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Bacitracin A.svg
Bacitracin ball-and-stick.png
Clinical data
Trade namesBaciguent, Baciim, others
  • AU: D
Routes of
Topical, intramuscular, Ophthalmic drug administration
ATC code
Legal status
Legal status
  • AU: S4 (Prescription only)
  • US: OTC / Rx-only
  • (4R)-4-[(2S)-2-({2-[(1S)-1-amino-2-methylbutyl]- 4,5-dihydro-1,3-thiazol-5-yl}formamido)-4-methylpentanamido]-4-{[(1S)- 1-{[(3S,6R,9S,12R,15S,18R,21S)- 18-(3-aminopropyl)-12-benzyl-15-(butan-2-yl)-3-(carbamoylmethyl)- 6-(carboxymethyl)-9-(1H-imidazol-5-ylmethyl)-2,5,8,11,14,17,20- heptaoxo-1,4,7,10,13,16,19-heptaazacyclopentacosan-21-yl]carbamoyl}- 2-methylbutyl]carbamoyl}butanoic acid
CAS Number
PubChem CID
Chemical and physical data
Molar mass1422.71 g·mol−1
3D model (JSmol)
  • CCC(C)C(N)NC4=NC(C(=O)N[C@@H](CC(C)C)C(=O)N[C@H](CCC(O)=O)C(=O)N[C@@H](C(C)CC)C(=O)N[C@H]3CCCCNC(=O)[C@H](CC(N)=O)NC(=O)[C@@H](CC(O)=O)NC(=O)[C@H](Cc1cnc[nH]1)NC(=O)[C@@H](Cc2ccccc2)NC(=O)[C@H](C(C)CC)NC(=O)[C@@H](CCCN)NC3=O)CS4
  • InChI=1S/C66H103N17O16S/c1-9-35(6)52(69)66-81-48(32-100-66)63(97)76-43(26-34(4)5)59(93)74-42(22-23-50(85)86)58(92)83-53(36(7)10-2)64(98)75-40-20-15-16-25-71-55(89)46(29-49(68)84)78-62(96)47(30-51(87)88)79-61(95)45(28-39-31-70-33-72-39)77-60(94)44(27-38-18-13-12-14-19-38)80-65(99)54(37(8)11-3)82-57(91)41(21-17-24-67)73-56(40)90/h12-14,18-19,31,33-37,40-48,52-54H,9-11,15-17,20-30,32,67,69H2,1-8H3,(H2,68,84)(H,70,72)(H,71,89)(H,73,90)(H,74,93)(H,75,98)(H,76,97)(H,77,94)(H,78,96)(H,79,95)(H,80,99)(H,82,91)(H,83,92)(H,85,86)(H,87,88)/t35?,36?,37?,40-,41+,42+,43-,44+,45-,46-,47+,48?,52?,53-,54-/m0/s1 checkY
 ☒NcheckY (what is this?)  (verify)

Bacitracin[1] is a polypeptide antibiotic. It is a mixture of related cyclic peptides produced by Bacillus licheniformis bacteria, that was first isolated from the variety "Tracy I" (ATCC 10716) in 1945.[2] These peptides disrupt gram-positive bacteria by interfering with cell wall and peptidoglycan synthesis.

Bacitracin is primarily used as a topical preparation, as it can cause kidney damage when used internally.[3] It is generally safe when used topically, but in rare cases may cause hypersensitivity, allergic or anaphylactic reactions, especially in people allergic to neomycin.[4][5]

Medical uses[edit]

A tube of bacitracin ointment for eyes

Bacitracin is used in human medicine as a polypeptide antibiotic and is "approved by the US Food and Drug Administration (FDA) for use in chickens and turkeys," though use in animals contributes to antibiotic resistance.[6]

As bacitracin zinc salt, in combination with other topical antibiotics (usually polymyxin B and neomycin) as an ointment ("triple antibiotic ointment," with the brand name Neosporin), it is used for topical treatment of a variety of localized skin and eye infections, as well as for the prevention of wound infections. A non-ointment form of ophthalmic solution is also available for eye infections.[7]

3D Chemical Structure of Bacitracin

Spectrum of activity and susceptibility data[edit]

Bacitracin is a narrow-spectrum antibiotic. It targets gram-positive bacteria, especially those that cause skin infections. The following represents susceptibility data for a few medically significant microorganisms.[8]

Mechanism of action[edit]

Bacitracin interferes with the dephosphorylation of C55-isoprenyl pyrophosphate, and a related molecule known as bactoprenol pyrophosphate; both of these lipids function as membrane carrier molecules that transport the building-blocks of the peptidoglycan bacterial cell wall outside of the inner membrane.[9]


Bacitracin was isolated by Balbina Johnson, a bacteriologist at the Columbia University College of Physicians and Surgeons.[10] Its name derives from the fact that a compound produced by a microbe in young Margaret Treacy's (1936–1994)[11] leg injury showed antibacterial activity.[12]

One strain isolated from tissue debrided from a compound fracture of the tibia was particularly active. We named this growth-antagonistic strain for the patient, "Tracy I." When cell-free filtrates of broth cultures of this bacillus proved to possess strong antibiotic activity and to be non-toxic, further study seemed warranted. We have called this active principle "Bacitracin.[10]

Bacitracin was approved by the US FDA in 1948.[13]


Bacitracin is synthesised via nonribosomal peptide synthetases (NRPSs), which means that ribosomes are not directly involved in its synthesis. The three-enzyme operon is called BacABC, not to be confused with BacABCDE of bacilycin synthesis.[14]


Bacitracin is composed of a mixture of related compounds with varying degrees of antibacterial activity. Notable fractions include bacitracin A, A1, B, B1, B2, C, D, E, F, G, and X.[15] Bacitracin A has been found to have the most antibacterial activity. Bacitracin B1 and B2 have similar potencies and are approximately 90% as active as bacitracin A.[16]

Society and culture[edit]


Some have claimed that bacitracin is a protein disulfide isomerase inhibitor, but this is disputed by in vitro studies.[17][18]


  1. ^ Elks J, Ganellin CR (1990). The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. Springer. pp. 119–. ISBN 978-1-4757-2085-3.
  2. ^ Originally grouped under B. subtilis, but nomenclature has since changed. See Podstawka A. "Bacillus licheniformis Tracy I | DSM 603, ATCC 10716, CCM 2181, IFO 12199, NBRC 12199, NCIB 8874, FDA BT1 | BacDiveID:686". Archived from the original on 2022-02-07. Retrieved 2022-02-07.
  3. ^ Zintel HA, Ma RA (October 1949). "The absorption, distribution, excretion and toxicity of bacitracin in man". The American Journal of the Medical Sciences. 218 (4): 439–445. doi:10.1097/00000441-194910000-00012. PMID 18140540. S2CID 2371497.
  4. ^ Spann CT, Taylor SC, Weinberg JM (July 2004). "Topical antimicrobial agents in dermatology". Disease-a-Month. 50 (7): 407–421. doi:10.1016/j.disamonth.2004.05.011. PMID 15280871.
  5. ^ Trookman NS, Rizer RL, Weber T (March 2011). "Treatment of minor wounds from dermatologic procedures: a comparison of three topical wound care ointments using a laser wound model". Journal of the American Academy of Dermatology. 64 (3 Suppl): S8-15. doi:10.1016/j.jaad.2010.11.011. PMID 21247665.
  6. ^ Pearl MC (12 September 2007). "Antibiotic use on the farm hurts people—and doesn't help the bottom line". Discover Magazine. Archived from the original on 2007-09-25.
  7. ^ "Healthgrades > Find a Doctor > Doctor Reviews > Hospital Ratings". Archived from the original on 2011-05-23.
  8. ^ "Bacitracin Susceptibility and Minimum Inhibitory Concentration (MIC) Data" (PDF). TOKU-E. Archived (PDF) from the original on 2018-12-22. Retrieved 2013-08-12.
  9. ^ Stone KJ, Strominger JL (December 1971). "Mechanism of action of bacitracin: complexation with metal ion and C 55 -isoprenyl pyrophosphate". Proceedings of the National Academy of Sciences of the United States of America. 68 (12): 3223–7. Bibcode:1971PNAS...68.3223S. doi:10.1073/pnas.68.12.3223. PMC 389626. PMID 4332017.
  10. ^ a b Johnson BA, Anker H, Meleney FL (October 1945). "Bacitracin: a new antibiotic produced by a member of the B. subtilis group". Science. 102 (2650): 376–7. Bibcode:1945Sci...102..376J. doi:10.1126/science.102.2650.376. PMID 17770204. S2CID 51066.
  11. ^ "Margaret Tracy & Balbina Johnson: The Women Behind Bacitracin". Archived from the original on 2014-04-28. Retrieved 2014-09-30.
  12. ^ "NewYork-Presbyterian | the Discovery of Bacitracin". 7 February 2017. Archived from the original on 27 February 2021. Retrieved 9 April 2020.
  13. ^ "Drugs@FDA: FDA-Approved Drugs". U.S. Food and Drug Administration (FDA). Archived from the original on 2021-07-27. Retrieved 2021-09-17.
  14. ^ Konz D, Klens A, Schörgendorfer K, Marahiel MA (December 1997). "The bacitracin biosynthesis operon of Bacillus licheniformis ATCC 10716: molecular characterization of three multi-modular peptide synthetases". Chemistry & Biology. 4 (12): 927–937. doi:10.1016/s1074-5521(97)90301-x. PMID 9427658.
  15. ^ "Committee for Veterinary Medicinal Products Bacitracin." The European Agency for the Evaluation of Medicinal Products, June 1998. Web. 18 Jan. 2013
  16. ^ Bell RG (January 1992). "Preparative high-performance liquid chromatographic separation and isolation of bacitracin components and their relationship to microbiological activity". Journal of Chromatography. 590 (1): 163–8. doi:10.1016/0021-9673(92)87018-4. PMID 1601975.
  17. ^ Karala AR, Ruddock LW (June 2010). "Bacitracin is not a specific inhibitor of protein disulfide isomerase". The FEBS Journal. 277 (11): 2454–62. doi:10.1111/j.1742-4658.2010.07660.x. PMID 20477872. S2CID 37519169.
  18. ^ Weston BS, Wahab NA, Roberts T, Mason RM (November 2001). "Bacitracin inhibits fibronectin matrix assembly by mesangial cells in high glucose". Kidney International. 60 (5): 1756–64. doi:10.1046/j.1523-1755.2001.00991.x. PMID 11703593.