Genetic characteristics of Coxsackievirus B5 isolated from acute flaccid paralysis patients in Yunnan province

Objective To analyze genetic features of VP1 region of three Coxsackievirus B5 (CVB5) strains isolated from acute flaccid paralysis (AFP) patients in Yunnan province,2015.Methods Human rhabdomyosarcoma (RD) cells and L20B cells were used for virus isolation.Reverse transcriptase polymerase chain reaction (RT-PCR) was adopted for the amplification of VP1 region of isolated CVB5 strains; then the amplificated genes were sent to Gene Company for sequencing fo target genes.The phylogenetic tree for the isolated strains and its representatives in gene bank were made with MEGA 6 software.Neighbour-joining method,kimura-2-parameter and 1 000 pseudo replicate datasets were used to construct the phylogenetic trees.Results Totally 23 non-polio enteroviruses (NPEV) strains were isolated from 213 AFP cases,including 3 CVB5 strains.The similarity of nucleotide of VP1 region between CVB5 isolates and its representatives was 80.7%-81.9%,while that of amino acid was 95.1%-96.5%.Phylogenetic trees analysis showed that the similarity between nucleotide of CVB5 isolates and that of Shandong isolate (JN712675) and Anhui isolate (KF751191) were 91.7%-92% and 92%-93%,respectively.Conclusion The 3 CVB5 strains isolated from AFP cases in Yunnan province are of high similarity to the Shandong isolate (JN712675) and Anhui isolate (KF751191).