Causal Agent:

Balamuthia mandrillaris is a free-living ameba that is morphologically similar to Acanthamoeba in tissue sections in light microscopy.

Life Cycle:

Balamuthia mandrillaris has only recently been isolated from the environment and has also been isolated from autopsy specimens of infected humans and animals. B. mandrillaris has only two stages, cysts The number 1 and trophozoites The number 2, in its life cycle. No flagellated stage exists as part of the life cycle. The trophozoites replicate by mitosis (nuclear membrane does not remain intact) The number 3. The trophozoites are the infective forms, although both cysts and trophozoites gain entry into the body The number 4 through various means. Entry can occur through the nasal passages to the lower respiratory tract The number 5, or ulcerated or broken skin The number 6. When B. mandrillaris enters the respiratory system or through the skin, it can invade the central nervous system by hematogenous dissemination causing granulomatous amebic encephalitis (GAE) The number 7 or disseminated disease The number 8, or skin lesions The number 9 in individuals who are immune competent as well as those with compromised immune systems. B. mandrillaris cysts and trophozoites are found in tissue.

Life cycle image and information courtesy of DPDx.