银川市2016-2022年手足口病柯萨奇病毒A6型分离株VP1基因特征分析

Genetic characteristics of VP1 region of coxsackievirus A6 isolated from hand,foot and mouth disease in Yinchuan from 2016 to 2022

目的 分析银川市2016-2022年引起手足口病的柯萨奇病毒A6型(CV-A6)VP1的基因特征,为手足口病的防治工作提供有效的参考依据。方法 收集2016-2022年银川市手足口病所有CV-A6核酸呈阳性的标本进行病毒分离培养,应用一步法聚合酶链式反应(RT-PCR)扩增其VP1区完整基因核酸片段进行核苷酸序列测定,利用测序结果进行系统发育树构建、同源性分析及氨基酸突变位点分析。结果 2016-2022年银川市共分离到手足口病CV-A6型毒株90株,测序后成功获得CV-A6 VP1区全长序列的毒株83株。完整VP1区基因均由915个核苷酸组成,编码305个氨基酸。系统发育分析显示,2016-2022年银川市83株CV-A6分离株均属于D3基因亚型的D3a分支;同源性分析表明,银川市83株CV-A6分离株与原型株Gdula株(AY421764-USA-1949)之间核苷酸相似性为82.1%~84.1%,氨基酸相似性为76.2%~80.5%,遗传距离较远;银川市83株CV-A6分离株与原型株Gdula株的VP1区氨基酸序列比较发现32个氨基酸位点出现变异。结论 2016-2022年银川市手足口病83株CV-A6分离株均属于D3基因亚型的D3a分支。加强对CV-A6的持续监测及基因特征分析,对科学防控CV-A6引起的手足口病及其疫苗研发具有重要意义。

Objective To analyze the genetic characteristics of coxsackievirus A6(CVA6)isolated from hand,foot and mouth disease(HFMD)from 2016 to 2022 in Yinchuan city of China,so as to provide an effective reference for prevention and treatment for HFMD.Methods CV-A6 nucleic acid positive samples of HFMD were collected for virus isolation and culture in Yinchuan from 2016 to 2022.One-step polymerase chain reaction(RT-PCR)was used to amplify the complete gene nucleic acid fragment of the VP1 region for nucleotide sequencing.The sequencing results were used for phylogenetic tree construction,homology analysis,and amino acid mutation site analysis.Results A total of 90 HFMD CVA6 strains were isolated,after sequencing,83 strains obtained the full-length sequence of the VP1 region of CVA6.The full VP1 gene had 915 bp,encoding 305 amino acids.The phylogenetic analysis showed that all the 83 strains of CVA6 belonged to the D3a branch of the D3 gene subtype.Homology analysis indicated that compared with the prototype strain of CVA6(Gdula),the nucleotide similarity was 82.1%~84.1%,and the amino acid homology was 76.2%~80.5%,and the genetic distance was far.The amino acid sequence of VP1 region of 83 CVA6 isolates was compared with the strain of CVA6(Gdula),and 32 amino acid sites were found to be mutated.Conclusion The 83 CVA6 isolates of HFMD in Yinchuan is sub-genotype D3a.Strengthening the continuous monitoring and gene characteristics analysis of CVA6 is of great significance for the scientific prevention and control of HFMD caused by CVA6 and vaccine research and development.