acanthamebiasis /əkan′thəmēbī″əsis/ , a potentially fatal meningoencephalitis infection caused by Acanthamoeba castellani, a free-living ameboflagellate. It is commonly acquired by swimming in water contaminated by the microorganism. Cleaning contact lenses in contaminated solution can also cause keratitis. Early treatment with a combination of oral fuconazole, sufadiazine, flucytosine, and intravenous pentamidine may be of benefit.