无菌性脑膜炎暴发中Echo30病毒的基因特征及分子进化分析

The genetic characterization and molecular evolution of echovirus 30 during outbreaks of aseptic meningitis

目的了解引起无菌性脑膜炎暴发的Echo30病毒的基因特征,分析其遗传变异规律及进化来源。方法对2003年济南章丘市无菌性脑膜炎暴发中分离到的Echo330病毒进行了VP1区全基因序列测定,与国内外报道的Echo30病毒VP1区序列进行同源性比较,并通过构建进化树分析其遗传进化规律。结果济南章丘市Echo30分离株VP1区核苷酸同源性在98．9％～99．5％之间,与同年山东省泰安市Echo30分离株同源性最高(98．5％～99．0％),与浙江、江苏两省的Echo30分离株同源性在98．2％～98．9％,而与1997年法国分离株(89．1％～89 7％)和2001年台湾省分离株(87．4％～87．6％)的同源性相差较大,与原型株Bastianni株同源性最低,在82．4％～82．8％。进化树分析显示,中国大陆近几年无菌性脑膜炎Echo30分离株独处一支,呈单源性发生关系。结论2003年,Echo30病毒在山东省部分地区发生了一定程度的传播,并导致了无菌性脑膜炎的局部流行,进化树分析表明,中国大陆Echo30分离株与国外早期的分离株相比,其抗原性不完全相同,已形成新的基因亚型。

Objective To study the variation and evolution rules and analyze the genetic characterization of echovirus 30 during an outbreak of aseptic meningitis. Methods For all the echovirus 30 isolates during the outbreaks in Zhangqiu city in 2003, complete VP1 genes were determined. Phylogenetic tree reconstruction and pairwise sequence were determined to compare the homological relationship and evolution rules between Zhangqiu strains and the other reported echovirus 30 in GenBank. Results Pairwise sequence comparisoms in VPI region indicated that there were 98.9 % 99.5 % identity of nucleotide acid among Zhangqiu strains, and having the highest homology with Taian strains （98.5 % 99.0% ） isolated in Shandong province. At the same time, when comparing with Zhejiang and Jiangsu strains, the nucleotide homology showed 98.2%-98.9%, relatively low identity with Taiwan strains （87.4 % -87.6 % ） and French strains（89.1% -89.7 % ） but only 82.4 % -82.8 % identity when comparing with echovirus 30 prototype strain Bastianni. Data from phylogenetic tree analyses indicated that all the echovirus 30 correlated with aseptic meningitis in China recently came from the same evolution linkage and formed a monophyletic cluster. Conclusion In 2003, there was an circulation of echovirus 30 in Shandong province which causing an endemic of aseptic meningitis in local areas. Data from phylogenetic tree analyses indicated that the antigenic characteristics of echovirus 30 in China's Mainland might be different from strains early isolated in other continents and formed a new genotype.