Bacitracine - Bacitracin

Bacitracin. Bacitracin, a cycHc peptide active against gram-positive bacteria, was discovered in 1943. Bacitracin received dmg certification in 1949 (60—62). Whereas human usage of bacitracin is almost exclusively topical, the vast majority of bacitracin manufactured worldwide is used as an animal feed additive. Reviews of work on bacitracin include its chemistry (63—67), comprehensive aspects (62), medical aspects (62,68), biosynthesis on large enzyme complexes and genetics (69—71), and production (71,72). 

Aztreonam (Azactam) Antibiotic Bacitracin (Bacitracin) Antibiotic... 

Bacitracin Bacitracins are polypeptide antibiotics that are isolated from a culture fluid of B. licheniformis. Ten individual bacitracins have been isolated bacitracins A, Ap B, C, D, E, Fp p2, Fj, and G. However, the drng itself, named bacitracin, that is used in medicine is a mixtnre of polypeptide antibiotics. All bacitracins are polypeptides that contain a thia-zole ring. However, bacitracin A, A-[[2-(l-amino-2-methylbntyl)-4,5-dihydro-4-thiazolyl] carbonyl]bacitracin F (32.7.11), makes up the main part of the isolated fractions [338-341]. 

Andrews BJ, Panitescu D, Jipa GH, VasUe-Bugarin AC, Vasiliu RP, Ronnevig JR. Chemotherapy for giardiasis randomized clinical trial of bacitracin, bacitracin zinc, and a combination of bacitracin zinc with neomycin. Am J Trop Med Hyg 1995 52(4) 318-21. 

The only clinically used members of this group are the bacitracins. Bacitracin is further used in veterinary medicine and as a supplement to the diets of animals, particularly farm animals . The subtilins are used in the food industry as preservatives. 

C. Bacitracin Bacitracin is a peptide antibiotic that interferes with a late stage in cell wall synthesis in gram-positive organisms. Because of its marked nephrotoxicity, the drug is limited to topical use. 

CONTROLLED RELEASE TECHNOLOGY - PHARMACEUTICAL] (Vol 7) -bacitracin treatment of [ANTIBIOTICS - PEPTIDES] (Vol 3)... 

Zinc bacitracin Zinc bearings Zinc blende... 

Antibiotics. Solvent extraction is an important step in the recovery of many antibiotics (qv) such as penicillin [1406-05-9] streptomycin [57-92-17, novobiocin [303-81-1J, bacitracin [1405-87-4] erythromycin, and the cephalosporins. A good example is in the manufacture of penicillin (242) by a batchwise fermentation. Amyl acetate [628-63-7] or -butyl acetate [123-86-4] is used as the extraction solvent for the filtered fermentation broth. The penicillin is first extracted into the solvent from the broth at pH 2.0 to 2.5 and the extract treated with a buffet solution (pH 6) to obtain a penicillin-rich solution. Then the pH is again lowered and the penicillin is re-extracted into the solvent to yield a pure concentrated solution. Because penicillin degrades rapidly at low pH, it is necessary to perform the initial extraction as rapidly as possible for this reason centrifugal extractors are generally used. 

Egg hatchabihty in chicken bacitracin zinc Egg production in chicken bacitracin methylene disahcylate... 

Antibiotics approved for use as growth enhancers in Hvestock and poultry include bacitracins, bambermycins, Hncomycin [154-21 -2] penicillin [69-53 ] streptomycin [57-92-1], tetracycHnes, tiamulin [55297-95-5] tylosin [1401-69-0] and virginiamycin [11006-76-1] (61). 

Methylene-5,5-disahcyhc acid is produced by heating two parts sahcyhc acid with 1—1.5 parts of 30—40 wt % formaldehyde in the presence of an acid catalyst (33). The resulting product is a mixture of isomers, primarily the 5,5 -isomer and small amounts of low molecular weight polymers. It is used as an intermediate in the production of bacitracin methylenedisahcylate, which is used in a feed supplement to promote growth and as a medicament in swine, feedlot catde, as well as chickens, turkeys, pheasants, and quail. 

Most polymyxin B sold for human use in the United States is in dermatological, otic, and ophthalmic preparations that usually contain one or more other spectmm extending antibacterials such as bacitracin, neomycin sulfate [1404-04-2], C23H4gNg023, linear gramicidin, oxytetracycline [79-57-2],... 

Bacitracin is produced and marketed as a mixture of at least nine water-soluble peptides. The principal (60 —80%) component is bacitracin A [22601-59-8], C33H2Q3N2y02gS. The most probable stmcture of bacitracin A is shown in Figure 1 (67,73). Bacitracin B [1402-99-9] is similar to bacitracin A except that one of the isoleucines of bacitracin A is replaced by a valine. Bacitracin F [22601-63-4], is a relatively inactive degradation... 

One unit of bacitracin USP is defined as the activity given by 26 micrograms of the dried FDA master standard. The USP requirement for commercial bacitracin is a potency of at least 40 units per milligram in a bioassay with Micrococcusflavus or Sarcina lutea. Pure bacitracin A has a potency of about 100 units per milligram. Standards for animal feed grades of bacitracin are available (71,81,82) as are analytical methods (67). 

Bacitracin given parenteraHy is sufftciendy nephrotoxic that it is rarely used in human medicine for other than topical indications (80). Thus safe and effective use, especially as the zinc salt, is limited almost completely to ointments, sprays, and solutions for skin and ophthalmic use in concentrations of 250 to 1000 units per milliliter. Bacitracin is only rarely skin sensitizing. As in the case of polymyxin, bacitracin is usually combined with other antibiotics to enlarge its spectmm of activity, or with corticoids or analgesics to reUeve pain or itching. 

In the United States, 100 times more bacitracin by weight is used as a feed additive than for human medicine. Most of this is BMD but some is the zinc salt. BMD can be used in subtherapeutic nutritional dosages for increase in feed efficiency and for growth promotion in poultry, swine, and feedlot cattie at concentrations of 2.6—33 g/t of feed (78,81,82). Prophylactic or therapeutic medicinal dosing at higher concentrations is used for necrotic enteritis in chickens, transmissable enteritis in turkeys, ulcerative enteritis in quail, dysentery in swine, and Hver abcess in cattie (see Feeds and feed additives). 

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