Naegleria fowleri

Naegleria fowleri. Trophozoite in cytospin preparation (Wright's stain, oil immersion). In this cytospin preparation of human cerebrospinal fluid, a degenerating ameba is seen surrounded by lymphocytes and polymorphonuclear leukocytes. The ameba is highly vacuolated, takes a pale stain, and the large central nucleus contains a large, pale-staining karyosome.