Return to main Sarcodina page

Cyst (dormant stage)

Entamoebas are grouped into those that produce cysts with one, four or eight nuclei.  A few species are known not to produce cysts.


The Entamoeba is a parasite.  This means that it lives off of a host.   Some harmless Entamoebas are living in you right now!

They are quite small, 20-35 um and have a simple life cycle that consists of an infective cyst stage (shown below left) and a multiplying Trophozoite stage (shown above).

Transmission of the infection occurs by ingesting the cysts that contaminate food or water supplies.  The cysts contaminate the supplies from the fecal material of infected animals.

Humans can be hosts to at least six species of Entamoeba however only one species, Entamoeba histolytica is known to cause disease.  Infection of this amoeba leads to amoebic dysentery.

Entamoeba gingivalis  can be found within the spaces between the teeth and is associated with periodontal disease and gingivitis. (This is why you should floss!)

Entamoeba coli is another entamoeba and is commensal of the human large intestine.  It is not the same as E-coli (Escherichia coli) which is a harmful bacteria one gets from eating raw or uncooked meat.

home forums links

Copyright 2015, Microbus, All rights reserved