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The present study describes detection of picobirnavirus (PBV) in faecal samples from bovine and buffalo calves employing the polyacrylamide gel electrophoresis (PAGE). A total of 136 faecal samples from buffalo (n = 122) and cow calves (n = 14) exhibiting clinical signs of diarrhoea and from healthy calves were collected during 2007-2010 from subtropical (central India) and tarai area of western temperate Himalayan foothills (Uttarakhand). The dsRNA nature of the virus was confirmed by nuclease treatment (RNase A, RNaseT1 and DNase 1). PAGE results confirmed 3.67% (5/136) positivity for PBV, showing a typical genomic migration pattern with two discrete bands with size of approximately 2.4 and 1.7 kbps for the larger and smaller segments, respectively. Among the five PBV samples identified, three were from buffalo calves and one from cow calf exhibiting clinical signs of acute diarrhoea, while one sample from non-diarrhoeic buffalo calf also showed the presence of PBV. None of the samples showed dual infection of rotavirus and PBV. The preliminary findings indicate sporadic incidences of PBV in bovine calves and emphasize the need for the development of better diagnostics for early detection and genetic characterization of these emerging isolates of farm animals of economic significance.

Group D rotavirus (RVD) is one of the evolving viral causes of acute gastroenteritis in avian species all over the world but its frequency in Indian poultry is not known. We report here the first sequence-confirmed RVD infection in 1-2 week old broiler chicks from northern India. Initial confirmation of type D rotavirus was done using polyacrylamide gel electrophoresis and VP6 gene based reverse-transcriptase-PCR (RT-PCR) for group D rotavirus, which produced a specific 742 bp amplicon in positive cases. The intestinal contents which showed presence of group D rotavirus strain were designated as RVD/Avian/India/PTN-14/2012/ GXP[X] and RVD/Avian/India/UKD-48/2012/GXP[X]. The comparative sequence analysis based on partial VP6 gene of type D rotavirus Indian strains revealed higher homology with the VP6 genes of the avian group D rotaviruses from Brazil, Germany, Netherlands, Bangladesh and UK, both at the nucleotide (87.2-89.6%) and amino acid (98.7-99.5%) levels. These two Indian avian RVD isolates clustered together, away from other Asian group D isolates from Bangladesh. The analysis of group specific VP6 protein showed amino acid changes at only two positions i.e. 228 and 384 when compared to the reference group D rotavirus strain (GenBank accession number: GU733448) confirming conserved nature of this protein. This seems to be the first sequence-confirmed detection of group D avian rotavirus in broiler chicks from India. The findings emphasise the importance of this virus in enteric infections of Indian poultry flocks. The study also emphasises the need for intensifying the epidemiological surveillance for group D rotaviruses in the near future.

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