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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 amplify and sequence the three VP1 coding sequences of echovirus 7 (E7) isolated from Yunnan encephalitis surveillance platform and compare them with those of E7 virus prototype strain (Wallace) and former Yunnan Province Acute flaccid paralysis (AFP) cases, healthy people, and E7 viruses isolated from environmental effluents were used to characterize the VP1 coding sequence. Methods The viral VP1 coding sequences of three strains were amplified by RT-PCR and sequenced. The MEGA 5.0 software was used to construct the VP1 coding sequence evolutionary tree of three viruses, the E7 virus prototype strain and the previously isolated E7 virus in Yunnan Province for gene characterization and molecular epidemiological analysis. Results Genotype A was found in Wallace and genotype B was isolated in Yunnan. Genotype B was divided into two subtypes: subtype 1 and subtype 2, Each subtype can be divided into two distinct lineages. Three strains of viral encephalitis belonged to lineage 2 of subtype 1. Conclusion E7 is an important virus. E7 isolated from Yunnan encephalitis monitoring platform in the phylogenetic tree constitutes a self-contained cluster and forms an independent branch. It is of great significance to study the E7 virus.