Entamoeba histolytica: Difference between revisions

'''''Entamoeba histolytica''''' is an [[anaerobic organism|anaerobic]] parasitic [[protozoa]]n, part of the [[genus]] ''[[Entamoeba]]''.<ref name=Sherris>{{cite book | author = Ryan KJ, Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th | pages=733–8 | publisher = McGraw Hill | year = 2004 | isbn = 0838585299}}</ref> It was first seen by [[Anton Van Leeuwenhoek]] and was then found out by [[Lamble]]. Predominantly infecting humans and other primates, ''E. histolytica'' is estimated to infect about 50 million people worldwide. It causes [[Amoebic Dysentery]]. Many older textbooks state that 10% of the world population is infected, but these figures predate the recognition that at least 90% of these infections were due to a second species, ''E. dispar''.<ref>{{cite journal |author= |title=Amoebiasis |journal=Wkly. Epidemiol. Rec. |volume=72 |issue=14 |pages=97–9 |year=1997 |month=April |pmid=9100475 |doi= |url=http://www.who.int/docstore/wer/pdf/1997/wer7214.pdf}}</ref> Mammals such as dogs and cats can become infected transiently, but are not thought to contribute significantly to transmission.

The Pathogenicpathogenic nature of ''E. histolytica'' was explainedfirst reported by [[LoschLösch]] in 1875, but it was not given its Latin name until Fritz [[Schaudinn]] described it in 1903. ''E. histolytica'', as its name suggests (''histo''–''lytic'' = tissue destroying), is [[pathogenesis|pathogenic]]; infection can lead to [[Dysentery|amoebic dysentery]] or amoebic [[liver abscess]].<ref name=Sherris/> E. histolytica produces an acid called histolysin that destroys the intestinal mucous. Symptoms can include fulminating dysentery, bloody diarrhea, weight loss, fatigue, abdominal pain, and [[Ameboma|amoeboma]]. The amoeba can actually 'bore' into the intestinal wall, causing [[lesion]]s and intestinal symptoms, and it may reach the blood stream. From there, it can reach different vital organs of the human body, usually the liver, but sometimes the lungs, brain, spleen, etc. A common outcome of this invasion of tissues is a liver abscess, which can be fatal if untreated. Ingested [[red blood cell]]s are sometimes seen in the amoeba cell cytoplasm.

''E. histolytica'' mediatesmay modulate the virulence of certain human viruses and is itself a host for its own viruses.

* [http://pathema.jcviamoebadb.org/cgi-binamoeba/Entamoeba/PathemaHomePage.cgi PathemaAmoebaDB-''Entamoeba'' Genome Resource]