1. Naegleria fowleri

2. Scientific classification Domain:Eukaryota Phylum:Percolozoa ClassHeterolobosea Order:Schizopyrenida Family:Vahlkampfiidae Genus:Naegleria Species:N. fowleri Binomial name: Naegleria fowleri

3. Naegleria fowleri ; also known as "the brain-eating amoeba") is a free-living excavate form of protist typically found in warm bodies of fresh water, such as ponds, lakes, rivers, and hot springs. It is also found in soil, near warm-water discharges of industrial plants, and unchlorinated swimming pools in an amoeboid or temporary flagellate stage.

4. There is no evidence of this organism living in ocean water
There is no evidence of this organism living in ocean water. It belongs to a group called the Percolozoa or Heterolobosea. It is an amoeba, Human infection comes from water containing the amoebae and usually follows swimming or diving in ponds. N. fowleri can invade and attack the human nervous system. Although this occurs rarely, such an infection nearly always results in the death of the victim. The case fatality rate is estimated at 98%. Over 200 cases of PAM have been reported world wide but the disease is commonly found from developed countries

5. History of discovery Physicians M. Fowler and R. F
History of discovery Physicians M. Fowler and R. F. Carter first described human disease caused by amebo-flagellates in Australia in 1965.] Their work on amebo-flagellates has provided an example of how a protozoan can effectively live both freely in the environment, and in a human host. Since 1965, more than 144 cases have been confirmed in a variety of countries. In 1966, Fowler termed the infection resulting from N. fowleri primary amoebic meningoencephalitis (PAM) in order to distinguish this central nervous system (CNS) invasion from other secondary invasions caused by other true amoebas such as Entamoeba histolytica. A retrospective study determined that the first documented case of PAM possibly occurred in Britain in 1909

6. Lifecycle Life Cycle Stages: Cyst, Flagellate, Trophozoite
Lifecycle Life Cycle Stages: Cyst, Flagellate, Trophozoite. Naegleria fowleri exists in nature in three forms: a cyst, a trophozoite (ameboid) and a flagellate. Cyst stage Trophozoites encyst due to unfavorable conditions. Factors that induce cyst formation can include food deprivation, crowding, desiccation, accumulation of waste products, and cold temperatures] N. fowleri has been found to encyst at temperatures below 10°C.

7. Trophozoite stage The reproductive stage of the protozoan organism, which grows fastest at around 42°C and proliferates by binary fission. The trophozoites are characterized by a nucleus and a surrounding halo. The trophozoites travel by pseudopodia, temporary round processes which fill with granular cytoplasm. The pseudopodia form at different points along the cell, thus allowing the trophozoite to change directions. In their free-living state, trophozoites feed on bacteria. In tissues, trophozoites phagocytize red blood cells and white blood cells and destroy tissue Flagellate stage A biflagellate form occurring when trophozites are exposed to a change in ionic concentration such as placement in distilled water. The transformation of trophozoites to flagellate form occurs within a few minutes.

9. PATHOGENESIS In humans, N
PATHOGENESIS In humans, N. fowleri can invade the central nervous system via the nose (specifically through the olfactory mucosa and cribriform plate of the nasal tissues). The penetration initially results in significant necrosis of and hemorrhaging in the olfactory bulbs. From there, the amoebae climbs along nerve fibers through the floor of the cranium via the cribriform plate and into the brain. The organism begins to consume cells of the brain piecemeal by means of a unique sucking apparatus extended from its cell surface. It then becomes pathogenic, causing primary amoebic meningoencephalitis (PAM or PAME). PAM is a syndrome affecting the central nervous system. PAM usually occurs in healthy children or young adults with no prior history of immune compromise who have recently been exposed to bodies of fresh water.

10. Symptoms Start 1 to 14 days after exposure
Symptoms Start 1 to 14 days after exposure. symptoms include, but are not limited to, changes in taste and smell, headache, fever, nausea, vomiting, and stiff neck. Secondary symptoms include confusion, hallucinations, lack of attention, ataxia, and seizures. After the start of symptoms, the disease progresses rapidly over 3 to 7 days, with death occurring from 7 to 14 days after exposure

11. Diagnostics Current research is focused on development of real time PCR diagnostic methods. One method being developed involves monitoring the amplification process in real-time with hybridization of fluorescent labeled probes targeting the MpC15 sequence – which is unique to N. fowleri. Another group has multiplexed three real-time PCR reactions as a diagnostic for N. fowleri, as well as Acanthamoeba spp. and Balamuthia mandrillaris. This could prove to be an efficient diagnostic test

12. DIAGNOSIS 1) BY CSF EXAMINATION where the fluid is cloudy to PURULUNT, with prominent neutrophil leucocytosis, elevated proteins and low glucose, resembling pyogenic meningitis failure to find bacteria in such specimen should raise the possibility of PAM. Wet film examination of CSF may show the trophozoites CYST are never seen in CSF or BRAIN 2) BY AUTOPSY trophozoites can be demonstrated in BRAIN histologically 3) BY CULTURE Can be obtained in AGAR seeded with Escherichia coli or in the usual cell culture used for virus isolation both trophozoites and cyst occur in culture

13. TREATMENT Involve the use AMPHOTERICIN B with limited success
TREATMENT Involve the use AMPHOTERICIN B with limited success. But the most effective one is the use of CHLORPROMAZINE , CDC has now investigate drug called Miltefosine for teating free living amoeba (FLA) caused by Naegleria fowleri, Balamuthia mandrillaris and Acanthamoeba spp.