Antigenic relationships between rotaviruses from different species as studied by neutralization and immunofluorescence.

Antigenic relationships between the Wa, Hochi, Ito, Hosokawa and Nemoto strains of human rotavirus, the SA-11 strain of simian rotavirus, the Lincoln strain of bovine rotavirus, the OSU strain of porcine rotavirus and the R-2 strain of lapine rotavirus, which were all established in cell culture, were studied by neutralization (NT) and immunofluorescence (IF) using guinea pig antisera against these strains. The strains could not be distinguished by indirect IF staining of infected cells because of marked cross reactions. On the other hand, the NT test clearly distinguished these strains, although there was a one-way antigenic relationship between some of them. The five strains of human rotavirus were clearly distinguished from each other by NT test. These human strains exhibited much higher homologous titers than heterologous titers, the former being at least eight-fold higher than the latter. The presence of at least five serotypes of human rotavirus was indicated.