Bacitracin

Bacitracin - the drug, which is a mixture of 10 close to the structure of antibiotics called bacitracin a, b, C, D, etc. B. was selected from the culture fluid of one of the strains of You. licheniformis. All b - polypeptides weakly alkaline.
Bacitracin - amorphous powder, soluble in water and lower alcohols, but insoluble in ether. In a dry condition at temperature below 56 degrees and in ointments containing no water, B. sustainable. Most antimicrobial activity has bacitracin A. In its molecule is 10 amino acids: L-isoleucine, L-leucine, D-phenylalanine, L-cysteine, L - and D-aspartic acid, D-glutamic acid, L-histidine, L-lysine and D-ornithine. Structure of other B. less studied. The spectrum of antimicrobial activity B. all close to penicillin (see), i.e., they inhibit the development of staphylococci and streptococci, and certain other gram-positive bacteria, meningokokkov and gonococci, pale Treponema, but little active against most gram-negative bacteria. B. active also in respect of some of the simplest, especially amoebae. Bacitracin effect on bacteria that are resistant to all antibiotics except penicillin.
After subcutaneous administration bacitracin causes local irritation and necrosis. So it intramuscular injections do. However parenteral application B. its limited nephrotoxic properties. B. very poorly absorbed from the gastrointestinal tract. In this regard, it is used per os for the treatment of amoebic dysentery and other diseases of the intestines caused by resistant to other drugs microbes. B. widely applied topically in the form of ointments in mixture with other antibiotics (neomycin, polymyxin and others) for the treatment of infectious diseases of the skin and eyes.
Cm. also Antibiotics.