Genetic variability and phylogenetic analysis of the VP2 gene of feline parvovirus in Harbin

This is the authors' abstract. We don't add key points for this paper.

Introduction: In 2023, a total of 450 fecal samples were collected from healthy cats and those suspected of being infected with Feline Panleukopenia Virus (FPV) in Harbin, China. Methods: The FPV VP2 gene was detected using polymerase chain reaction (PCR). Positive samples were then subjected to VP2 sequence analysis, phylogenetic analysis, recombination analysis, and selective pressure analysis. Results: VP2 sequence analysis showed that the nucleotide similarity of the full-length VP2 gene ranged from 98.7 to 100%, with 19 amino acid mutations observed compared to the 2008 Felocell vaccine strain (GenBank: EU49868.1). Phylogenetic analysis demonstrated that all 42 detected FPV strains clustered with recent domestic isolates. Recombination analysis identified two strains (HRB2312 and HRB2324) as recombinants between FPV and Canine Parvovirus type 2c (CPV-2c). Selective pressure analysis did not detect any positively selected sites. Discussion: The findings suggest that the FPV lineages circulating in China have remained relatively stable in recent years, with evolution influenced by both random genetic drift and gene recombination. This study provides insights into the genetic diversity of FPV in Harbin, highlighting point mutations and recombination events. Further investigation is warranted to determine the antigenic compatibility of circulating recombinant strains with traditional vaccine strains.