Naegleria fowleri

Revision as of 15:24, 14 August 2015 by YazanDaaboul (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

WikiDoc Resources for Naegleria fowleri

Articles

Most recent articles on Naegleria fowleri

Most cited articles on Naegleria fowleri

Review articles on Naegleria fowleri

Articles on Naegleria fowleri in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Naegleria fowleri

Images of Naegleria fowleri

Photos of Naegleria fowleri

Podcasts & MP3s on Naegleria fowleri

Videos on Naegleria fowleri

Evidence Based Medicine

Cochrane Collaboration on Naegleria fowleri

Bandolier on Naegleria fowleri

TRIP on Naegleria fowleri

Clinical Trials

Ongoing Trials on Naegleria fowleri at Clinical Trials.gov

Trial results on Naegleria fowleri

Clinical Trials on Naegleria fowleri at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Naegleria fowleri

NICE Guidance on Naegleria fowleri

NHS PRODIGY Guidance

FDA on Naegleria fowleri

CDC on Naegleria fowleri

Books

Books on Naegleria fowleri

News

Naegleria fowleri in the news

Be alerted to news on Naegleria fowleri

News trends on Naegleria fowleri

Commentary

Blogs on Naegleria fowleri

Definitions

Definitions of Naegleria fowleri

Patient Resources / Community

Patient resources on Naegleria fowleri

Discussion groups on Naegleria fowleri

Patient Handouts on Naegleria fowleri

Directions to Hospitals Treating Naegleria fowleri

Risk calculators and risk factors for Naegleria fowleri

Healthcare Provider Resources

Symptoms of Naegleria fowleri

Causes & Risk Factors for Naegleria fowleri

Diagnostic studies for Naegleria fowleri

Treatment of Naegleria fowleri

Continuing Medical Education (CME)

CME Programs on Naegleria fowleri

International

Naegleria fowleri en Espanol

Naegleria fowleri en Francais

Business

Naegleria fowleri in the Marketplace

Patents on Naegleria fowleri

Experimental / Informatics

List of terms related to Naegleria fowleri

This page is about microbiologic aspects of the organism(s).  For clinical aspects of the disease, see Primary amoebic meningoencephalitis.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Naegleria fowleri (also known as the brain eating amoeba) is a ubiquitous, free living amoeba typically grows contaminated, warm (25–35 °C / 77–95 °F), fresh water (e.g. lakes or hot springs). It belongs to a group called the Percolozoa or Heterolobosea. N. fowleri is transmitted to the humans through the nose when individuals swim/dive in lakes. Drinking contaminated water, however, does not result in transmission. N. fowleri causes primary amebic meningoencephalitis (PAM), a rare disease whereby N. fowleri invades the human central nervous system through the cibriform plate and causes fulminant fatal meningoencephalitis in the majority of cases.[1][2]

Taxonomy

Biology

Shown below is an the life cycle of N. fowleri:

  • N. fowleri grows ideally at 42 °C (108 °F), but it can tolerate temperatures as high as 45 °C (113 °F).[3]
  • There are 3 morphological stages in the life cycle of Naegleria fowleri:[3]
  • Trophozoite: 10-30 mu - Infective stage characterized by the presence of contractile vacuoles. It reproduces by binary fission. It uses pseudopods structure to ingest other organisms, red blood cells, and white blood cells.
  • Flagellate: A temporary stage when the organism is exposed to changes in pH (e.g. from culture to distilled water).
  • Cyst: 7-14 μm - A resistant stage whereby the organism is protected by a dense cell wall that can tolerate harsh environments, such as cold weather or states of low nutrition. Cysts may be transmitted to the human host and transformed into trophozoites.

Structure

  • N. fowleri is a facultatively aerobic, heterotrophic organism.[4]
  • In its trophozoite form, it may appear either ameboid or flagellated.
  • It contains the following structures for survival and growth:
  • Mitochondria
  • Pseudopods
  • Flagella
  • Contractile vacuoles

Tropism

  • N. fowleri invades the central nervous system (highly oxygenated environment) and causes meningoencephalitis.[3]
  • N. fowleri is transmitted to humans via the nasal cavity into the cribriform plate.
  • It invades the subarachnoid spaces by migrating along the mesaxonal of unmyelinated olfactory nerves.
  • When it reaches the subarachnoid space, it may then disseminate to other tissues of the central nervous system.
  • It migrates along the mesaxonal spaces of unmyelinated

Natural Reservoir

  • The natural reservoir of N. fowleri are typically fresh water lakes and hot springs.
  • N. fowleri has also been isolated from:[4]
  • Soil
  • Swimming pools
  • Home showers
  • Sewers
  • Cooling towers

References

  1. "The Centers for Disease Control and Prevention, Division of Parasitic Diseases - Naegleria Infection Fact Sheet". Retrieved 2007-10-09.
  2. "6 Die From Brain-Eating Amoeba in Lakes". Retrieved 2007-10-03.
  3. 3.0 3.1 3.2 John DT (1982). "Primary amebic meningoencephalitis and the biology of Naegleria fowleri". Annu Rev Microbiol. 36: 101–23. doi:10.1146/annurev.mi.36.100182.000533. PMID 6756287.
  4. 4.0 4.1 Park JS, Simpson AG, Lee WJ, Cho BC (2007). "Ultrastructure and phylogenetic placement within Heterolobosea of the previously unclassified, extremely halophilic heterotrophic flagellate Pleurostomum flabellatum (Ruinen 1938)". Protist. 158 (3): 397–413. doi:10.1016/j.protis.2007.03.004. PMID 17576098.

External links