Entamoeba hartmanni is a non-pathogenic amoeba found worldwide that does not have an invasive stage and does not ingest red blood cells. It has a similar life cycle to E. histolytica where cysts are ingested and excyst in the small intestine, trophozoites multiply in the large intestine and produce cysts which are passed in stool. Infections with E. hartmanni are typically asymptomatic and it is considered non-pathogenic so treatment is usually not indicated.

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 12μm, with a size range of
5 to 15μm.
• Finger-shaped pseudopods exhibiting
nonprogressive motility are standard.
• Contain one nucleus.
• Peripheral chromatin is usually present.

4. Cysts
• Range in size from 5 to 12μm,
with an average size of 7 to 9μm.
• 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.