埃可病毒7型分离株全基因序列分析  

Complete Genome Sequence of the Echovirus 7 Strain Isolated in Zhejiang Province,China

作　　者：邱晓枫[1] 吕华坤[2] 刘小东 潘劲草[1] 汪皓秋[1] 陈树昶[1] QIU Xiaofeng;LYU Huakun;LIU Xiaodong;PAN Jincao;WANG Haoqiu;CHEN Shuchang(Hangzhou Center for Disease Control and Prevention,Hangzhou 310021,China;Zhejiang Provincial Center for Disease Control and Prevention,Hangzhou 310051,China)

机构地区：[1]杭州市疾病预防控制中心,杭州310021 [2]浙江省疾病预防控制中心,杭州310051

出　　处：《病毒学报》2020年第6期1050-1058,共9页Chinese Journal of Virology

基　　金：杭州市农业与社会发展科研计划项目(项目号:20170533B76),题目:杭州市区手足口病患儿中埃可病毒的检测及其分子特征研究;浙江省公益技术应用基金(项目号:2012C33063),题目:儿童重症病毒性脑炎早期识别和干预关键技术研究。

摘　　要：埃可病毒7型(Echovirus 7,ECHO7)属于小RNA病毒科人肠道病毒属,常引起儿童病毒性脑炎、手足口病和急性迟缓性麻痹等疾病。为了解病毒性脑炎患者脑脊液中分离获得的一株ECHO7毒株(40/Longyou/ZJ)的全基因组特征,进行全基因组测序并分析其分子变异和遗传进化特点。设计引物,提取病毒RNA,PCR扩增和序列测定获得全基因序列。利用Mega4.1、DNAstar、RDP4和SimPlot3.5.1软件分析全基因序列。40/Longyou/ZJ病毒株基因组全长7426个核苷酸(nt),5′端和3′端分别为741nt和100nt的非编码区(Untranslated region,UTR),5′UTR和3′UTR间为一个6585nt长的开放阅读框,编码含2194个氨基酸的多聚蛋白。与GenBank中12株ECHO7代表株的全序列比较发现,核苷酸相似性为79.3%~85.7%,氨基酸相似性为95.5%~97.8%。基于5′UTR、P1和P2区构建的遗传进化树中,40/Longyou/ZJ株与ECHO7参考株均在同一进化分支;但在P3区的遗传进化树中却与其他肠道病毒B组病毒聚类。RDP4和SimPlot3.5.1软件分析均证实40/Longyou/ZJ分离株与柯萨奇病毒B组4型(Coxsackievirus B4,CVB4)存在基因自然重组现象,重组位点主要在编码逆转录酶蛋白的3D区。本研究首次对我国脑脊液中分离的ECHO7进行全基因序列测定和分析,发现40/Longyou/ZJ分离株与CVB4存在基因重组,对研究ECHO7的遗传特性具有重要意义。Echovirus 7 belongs to the genus Enterovirus and family Picornaviridae.Viral encephalitis,hand,foot,and mouth disease and acute flaccid paralysis have been reported to be associated with echovirus 7 infection.We wished to identify the complete genome sequence of an echovirus 7 strain(40/Longyou/ZJ)isolated from the cerebrospinal fluid(CSF)of patient with viral meningitis in Zhejiang Province,China.A full genome analysis was conducted to reveal molecular variations and evolutionary characteristics.Thirteen overlapping clones covering the whole viral genome(excluding the poly-A tail)were obtained by reverse transcription-polymerase chain reaction and sequenced.Their nucleotide and amino-acid sequences were aligned with other echovirus-7 isolates.Phylogenetic and pairwise alignment analyses based on the genome were conducted with Mega4.1,RDP4,DNAstar and SimPlot3.5.1.The genome of echovirus 7 was 7,426 nucleotides in length,and contained a 741-nt 5′untranslated region(5′UTR)and a 100-nt 3′UTR.The entire open-reading frame contained 6,585 nt and encoded a single 2,194-amino-acid polyprotein.Compared with 12 representative strains of echovirus 7 in GenBank,the nucleotide similarity was 79.3%–85.7%,and the aminoacid similarity was 95.5%–97.8%.The phylogenetic tree was based on 5′UTR,P1 and P2 regions,respectively,and the 40/Longyou/ZJ strain and echovirus-7 reference strains were in the same evolutionary branch.In the phylogenetic tree based on the P3 region,the 40/Longyou/ZJ strain was a cluster with other enterovirus group-B viruses.These results were assessed by RDP4 and SimPlot3.5.1,which confirmed a natural recombination between 40/Longyou/ZJ isolates and coxsackievirus B4(CVB4).The main recombination regions were in the three-dimensional region that encoded the reverse transcriptase protein.This report is the first to describe the complete genome of echovirus 7 isolated from the CSF of a person in China.The 40/Longyou/ZJ isolate underwent gene recombination with CVB4,which is important for study of th

关 键 词：埃可病毒 全基因组 序列分析 重组 

分 类 号：R373.24[医药卫生—病原生物学]