VP6 gene based genetic diversity among group a rotaviruses of bovine and human
Abstract
Rotavirus has been recognized as one of the most important cause of severe gastroenteritis in young children and neonates of most of animal species. Rotaviruses have been classified into seven groups (A to G) by genomic RNA electrophoretic patterns and group-specific proteins. The major immunogenic protein, VP6 harbors the group and subgroup specific epitopes which play important role in studying the epidemiology of rotavirus strains In addition, major inner capsid protein is the main protein detected by commercial diagnostic tests. Significant morbidity caused by rotaviral diarrhoea has pressed the need of accurate and sensitive detection of rotavirus. Keeping this perspective in view, the present study was envisaged to study of genetic diversity of rotavirus in bovine and human. A total of 100 diarrheic faecal samples from bovine calves below six month of age from organized dairy farm and 100 diarrheic faecal sample from human neonates below 24 month of age from different children hospitals situated near hisar, were screened and 9 (9%) in bovine and 38 (38%) in human found positive for group A rotavirus by RNA-PAGE. All positive sample of bovine rotavirus revealed long electropherotypes but in case of human both short and long electropherotypes found. VP6, VP4 and VP7 genes were amplified as evidence by an expected PCR product of 1356bp (VP6) of human and 1339bp (VP6), 864 (VP4) and 1062bp (VP7) of bovine rotavirus. Typing by RT-PCR was done using specific primers representative of VP4 and VP7 genotypes. Genotyping by nested PCR typed G6, G10, P[1] and P[11] genotypes. Amplified VP6 gene of bovine and human rotaviruses were cloned and screened by touch PCR. The positive recombinant bacterial colonies were subjected to sequencing. The sequences were analysed using BlastN and aligned by ClustalX/W . The percent identity and distance matrices of partial VP6 gene of human rotavirus and full length of bovine rotaviruses were generated by MEGA version 4 software. Phylogenetic trees were constructed by analyzing of nucleotide by MEGA 4 software. Unusual ressortants of group A rotaviruses isolated from bovine calves and human neonates shows genomic constellations and indicate interspecies transmission occur.