云南新分离四株流行性乙型脑炎病毒全基因组序列特征研究  

Molecular characteristics of full-length genomes of four strains of Japanese encephalitis virus newly isolated in Yunnan

作　　者：孙玉杰[1,2] 冯云[1] 章域震[1] 杨卫红[1] 张海林[1] 

机构地区：[1]云南省地方病防治所/云南省自然疫源性疾病防控技术重点实验室,云南大理671000 [2]大理大学公共卫生学院,云南大理671000

出　　处：《疾病监测》2015年第8期618-623,共6页Disease Surveillance

基　　金：国家自然科学基金(No.30560142)~~

摘　　要：目的对云南省2009年和2010年分离的4株流行性乙型脑炎（乙脑）病毒进行全基因组序列测定和分析,阐明近期乙脑病毒流行株的分子生物学特征及基因型。方法通过反转录-聚合酶链反应和核苷酸序列测定方法获得病毒全基因组序列,采用Clustal X、DNAstar和Mega等生物学软件进行核苷酸和推导氨基酸序列分析及系统进化分析。结果 2009年和2010年在云南省中部和西部地区三带喙库蚊（Culex tritaeriorhynchus）中分离到4株乙脑病毒,其中YN09M57株基因组全长10 967 bp,DH10M865、DH10M978和DHL10M62株基因组全长均为10 965 bp,均编码3432个氨基酸。这4株病毒核苷酸和氨基酸同源性分别为98.3%~99.9%和99.5%~99.9%,与来自Gen Bank的7株基因Ⅰ型乙脑病毒核苷酸和氨基酸同源性分别为98.3%~99.9%和99.7%~99.9%;与基因Ⅱ、Ⅲ、Ⅳ和Ⅴ型参考株核苷酸和氨基酸同源性分别在78.7%~89.7%和91.4%~98.4%;与乙脑减毒活疫苗SA14-14-2株在E蛋白编码区有15个氨基酸位点差异,均位于抗原关键位点之外。基于E基因、全基因组系统进化分析显示云南4株乙脑病毒均为基因Ⅰ型,并形成2个进化分支,分别与相邻省份和东南亚流行株进化关系较近。结论云南新分离4株乙脑病毒属基因Ⅰ型,虽然它们之间及其与该型参考株核苷酸和氨基酸位点存在某些差异,但决定病毒毒力和抗原性的关键位点未见明显变化。本研究提示这些乙脑病毒流行株具有稳定的遗传特性和地域特征。Objective To understand the biological characteristics and genotype of Japanese encephalitis virus（ JEV）strains newly isolated in Yunnan province. Methods The sequencing of full-length genomes was conducted for 4 strains of JEV isolated in Yunnan during 2009- 2010. Clustal X,DNAstar,MEGA and other software was used to analyze the nucleotide（ nt） data, deduced amino acid（ aa） sequence and phylogenetic trees. Results Four JEV strains（ YN09M57,DH10M865,DH10M978 and DHL10M62） were isolated from Culex tritaeniorhynchus samples in central and western Yunnan. The result of sequence analysis showed that the length of genomes of YN09M57 was 10 967 nt,encoding 3432 aa polyprotein,the lengths of genomes of DH10M865,DH10M978 and DHL10M62 were all 10 965 nt,encoding 3432 aa polyprotein. The 4 strains shared homology of genome ranging from 98. 3% to 99. 9% in nt and from99. 5% to 99. 9% in aa. Compared with 7 JEV strains genotype Ⅰ in Gen Bank,the homology ranged from 98. 3% to99. 9% in nt and from 99. 7% to 99. 9% in aa,and the homology with JEV genotype Ⅱ,Ⅲ,Ⅳ and Ⅴ in Gen Bank ranged from 78. 7% to 89. 7% in nt and from 91. 4% to 98. 4% in aa,respectively. There were 15 aa divergences which were not the key virulence loci in E protein compared with vaccine strain SA14- 14- 2. Phylogenetic analyses based on E and full-length genomes all showed that the 4 JEV strains from Yunnan belonged to genotype Ⅰ. The result also showed that 4 newJEV strains had close phylogenetic relationship with the strains from neighboring provinces and Southeast Asian. Conclusion This study indicated that JEV strains newly isolated in Yunnan were the members of JEVgenotype Ⅰ. The key virulence loci and antigenic loci in E protein did not change. These results suggested that these strains had relatively stable genetic characteristics and distinct regional features.

关 键 词：流行性乙型脑炎病毒 全基因组 同源性分析 系统进化分析 

分 类 号：R373.21[医药卫生—病原生物学]