Molecular insights into the phylogeny of canine parvovirus 2 (CPV-2) with emphasis on Korean isolates: a Bayesian approach

Abstract

A Bayesian approach was utilized to further investigate the molecular phylogeny of canine parvovirus 2 (CPV-2) with emphasis on Korean isolates, and the complete VP2 gene sequences for 23 Korean isolates in 2007 and two vaccine strains were determined. Of the 44 Korean CPVs, 40 were identified as CPV-2a, three as CPV-2b, and the remaining one as a CPV-2a variant having a Gly300Asp mutation. Compared with CPV-2a, our findings also showed the presence of six additional amino acid substitutions (Thr440Ala, Ile418Thr, Pro435Ser, Asp413Asn, Thr322Ser, and Tyr324Ile) within the VP2 gene of the Korean isolates. In the phylogenetic tree, the overall Korean CPVs did not emerge as an independent clade within the global CPVs, nor did they show a close relationship to the CPVs from any other country. Our VP2 sequence data also revealed no geographic influence on the spread of CPVs worldwide. dN/dS analysis showed that purifying selection is acting on the VP2 gene of Korean CPVs.