Entamoeba gingivalis

Trophozoites.
The trophozoite of Entamoeba gingivalis ranges in size from 8 to 20 ?m and morphologically resembles that of E. histolytica (Fig. 3-18; Table 3-13). E. gingivalis trophozoites characteristically exhibit active motility. The multiple pseudopods vary in their appearance as the trophozoite moves. The pseudopods may appear long when seen at one point in time and short and blunt the next time that they are seen The single nucleus contains a central karyosome surrounded by peripheral chromatin that is for the most part fine and evenly distributed. Achromatic granules arranged in strands may be visible extending from the karyosome to the peripheral chromatin ring.
A number of inclusions are typically found in the finely granular cytoplasm including food vacuoles containing phagocytosed and partially digested white blood cells (leukocytes and epithelial cells of the host, bacteria and ingested red blood cells, although not as commonly found as in E. histolytica trophozoites .It is important to note that E. gingivalis is the only ameba that ingests white blood cells. This distinguishing characteristic is helpful when it is necessary to differentiate E. gingivalis from E. histolytica.
Cysts.
There is no known cyst stage of E .gingivalis .
Laboratory Diagnosis
An accurate diagnosis of E. gingivalis trophozoites may best be made by examining mouth scrapings , particularly from the gingival area. Material from the tonsillar crypts and pulmonary abscess, as well as sputum, may also be examined. Vaginal and cervical material may be examined to diagnose E. gingivalis in the vaginal and cervical areas.