''Entamoeba gingivalis'' is an

opportunistic Opportunism is the practice of taking advantage of circumstances – with little regard for principles or with what the consequences are for others. Opportunist actions are expedient actions guided primarily by self-interested motives. The term ...

Amoebozoa (reported by some as an effect of disease; not a cause ence status as a commensal and is the first

amoeba An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudop ...

in humans to be described. It is found in the mouth inside the gingival pocket biofilm near the base of the teeth, and in periodontal pockets. ''Entamoeba gingivalis'' is found in 95% of people with

gum disease Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main caus ...

and rarely in people with healthy gums.

Cyst A cyst is a closed sac, having a distinct envelope and division compared with the nearby tissue. Hence, it is a cluster of cells that have grouped together to form a sac (like the manner in which water molecules group together to form a bubble) ...

formation is not present; therefore transmission is direct from one person to another by kissing, or by sharing eating utensils. Only the

trophozoite A trophozoite (G. ''trope'', nourishment + ''zoon'', animal) is the activated, feeding stage in the life cycle of certain protozoa such as malaria-causing ''Plasmodium falciparum'' and those of the ''Giardia'' group. (The complement of the trophozoi ...

s are formed and the size is usually 20 micrometers to 150 micrometers in diameter. ''Entamoeba gingivalis'' have pseudopodia that allow them to move quickly and phagocytise the nucleus of polynuclear

neutrophil Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying ...

s by exonucleophagy in periodontal disease. Their spheroid nucleus is 2 micrometers to 4 micrometers in diameter and contains a small central

endosome Endosomes are a collection of intracellular sorting organelles in eukaryotic cells. They are parts of endocytic membrane transport pathway originating from the trans Golgi network. Molecules or ligands internalized from the plasma membrane can ...

. There are numerous food

vacuole A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic m ...

s, which consists mostly of phagocitised PMN nucleus, blood cells, and bacteria. It also causes pyorrhoea.

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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. The food so gulped down is gradually digested inside the endoplasm. Phagocytosis can sometimes continue for more than 20 polynuclear neutrophil nuclei. This activity leaves a denucleated cell, unable to achieve either its NETS activity or its preprogrammed apoptosis. It will release PMN-uncontrolled

proteolytic enzyme A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the for ...

s on surrounding tissues and could be considered a pathogen from this vampirising activity.

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{{Taxonbar, from=Q264363 Conosa Parasitic amoebozoa Articles containing video clips

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