indicated that EV71 isolated from HEMD patients in Ningbo was belong to C4a evolution branch of C4 subgenotype with several transmission chains.The data confirmed that these strains co-evolve with other C4 subgenotype isolated in China.