柯萨奇病毒A组4型云南分离株的基因特征分析

Genetic analysis of coxsackievirus A4 isolated for Yunnan province of China

目的对中国云南省6株和其他10个省(含中国台湾省)不同时间、不同来源分离的柯萨奇病毒A组4型(coxsackievirus A4,CV-A4)VP1区基因特征进行分析。方法对云南省2014年手足口病实验室监测系统、2012年健康人群和2004年急性迟缓性麻痹(acute flaccid paralysis,AFP)监测系统中分离到的6株CV-A4病毒VP1区基因进行基因扩增和测序;按参考文献下载基因库中CV-A4病毒VP1区基因参考序列和其他省CV-A4基因序列,用MEGA 5.0软件计算不同毒株的核苷酸和氨基酸差异率,并构建系统进化树,进行基因特征和分子流行病学分析。结果云南6株CV-A4均为基因1型的B亚型(genotype1,subtype B)。与国内其他省毒株比较,除1998年2株山东省和2006年1株吉林省AFP分离株为基因1型的A亚型(genotype 1,subtype A),台湾省4株(AB571583、AB571584、AB571586、AB571587)为基因2型的B亚型(genotype 2,subtype B)外,其他中国分离株均为基因1型的B亚型。结论除CVA4病毒的原型株High Point(AY421762)外,国内外CV-A4病毒存在两个基因型,两个基因型又分为两个亚型,即A和B亚型;中国分离株大都为基因1型,其中又以B亚型为主。不同于EV-A71和CV-A16,CV-A4的基因型分布不是很广。

Objective To analyzea the genetic characteristics of coxsackievirus A4（CV-A4）isolated from Yunnan province of China. Methods RT-PCR and VP1 gene sequencing were done for 6CV-A4 strains isolated from hand,foot and mouth disease（HFMD）surveillance system in 2014,healthy children（HC）in2012and acute flaccid paralysis（AFP）surveillance system in 2004 in Yunnan province of China.VP1 gene sequences of CV-A4 reference strains and strains isolated from other provinces in China were downloaded from the GenBank and their nucleotide（nt）and amino acid（aa）diversities were calculated by MEGA 5.0software,the phylogenetic tree was constructed and the genetic characteristics and molecular epidemiology were analyzed. Results Phylogenetic analysis for 6Yunnan CV-A4 strains showed that all belong to genotype 1subtype B.Compared with other strains in China,2strains isolated in Shandong province in 1998 and 1strain from Jilin province in 2006 from AFP cases were genotype 1subtype A,4Taiwan Residents strains（AB571583,AB571584,AB571586 and AB571587）were genotype 2subtype B,all other Chinese strains were genotype 1subtype B,indicating that genotype 1subtype B was the prominent strain in China. Conclusions Except the prototype strain（High Point,AY421762）,the CV-A4 strains can be genetically divided into two genotypes（genotype 1and 2）,each can be further divided into two subtypes（subtype A and B）,most Chinese strains were categorized to genotype 1,subtype B,which is the predominant genotype in China.