Detection of bovine coronaviruses from adult cows with epizootic diarrhea and their antigenic and biological diversities.

Bovine coronavirus (BCV) was detected by reverse transcriptase-PCR, immune electron microscopy or virus isolation from adult cows at 6 out of 6 outbreaks of epizootic diarrhea in Japan. Six BCVs isolated in feces, intestinal content or tracheal exudate of the cows were analyzed for their antigenic properties by cross virus neutralization (VN) tests. The isolates were divided into two groups, one of which had closely related antigenicity with the reference Mebus and Kakegawa strains of BCV, and another which showed significant differences in VN antibody titers from the reference strains. Two isolates in the latter group, which were from the enteric and respiratory tracts of the same cows, respectively, were distinguished from each other by ELISA using monoclonal antibodies against the Kakegawa strain. The isolates showed various hemagglutination and receptor destroying enzyme titers against chicken or mouse erythrocytes.