From Big Medical Encyclopedia

O-AGGLYUTINATSIYA (late lat. agglutinatio pasting; synonym somatic agglutination) — the pasting of bacteria resulting from interaction of somatic O-antigen of bacteria with the corresponding O-antibodies of blood serum. O-agglutination is described by E. Veyl and A. Felix in 1916 during the studying of agglutination vulgar a protea. At O-agglutination flagellums of the agglutinated bacteria remain intact, and pasting of bacteria happens due to formation of compact units, in to-rykh a cell, as a rule, interact the poles. It gives to O-agglutination a specific fine-grained look that distinguishes it from krupnokhlopchaty N-agglutination.

Use in reaction of Au agglutinum-tsii of the known O-serums allows to identify a look or a serotype (serovar) of the activator. O-serums receive by immunization of animals bacteria, at to-rykh N-antigen as a result of warming up or processing is destroyed by absolute alcohol of culture of bacteria and O-antigen is kept. For the purpose of definition of O-antibodies in blood serum of patients by means of reaction of O-agglutination apply bacterial O-diagnosticums (see. Diagnosticums ). Reaction of O-agglutination is carried out in two options: on a slide plate (orientation response) and in test tubes with various cultivations of blood serum — so-called developed, or linear, agglutination (see. Agglutination ).

In clinic inf. diseases reaction of O-agglutination is used as for definition of O-antibodies in blood serum to activators of many inf. diseases (salmonellosises, a typhoid, paratyphus, kolibak-terioza, iyersinioza, dysentery, epidemic cerebrospinal meningitis, etc.), and for definition of O-antigen of bacteria in biol, liquids of an organism of patients (in blood, urine, excrements, cerebrospinal liquid, saliva).

Various options of O-agglutination, napr are used, at diagnosis of a typhoid put reaction of O-agglutination with Au-bakteri-alnym diagnoyetikumy (see. Vidalya reaction ). Reaction of O-agglutination gains diagnostic value since 2nd week from the beginning of a disease when in an organism of patients of the O-antibody collect in the quantity sufficient for formation of agglutinate at a caption of blood serum 1: 400 and above. At immunizirovanny persons Au-agglyutipa-tion is possible at a high caption of serum (1: 800 and above) also comes to light in earlier terms from an onset of the illness that should be considered at assessment of results of this reaction. The diagnostic value of reaction of O-agglutination increases at a research of the so-called pair blood sera taken from patients at an interval of 4 — 5 days when dynamics of increase of specific O-antibodies is considered. At vaccinated (healthy) such dynamics is absent. The diagnostic importance of reaction of O-agglutination remains several weeks later or months after a disease that is used for retrospective diagnosis of a disease, and also in seroepidemiologichesky researches.

O-agglutination is used at identification of the activator with an infirmity specific monoretsei-even, e.g. salmonellezny, serums to various receptors of O-antigen of the activator designated according to Kauffmann's scheme — Whyte in the Arab figures 1, 2 3, 4 etc. (see. Salmonelloses ). Specificity of O-agglutination, and from here and its diagnostic value, is connected with specificity of the components (antigens and antibodies) used in reaction therefore great value is gained by works on creation of artificial antigens of activators (e.g., salmonellas) and antiserums to them. For the purpose of sensitization and the diagnostic value of reaction of O-agglutination at serol, it is offered to diagnosis of nek-ry diseases to use the reaction of O-hemagglutination representing one of options of reaction of indirect (passive) hemagglutinations (see). In it as a diagnosticum use erythrocytes, latex, alizarine, cellulose, on to-rykh O-antigens or O-antibodies are adsorbed.

For definition of O-antibodies in blood serum of patients reaction of indirect hemagglutination is widely used (in diagnosis of a typhoid, paratyphus, salmonelloses, dysentery, colienterites, cholera and other diseases), in a cut the corresponding erythrocyte diagnosticums, sensibilized are applied by O-antigens that allows to define antibodies in blood serum already with 3 — the 4th day from an onset of the illness. So, at a typhoid reaction of indirect hemagglutination with blood serum of the patient is positive (a caption 1: 640 and above) from the 3rd day of a disease. Definition of O-antibodies by means of reaction of indirect hemagglutination can be used for forecasting of possible complications at patients; e.g., during the prerecurrent period at patients with a typhoid O-antibodies in blood serum sharply fall. Great diagnostic value is got by definition in blood serum of sick specific antigens of salmonellas, a cholera vibrio, shigellas and other activators as O-antigen by means of erythrocyte antitelny diagnosticums can be found in blood serum from the 1st day from an onset of the illness. E.g., at cholera or a vibrionositelstvo O-antigen is found in credits 1: 40 and above (a positive caption) already with 1 — the 3rd day from an onset of the illness. Detection of O-antigen by means of various reactions has not only diagnostic, but also pathogenetic value as O-antigen of gram-negative bacteria is a component of endotoxin causes damage to many systems and bodies of patients up to development of endotoxic shock.

Bibliography: Pokrovsk V. I., etc. Artificial immunity and infectious process, M., 1979; Practical immunology, under the editorship of P. N. Burgasov and I. S. Bezdenezhnykh, page 33, M., 1969; The Guide to microbiological diagnosis of infectious diseases, under the editorship of K. I. Matveev, page 50, M., 1973; Stanislavsky E. S. Bacterial structures and their antigenicity, page 142, M., 1971; Timakov V. D. Microbiology, page 202, M.,-1973; E. N. Immunologiya's Ways, immunodiagnosis, immunoprevention of infectious diseases, Chisinau, 1977; Zinsser H. Microbiology, N. Y., 1976.

L. A. Zamchuk; And. B. Hems (wedge.).