Oral amoeba
Last reviewed: 23.04.2024
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Oral amoeba (Entamoeba gingivalis) - a species of unicellular organisms (protista) such as sarcodaceae - belongs to the subfamily of Amoebozoa and is one of six species of endoparasites of this group that can live inside a person. Unlike dysenteric, the oral amoeba is not recognized as a pathogenic protozoic (protozoan) and is considered a medical non-pathogenic commensal in medical parasitology. Although scientific research on the possible pathogenic action of this species of amoeba has been ongoing since its discovery in the middle of the 19th century.
The oral amoeba is home to soft dental plaque and periodontal (gingival) pockets at the base of the teeth, also found in carious teeth and lacunae of palatine tonsils. It is believed that these protists live in the mouth of almost every adult.
[Structure of the oral amoeba
By its structure, the oral amoeba is trophozoite, that is, it has the vegetative form of a unicellular body.
This amoeba does not form cysts, and its entire life cycle passes only in the trophozoite stage, 5 to 50 μm in diameter, but usually does not exceed 10-20 μm.
The structure of the oral amoeba differs in that its cell does not have a constant configuration and is limited by a dense layer of transparent and viscous ectoplasm, the plasma membrane. Under this layer is a more liquid granular endoplasm, and both layers differ at high magnification only when the amoeba is in motion.
Endoplasm contains one small and subtle nucleus of a spherical shape, covered with a membrane, and inside it - unevenly distributed small chromatin accumulations (karyosomes) consisting of proteins and RNA.
The organoids of the movement E. Gingivalis are pseudopodia (pseudopods) in the form of cytoplasm outgrowths that appear when the amoeba needs to move. By the same outgrowths, it seizes food - polymorphonuclear leukocytes (neutrophils), remains of dead mucous cells (cellular detritus) and dental plaque forming bacteria.
Food is inside the body of the amoeba (in the cytoplasm) and digested in phagosomes - digestive vacuoles. This process is called phagocytosis. And undigested residues are excreted through any part of the body protista.
E. Gingivalis multiplies by binary fission with the formation of two smaller daughter cells.
Symptoms
In fact, the symptoms of oral amoeba, that is, there are no signs of its presence in the oral cavity.
The final verdict of parasitologists regarding the actual pathogenicity of oral amoeba has not yet been pronounced. The question continues to be debated, and the starting point of a negative attitude towards the oral amoeba is its detection in people with a gum disease such as periodontitis (alveolar pyorrhea). As reported in the journal Dental Research, oral amoeba is present in 95% of patients with this disease, but E. Gingivalis is detected in half of patients with healthy gums ...
To date, there is no conclusive evidence that the oral amoeba is involved in the development of periodontitis and can cause the excretion of pus.
Oral or oral amoeba is synanthropic, that is, an organism coexisting with a human being, and, as the researchers note, the owner, in whose mouth E. Gingivalis lives, provides her with "home and food". And the trophozoites of this amoeba do not cause a direct damage to the health of the owner. Even there is a version that this simple helps to reduce or prevents the level of other, potentially harmful microorganisms, as bacteria enter its "diet". Looking at the situation from this point of view, we can assume that oral amoeba brings certain benefits to the host man.
Diagnostics
To find E. Gingivalis in the oral cavity of a person is possible only with the help of laboratory examination of smears from periodontal pockets and scrapings of plaque. There are also cases of detection of oral amoeba in sputum.
In this case, according to experts, mouth amoeba can be confused with amoeba dysenteric (Entamoeba histolytica) with a lung abscess. But the distinctive feature of Entamoeba gingivalis is that its trophozoites often contain absorbed leukocytes.