Genomic typing and phylogenetic analysis of canine parvovirus detected in the state of Odisha, India

Canine parvovirus type 2 (CPV-2) comprises three major antigenic variants CPV-2a, CPV-2b and CPV-2c. Their mutated variants in geographically distinct locations need to be investigated to understand viral evolution and for development of effective management measures. In the present study, 71 faecal and 12 blood samples from suspected dogs in the state of Odisha, India were analyzed by PCR. Faecal lysate, extracted by the fast boiling method was found to be more sensitive as a template for PCR compared to DNA extracted from faecal samples by the phenol-chloroform method. The results revealed 29 positive cases (583 bp amplicon) out of 71 faecal samples, and 5 positive cases out of 12 blood samples examined, with a few variations in the results from blood and faecal samples in the same cases, thus suggesting the necessity of screening both blood and faecal samples for diagnosis. Restriction digestion of the 583 bp PCR amplicon with Mboll (PCR-RFLP) confirmed the strain not to be CPV-2c. Further sequencing of the 583 bp fragments recognized the variant as one of the mutated CPV-2a strain. Interestingly, an additional presence of CPV-2a mutant of 525 bp was observed in eleven of the positive faecal samples, along with the 583 bp fragment in PCR that needs further characterization. These two CPV-2a variants shared a common clade with other CPV-2a variants in the phylogenetic tree separating CPV-2b and CPV-2c. Our results confirm the dynamic changes in CPV variants and emphasize the importance of CPV surveillance for understanding of viral epidemiology. Key words: canine parvovirus, diagnosis, PCR, new variant Pasji parvovirus tip 2 (PPV-2) ima tri glavne antigenske varijante: PPV-2a, PPV-2b i PPV-2c. Radi razumijevanja njegove evolucije i razvijanja ucinkovitih mjera suzbijanja potrebno je istraziti njegove mutante iz razlicitih geografskih podrucja. U ovom je radu lancanom reakcijom polimerazom bio pretrazen 71 uzorak fecesa i 12 uzoraka krvi pasa sa sumnjom na parvovirusnu infekciju u drzavi Odisha u Indiji. Postupak dobivanja fekalnog lizata brzim kljucanjem pri 100°C pokazao se osjetljivijim u odnosu na ekstrakciju DNA iz uzoraka fecesa fenol-kloroformom. Rezultati su pokazali da je od 71 pretrazenog uzorka fecesa 29 bilo pozitivnih (583 bp umnozak), a od 12 pretrazenih uzoraka krvi sedam pozitivnih s razlicitim nalazima kod istih slucajeva, sto govori da je za postavljanje dijagnoze potrebno pretraziti oba uzorka od iste zivotinje. Cijepanje odsjecka 583 b