Isolated Bovine Rotavirus In A Diary Farm In Daqing And Analyzed Full Genomic Sequence

Group A rotavirus are one of the most frequently detected viral agents associated with the acute diarrhea in neonatal calves. Bovine rotavirus belongs to a genus rotavirus in the Reoviridea family. A complete viral particle contains a segments of 11 double-stranded RNA (dsRNA) that encode 6 structural (VP1-4, 6 and 7) and 6 nonstructural (NSP1-6) protein. Neonatal calves are susceptible to rotavirus, rotavirus cause disease including asymptomatic, mild , severe or fatal infection with excessive fluid loss and severe electrolyte imbalance. In order to investigate the situation of rotavirus strains circulating and popular strain in diary farm, Daqing region.A total of 117 fecal specimens were collected from diarrhea calves under 4 weeks-age on diary farm in Daqing region in China from 2008 to 2009. Ten specimens were detected to be positive by a Rotavirus Group A Diagnose Kit, which confirm that the rotavirus was important viral agent associated with diarrhea in this farm. According to RT-PCR, only G10P[11] rotavirus were found in positive samples. A G10P[11] rotavirus, designed as the DQ-75 strain, was isolated successfully from a positive specimen numbered 75. Full genomic analysis of DQ-75 strain based on nucleotide percentage identity cut-off values defining genotypes for 11 rotavirus gene segments was proposed, we found that genotypes of gene segments of VP7,VP4,VP1,VP2,VP3,VP6,NSP1,NSP2,NSP3,NSP4 and NSP5 of DQ-75 strain were G10,P[11],R2,C2,M2,I2,A3,N2,T6,E2 and H3, respectively. Phylogenetic analyzing found that DQ-75 strain was a reassortment strain including intraspecies and interspecies, gene segments of NSP1 and NSP5 could originate from genotype G6P[1] bovine rotavirus; gene segment of NSP2 could originate from genotype G6P[5] bovine rotavirus; gene segment of NSP3 could originate from genotype G10P[14] bovine rotavirus A64 strain; gene segments of VP1,VP2,VP3 and VP6 could originate from lamb, gene segments of VP7,VP4 and NSP4 are evoluting among genotype G10 bovine rotavirus.Homology of the nucleotide and deduced amino acid sequences of the genome segments encoding VP7 of DQ-75 strain, DQ-07 strain isolated in Daqing 2007, AD-08 strain isolated in Anda 2008 and HM26 strain were 96.5%,96.5%,96.8% and 97.5%,97.5%,98.5%, respectively. Analysis of antigen sites of four G10P[11] bovine rotavirus above, we proposed that G10 bovine rotavirus strain protected themselves by amino mutation of 5 main antigenic regions.In this study we detected G10P[11] bovine rotavirus in a diary farm, Daqing region and isolated a strain DQ-75. Analysis of the first full genomic sequence of G10P[11] bovine rotavirus. and understood molecular characteristic of G10P[11] bovine rotavirus. Giving some theoretical background about reseaching G10P[11] bovine rotavirus.