Ravishankar, ChintuG, LOGESHWARAN2021-01-122021-01-122019-07-15https://krishikosh.egranth.ac.in/handle/1/5810159929Pig farming is a source of income for small and marginal farmers in Kerala. One of the important health problems in suckling and recently weaned piglets is neonatal diarrhoea. Rotaviruses belonging to Group A are one of the most frequently detected viral agents associated with diarrhoea in swine. Though the incidence of rotaviruses in Kerala has been established, a thorough study of the agent with respect to genotypes of the virus has not been carried out. Hence this study was undertaken to detect the presence of rotavirus in faecal samples of piglets by reverse transcriptase polymerase chain reaction (RT-PCR) and to genotype the virus by nucleotide sequencing. A total of 100 diarrhoeic faecal samples were collected from piglets reared in organized farms in Wayanad, Kozhikode, Palakkad, Thrissur and Ernakulam districts of Kerala. All these faecal samples were screened for the presence of porcine rotavirus (PRV) by RT-PCR. Of the 100 diarrhoeic faecal samples, 12 (12 per cent) samples was found to be positive for VP6 gene as evidenced by a 309 bp amplicon. Positive samples were obtained from Palakkad and Wayanad districts only. On analysis of the nucleic acid sequence of VP6 gene, it was observed that majority of the viruses were of inner capsid type I5 and one was of I14 type. When the positive samples were tested by RT - PCR for VP7 and VP4 gene, 10 (83.33 per cent) and 11 (91.66 per cent) samples were positive in the first round RT-PCRs yielding amplicons of 1062 and 876 bp respectively. When representative samples were tested in the semi nested PCR for VP7 gene amplicons corresponding to G2, G4, G5, G6 and G9 genotypes were obtained. In the semi nested RT-PCR for VP4 gene, P[6], P[19] and P21-5 genotypes were detected. Some of the sequences showed close similarity to rotaviruses isolated from humans and from bovines. Of the G and P types detected, G2, G9 and P[6] have been reported in humans in Kerala. Hence the results of the study indicated that the rotaviruses of pigs in Kerala are genetically diverse.EnglishThesis