Episodes TWiP 39: I encyst, said the amoeba April 26, 2012 Tagged as: acanthamoeba castellani, keratitis, naegleria fowlerii, parasite, parasitism, podcast, primary amoebic meningoencephalitis, twip Vincent and Dickson review the biology and pathogenesis of the amoebae Naegleria fowlerii and Acanthamoeba castellani.