惠州市手足口病病原构成及肠道病毒71型VP1基因序列分析

Etiology of hand foot and mouth disease and genetic analysis of the VP1 region of enterovirus 71 in Huizhou

目的探讨引起本地区手足口病病原谱构成及其肠道病毒71型（Enterovirus 71,EV71）的分子特征,为手足口病的综合防治提供科学依据。方法采集501例临床表现为手足口病感染者的标本及其相关临床资料,通过real time RT-PCR方法确定肠道病毒型别,对EV71型分离株进行VP1片段测序,测序结果利用DNAStar软件进行核苷酸、氨基酸序列分析和同源性比较,并用Mega 5.0软件构建系统发生树。结果通过real time RT-PCR特异性检测发现,EV71、Cox A16和其他肠道病毒的阳性率分别为56.69%（284/501）、10.38%（52/501）、13.17%（66/501）。测序结果表明12株EV71分离株之间的VP1基因核苷酸同源性为97.9%-99.6%,氨基酸同源性为99.3%-100%。构建系统发生树表明,12株病毒基因与C基因型代表株与C4基因亚型最为相近,并且可进一步划分为C4a进化枝。说明本研究的12株病毒皆属于EV71病毒C基因型、C4a亚型。结论 EV71和CoxA16是本地区手足口病的主要病原体,因此加强EV71和Cox A16的监测特别是EV71的检测,有助于更好地预防和控制手足口病。EV71型惠州分离株均属于C4基因亚型的C4a进化分支,与2004年以来的中国大陆EV71病毒流行的基因型完全一致。

Objective To understand the etiological characteristics of hand foot and mouth disease （HFMD） and the molecular epidemiological characteristics of enterovirus 71 （ EV71 ） in Huizhou, and to provide evidence for scientific control and preven- tion of HFMD. Methods Specimens and related clinical data were collected from 501 suspected HFMD cases. Real - time RT - PCR was.carried out for the identification and typing of enterovirus. VP1 genes of the EV71 isolates were sequenced. And DNAStar was used to analyze the results, especially the degree of nucleotide sequence and amino acid sequence and to compare the homology, and use Mega 5.0 to construct the phylogenetic tree. Results The real - time RT - PCR assay indicated that the positive rates of EV71, CoxA16 and other enterovirus in 501 specimens from suspected HFMD cases were 56.69% （284/501） , 10.38% （52/501） and 13.17% （66/501）, respectively. The degree of nucleotide and amino acid sequence homology among the 12 isolated strains ranged from 97.9% to 99.6% and 99.3% to 100% %, respectively. Phylogenetic tree showed that, 12 strains of the virus gene was most similar to C gene and C4 gene type strains subtype, and can be further divided into C4a clade. It shows that these 12 EV71 isolated strains were within genotype C subgenogroup C4 in the phylogenetic tree. Conclu- sion EV71 and CoxA16 were the major pathogens of HFMD in Huizhou. It is necessary to improve the surveillance of EV71 and CoxA16, especially EV71, for the better prevention and control of HFMD. EV71 isolated in Huizhou city were phylogeneti- cally related to CAa in the CA subgenotype, the genotype of these isolates is in line with the EV71 circulating in China's Mainland since 2004.