The term "brain-eating amoeba" has been used to refer to several microorganisms:
Naegleria fowleri, which causes primary amoebic meningoencephalitis Acanthamoeba spp., which causes the slow-acting infection acanthamoebiasis Balamuthia mandrillaris, which causes balamuthiasis Paravahlkampfia francinae, which causes a form of primary amoebic meningoencephalitis Sappinia pedata, which causes a form of granulomatous amoebic encephalitis