手足口病病毒EV71衣壳蛋白VP1基因特征分析

Analysis of the genetic characteristics of capsid protein VP1 in EV71 causing hand,foot,and mouth disease

目的分析幼童手足口病病毒EV71衣壳蛋白VP1基因特征,为手足口病临床预防和控制提供指导。方法随机收集604例手足口病幼童患者标本,培养病毒株并分离鉴定。采用RT-PCR扩增EV71及其VP1区基因,经基因产物测序分析毒株的核苷酸和氨基酸序列同源性。结果604例手足口病幼童患者标本中,男性患者369例(61.09%)和女性235例(38.91%);(34.60%).1~岁179例(29.64%),2~岁216例(35.76%)和3~岁209例(34.60%)。共分离出病毒129株,分离率21.36%,其中EV71 61株(占47.29%),CoxA16 28株(占21.71%),其他肠道病毒40株(占31.01%)。61株EV71的VP1区基因序列间核苷酸同源性95.7%~100.0%,氨基酸同源性97.3%~100.0%。与C4a亚型代表株的核苷酸同源性96.4%~98.9%,氨基酸同源性99.0%~100.0%。与CoxA16原始株G-10、A、B基因型代表株VP1区以及C4b、C5亚型代表株的核苷酸同源性分别为66.0%~68.9%、78.6%~82.8%、83.2%~85.5%、95.2%~97.4%和84.5%~87.6%,氨基酸同源性分别为71.4%~75.7%、90.5%~93.6%、95.1%~96.0%、99.0%~99.8%和97.6%~99.4%。结论手足口病发病以3~4岁男性幼童为主,且以EV71为主。所分离的EV71流行株属于C4亚型。

Objective The genetic characteristics of capsid protein VP1 in EV71 causing hand,foot,and mouth disease in young children were analyzed to guide the clinical prevention and control of hand,foot,and mouth disease.Methods Samples were randomly collected from 604 young pediatric patients,and the virus was isolated and identified.EV71 and the gene encoding the VP1 region were amplified with RT-PCR,and the homology of nucleotide and amino acid sequences of the virus was analyzed by sequencing gene products. Results Of the 604 young pediatric patients with hand,foot,and mouth disease,369（61.09%）were males and 235（38.91%）were females.One hundred and seventynine patients（29.64%）were age 1-2,216（35.76%）were age 2-3,and（34.60%）were age 3 or over.One hundred and twenty-nine strains of viruses were isolated from the samples at a rate of 21.36%.The isolated strains included 61 strains of EV71（47.29%）,28 strains of CoxA16（21.71%）,and 40 strains of other enteroviruses（31.01%）.Among the 61 strains of EV71,the nucleotide similarity of the gene encoding the VP1 region was 95.7%-100.0%and amino acid similarity was 97.3%-100.0%.In the EV71 C4 asubtype,the nucleotide similarity of the gene encoding the VP1 region was 96.4%-98.9% and the amino acid similarity was 99.0%-100.0%.In the predominant CoxA16 strain（G-10）,the nucleotide similarity of the gene encoding the VP1 region was 66.0%-68.9%.In CoxA16 genotype A,the nucleotide similarity of the gene encoding the VP1 region was 78.6%-82.8%.In CoxA16 genotype A,the nucleotide similarity of the gene encoding the VP1 region was 83.2%-85.5%.In the EV71 C4 bsubtype,the nucleotide similarity of the gene encoding the VP1 region was 95.2%-97.4%.In the EV71 C5 subtype,the nucleotide similarity of the gene encoding the VP1 region was 84.5%-87.6%.In the predominant CoxA16 strain（G-10）,the amino acid similarity was 71.4%-75.7%.In CoxA16 genotype A,the amino acid similarity was 90.5%-93.6%.In CoxA16 genotype B,the amino acid similarity was 95.1%-96.0%.In the EV71 C4 bsubtype,the amino acid similarity was 99.0%-99.8%.In the EV71 C5 subtype,the amino acid similarity was 97.6%-99.4%. Conclusion Hand,foot and mouth disease mainly developed in youngmale pediatric patients 3-4 years of age,and the virus responsible was mainly EV71.Isolated strains of EV71 belonged to the C4 subtype.