MOLECULAR EPIDEMIOLOGY OF CANINE PARVOVIRUS TYPE 2A AND 2B AMONG SHELTER DOGS — THE NEW RECOMBINATION IN VIRUS

Canine parvovirus type 2 (CPV-2) is a severe enteric pathogen mainly affecting dogs. CPV-2 contains three antigenic variants (2a, 2b, and 2c) that are distributed internationally. Detection and characterization of the currently circulating CPV-2 strains are vital for the understanding of viral evolution, transmission, and the development of methods to control its spreading. Herein, we analyzed the strains in central Taiwan to provide information of local viral evolution, diversity, and epidemiology. Stool and blood samples from 24 dogs and 2 cats were genotyped by PCR amplification of strain-specific VP2 sequence collected during 2011–2013. 60% (16/26) of them were positive and 100% (16/16) of these positive samples were type 2b. Then, the full length VP2 gene was sequenced in 6 CPV-positive samples and a maximum-likelihood phylogenetic tree was constructed using both Taiwan and other strains worldwide. Surprisingly, all Taiwan CPVs showed high relatedness to type 2a. Recombination analysis revealed a recombination of VP2 gene between type 2a and 2b. This study demonstrates a recombination between CPV-2a and 2b in nature that contributes to the genetic diversity and evolution of CPV-2.