Genetic characterization of the complete genome of a mutant canine parvovirus isolated in China.

A field canine parvovirus (CPV) strain, CPV-SH14, was previously isolated from an outbreak of severe gastroenteritis in Shanghai in 2014. The complete genome of CPV-SH14 was determined by using PCR with modified primers. When compared to other CPV-2 strains, several insertions, deletions, and point mutations were identified in the 5' and 3' UTR, with key amino acid (aa) mutations (K19R, E572K in NS1 and F267Y, Y324I and T440A in VP2) also being observed in the coding regions of CPV-SH14. These results indicated that significant and unique genetic variations have occurred at key sites or residues in the genome of CPV-SH14, suggesting the presence of a novel genetic variant of new CPV-2a. Phylogenetic analysis of the VP2 gene revealed that CPV-SH14 may have the potential to spread worldwide. In conclusion, CPV-SH14 may be a novel genetic variant of new CPV-2a, potentially with a selective advantage over other strains.