From Big Medical Encyclopedia

THE SELECTION DECONTAMINATION (English decontamination, disinfecting, from armor. the de-prefixes extraction, destruction + contaminatio mixing, merge) — selective elimination from digestive tract of the person of aerobic bacteria (gram-negative sticks and gram-positive cocci) and fungi germicides for the purpose of increase in resistance of an organism to an infection. At S. anaerobic microflora went. - kish. a path it is not damaged.

Villages of carry out at diseases with an immunodeficiency (see. Immunological insufficiency ) at the increased risk of autoinfection, at threat of development of sepsis in cases of extensive injuries, burns, cytotoxic and immunodepressive therapy, organ and tissue transplantation. At various diseases with a heavy granulocytopenia or S.'s pancytopenia of sharply reduces frequency inf. complications. The method is effective also at other diseases which are followed by decrease in resistance of an organism and also at a medicinal allergy, nek-ry forms of osteomyelitis, a chronic furunculosis, etc. The selection decontamination is a new effective method of prevention intrahospital infections (see) and fight against them.

Before emergence of a method C. of applied total decontamination — whenever possible liberation of an organism of the owner from all microflora. Originally both methods were developed in gnoto-biological laboratories.

Dekontaminirovanny, almost «amicrobic» patients are placed in the isolation center of gnotobiologiches-whom of type for protection against exogenous microflora (see. Chamber sterile ). After the end of treatment recover normal intestinal microflora by «settling» by its corresponding species of bacteria that is reached, e.g., by appointment bifidumbacterium (see).

Normal microflora intestines (see) generally consists of sporeless strict anaerobes of the sorts Bacteroides, Bifidobacterium, Eubacterium, Lactobacillus, etc. They live as on a mucosal surface of a cover as a result of adhesion to epithelial cells, and in a gleam of intestines, interfering with its settling (colonization) by opportunistic and pathogenic microorganisms. At the same time as a part of normal intestinal microflora there are aerobic microorganisms (see. Aerobes ), rough reproduction to-rykh is interfered by obligate anaerobe bacterias (see). This ecological pattern caused by competitive, antagonistic and other features of anaerobe bacterias of intestines received the name of kolonizatsionny resistance. This mechanism of protection from ekzo-and an endogenous infection is broken at an irrational antibioticotherapia. Broad use of antibiotics for a row of years is followed by change of etiological structure of intrahospital infections. Became frequent inf. the complications caused by gram-negative aerobic bacteria of the sorts Pseudomonas, Klebsiella, Proteus, Escherichia, Providencia, Serratia, etc.

At treatment of various diseases of nek-ry antibiotics of a broad spectrum of activity there are considerable changes of species composition of normal intestinal microflora, up to disappearance of the strict anaerobes creating kolonizatsionny resistance. Depending on influence on kolonizatsionny resistance antimicrobic to lay down. drugs are divided into three groups: strongly suppressing kolonizatsionny resistance (tetracycline, natural and semi-synthetic penicillin, chloramphenicol, furasolidone); moderately acting on kolonizatsionny resistance at use in high doses (e.g., rifampicin); the drugs which are not operating on kolonizatsionny resistance even at appointment in high doses (cephalosporins, Nevigramonum, co-trimoxazole, gentamycin, polymyxin, Amphotericinum In, nystatin, levorinum). For S. use the drugs which are not operating on kolonizatsionny resistance.

Before the choice of the scheme of an antibioticotherapia and in process. treatments it is important to know the level of kolonizatsionny resistance of the patient. On laboratory animals (see) kolonizatsionny resistance define by infection of per os with various doses of opportunistic, pathogenic, antibiotic-resistant strains of bacteria. However for a wedge, uses most we accept the express biochemical method (high-voltage paper electrophoresis with the subsequent coloring by ninhydrin) applied At a shed (G. W. Welling, 1979). It is based on identification beta aspartyl - glycine in water extract of excrements. This substance is formed in intestines of proteins about asparagine - the glycine sequence of amino acids and not split by usual proteases. In healthy people and animals beta aspartyl - glycine is not found in excrements since collapses beta aspartyl - peptidase of obligate anaerobic bacteria. At decrease in quantity of obligate anaerobic bacteria or their full destruction by antibiotics in excrements appears beta aspartyl - glycine.

See also Gnotobiologiya , the Managed abacterial environment .

Bibliography: Stepanov, E. A., H ah and in and O. V. and Ginodman G. A. Kritery of «kolonizatsionny resistance» and perspective of an antibioticotherapia, Klin, hir., No. 8, page 68, 1981; Ava O. V., Mountain B. M. and Ruban of Page 3 Withered. Microbiological and immunological aspects of a gnotobiologiya, page 131, M., 1982; Dietrich M., F 1 i e d n e T. M. and. To r i e g e r D. Germfree technology in clinical medicine, production and maintenance of gnotobiotic states in man, in book: Germfree research, ed. by J. B. Heneghan, p. 21, N. Y. — L., 1973; New criteria for antimicrobial therapy, maintenance of the digestive tract colonization resistance, ed. by D. Van der Waaij a. J. Yerhoef, Amsterdam — Oxford, 1979.

O. V. Chakhava.