ENTEROCOCCI

From Big Medical Encyclopedia

ENTEROCOCCI — fecal streptococci, bacteria this. Strep to a tococ-saseaa, sort. Streptococcus.

AA. are inhabitants of intestines of the person and hematothermal animals, they are considered as sanitary and indicative and opportunistic microorganisms. On an antigenic structure (group-specific teykhoyevy to - those) they are united in serological group D on R. S. Lancefield where they are included also S. bovis, S. equinus close to enterococci on ecology. Distinguish the following types and biovara of enterococci: S. faecalis,

S. faecalis var. liquefaciens, S. faecalis var. zymogenes, S. faecium, S. fae-cium var. durans. In a type of S. faecalis 11 serotypes (serovars), and in a type of S. faecium — 19 are allocated. Attempts of a lysotypy, differentiation E. on sensitivity to bacteriocines were unsuccessful. Among E. ability to produce specific antibiotic substances — the bacteriocines suppressing life activity of bacterial cells of other strains of the same look or phylogenetic sibling species (see Bakte-riotsinogeniya) is eurysynusic. Antagonism of enterococci (see Antagonism of microbes) to some other microbes is known (e.g., staphylococcus, a stick of plague).

Accurate differences of enterococci from streptococci (see) on a number of signs indicate the need to allocate E. in an independent sort. It was confirmed in comparative researches on hybridization nucleinic to - t, and also the analysis of immunotyping of a proteinaceous complex of enterococci, in Krom relationship with streptococci of other serological groups is not revealed. However still E. in the form of a patrimonial rank are not allocated.

AA. find in water, the soil, foodstuff and on various objects. The main habital of S. faecalis are intestines of the person, S. faecium — intestines of pigs, S. bovis — intestines of cows, S. equinus — intestines of horses.

AA. — spherical or oval bacteria with a diameter of 0,5 — 1 microns connect in couples or short chains (in liquid mediums). AA. differ markedly the expressed polymorphism of cells, nek-ry strains are mobile, have 1 — 4 flagellum. Phenomena of genetic transformation and conjugation are found in enterococci. Conjugation is defined by existence of transmissibelny plasmids (see). In comparison with other streptococci E. are steadier against action of environmental factors: maintain heating at t ° 60 ° within 30 min., 40% of bile are capable to breed in environments from 6,5% of sodium chloride, at

pH 9,6 — 10,2. Such substances as potassium tellurite, sodium azide, bilious salts, crystal violet, nalidixic to - that, and also penicillin and Neomycinum do not oppress growth

E., what is used in creation of elective mediums for enterococci (see. Selection environments). Problem of identification E. completely it is not solved since signs, hl. obr. fermentation of separate carbohydrates, are changeable, and «atypical» strains, especially after long vegetation in the environment are rather often allocated.

As sanitary and indicative microorganisms E. have a number of advantages before colibacilli: are more resistant to physical. and to chemical influences, do not breed in the environment, can be allocated from strongly contaminated objects with crops for the selection environments. There are distinctions between enterococci of human and animal origin. In a number of the countries E. are used as a sanitarnopokazatelny microbe for definition of the fecal pollution of water of open reservoirs centralized and individual water supply. This indicator is entered into the European and International quality standards of drinking water and the unified methods of a research developed by the commission of experts of SEV. In the USSR the index of enterococci is defined at a coli-index more than 10 000 (see Kolya-in-deks, a coli-index). For this purpose tenfold cultivations of water sow in two parallel rows alkaline polimiksinovoy Wednesdays. After an incubation within 24 hours at t ° 37 ° make the preliminary account and seeding from bottles or test tubes with signs of growth (opacification, discoloration of the environment) on sectors of the milk and inhibitory environment in Petri dishes. In 24 hours of an incubation carry out the second seeding on the milk and inhibitory environment. Growth E. on the milk and inhibitory environment it is characterized by formation of colonies with black gloss. The index is calculated according to special tables. As S. faecalis is died off in the environment quicker, than S. faeci-um, detection of the first look E. confirms fresh fecal pollution by the person of the studied object.

AA. are capable to breed in foodstuff even at the room temperature. Contaminated E.

food causes food toxicoinfections (see T of oxycoinfection food), at to-rykh a thicket proteolytic options S are allocated. faecalis.

AA. are capable to cause pyoinflammatory processes of various localization in the person, to-rye proceed usually inertly, chronically. There can be monoinfections, but a thicket E. there are in associations with colibacillus (see), Proteus (see Proteus), stafilokokkam (see). From the pus separated wounds, upper respiratory tracts hemolitic options S are more often allocated. faecalis. The majority of the taken strains are steady against penicillin, Neomycinum, possess a number of signs of pathogenicity — coagulate plasma, produce hyaluronidase, DNA-ase, fibrinolysin, a lecithinase, proteinase, a lysozyme, are virulent in experiences of infection of mice. Signs of pathogenicity are shown at svezhevydelenny cultures and disappear during the resowings in a lab. conditions.

Bibliography: White hares V. D., Khodyrev A. P. and Totolyan A. A. Streptococcal infection, L., 1978;

Vershinina V. I. and Iskhakova of Page X. Proteinaceous complexes of enterococci, antigenic range and questions of taxonomy, Zhurn. mikr., epid. and immun., No. 2, page 51, 1982; To about r sh L. E. and Artyomov T. 3. The accelerated methods of a sanitary and bacteriological research of water, M., 1978; The Multivolume guide to microbiology, clinic and epidemiology of infectious diseases, under the editorship of H. N. Zhukova-Verezhnikov, t. 6, page 489, M., 1964; The Reference book on microbiological and virologic methods of a research, under the editorship of M. O. Birger, page 254, M., 1982; Bergey’s manual of determinative bacteriology, ed. by R. E. Buchanan a. N. E. Gibbons, Baltimore, 1975.

A. M. Smirnova.

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