*This web page was produced as an assignment for an undergraduate course at Davidson College.

Life Cycle

N. fowleri is a free-living inhabitant of fresh water and soil. The ameboid trophozoite form reproduces by binary fission and also gives rise to the encysted and flagellated forms, which do not reproduce. Naegleria fowleri is thermophilic, preferring warm water and reproducing successfully at temperatures up to 46°C. In temperate climates, the amebas overwinter as cysts in bottom sediments of lakes, swimming pools and rivers.

Depending of the strain, N. fowleri may become pathogenic when it is inhaled. If it is pathogenic, it may enter the body if the host inhales contaminated soil or water. In order to be pathogenic, it must be in the trophozite or flagellated form. Once inhaled, N. fowlerican be penetrate nasal tissue and cause severe necrosis in the olfactory bulb. After penetrating the cribiform plate, a semiporous barrier, it follows the olfactory nerve and spreads to the meninges, which isthe membrane surrounding the brain. Now, it may penetrate the meninges and make its way into the brain. N. fowleri then starts to literally eat the brain and cause PAM, or primary amebic meningoencephalitis. The damage can be seen in the picture to the right as indicated by the arrows.






Life Cycle

Humoral Immune Response

Cellular Immune Response

Evasion of The Immune System




If you have any question or suggestions regarding this site, please contact Alex Kim (alkim@davidson.edu)