Billede:Entamoeba histolytica Amebiasis LifeCycle.gif

Fra Wikipedia, den frie encyklopædi

Entamoeba_histolytica_Amebiasis_LifeCycle.gif (28KB, MIME type: image/gif)


Denne fil er fra Wikimedia Commons, en samling af åbent indhold som Wikimedia Foundation er vært for.
Beskrivelsen fra siden med beskrivelse af billedet er vist nedenfor.


[edit] Summary

Description

Amebiasis [Entamoeba histolytica]

Life Cycle of Entamoeba histolytica

Cysts and trophozoites are passed in feces . Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Infection by Entamoeba histolytica occurs by ingestion of mature cysts in fecally contaminated food, water, or hands. Excystation occurs in the small intestine and trophozoites are released, which migrate to the large intestine. The trophozoites multiply by binary fission and produce cysts , and both stages are passed in the feces . Because of the protection conferred by their walls, the cysts can survive days to weeks in the external environment and are responsible for transmission. Trophozoites passed in the stool are rapidly destroyed once outside the body, and if ingested would not survive exposure to the gastric environment. In many cases, the trophozoites remain confined to the intestinal lumen ( : noninvasive infection) of individuals who are asymptomatic carriers, passing cysts in their stool. In some patients the trophozoites invade the intestinal mucosa ( : intestinal disease), or, through the bloodstream, extraintestinal sites such as the liver, brain, and lungs ( : extraintestinal disease), with resultant pathologic manifestations. It has been established that the invasive and noninvasive forms represent two separate species, respectively E. histolytica and E. dispar. These two species are morphologically indistinguishable unless E. histolytica is observed with ingested red blood cells (erythrophagocystosis). Transmission can also occur through exposure to fecal matter during sexual contact (in which case not only cysts, but also trophozoites could prove infective).

Source

DPD CDC http://www.dpd.cdc.gov/dpdx/images/ParasiteImages/A-F/Amebiasis/Amebiasis_LifeCycle.gif

Date
Author
Permission


[edit] Licensing

Public domain This work is in the public domain in the United States because it is a work of the United States Federal Government under the terms of Title 17, Chapter 1, Section 105 of the US Code. See Copyright.

Note: This only applies to works of the Federal Government and not to the work of any individual U.S. state, territory, commonwealth, county, municipality, or any other subdivision.


عربية | Česky | Deutsch | Español | Italiano | 日本語 | Magyar | Français | Português | 简体中文 | 正體中文 | +/-

De følgende sider henviser til dette billede: