Molecular Characterization and Phylogenetic Analysis of CPV-2 from Diarrheic Dogs in and Around Nagpur

Background: Canine Parvovirus (CPV) is a major viral infection that results in acute hemorrhagic gastroenteritis and myocarditis in puppies aged 3-4 months. Despite successful vaccination, it produces significant morbidity and mortality. Inadequate immunity and current kennel practices such as early weaning have predisposed the young canines to CPV. The present study aimed to characterize different antigenic types of CPV-2 in Nagpur region. Methods: In the current investigation, 50 fecal samples were obtained from dogs suspected of having CPV-2 from 2020-2023 in Nagpur, India and subjected to various detection tests such as haemagglutination test, polymerase chain reaction (PCR), Nested PCR (NPCR) followed by VP2 gene sequencing and phylogenetic analysis. Result: A total of 9 (18%) of the 50 samples tested positive for the haemagglutination test, while 19 (38%) and 29 (58%) tested positive for conventional PCR and NPCR. NPCR was found to be the most sensitive detection tool of all of them. Sequence analysis found 99.85%-100% similarity with CPV-2b and 2c antigenic type sequences from China and 99.79% identity with sequences from Mizoram state of India. CPV-2b and CPV-2c were the major antigenic types circulating in Nagpur, India. This study will help us to understand the circulating antigenic types of CPV-2 in Nagpur region and promote the formulation of novel diagnostics and vaccines.