TELLURIC ENVIRONMENTS

From Big Medical Encyclopedia

TELLURIC ENVIRONMENTS — the mediums containing potassium tellurite (K 2 TeO 3 ); are used as the selection microorganisms at allocation having relative nonsensitivity to potassium tellurite.

From among pathogenic and opportunistic pathogenic bacteriums tellurium of an it of potassium Corynebacterium diphtheriae, Corynebacterium ulcerans, Cory-nebacterium pseudodiphtheriticum, Vibrio cholerae, Vibrio cholerae eltor, Streptococcus faecalis and its options, Listeria monocytogenes are steady against small concentration; growth of the bacteria accompanying them suppresses potassium tellurite. Suppression of growth of many gram-negative and gram-positive microorganisms is explained with increase in permeability of phospholipidic membranes of a cell wall of these bacteria under the influence of potassium tellurite. T. pages make on the basis of Wednesdays, optimum for growth of the allocated microorganism.

Potassium tellurite — unstable connection. Usually prepare initial 2% solution of tellurite, will sterilize it in the water bath at t ° 100 ° within 30 min. and store in the dark place, adding to mediums before their use. For allocation of korinebakteriya (see Corynebacterium) use various options blood (including Wednesday Klauberg-P) or serumal (including the environment of Tinedeyl) an agar, the containing 0,03 — 0,04% of potassium tellurite. The telluric blood agar provides higher vysevayemost of diphtheritic bacteria, than a telluric serumal agar. Add 0,02% of potassium tellurite to the semi-fluid serumal agar used as the environment of enrichment at allocation of diphtheritic bacteria. On T. pages diphtheritic bacteria grow in the form of black brilliant or opaque dryish colonies. Black color is caused by crystals of the metal tellurium formed as a result of recovery activity of bacteria and also at the expense of sulphurous tellurium — a product of interaction of metal tellurium with the hydrogen sulfide formed as a result of action of diphtheritic bacteria on cystine of a nutritious basis. On the Wednesday with a light basis — a cystine-tellu-rit-serumal agar of Tinsdeyl sulphurous tellurium is swept up in the form of a dark brown aura around colonies of the activator. The optimum environment for allocation of an enterokokk — Str. faecalis and its options (Str. zymogenes and Str. liquefaciens) contains potassium tellurite (0,07%) along with other inhibitors of foreign flora. Colonies of Str. faecalis have black color at the expense of crystals of metal tellurium. For differentiation steady against Str tellurite. faecalis and its options from telluritochuvstvitelny Str. faecium recommend a sugar and barmy agar with potassium tellurite (0,05%). From the environment and excrements of animals apply fluid and dense mediums with potassium tellurite (0,01 — 0,02%) to allocation of listeriya. For primary allocation of a cholera vibrio add potassium tellurite (0,001%) to peptone water that gives to vibrioes the selective advantages before other enterobakteriya more sensitive to potassium tellurite.


Bibliography: Gershun V. I. Comparative assessment of elective environments for allocation of listeriya, Veterinary science, No. 4, page 101, 1972; G. P. Sred's Guelder-rose for one-stage detection of proteolytic enterococci (Str. faecalis and var liquefaciens) in raw and pasteurized milk, Vopr. food, t. 30, No. 2, page 86, 1972; I. V. Lys kina and O. S. Zabolotnaya, To a question of check and evaluation test of the potassium tellurite applied to allocation of a cholera vibrio, Probl. especially dangerous infections, century 6, page 127, 1973; The Reference book on microbiological and virologic methods of a research, under the editorship of M. O. Birger, page 67, M., 1982; Shvaydetskaya 'G. V. The comparative characteristic of the differential and diagnostic mediums offered in recent years for diagnosis of diphtheria and simplification of technology of preparation of some of them, in book: It is put. infections, under the editorship of T. G. Filosofova, etc., century 7, page 48, Kiev, 1977.


H. N. Kostyukova.

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