2010年六安市肠道病毒71型的分子流行病学特征

Molecular epidemiological characterization of enterovirus 71 in Lu′an city of Anhui province in 2010

目的:探讨六安市手足口病患者中EV71的流行趋势及其基因特征,为手足口病的进一步防控提供科学依据。方法:六安市疾控中心从手足口病患儿中采集咽拭子标本进行肠道病毒核酸检测,选取其中8份EV71核酸阳性标本进一步进行VP1全基因序列测定,结果使用Bioedit和DNA Star软件与世界各地EV71各型参考株及我国大陆的EV71流行株序列进行对比分析,构建种系进化树。结果:8株病毒核酸VP1基因全长均为891个核苷酸,编码297个氨基酸,与我国大陆分离的C4a基因型最为相近,核苷酸同源性在96.7%～99.4%之间,氨基酸同源性在97.0%～100%之间;而与A、B基因型参考株差异较大,核苷酸同源性分别为82.6%～83.2%、83.1%～85.0%;氨基酸同源性分别为96.6%～97.0%、96.0%～97.7%;说明本文的8株病毒均属于EV71 C4a基因型。结论:六安市2010年EV71流行株在种系进化上与我国大陆近几年分离的毒株具有较高的同源性,同属于C4a基因型,目前C4a亚型病毒在我国大陆可能有较广泛的分布和传播。本研究对于肠道病毒的基础研究和防范EV71在中国的大规模暴发与流行具有重要意义.

Objective：To analyze the genetic characteristics and prevalence trends of Enterovirus 71（EV71） in patients with hand,foot and mouth disease（HFMD）in Lu′an City,Anhui Province,and provide scientific basis for further prevention and control of HFMD in this area.Methods： Throat swab specimens from HFMD patients from Lu′an city were collected for enterovirus nucleic acid detection in Lu′an CDC,and eight EV71 positive samples were randomly selected to conduct sequence determination of VP1 full length.The nucleotide sequences were aligned with EV71 reference strains around the world and the various types of EV71 strains in China's Mainland by Bioedit and DNASTAR software.Phylogenetic tree was constructed by clustal W method.Results： The complete VP1 genes from all eight specimens were 891 nt in length,encoding 297 amino acids.Sequence analysis showed that the homogeneity of these 8 strains shared 96.7%to 99.4% in nucleotide acid identity,and 97.0%to 100% in amino acid identity to the representative strains of C4a genotype isolated in China.But when compared to the reference strain of genotype A and B,there were only 82.6%-83.2%,83.1%-85.0% in nucleotide acid identity and 96.6%-97.0%,96.0%-97.7% in amino acid identity among them.These results suggested that these 8 virus strains belonged to the EV71 C4a subgenotype.Conclusion： The strains isolated from Lu′an city in 2010 are closely related to those isolated from other provinces in China and all of them belong to C4a subgenotype.It indicated that the C4a genotype probably widely distributes and spreads in mainland of China.The present research is important for the basic research of enterovirus and prevention and control of the EV71 outbreak in China.