Acanthamoeba /əkan′thəmē″bə/ , a genus of free-living ameboid protozoa typically found in moist soil and water. The organisms may enter the body through a break in the skin or even though the nasal mucosa, olfactory nerve, and mucous membranes of the eye. It may cause severe infections, such as keratitis (eye infection that can lead to blindness especially with contact lens wearers), and systemic infections of the lung, genitourinary system, brain, and central nervous system. Disseminated cutaneous lesions caused by this organism are seen particularly in patients with AIDS. Although an infection may be fatal, cases are more commonly chronic and can persist for months.