Baciguent

DescriptionBacitracin is a mixture of similar peptides produced by fermentation of the bacterium Bacillus subtil is. The A-type component predominates. Its mode of action is to inhibit both peptidoglycan biosynthesis at a late stage (probably at the dephosphorylation of the phospholipid carrier step) and disruptions of plasma membrane function.

Usesantibiotic agent effective against gram-positive organisms and spirochetes; in products for topieal treatment, ear medications and ophthalmie drugs

UsesPolypeptide antibacterial.

UsesBacitracin is a peptide antibiotic effective against gram-postive bacteria. Bacitracin is an inhibitor of peptidoglycan synthesis. Bacitracin disrupts bacterial cell wall synthesis by inhibiting depho sphorylation of lipid pyrophosphate. Bacitracin also strongly inhibits proline endopeptidase from human muscle.

General DescriptionThe organism from which Johnson et al. produced bacitracinin 1945 is a strain of B. subtilis. The organism hadbeen isolated from debrided tissue from a compound fracturein 7-year-old Margaret Tracy, hence the name “bacitracin.”Bacitracin is now produced from the licheniformisgroup (B. subtilis). Like tyrothricin, the first useful antibioticobtained from bacterial cultures, bacitracin is a complex mixture of polypeptides. So far, at least 10 polypeptideshave been isolated by countercurrent distribution techniques:A, A1, B, C, D, E, F1, F2, F3, and G. The commercialproduct known as bacitracin is a mixture of principallyA, with smaller amounts of B, D, E, and F1–3.The official product is a white to pale buff powder that isodorless or nearly so. The activity of bacitracin is measured in units per milligram.The potency per milligram is not less than40 units/mg except for material prepared for parenteral use,which has a potency of not less than 50 units/mg. It is a bactericidalantibiotic that is active against a wide variety ofGram-positive organisms, very few Gram-negative organisms,and some others. It is believed to exert its bactericidaleffect through inhibition of mucopeptide cell wall synthesis.Its action is enhanced by zinc. Although bacitracin hasfound its widest use in topical preparations for local infections,it is quite effective in several systemic and local infectionswhen administered parenterally. It is not absorbedfrom the GI tract; accordingly, oral administration is withouteffect, except for the treatment of amebic infectionswithin the alimentary canal.