Isolation of cytopathic porcine rotavirus in cell roller culture in the presence of trypsin.

Cytopathic porcine rotavirus was isolated in roller tube cultures of MA-104 cells. Faeces of a piglet suffering from diarrhoea, were treated with trypsin which was also added to the maintenance medium. Using stationary cultures, virus was not isolated from the same materials. The cytopathic effect was clearly observed after 8 serial passages and the virus titer at the 14th passage level was 10(7) median tissue culture infective doses per ml, or higher. At the 27th passage, rotavirus particles were seen by negative contrast electron microscopy at a density of 1.36 to 1.38 g/cm3 in CsCl centrifugation gradients. There are partial cross-neutralization between the Lincoln strain of bovine rotavirus and porcine rotavirus from pigs or tissue cultures. Gnotobiotic piglets were inoculated with pig-passaged virus and viral antigen was detected in epithelial cells of small intestinal villi by immunofluorescence. The highest titer of virus was detected in faeces 72 hours after inoculation. The cell culture adapted virus which produce a cytopathic effect was designated the strain S 80 of porcine rotavirus.