Entamoeba gingivalis

Entamoeba gingivalis is an opportunistic Amoebozoa[citation needed] (reported by some as an effect of disease; not a cause [hence status as a commensal])[2][3][4] and is the first amoeba in humans to be described.

Entamoeba gingivalis have pseudopodia that allow them to move quickly and phagocytise the nucleus of polynuclear neutrophils by exonucleophagy in periodontal disease.

There are numerous food vacuoles, which consists mostly of phagocitised PMN nucleus, blood cells, and bacteria.

The main activity of the amoeba Entamoeba gingivalis in the infected periodontal crevices, besides moving, consists in feeding on the nucleus of white blood cells.

The amoeba penetrates into the cytoplasm to reach the nucleus and literally suctions its contents via the negative pressure of the pseudopod.

Entamoeba gingivalis from aggressive periodontal disease patient biofilm using phase contrast microscope 1000x. It is recognizable through its dense core in the middle, formed by a central point encircled by a circular halo and surrounded by bigger phagosomes inside a greyish cytoplasm.
From the top of the image, Entamoeba gingivalis is sipping a white cell nucleus, imperceptibly through negative suction apparently. Halfway through the process, it starts enveloping its prey in the middle, to better digest it in a future phagosome.