ISOLATION OF ROTAVIRUSES FROM CALVES WITH ACUTE ENTERITIS AND THEIR CULTIVATION IN-VITRO

Five bovine rotavirus strains were isolated in monolayers of MA-104 cell culture from faeces of 3-to 11-day-old calves suffering from gastroenteritis. Cytophatic effect, accompanied by the release of cells from the glass surface of cultivation flasks was observed from the 5th to the 6th passage. After the stabilization of the cytopathic effect, the highest virus concentration was observed in cell cultures that had been frozen 18-36 hrs after inoculation. Electron microscopy revealed particles with typical rotavirus morphology. Antigenic relationship of the isolates with the reference strain Lincoln was confirmed by ELISA. The isolates were classified as members of the serological group A by ELISA and immunofluorescence assay. The identity of the rotavirus isolates was also confirmed by electrophoresis in agarose gel. The assay confirmed that their genome consists of segmented viral RNA, which produced in the electric field migration patterns, electrophorogrammes, typical of rotaviruses. In 4 isolates the migration speed of the segments in the electric field was identical with that of the reference strain. A different electropherotype was identified in the remaining isolate.