[Immunofluorescence reaction for rotavirus analysis in fecal specimens].

Testing for rotavirus detection in faeces from infants with acute diarrhea can be carried out, with high sensitivity, by immunofluorescence on rhesus monkey kidney cell lines (MA-104). Preincubation of viral inoculum with trypsin enhances further the sensitivity. In the present study we tried to assess the optimal conditions for detection of viral antigens, by analyzing the expression of virus-specific proteins at different times of infection and the effects of trypsin presence during virus adsorption and replication. Maximal production of viral antigens was obtained by infecting the cells 4 hours after cell-seeding and incubating them for 18 hours afterwards. In experiments with simian rotavirus SA-11, pretreated with trypsin and then with a trypsin inhibitor, a marked reduction in the percentage of fluorescent cells was observed thus indicating a role of the enzyme both on the virus and on the cell layer.