Naegleria

Naegleria fowleri is a free-living amoeba that occurs ubiquitously in soil and water worldwide. As the infective form for humans, N. fowleri trophozoite enters the nasal cavity during recreational activities in contaminated water, crosses the olfactory neuroepithelium, travels through the olfactory nerves and the cribriform plate, and reaches the olfactory bulbs in the central nervous system, where it produces primary amoebic meningoencephalitis (PAM). Characterized by an extensive and robust inflammatory reaction, this acute and fatal disease is mainly attributed to the activities of neutrophils and some macrophages. In the absence of accurate diagnosis and specific treatment, this disease has a mortality rate of 95%-97% and a recovery rate of only 5%. Therefore elucidation of the pathogenic mechanisms and identification of the virulence factors of N. fowleri are critical for the development of novel therapeutic approaches for its ultimate control and eradication.