Concanavalin A-induced agglutination of Acanthamoeba

VIRULENT strains of Acanthamoeba produce cytopathic effects in mammalian tissue cultures1–3, and cause acute meningoencephalitis in laboratory animals after intranasal inoculation1. In humans, Acanthamoeba seem to produce cerebral lesions in defence-weakened individuals4–7. We have begun studies of the cell surface of Acanthamoeba since virulent strains must make direct contact with a host cell before initiation of degenerative changes in mammalian tissue cultures2,3. The sensitivity of avirulent and virulent strains to concanavalin A (con A)-induced agglutination was investigated first as there was no evidence that carbohydrate-containing components were exposed at the cell surface of Acanthamoeba. Our results indicate that both avirulent and virulent Acanthamoeba were sensitive to con A-induced agglutination. In contrast to the results of studies of avirulent and virulent Entamoeba histolytica8, however, the avirulent strain was more sensitive to con A.