Phylogenetic analysis of porcine circovirus type 2 (PCV2) isolates from China with high homology to PCV2c

Abstract

Porcine circovirus type 2 (PCV2) is an important emerging pathogen that has been causatively associated with multifactorial disease syndromes in pigs and other species. It has a worldwide distribution and causes significant economic losses in the swine industry. Its genome is dynamically evolving through recombination and mutation, and the circulating genotypes of PCV2 strains in Asia are PCV2a, PCV2b and PCV2d. In this study, 12 PCV isolates were evaluated and identified by amplification, sequencing, and phylogenetic analysis, and the results revealed a new monophyletic group of PCV in China. More importantly, three of these isolates shared high homology within the ORF1 region with a strain of genotype PCV2c that was detected only in Denmark. Phylogeographic analysis of these isolates suggested that the isolates may have arisen in Denmark and that they were then transported to China.