Prevalence and genotypic (G and P) determination of porcine group A rotaviruses from different regions of India

Group A rotaviruses can infect both humans and animals and have been recognized as an important cause of diarrhea in porcine. In this study, we report the prevalence and molecular epidemiology of rotaviruses detected in piglets in different regions of India. A total 275 fecal samples (180 diarrheal and 95 non-diarrheal) from piglets were collected from the western (135), southern (60), northern (20), and North-Eastern Hill (NEH) (60) regions of India and tested for rotaviruses. All the samples were subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and reverse transcription-polymerase chain reaction (RT-PCR). Rotaviruses were detected in 10.18 % of samples by SDS-PAGE and/or RT-PCR with a maximum of 30 % from the NEH region followed by 7.4 % from the western region. Samples from the southern and northern regions were found to be negative. Only 10 isolates were subjected to genotypic characterization using amplification of VP7 and VP4 genes followed by two separate multiplex PCR assays for G genotyping and another two for P genotyping using genotype-specific primers. Of these, three isolates could be typed as G4 specificity, one with G9, and three as P[6] leading to identification of an uncommon strain, G4P[6]. One isolate was further confirmed by nucleotide sequencing. The data demonstrate genetic diversity of porcine rotavirus strains and suggest that pig farms may serve as potential reservoirs for human infections.