云南省一株柯萨奇病毒B组5型分离株的全基因组解析

Genome-wide analysis of a coxsackievirus B5 strain isolated from Yunnan province

目的对云南省2022年一例流感样病例的咽拭子分离得到的柯萨奇病毒B组5型(coxsackievirus B5,CVB5)病毒株进行全基因组测序,并分析其遗传进化、基因突变和重组特征。方法通过人宫颈癌细胞培养获得病毒分离株,应用全基因组测序技术对分离株进行病毒基因序列测定,采用MEGA、RDP4及SimPlot软件,解析病毒基因组学特征。结果分离株YN-01/CHN/2022与2株广东CVB5流行株核苷酸同源性为96.6%,属GⅠ.C1分支,与国内大多其他CVB5流行株相似度低(≤90.3%),揭示国内CVB5流行株间基因组差异较大。该分离株VP1序列存在2个特有的氨基酸突变(T246A和T275A),但其95位氨基酸未发生改变。基因重组分析显示YN-01/CHN/2022可能为重组株,重组位点发生在P1区VP4(940)和P2区2A(3540)。结论本研究分离株YN-01/CHN/2022属于CVB5 GⅠ.C1基因型,存在特异的核苷酸分歧,也证实了CVB5基因组有重组现象发生。该数据提示增强CVB5分子流行病学研究工作,持续追踪病毒进化规律,不断提高相关疾病防控工作的精准性。

Objective To sequence the whole genome of the coxsackievirus B5(CVB5)strain isolated from a throat swab of an influenza-like case in Yunnan province in 2022,and to analyze the characteristics of genetic evolution,mutation and recombination.Methods The virus strain was isolated by cell culture using human cervical cancer cells.The whole genome sequencing techniques were applied for whole-genome sequencing.MEGA,RDP4 and SimPlot software were used to analyze genomic characteristics.Results The nucleotide similarity of the isolate YN-01/CHN/2022 and two CVB5 epidemic strains in Guangdong was 96.6%.The strain belonged to GI.C1 branch,and had low similarity(≤90.3%)with most other CVB5 epidemic strains in China,indicating the existence of significant genomic differences among the CVB5 epidemic strains in China.There were two specific amino acid mutations(T246A and T275A)in the VP1 sequence of the isolated strain,but no changes were found in amino acid of position 95.Recombination analysis showed that the YN-01/CHN/2022 may be a recombinant strain,and the recombination sites occurred in P1-VP4(940)and P2-2A(3540).Conclusions The isolate strain YN-01/CHN/2022 belonged to GⅠ.C1 genotype of CVB5 with specific nucleotide divergence and confirmed recombination of CVB5 genome.These data suggested that the molecular epidemiology research of CVB5 should be strengthened to track virus evolution continuously and unremittingly improve the accuracy of the prevention and control of related diseases.