Naegleria fowleri

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Image:Free-living amebic infections.gif Naegleria fowleri is a free living amoeba typically found in warm fresh water, from 25-35 degrees Celsius in a flagellated stage. It belongs among a group called the Percolozoa or Heterolobosea. In humans, N. fowleri can become pathogenic, causing primary amoebic meningoencephalitis (PAM or PAME), a syndrome affecting the central nervous system, characterized by changes in olifactory perception (taste and smell), followed by vomiting, nausea, fever, headache, and the rapid onset of coma and death.

PAM usually occurs in healthy children or young adults with no prior history of immunocompromisation who have recently been exposed to bodies of fresh water. N. fowleri invades the central nervous system via penetration of the olfactory mucosa and nasal tissues, resulting in significant necrosis of and hemorrhaging in the olfactory bulbs. From there, amoebae climb along nerve fibers through the floor of the cranium and into the brain. The prognosis is bleak for those that contract PAM, as only two patients have survived in a clinical setting. Amphotericin B devastates N. fowleri organisms in laboratory settings, and is the preferred choice in N. fowleri treatment, in addition to systemic rifampin. A more aggressive antibody serum based treatment is being pursued, and may eventually prove more effective than modern broad antibiotic targeting.

N. fowleri can be grown in several kinds of liquid axenic media or on non-nutrient agar plates coated with bacteria. Detection in water is performed by centrifuging a water sample with Escherichia coli added, and then applying the pellet to a non-nutrient agar plate. After several days the plate is microscopically inspected and Naegleria cysts are identified by their morphology. Final confirmation of the species' identity can be performed by various molecular or biochemical methods.[1]de:Naegleria fowleri fr:Naegleria fowleri pt:Naegleríase