Entamoeba hartmanni

Morphology, life cycle, diagnosis, symptoms, and treatment.

1. Entamoeba hartmanni Prepared by: Veronica Baje

2. Entamoeba hartmanni Entamoeba hartmanni  is a non-pathogenic amoeba with worldwide distribution. Its life cycle is similar to that of E. histolytica but it does not have an invasive stage and does not ingest red blood cells

3. Trophozoites Measures a mere 8 to 12 μ m, with a size range of 5 to 15 μ m. Finger-shaped pseudopods exhibiting nonprogressive motility are standard. Contain one nucleus. Peripheral chromatin is usually present.

4. Cysts Range in size from 5 to 12 μ m, with an average size of 7 to 9 μ m. The spherical cysts may have one, two, three, or four nuclei.

5. Life Cycle  Cysts are typically found in formed stool, whereas trophozoites are typically found in diarrheal stool. Intestinal colonization with nonpathogenic amebae occurs after ingestion of mature cysts in fecally contaminated food, water, or fomites. 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 

6. Laboratory Diagnosis Stool examination for trophozoites and cysts

7. Clinical Symptoms Infections with E. hartmanni are typically asymptomatic.

8. Treatment Although some questions exist regarding the pathogenicity of E. hartmanni , it is generally considered a nonpathogen and treatment is usually not indicated.