Detection of rotavirus serotypes G1, G2, G3, and G11 in feces of diarrheic calves by using polymerase chain reaction-derived cDNA probes.

On the basis of antigenic variability in the VP7 outer capsid glycoprotein, at least 14 G serotypes exist for group A rotaviruses. Serotypic diversity exists among bovine rotaviruses (BRV), with serotypes G1, G6, G8, and G10 reported for cattle. Although G1 and G8 rotaviruses were originally described for humans, the recent isolation of G6 and G10 rotaviruses from humans further emphasizes the serotypic similarity between human and bovine rotaviruses and the possible zoonotic potential of rotaviruses. Results of our previous studies have indicated that more than 24% of BRV-positive field samples from diarrheic calves were nonreactive with cDNA probes or monoclonal antibodies to serotypes G6, G8, and G10. In this study, cDNA probes were prepared by polymerase chain reaction amplification of the hyperdivergent regions of the VP7 genes (nucleotides 51 to 392) from human (G1, G2, and G3) and porcine (G4, G5, and G11) rotaviruses. These probes were used in a dot blot hybridization assay to further characterize the G types of 59 BRV strains (fecal samples from diarrheic calves in Ohio, Nebraska, Washington, and South Dakota) that were nonreactive with cDNA probes to G6, G8, and G10. Rotaviruses belonging to serotypes G1 (n = 7), G2 (n = 1), G3 (n = 2), and G11 (n = 3) were identified among the BRV field samples. The BRV associated with these G types accounted for 22% of the samples tested; the other 78% of these samples remained untypeable with these probes. To our knowledge, this is the first report in the United States of the identification among BRV isolates of rotavirus serotypes G1, G2, G3, and G11.