山东省2007年肠道病毒71型基因特征分析

Genetic Characterization of Enterovirus 71 Strains Isolated in Shandong Province,2007

目的阐明引起山东省2007年手足口病(Hand-Foot-Mouth Disease,HFMD)流行的肠道病毒71型(Entero-virus71,EV71)基因特征。方法对从山东省2007年HFMD患者分离到的EV71,采用逆转录-聚合酶链反应(Re-verse Transcription Polymerase Chain Reaction,RT-PCR),进行VP1编码区基因扩增,并对扩增产物进行序列测定和分析。结果从山东省2007年HFMD患者标本中共分离到50株EV71。根据VP1部分基因核苷酸序列与EV71其它基因型和亚型参考株建立亲缘性关系树,50株病毒与C4亚型代表株聚为一簇。对其中的17个代表株进行VP1编码基因全序列测定,根据VP1全基因序列构建亲缘性关系树,17个代表株与C4亚型仍然聚为一簇,与C4亚型代表株的核苷酸序列同源性为92.3%～93.8%。结论引起山东省2007年HFMD的EV71均为C4亚型,但与中国大陆以往分离的C4亚型毒株有较大差异,提示C4亚型毒株在中国大陆传播了较长时间,有多个不同分支的C4亚型毒株曾在中国大陆流行。应加强对引起HFMD的EV71作分子流行病学监测,阐明现阶段流行的EV71基因型别和基因特征。

Objective To reveal the genetic characteristic of enterovirus 71 （EV71） strains isolated during an epidemic of Hand-Foot-Mouth Disease （HFMD） in Shandong in 2007. Methods EV71 strains were isolated from the patients of HFMD during the epidemic in Shandong, 2007. The VP1 coding gene of EV71 strains was amplified by reverse transcription-polymerase chain reaction （RT-PCR）and sequenced. Then the sequences were analyzed by software. Results 51 EV71 strains were isolated from the patients of HFMD in Shandong. The phylogenetic tree was constructed between isolated and other EV71 reference strains based on alignment of the par- tial sequence of VP1 gene. Fifth-one isolated strains clustered with the reference strains of C4 subgenotype. Seventeen isolated strains were selected for sequencing of complete VP71 coding gene. They also clustered with reference strains of C4 subgenotype in the phylogenetic tree. The nucleotide identity with C4 reference strains is 92.3%-93.8%. Conclusions The isolated strains in this study are all C4 subgenotype,the same as most of the isolates in China. But there is a large variation compared with the C4 strains isolated in China before. It suggested that strains of C4 subgenotype may have been spreading for a long time in China and C4 strains belonging to several different clades have been prevalent. To reveal the genotype and genetic characteristic of EV71 prevalent in China,we still need to get more molecular epidemiologic data.