Abstract: Objective To investigate the isolation,identification and molecular epidemiological characteristics of the CVA6 of hand foot mouth disease (HFMD) epidemic in Jiujiang.Methods Throat swabs from children with hand foot mouth disease were collected and the suspends was inoculated into RD cells.The isolation and pathogenicity of CVA6 were detected by CVA6 virus-induced cytopathic effect (CPE) analysis,MTT assay,CVA6 virus-specific nucleic acid polymerase chain reaction (PCR), and homology and phylogenetic analysis.Results The CPE cells were found after 5 generations in RD cells incubated with the supernatant. RD cells were infected with the supernatant collected for 2 consecutive infections, and the same CPE appeared. The VP1 region of the CVA6 virus was identified by sequence alignment to confirm that the viruses were CVA6, named JJ2012037 and JJ2012039 respectively.The MTT detection showed that CVA6 could inhibit the proliferation of host cells in a time-dependent manner. Nucleotide sequence homology analysis was carried out by using VP1 sequences of CVA6 strains from different countries and regions.The results showed that the homology of the CVA6 strain was as high as 99.2-99.6% with the strain separated from Shanghai.Conclusion Two strains of the epidemic CVA6 strain of hand-foot-mouth disease have been successfully isolated.The molecular epidemiology of the two CVA6 strains is close to the epidemic of CVA6 from shanghai, which may be the same subtype of the gene.

Key words: coxsackievirus A6 virus (CVA6), identification, epidemiological characteristics