Isolation, propagation, and characterization of a second equine rotavirus serotype

A rotavirus designated strain H-2 was isolated in primary African green monkey kidney cells from a foal with diarrhea. This cell culture-adapted strain was found to be similar, if not identical, to simian rotavirus (strains MMU18006 and SA-11) and canine rotavirus (strain CU-1) and, in addition, demonstrated a one-way antigenic relationship with five human rotavirus strains (P, B, no. 14, no. 15, and YO) of the third human rotavirus serotype by the plaque reduction neutralization test. This is the fifth example of an animal rotavirus which shares serotypic specificity with a human rotavirus. The H-2 strain is distinct from the H-1 strain (Y. Hoshino et al., J. Clin. Microbiol., in press) of equine rotavirus not only in serotypic specificity by neutralization but also in subgroup specificity, hemagglutinating activity, and RNA electrophoretic migration pattern, thus establishing the existence of a second equine rotavirus serotype. This H-2 isolate is also distinct by neutralization from three other human rotavirus serotypes, 1 (Wa), 2 (DS-1), and 4 (St. Thomas no. 4), as well as bovine (NCDV), and porcine (OSU) rotaviruses.