Entamoeba histolytica

Entamoeba histolytica

Entamoeba histolytica is a protozoan parasite, which can impute the Entamoebidae. He is the causative agent of amoebic dysentery, mainly affects humans and other mammals under experimental conditions.

Features

It belongs to the amoeba and therefore has no "solid " appearance, locomotion is done via pseudopodia ( pseudopodia ), which are everted from the cell. Minuta, the mold is up to 5 microns, and the Magna - shape up to 50 microns in size. Are formed with a size of 15 microns cysts.

Life cycle

The amoebas enter as cysts in the small intestine, there emerges a four-core stage, which in turn colonized the colon and where it divides into eight trophozoites. These form a commensal with the host in most cases. The trophozoites differ from cysts that leave the intestine with the feces. There will be a precipitation amount of up to 45 million cysts per day.

Harmful effect

Two forms can be distinguished, which minuta and the Magna -shape. Minuta forms live in the large intestine of the host and usually call diarrhea forth, but the heal by itself. The Magna - forms, however, penetrate actively into the colonic tissue and loosen it up. If they get in this way into the bloodstream, so they settle increases in internal organs and from there open out abscesses. However, only the Minuta - form shapes from cysts and are carried on to the next host, the Magna - forms remain in the original host.

The caused by E. histolytica disease is called dysentery, amoebic dysentery or amoebiasis accurate. Through tissue-dissolving digestive secretions causing this purulent ulcers that can break.

The result can be diarrhea, peritonitis and abscesses of the liver abdominal pain jelly-like. If left untreated, the disease can cause desiccation ( dehydration ) to death. Often the disease until years or decades after the infection breaks out.

Dissemination

Entamoeba histolytica is spread worldwide and can be found especially in areas with poor sanitary conditions in the wastewater or polluted drinking water. Outbreaks are recorded subsequent to disasters when insufficiently pure drinking water is available. Also errors in the sewer system can cause amoebic dysentery, as over 1,000 cases were observed with 58 dead, for example, at the World Expo 1933 in Chicago, caused by a transgression of waste water into the potable water supply.

More common Entamoeba dispar, a species that was previously provided to Entamoeba histolytica. It does not form a Magna - forms, and is visually indistinguishable from the minuta form of Entamoeba histolytica. It usually causes only diarrhea, which subside by itself ..

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