gramicidin


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Related to gramicidin: framycetin

gramicidin

(grăm'ĭsīd`ən), antibioticantibiotic,
any of a variety of substances, usually obtained from microorganisms, that inhibit the growth of or destroy certain other microorganisms. Types of Antibiotics
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 obtained from the bacterial species Bacillus brevis, which is found in soil. Gramicidin is particularly effective against gram-positive bacteria (see Gram's stainGram's stain,
laboratory staining technique that distinguishes between two groups of bacteria by the identification of differences in the structure of their cell walls. The Gram stain, named after its developer, Danish bacteriologist Christian Gram, has become an important tool
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). Because the drug is highly toxic, it cannot be administered internally and so is used only on the skin as a lotion or ointment. It is used primarily in the treatment of infected surface wounds, and in eye, nose, and throat infections. In 1939 the American microbiologist René Dubos isolated the substance tyrothricin and later showed that it was composed of two substances, gramicidin and tyrocidine. These were the first antibiotics to be manufactured commercially.

Gramicidin

 

a medicinal preparation of the antibiotic group, bacteriostatic and bactericidal against streptococci and staphylococci, the causative microorganisms of anaerobic infections, and other microbes. Gramicidin is applied locally as a solution or paste in the treatment of suppurative and inflammatory diseases, ulcers, and bedsores, as well as in the form of a paste as a contraceptive.

gramicidin

[‚gram·ə′sīd·ən]
(microbiology)
A polypeptide antibacterial antibiotic produced by Bacillus brevis ; active locally against gram-positive bacteria.
References in periodicals archive ?
Demain , Nutrition of Bascillus brevis ATCC 9999, the producer of gramicidin S in : Antimicrobial Agents Chemotherapy, Vol.
Activity of PSII+PSI was assayed with diphenylcarbazide (DPC) as the electron donor and MV as the acceptor in 60 mM NaCl, 40 mM Tricine-KOH (pH 8.0), 4 mM Mg[Cl.sub.2], 4 mM DPC, 0.5 mM ascorbate, 2.0 [micro]M gramicidin, 1.0 mM NA[N.sub.3], and 25 [micro]M MV with 100 units m[L.sup.-1] superoxide dismutase.
The fluorescence ratio of a single cell was recorded in normal Ringer's, followed by application of 10 [[micro]molar] gramicidin, an ionophore that inserts into the plasma membrane forming a pore permeable to small ions.
They discovered that the new nanotubes conducted ions as effectively as the eight-ringed ones and more efficiently than gramicidin A, a natural peptide channel with antibiotic properties.
The artificial membrane is studded with synthetic ion channels, based on the design of a natural ion-channel made of a polypeptide called gramicidin A, found in the common soil-dwelling microbe Bacterium brevis.
Albeit there are a few patch-clamp studies on granulocytes which provide valuable information, they can be associated with possible limitations as electrophysical measurements in neutrophils are difficult by nature, for example, description of NADPH oxidase of other cells (eosinophils [16, 19, 24], the granulocytic cell line HL-60 [21, 22], or macrophages [15]), application of intracellular milieu changing ionophores (e.g., valinomycin, gramicidin, and amphotericin) [11, 18, 23], or the use of enucleated neutrophils [17, 20].
Topical therapy of triple-antibiotic (neomycin, polymyxin B sulfates, and gramicidin) ophthalmic solution was administered q 6-8 h along with meloxicam (0.5 mg/kg SC once, then 0.5 mg/kg PO q24h) systemically for pain.
Cyclic peptides are common structural motifs in natural products and medicines (vancomycin, gramicidin).
Synthesis, biological activity and solution structure of new analogues of the antimicrobial Gramicidin S.