[Genomic characteristics of coxsackievirus B5 A210/KM/09 strain isolated in Yunnan, China].

Objective: To characterize the complete genome sequence of coxsackievirus B5 (CVB5)A210/KM/09 strain which was isolated from Yunnan, China, 2009.
Methods: Eight overlapping clones covering the whole viral genome (excluding the poly-A tail)were obtained by RT-PCR and sequenced, with their nucleotide and amino acid sequences compared with other known CVB5 strains.
Results: The genome of the CVB5 A210/KM/09 strain had 7 372 nucleotides in length, and containing a 742-nt non-translated region (NTR) at the 5' end and a 98-nt NTR at the 3' end. The entire open reading frame contained 6 555 nt, encoding a 2 185-aa polyprotein. In the coding region, there appeared no nucleotide deletion or insertion, but some changes of amino acid seemed unique. Based on the complete genome sequence alignments, CVB5 isolate A210/KM/09 strain showed the highest nucleotide (92.5%) and amino acid (97.3%) identities to the CVB5/CC10/10. It also shared nucleotide (80.1%-92.5%) and amino acid (95.0%-97.3%) homology with other CVB5 strains: 17Y, 19CSF, 20CSF, 1954/85/US, 2000/CSF/KOR, 03001N, CoxB5/Henan/2010, VB5/SD/09 and Faulkner. Blast between genome fragments, A210/KM/09 showed similarity on nucleotide (80.1%-92.5%) and amino acid (95.0%-97.3%) identities with other CVB5 strains. The phylogenetic tree, constructed on the complete VP1 regions, indicated that CVB5 could be divided into genotype A, B, C and D. while Genotype C and D could be further divided into C1-C4 and D1-D4 subgenotypes.
Conclusion: A210/KM/09 and other CVB5 predominant strains isolated in China belonged to CVB5 subgenotype C4.