Entamoeba gingivalis is a non-pathogenic ameba that inhabits the human oral cavity, residing in gingival pockets near the base of teeth. It feeds on bacteria and debris in the oral cavity but does not cause disease. While often found in patients with periodontal disease, it does not have a causative relationship. Entamoeba gingivalis trophozoites resemble those of the pathogenic E. histolytica but do not form cysts. It is transmitted between people orally but does not typically cause symptoms.

1. Entamoeba
gingivalis
Prepared by: Veronica Baje

2. Entamoeba
gingivalis
• Entamoeba gingivalis is a non-
pathogenic ameba that inhabits
the human oral cavity and
occasionally other sites. Although
it is often found in conjunction
with periodontal disease, no
causative association has been
definitively identified.

3. Trophozoites
• Measure 10-20 µm.
• Possess a single nucleus that contains a
small, centrally-located karyosome and fine
peripheral chromatin.
• The cytoplasm often contains ingested
leukocytes, bacteria and other debris, very
rarely red blood cells.
• The trophozoites may also extend agranular
pseudopodia while the main cell cytoplasm
remains granular in appearance.
• Living specimens can move quickly.

4. Cysts • There is no known cyst stage for Entamoeba
gingivalis.

5. Life Cycle
• Trophozoites live in the oral cavity of humans,
residing in the gingival pockets near the base
of the teeth.
• They are not considered pathogenic, and feed
on bacteria and other debris. Trophozoites are
transmitted person-to-person orally by kissing
or fomites (such as eating utensils) .
• The trophozoite stage of E. gingivalis is
morphologically similar to that of E. histolytica.
• The two should be differentiated, as both can
be coughed up in sputum specimens (if E.
histolytica is present in pulmonary abscesses).

6. Clinical
Symptoms
• Infections of E. gingivalis occurring in the
mouth and in the genital tract typically
produce no symptoms.
• Nonpathogenic E. gingivalis trophozoites are
frequently recovered in patients suffering
from pyorrhea alveolaris.
• It appears that the trophozoites thrive under
disease conditions but do not produce
symptoms of their own.

7. Laboratory
Diagnosis
• An accurate diagnosis of E. gingivalis
trophozoites may be best made by mouth
scrapings, particularly from the gingival area.

8. Treatment
• Treatment of E. gingivalis is typically not
indicated because the organism is generally
considered a nonpathogen.