[Immunofluorescent diagnosis of rota-, corona- and pestivirus infections in calves].

: Bovine hyperimmune fluorescent sera were obtained for indication of the rota- and corona-virus infections in calves, which were highly specific and of immunofluorescent titers within the 1:32-64 range. Their testing was carried out via the direct immunofluorescence method, using histologic cross-sectioned material and impression preparations of the mucous membrane of calves died of enteritis as well as cell cultures of fetal calf kidney and organic cultures of calf trachea all contaminated, resp., infected with feces. The study of the intestinal membrane of a total of 100 diseased calves, employing this method, has demonstrated a rotavirus antigen in 38.0 per cent of the cases, and a coronavirus one--in 37.0 per cent. The causative agent of mucous disease (a pestivirus) was demonstrated by means of the respective conjugate in 47.3 per cent of the cases, using abomasal membrane of a total of 55 calves. Rota- and corona-virus infections were also established in the abomasal membrane of diseased calves, and pesti-virus infections--in the intestinal mucosa as well. Established were also mixed infections with the three viruses taking part at various combinations. A celloidin method was worked out for making immunofluorescent preparations of infected monolayer cell cultures. In the cell cultures infected with feces the totavirus antigen was demonstrated in 19.4 per cent of the cases, and the coronavirus one--in 25.6 per cent.