G and P genotyping of bovine group A rotaviruses in faecal samples of diarrhoeic calves by DIG-labelled probes

Abstract

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> The nucleic acid probes specific to genome segments 9 and 4 of bovine group A rotaviruses (BRVs) were developed for detection and determination of the G (G6 and G10) and P (P1, P5 and P11) types in field samples of diarrhoeic bovine calves. The type specific DNA probes were prepared by polymerase chain reaction amplification of hyper divergent regions of VP7 and VP4 genes from three genotypically distinct (G or P types) reference strains of BRV, viz. B223 (G10P11), NCDV (G6P1) and UK (G6P5), labelled with Digoxigenin (DIG). These G and P genotype specific DIG-labelled probes were evaluated for genotyping of rotaviruses of bovine origin directly in faecal samples. Of 308 calf diarrhoeic samples, 138 (44.81 %) were positive for BRV infection in nucleic acid hybridization assay, using VP7 and VP4 gene specific probes independently. Of probe positive samples (138), 112 were typeable by both G and P typing nested probes; 109 samples were typed as P11 (97.32%) and 3 as P1 (2.68%), and 97 as G10 (86.61%) and 15 as G6 (13.39 %). Surprisingly, none of the samples was typed as P5, indicating non-occurrence of P5 genotype among bovine rotaviruses in Haryana and adjoining areas of India. Furthermore, G10P11 was found to be the most prevalent combination among field rotavirus strains examined; whereas, G10P5 and G10P1 combinations were not reported in any of the samples. </smarttagtype></smarttagtype>