A Phylogenetic study of canine parvovirus in Alborz province

Canine parvovirus-۲ (CPV-۲) causes severe and highly contagious disease in dog, particularly puppies, with worldwide distribution. The viral agent is small, nonenveloped, single stranded DNA virus and belongs to the Parvoviridae family. The virus possesses two major open reading frames (ORF) encoding nonstructural and structural (Capsid) proteins. VP۱ and VP۲ proteins construct the viral capsid, in that VP۲ is the major and outer capsid protein, comprises epitopic antigenic sites and plays critical role in determining viral host range and tissue tropism. Mutation in the VP۲ protein is frequent, which may lead to the emergence of new CPV strains and variants. In order to identify the molecular characterization of circulating CPV in Iran, the full length of the VP۲ sequence of two CPV-۲ isolates from Alborz Province was characterized. The viral genomes were extracted from the feces of two diarrheic puppies and the DNA fragments including VP۲ gene were amplified by using PCR and specific primers. The amplified DNA fragments were sequenced in both directions by using external and internal primers, and the obtained sequence were assembled to produce a ۱۷۵۲ bp sequence including the full length of the VP۲ gene. Comparison of the VP۲ gene from the Iranian CPV-۲ isolates with those available in the GeneBank revealed that the both CPV-۲ isolates were ۲a type of the virus. The Iranian CPV-۲a isolates shared ۹۵.۸% nucleotide sequence identity and they were both found to be most identical to the available sequences originated from China since ۲۰۰۸. These results again emphasize that CPV-۲ is a highly variable pathogen which can be spread over the countries and the world. To better understanding the molecular epidemiology of the circulating canine parvoviruses in Iran, molecular characterization of more viruses across the country is recommended.

کلیدواژه ها:

CPV-۲ ، VP۲ ، Molecular epidemiology