人肠道病毒A71型分离株全基因组序列及毒力相关位点分析  

Genetic Evidence for Recombination and Mutation in the Emergence of Human Enterovirus 71

作　　者：刘爱平[1] 谭徽[1] 谢群[1] 陈柏塘[1] 刘晓峰[1] 张勇[2] 

机构地区：[1]郴州市疾病预防控制中心,郴州423000 [2]中国疾病预防控制中心病毒病预防控制所、世界卫生组织西太区脊髓灰质炎参比实验室、卫生部医学病毒与病毒病重点实验室,北京102206

出　　处：《病毒学报》2014年第5期572-578,共7页Chinese Journal of Virology

基　　金：郴州市科技计划项目(CZ2013108)

摘　　要：为了解人肠道病毒A71型（Enterovirus A71,EV-A71）的基因重组和遗传进化特征,探索其毒力相关位点。本研究通过对郴州市3株EV-A71分离株进行全基因组序列测定和分析,应用RDP软件（版本4.1.6）将其与231条EV-A71全基因组序列进行比较分析,检测可能的重组事件及重组位点;采用SimPlot软件（版本号3.5.1）对重组序列、2条亲本序列和其他A组肠道病毒（EV-A）代表株序列进行相似性分析;采用MEGA软件（版本5.2）构建系统发生树;结果发现郴州市3株EV-A71毒株均检测到重组信号,其共同的亲本主序列为广东省2009年毒株,亲本亚序列为中国台湾地区2008年毒株;我国C4b进化分支EV-A71代表株（分离于1998年的SHZH98株）和C4a进化分支EV-A71代表株（分离于2008年的安徽阜阳株）均与CVA4、CVA14及CVA16原型株在3D区域检测到型间重组信号。采用SPSS软件（版本19.0）对不同病例类型的变异位点作卡方检验以筛选出可能的毒力相关位点。发现死亡病例组与重症病例组间未找到具有统计学意义的突变位点;而死亡与重症病例合并组与一般病例组进行比较,共发现18个突变位点具有统计学意义,这些突变位点仅分布于P2区和P3区,而P1区未见。我国大陆的EV-A71流行株与EV-A其他毒株的型间重组早在1998年前即已经发生,并且在2008~2012年的手足口病暴发疫情中,EV-A71的型内重组频繁发生。此外,EV-A71毒力的改变可能与非衣壳蛋白区的变异相关,因此应该关注非衣壳蛋白基因改变对病毒毒力的影响。We wished to understand the genetic recombination and phylogenetic characteristics of human en- terovirus A71 （EV-A71） and to explore its potential virulence-related sites. Full-length genomes of three EV-A71 strains isolated from patients in Chenzhou City （China） were sequenced and analyzed. Possible re- combination events and crossover sites were analyzed with Recombination Detection Program v4. 1.6 by comparison with the complete genome sequences of 231 strains of EV-A71. Similarly, plot and bootscan- ning analyses were undertaken with SimPlot v3.5.1. Phylogenetic trees based on the sequences of VP1 re- gions were constructed with MEGA v5. 2 using the Kimura two-parameter model and neighbor-joining method. Results suggested that recombination events were detected among the three EV-A71 isolates from Chenzhou City. The common main parent sequence was from JF799986 isolated from samples in Guang- zhou City （China） in 2009, and the minor parent sequence was TW/70516/08. Intertypic recombination e- vents were found in the C4b strain （strain SHZH98 isolated in 1998） and C4a strain （Fuyang strain isola- ted in 2008） with the prototype strains of CVA4 and CVA14 in the 3D region. The chi-square test was used to screen-out potential virulence-related sites with nucleotide substitutions of different types of hand, foot, and mouth disease （HFMD） cases using SPSS v19.0. Results suggested that there were no signifi- cant nucleotide substitutions between death cases and severe-HFMD cases. Eighteen significant nucleotide substitutions were found between death/severe-HFMD cases and mild-HFMD cases, and all these 18 sub- stitutions were distributed only in P2 and P3 regions. Intertypic recombination among the predominant cir- culating EV-AT1 strains in the Chinese mainland and other EV-A strains probably dates before 1998, and intratypic recombination might have occurred frequently in the HFMD outbreak from 2008 to 2012. Substi- tutions in the non-capsid region may be correlated with the changes in viru

关 键 词：人肠道病毒A71型 全基因组序列 毒力 基因重组 基因突变 

分 类 号：R373.24[医药卫生—病原生物学]