ACANTHAMOEBA SPP - OPPORTUNISTIC PATHOGENS

Members of the genus Acanthamoeba are free-living amebae that are major predators of bacteria. They serve as important laboratory models for understanding the cellular biology and biochemistry of locomotion, phagocytosis, and cell differentiation. Some species of Acanthamoeba can be opportunistic human pathogens, causing amebic meningoencephalitis and keratitis. There also is reason to think that they may be symbionts of plants. Human keratitis caused by Acanthamoeba spp. has been clearly linked to contact lens wear. Once transmitted by the lens to the surface of the cornea, acanthamebas are able to attach to the surface by using junctional complexes formed between trophozoites and surface epithelial cells, as well as by manipulation of the acanthopodia between cell junctions (possibly seeking bacteria). Penetration of the cornea beyond the surface squamous layer may involve both elaboration of enzymes and active phagocytosis.