Identification of group B rotaviruses with short genome electropherotypes from adult cows with diarrhea

Abstract

Two field strains (BB-RVLV and KD) of group B rotaviruses from adult dairy cows with diarrhea displayed short genome electropherotypes. Gnotobiotic calves inoculated with fecal filtrates of each group B rotavirus developed diarrhea, and only group B rotaviruses or antigens were detected in the feces by immunoelectron microscopy and in intestinal epithelial cells by immunofluorescent staining, respectively. The feces or intestinal contents of the cows and inoculated calves were negative for group A and C rotaviruses by enzyme-linked immunosorbent assay, immunoelectron microscopy, or cell culture immunofluorescence assays. Comparison of the genome electropherotypes of the calf-passaged BB-RVLV and KD strains with the original samples and reference bovine group A, B, and C rotaviruses revealed conservation of their short-genome electropherotypes and double-stranded RNA migration patterns characteristic of group B rotaviruses. To our knowledge, our previous study (L. J. Saif, K. V. Brock, D. R. Redman, and E. M. Kohler, Vet. Rec. 128:447-449, 1991) and this report are the first description of bovine group B rotaviruses (in a mixed infection with bovine coronavirus or singly in fecal contents) in adult cows with diarrhea and this is the first report of short-genome electropherotypes among group B rotaviruses.

Molecular characterization of a novel bovine group A rotavirus

“…Bovine group B and C rotaviruses cause diarrhea in adult cattle (Parwani et al, 1996;Chang et al, 1997;Tsunemitsu et al, 1999a, b;Hayashi et al, 2001;Mawatari et al, 2004); in the case of BoRV-A, however, there were only few reports associating it with diarrhea in adult cattle (Sato et al, 1997). There were several reports of adult diarrhea caused by RV-A in humans (Hrdy, 1987;Iturriza-Gómara et al, 2000;Del Refugio Gonzalez-Losa et al, 2001;Griffin et al, 2002).…”

Detection of group B rotaviruses in fecal samples from diarrheic calves and adult cows and characterization of their VP7 genes

“…The reference group A BRV strains have been described previously and include NCDV-Lincoln (G6P [1]), IND (G6P [5]), B223 (G10P [11]), and 2292B (G10P [11]) strains (4). The group B BRV strains include ATI and the Mebus strains (from calves) and KD and WD653 strains (from adult cows); the group C BRV include the Shintoku strain (19,22,24,29). All group A strains and the group C Shintoku strain were grown in Rhesus monkey kidney cells in the presence of pancreatin (50 g/ml) (21,29).…”

“…Electrophoresis was conducted at 12 mA for 14 to 16 h. The dsRNA bands were visualized by silver staining (14). Fifty-three fecal samples from diarrheic adult cows were processed for IEM as previously described (19). The processed samples were incubated separately with group A-, B-, or C-rotavirusor bovine coronavirus-specific hyperimmune antisera, and the mixtures were then pelleted, negatively stained with phosphotungstic acid, applied to grids, and examined by electron microscopy (19,23).…”

“…Inoculation of gnotobiotic calves with group B rotaviruses. Three samples containing only group B BRV (determined by IEM and RT-PCR) were passaged in newborn (1-to 5-day old) gnotobiotic calves which had been derived, fed, inoculated, and maintained as previously described (19). All calves were oronasally inoculated with diluted (1:10) fecal filtrates of live virulent group B BRV strains (ATI and Mebus [calf] and WD653 [adult cow]).…”

“…Group B rotaviruses may be emerging pathogens for humans and appear to be associated with diarrhea in adults and older children more than in neonates (3,22). In calves and adult cows, group B rotaviruses have been reported in association with sporadic cases of diarrhea (1,2,18,19). The group B rotaviruses are difficult to grow in cell culture, and in the host they are shed in low titers in the feces, making it difficult to detect and further characterize these viruses (3,22).…”