bacitracin

A cyclic polypeptide antibiotic used to prevent wound infections, treat pneumonia and empyema in infants, and to treat minor skin injuries (e.g. cuts, scrapes, burns) and eye infections.
It is produced by Bacillus licheniformis, that was first isolated from the wound of a 7-year-old girl, Margaret Tracy.
It is synthesised via nonribosomal peptide synthetases. (Ribosomes are not directly involved in its synthesis.)

It 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. Commercially prepared ones are mostly bacitracin A, that has the most antibacterial activity.
It targets gram-positive bacteria, especially those that cause skin infections.
It disrupts gram-positive bacteria by interfering with cell wall and peptidoglycan synthesis.

It is primarily used as a topical preparation, as it can cause kidney damage when used internally.
In rare cases, it may cause hypersensitivity, allergic or anaphylactic reactions, especially in people allergic to neomycin.

(Dosage forms of medication)
• ointment ("triple antibiotic ointment"): Bacitracin zinc salt in combination with other topical antibiotics (usually polymyxin B and neomycin). Used for topical treatment of localized skin and eye infections and prevention of wound infections.
• ophthalmic solution: Used for eye infections.

Neomycin is an aminoglycoside antibiotic that displays bactericidal activity against gram-negative aerobic bacilli and some anaerobic bacilli where resistance has not yet arisen.

Polymyxin B is an antibiotic used to treat meningitis, pneumonia, sepsis, and urinary tract infections. While it is useful for many gram-negative infections, it is not useful for gram-positive infections.

C55-isoprenyl pyrophosphate (C55-PP) is an essential molecule involved in the construction of the bacterial peptidoglycan cell wall. It is a receptor found in the plasma membrane of bacteria allowing glycan tetrapeptide monomers synthesized in the cell cytoplasm to translocate to the periplasmic space.
Bacitracin interferes with the dephosphorylation of C55-PP and bactoprenol pyrophosphate. C55-PP and bactoprenol pyrophosphate serve as lipid carriers that transport peptidoglycan precursors across the bacterial cell membrane.

Cf. penicillin, vancomycin, tunicamycin, 7-O-malonyl macrolactin A

[doodle-]

The phone people make it hard to hide the fizzy. So everyone are supposed but B.

Ok, if the A B C are capped at this: [!] figure, what would it all live like?