An overview of Entamoeba histolytica Schaudinn

Entamoeba histolytica Schaudinn (1903) is an inner amoeba of inner amibacin. In the past, it was thought that the Entamoeba histolytica Schaudinn was generally cohabited in the host colon, but only under certain conditions invading the intestinal wall or from the bloodstream to other organs and causing disease. In 1928, Brumpt had proposed two kinds of Entamoeba histolytica Schaudinn, one of which could cause amebiasis, while the other was similar to the amoeba morphology in the dissolved tissue, with the same life history but no pathogenesis And named Entamoeba dispar. Causing amebiasis is dissolved in the organization of amoeba, and Disparene amoeba is pathogenic.

The morphology of Entamoeba histolytica Schaudinn

Dissolved tissue amoeba can be sub-cyst and trophozoites two different periods, mature 4-core capsule for the infection period. The size of the trophozoites of Entamoeba histolytica Schaudinn is between 10 and 60μm. When it is isolated from the diseased tissue, it often contains red blood cells and sometimes white blood cells and bacteria. Nourishing body with a single orientation of the pseudopodia and movement, a transparent mass and rich in particulate matter, with a spherical bubble nucleus, diameter 4~7μm. The edge of the thin nuclear membrane with uniform distribution of uniform, uniform size of the chromatin granules. However, the trophozoites in the culture medium often have more than two nuclei, surrounded by a slender colorless filamentous structure.

The process of forming the cysts in the intestine is called encystation. Nourishing body in the intestine outside the organ or the outside can not become a capsule. In the intestine trophoblast gradually shrink, stop the activity into a similar spherical cystic precyst, later into a nuclear cyst and two split proliferation. The cytoplasm has a special nutrient storage structure that is the chromatoid body, was short rod-shaped, the identification of insects meaningful. There are glycogen vacuole in immature cysts. Mature capsule has four nuclei, round, diameter 10~16μm, cyst wall thickness of about 125~150nm, smooth. The nucleus is a vesicular nucleus, similar to trophozoites but slightly smaller.

Life history of Entamoeba histolytica Schaudinn

A suitable host for amoeba in human-soluble tissue, cats, dogs and rats can also be used as occasional hosts. The life history of Entamoeba histolytica Schaudinn includes cystic phase and trophozoites. The infection period is a quadruple-containing mature capsule. Fecal contaminated food, drinking water in the infectious capsule through the mouth through the stomach and small intestine, at the end of the ileum or colon neutral or alkaline environment, due to cysts in the movement of insects and intestinal enzymes, Cyst wall in a certain point thinning, cysts within the body of several elongation, pseudopodia telescopic, worms bite out. 4 nuclear parasites by three cytoplasmic division and a nuclear division into eight trophozoites, then the upper end of the colon feeding bacteria and two split proliferation. Parasites in the process of moving down the intestine, with the contents of the contents of the dehydration and environmental changes and other factors to stimulate the formation of round front cysts, secrete a thick wall, the second mitosis to form a quad-core Cysts, with feces. The capsule can survive and remain infectious in the damp environment for several days to one month, but is easy to die in a dry environment.

Nourishing body can invade the intestinal mucosa, swallow red blood cells, destruction of the intestinal wall, causing intestinal wall ulcers, but also with the blood flow into other tissues or organs, causing parenteral amoebiasis. With the necrotic tissue shedding into the intestine of the trophozoites, can be excreted through the peristalsis with the feces excreted, the trophozoites in the external natural environment can only live for a short time, even if swallowed by the digestive tract by digestion by the digestion.

Dissolution of Entamoeba histolytica Schaudinn

The active phase is only present in the host and fresh loose feces. The cysts survive in the host's water, soil and food, especially in the damp environment. The capsule is easily killed by high temperature and freezing temperatures, and can only survive for several months in the host. When the cysts are swallowed, they are in the digestive tract, causing infection. Trophozoites are easy to kill, can not live through the acidic stomach caused by infection.

Pathogenesis of Entamoeba histolytica Schaudinn

The amoebicidal body in the dissolved tissue has the ability to invade the host tissue or organ, adapt to the host's immune response and express the causative factor. Trophoblast expression of the causative factor can destroy the extracellular matrix, contact-dependent dissolution of host tissue and resistance to complement dissolution, which destroy the extracellular matrix and dissolution of the host tissue is an important way of invasion of insects. The transcriptional level of these pathogenic factors is an important mechanism to regulate its pathogenic potential.

Among the pathogenic factors affecting Entamoeba histolytica Schaudinn, three pathogenic factors have been extensively studied and elucidated at the molecular level: that is, 260kDa Gal/GalNAclectin Host cells; amoeba pore formation in the host cell pore formation; cysteine proteinases, dissolved host tissue.

The trophozoites are first adsorbed on the intestinal mucosa by the 260 kDa lectin, which then secrete perforin and protease to destroy the intestinal mucosal epithelial barrier and puncture cells, killing the host intestinal epithelial cells and immune cells, causing ulcers, which can lead to parenteral infection It is the characteristic of the pathogenesis of Entamoeba histolytica Schaudinn.

Treatment and Prevention of Entamoeba histolytica Schaudinn

Metronidazole for the current treatment of amebiasis drug of choice. Amebiasis is a worldwide public health problem. In the treatment of the disease, comprehensive measures should also be taken to prevent infection. Specific methods include harmless treatment of feces to kill cysts; Food, from pollution; do a good job of environmental hygiene and get rid of harmful insects; strengthen health education to improve self-protection ability.