Entamoeba gingivalis

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

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.