Detection of a new canine parvovirus mutant in Iran

BACKGROUND: Canine Parvovirus (CPV) is one of the major causes of fatal gastroenteritis in young dogs. After emergence of CPV-2, two new variants were reported and named CPV-2a and CPV-2b. In 2001 the newest variant was reported and named CPV-2c. The difference between CPV strains is related to amino acid changes in viral capsid protein (VP2). OBJECTIVES: The aim of the present study was genetic characterization of common CPV-2 strains which are prevalent in Iran. METHODS: Total of 50 fecal samples were examined by specific PCR primers for VP2 gene which codes virus capsid protein. PCR products were bidirectionally sequenced. RESULTS: Sequence analysis results showed that based on the nucleotides encoding for residue 426 (nt 4062 to 4064) all previously assumed CPV-2b samples were true CPV-2b, except for strain Ir28 which showed substitution of Asp (GAT) with Gly (GGT). The sequence alignment also showed that strains Ir3 and Ir19 are similar to the reference strain M74849.1 (CPV-2b) but other strains differed by exhibiting further synonymous substitutions. CONCLUSIONS: A novel mutation in CPV-2 gene of Ir28 strain may lead to emergence of a new variant. This finding also emphasizes the previous study results which indicate the high evolution rate of CPV.