PAWAR PURUSHOTHAM, KALYANI P. AND DHANALAKSHMI K.
Abstract
The canine parvoviral disease is one of the significant viral diseases of canines, mainly younger dogs responsible for vomition, acute hemorrhagic enteritis, myocarditis, and immunosuppression. Few years after its exposure CPV-2 was completely turned into two new antigenic variants designated CPV-2a and CPV-2b. A third variant, CPV-2c, became discovered in 2000 in Italy. This is a mutant of CPV-2b which involved the substitution Aspartate (Asp) 426 Glutamate (Glu) happening in a main neutralizing epitope of the capsid. So, the present study was attempted to study the virusââ¬â¢s molecular characterization and phylogenetic analysis. Hundred faecal samples from the suspected clinical dogs exhibiting fever, and hemorrhagic enteritis referred to various private clinics in Hyderabad, were collected and subjected to isolation studies. In conventional PCR, sixty-seven samples yielded a single DNA amplicon of 681 bp with CPV-2ab primers. The same samples were further screened by CPV-2b specific primers and fifty samples yielded a single DNA amplicon of 427 bp to be confirmed as CPV-2b type. The final seventeen samples which were not responding to CPV-2b primers and responding to CPV-2ab primers were considered as CPV-2a type. All the 100 samples were further screened for CPV-2c type by CPV-555 primers that yield a single DNA amplicon of 583 bp which upon digestion with enzyme MboII generates two fragments of 500 bp and 83 bp for CPV-2cand remained undigested after MboII digestion, indicating that they are not of CPV-2c type but either CPV-2a or CPV-2b types as showed above. Phylogenetic analysis revealed that CPV-2a and CPV-2b of the current study had the closest sequence similarities with the Indian variants of CPV-2 available in GenBank.