Sensitivity to amphotericin B of a Naegleria sp. isolated from a case of primary amoebic meningoencephalitis.

An amoeba of the genus Naegleria causing fatal meningoencephalitis in a human subject has been investigated for its sensitivity to several drugs. Penicillin, sulphadiazine, chloramphenicol, oxytetracycline hydrochloride, streptomycin, methotrexate, emetine, quinine, and metronidazole had no effect on the organism in vitro at levels in excess of those likely to be attained therapeutically in the brain. Amphotericin B was highly amoebicidal in vitro and protected mice from infection with the organism. Used in high dosage by the intraventricular as well as the intravenous route, this drug might be successful in the treatment of further cases of primary amoebic meningoencephalitis.