First detection and genetic analysis of fox-origin porcine circovirus type 2.

Porcine circovirus type 2 (PCV2) is a causative agent of porcine circovirus-associated disease (PCVAD), which is a serious problem in the swine industry worldwide. In recent years, nonporcine-origin PCV2 has attracted more and more attention of the researchers. This study reported on the first identification of PCV2 in farmed foxes with reproductive failure. Three fox-origin PCV2 strains were successfully isolated, sequenced, and designated as FoxHB1, FoxHB2, and FoxHB3 respectively. Pairwise-sequence comparisons of the complete genomes revealed that three fox-origin PCV2 strains had nucleotide identities varied from 91.9% to 99.7% with representative strains of PCV2 different genotypes. Meanwhile, phylogenetic analysis based on complete genomes of 44 PCV2 strains indicated that the fox-origin PCV2 strains belonged to Chinese epidemic genotypes PCV2b and PCV2d. These results provided the first supported evidence that PCV2 could infect foxes, implying that the cross-species transmission of PCV2 would be a big threat to Chinese fur animal-bearing industry.