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Aug 23, 2023 · Entamoeba coli has three distinct morphological forms: trophozoite, pre-cystic stage, and cystic stage. The most distinguishing feature is the eight-core nuclei, which develops as the cyst begins to mature.
- Akhlema Haidar, Orlando De Jesus
- 2023/08/23
Entamoeba coli, E. hartmanni, E. polecki, Endolimax nana, and Iodamoeba buetschlii are generally considered nonpathogenic and reside in the lumen of the large intestine in the human host. Both cysts and trophozoites of these species are passed in stool and are considered diagnostic .
Usually, the amoeba is immobile, and keeps its round shape. This amoeba, in its trophozoite stage, is only visible in fresh, unfixed stool specimens. Sometimes the Entamoeba coli have parasites as well. One is the fungus Sphaerita spp. This fungus lives in the cytoplasm of the E. coli.
Entamoeba coli has a worldwide distribution and is one of the most commonly reported Entamoeba species in clinical specimens. Non-human primates may serve as reservoir hosts. Trophozoites of E. coli measure 15–50 μm and have a single nucleus with irregular peripheral chromatin and a usually eccentric karyosome.
Infection with Entamoeba histolytica (and E.dispar) occurs via ingestion of mature cysts from fecally contaminated food, water, or hands. Exposure to infectious cysts and trophozoites in fecal matter during sexual contact may also occur. Excystation occurs in the small intestine and trophozoites are released, which migrate to the large intestine.
General Concepts. Entamoeba Histolytica. Clinical Manifestations. Patients have acute or chronic diarrhea, which may progress to dysentery. Extraintestinal disease may be present as a complication or as a primary problem (e.g., liver, lung or brain abscess, or skin or perianal infection). Structure.
Other amebas within this group are Entamoeba coli, Entamoeba hartmanni, Entamoeba polecki, and Iodamoeba buetschlii. These organisms have the same life cycle ( Figure 262-1 ), characterized by a trophozoite stage, which lives in the colon, and a cyst stage, which is infectious.
