ABSTRACT
<p><b>OBJECTIVE</b>To analyze the genetic characterization of the complete genome from a human coxsackievirus B3 strain A103/KM/09 isolated in Yunnan province, 2009.</p><p><b>METHODS</b>By using RT-PCR, all the eight fragments which containing about 1000 nucleotides and covering full viral genome, were sequenced. By using Mega 5.05,Geneious, RDP 3 and SimPlot 3.5.1 software, sequences were aligned with other enterovirus reference sequences. Phylogenetic and recombination analysis were also carried out.</p><p><b>RESULTS</b>The A103/KM/09 isolate genome showed 7389 nucleotides in length , encoding for 2185 amino acids. In the complete genome, the homology of nucleotide and amino acid among the seven coxsackievirus B3 isolates were 81.0%-88.0% and 95.7%-98.0%, respectively. There appeared 81.0% and 95.7% homology when compared with that of Nancy prototype strain. Results from the Phylogenetic analysis showed that the coxsackievirus B3 formed five distinct clades, I-V. Nucleotide divergence rates between clades were 16.2%-24.3% . The A103/KM/09 strain belonged to clade V. Clade V was further divided into four sub-clades,A-D. The nucleotide divergence between sub-clades was 4.3%-11.4%. Putative recombinant event for A103/ KM/09 was detected.</p><p><b>CONCLUSION</b>All coxsackievirus B3 isolates could be divided into five clades, with A103/KM/09 strain belonged to Clade V-D. Evolution of coxsackievirus B3 had occurred in China.</p>