埃可病毒7型云南分离株VP1编码序列基因特征分析

Genetic characteristics of the Echovirus 7 isolated in Yunnan province of China

目的对从云南省病毒性脑炎监测平台中分离到的3株埃可病毒7型(echovirus 7,E7)VP1编码序列进行扩增和测序,并与E7病毒原型株(Wallace)及以前云南省急性弛缓性麻痹(acute flaccid paralysis,AFP)病例、健康人群和环境污水中分离的E7病毒一起进行VP1编码序列基因特征分析。方法用RT-PCR方法扩增3株病毒VP1编码序列并进行序列测定。用MEGA 5.0软件构建3株病毒、E7病毒原型株及云南省以前分离的E7病毒的VP1编码序列进化树,进行基因特征和分子流行病学分析。结果 E7病毒原型株(Wallace)为基因型A,云南分离株为基因型B,基因型B又可分为两个亚型,即亚型1(subtype 1)和亚型2(subtype 2),每个亚型又可分为两个不同的进化分支(lineage)。3株病毒性脑炎分离株属于亚型1的进化分支2(lineage 2)。结论 E7是一个重要的病毒,在基因进化树中云南省脑炎监测平台分离的E7自成一簇,单独构成一个进化分支,加强E7病毒的研究具有重要意义。

Objective To study the genetic characteristics of Echovirus 7（E7）isolated in Yunnan province of China. Methods The VP1 coding sequences of 3 Echovirus 7（E7）strains isolated from viral meningitis surveillance system in Yunnan province of China were amplified and sequenced,and compared with E7 strains isolated from acute flaccid paralysis（AFP）patients, healthy children and environmental waste water.Phylogenetic tree was constructed for E7 strains by MEGA 5.0software. Results The prototype strain of E7（Wallace）belonged to genotype A,Yunnan strains were grouped to genotype B.Genotype B was further divided into two subtypes,each subtype could be divided into two lineages.Three isolates from viral meningitis were categorized to lineage 2 subtype 1 of genotype B. Conclusions Phylogenetic analysis showed that E7 isolated from viral meningitis surveillance system were clustered in a unique group to lineage 2 of subtype 1 in genotype B.