Molecular characterization of Canine parvo virus strains in vaccines by polymerase chain reaction and restriction endonuclease analysis

Canine parvovirus 2 (CPV-2) is one of the most important viruses causing hemorrhagic gastroenteritis and myocarditis of dogs around the world. The picture has been complicated further due to two other mutants of CPV namely CPV-2a and CPV-2b. In this study, the molecular characterization of strains present in the CPV vaccines available in the Indian market had been done by using polymerase chain reaction (PCR) and restriction endonuclease (RE) analysis. The viral DNA from faecal sample and vaccine strains were extracted by using phenol-chloroform method. PCR were carried out with two different primer pairs to distinguish the vaccine strains and strain prevalent in field condition in India. The primer pair pCPV-2ab recognize CPV-2a and CPV-2b variants and the primer pair pCPV-2b recognize only the CPV-2b variants while the primer pair pCPV recognize all CPV-2 variants. The PCR product using primer pCPV were further analyzed by using RE analysis. Our results in this study showed that the CPV strain used in commercially available vaccine preparation was different from the strain prevalent in the disease condition in India.