江苏省2012-2014年柯萨奇病毒A组16型分子流行病学特征分析

Analysis on molecular epidemiology of Coxsackievirus A16 strains isolated from 2012 to 2014 in Jiangsu Province

目的 了解江苏省2012-2014年柯萨奇病毒A组16型（coxsackievirus A16,CA16）流行毒株基因型概况。方法 收集江苏省2012-2014年儿童手足口病标本并送样,进行病毒分离培养获取相应毒株,用CA16特异性引物通过反转录聚合酶链反应技术进行VP1区基因片段扩增和测序,利用生物信息学软件对序列进行分析,并与CA16参比株序列进行同源性比较并构建基因进化树。结果 分离得到82株CA16毒株,测序结果显示全部属于基因亚型B1,VP1基因分析显示其中9株毒株序列的基因亚型为B1a,另外73株毒株序列的基因亚型为B1b。CA16分离株VP1区核苷酸和氨基酸同源性分别为87.8%-100.0%和97.5%-100.0%;与CA16国际标准株G10核苷酸和氨基酸同源性分别为75.2%-78.2%和90.5%-91.9%。结论 江苏省2012-2014年分离获得CA16毒株属于基因亚型B1,以B1a和B1b两个分支共同进化和流行,其中又以B1b为优势亚型。

Objective To analyze genetic characteristics of Coxsackievirus A16（ CA16） strains isolated from Jiangsu Province from 2012 to 2014. Methods The clinical specimens were collected from children diagnosed as hand foot and mouth disease from 2012 to 2014,and CA16 virus strains were obtained by means of the specimens culture. The fulllength VP1 gene fragments were amplified by reverse transcription polymerase chain reaction（ RT-PCR） technique. Then,the amplified products were used for gene sequencing,sequence analysis were conducted by using bioinformatics software,phylogenetic tree was constructed and compared with CA16 reference strains for sequence homology. Results A total of 82 positive specimens were identified as CA16 from the confirmed HFMD patients and all CA16 strains＇ VP1 gene were sequenced successfully. For all the 82 strains,9 strains were identified as B1 a genotype and the others were B1 b genotype,respectively. Sequence analysis results of these 82 strains showed that the nucleotide identity of 82 strains＇ VP1 genes ranged from 87. 8% to 100. 0% and the amino acid identity of 82 strains＇ VP1 proteins ranged from 97. 5% to 100. 0%. Compared with the ptototype strain CA16-G10,the homology of nucleotide sequences and amino acid sequences of VP1 gene were 75. 2%to 78. 2% and 90. 5% to 91. 9% respectively. Conclusions The CA16 strains isolated from 2012 to 2014 in jiangsu province belonged to subgenotype B1. The transmission mode showed that the dominant subgenotype of B1 b and secondary subgenotype of B1 a,were co-circulating together in Jiangsu Province. Both subgenotypes had close phylogenetic relationship.