广州市柯萨奇病毒A10型VP1区基因特征分析

Genetic characteristics of VP1 region of coxsackievirus A10 in Guangzhou

目的了解广州市手足口病(hand,foot and mouth disease,HFMD)病例中柯萨奇病毒A10型(coxsackievirus A10,CV-A10)VP1区基因特征。方法采用荧光RT-PCR法对2017—2020年广州市HFMD病例标本进行检测确定病毒型别。对CV-A10阳性病例流行病学特点进行分析。挑选CV-A10阳性代表样本进行病毒培养和VP1区基因扩增测序,采用DNAstar7.1及Mega 6.0对测序序列进行分析。结果2017—2020年共检测肠道病毒阳性样本8430份,其中CV-A10阳性样本564份(6.69%)。CV-A10阳性病例主要集中在5-7月,以5岁以下儿童为主,男女性别比为1.42∶1。本研究共获得68株CV-A10毒株VP1区全长序列,对其进行序列分析表明,CV-A10毒株之间核苷酸和氨基酸同源性分别为90.8%~100%和96.9%~100%,与原型株Kowalik(AF081300)核苷酸和氨基酸同源性为69.8%~71.8%和91.4%~93.8%。分子进化树分析显示,广州市CV-A10毒株均位于C2亚型中的Cluster1和Cluster32个分支上。结论CV-A10是引起广州市HFMD的优势病原体之一,其基因型均为C2亚型,2017—2020年共有2个分支在广州市共同流行。

Objective To analyze the genetic characteristics of VP1 region of Coxsackievirus A10(CV-A10)in hand,foot and mouth disease(HFMD)cases in Guangzhou.Methods Samples of HFMD cases in Guangzhou from 2017 to 2020 were detected by reverse transcription-quantitative polymerase chain reaction(RT-qPCR)method to determine the serotypes of enterovirus.The epidemiological characteristics of CV-A10 positive cases were analyzed.The CV-A10 representative samples were selected and cultured,and VP1 region was amplified and sequenced.DNAstar7.1 and Mega 6.0 were used to analyze the sequence.Results A total of 8430 positive samples of enterovirus were tested from 2017 to 2020,among which,564(6.69%)were positive for CV-A10.The CV-A10 positive cases were mainly concentrated in children under 5 years old from May to July,and the male to female ratio was 1.42∶1.A total of 68 CV-A10 strains of full-length VP1 region were obtained in this survey.The sequence analysis showed that the nucleotide and amino acid homologies of CV-A10 strains were 90.8%-100%and 96.9%-100%,respectively.The nucleotide and amino acid homologies with the Kowalik(AF081300)were 69.8%-71.8%and 91.4%-93.8%,respectively.Molecular phylogenetic tree analysis showed that all CV-A10 strains in Guangzhou were located in Cluster 1 and Cluster 3 branches of C2 subtype.Conclusions CV-A10 was one of the major pathogens causing HFMD in Guangzhou,and all insolates belonged to C2 subtype.Two branches,Cluster 1 and Cluster 3,were prevalent in Guangzhou from 2017 to 2020.