Detection of avian rotaviruses from diarrhoeic poultry in India

An investigation was carried to understand the prevalence of avian rotaviruses in young poultry birds in Haryana. During 2001-2002, 345 faecal samples from different poultry farms showing symptoms of enteritis were examined for avian rotaviruses. The RNA extracted from faecal suspension was subjected to RNA-PAGE and silver staining. Eighty (23.19%) samples were found positive for avian rotaviruses by PAGE showing separation of 11 dsRNA segments. The migration of 11 dsRNA segments was in an electropherotype pattern of 5:1:3:2, which is typical of avian rotaviruses. The segment 5 was very close to segment 4 and segment 6 was distantly located. The segments 10 and 11 migrated very closely as compared to mammalian rotaviruses. The segments 7, 8 and 9 in all avian strains migrated in a triplet which is characteristic of group A rotaviruses. This is probably the first report of detection of group A avian rotaviruses in poultry in India. Four different electropherotype patterns based on VP7 gene variations encoded by genomic segments 7, 8 or 9 were observed. These VP7 gene based variations in electrophoretic migration patterns suggested genomic diversity among avian rotaviruses. The ability to characterise individual virus strain by genetic analysis of their dsRNA migration pattern could be potentially useful in epidemiological investigations.