Bacitracin belongs to the polypeptide antibiotics and is used to prevent or treat wound infections, skin and eye infections. It is usually administered as an ointment for external use. Occasionally, the drug is also used intramuscularly in the treatment of pneumonia and empyema (collection of pus in an organ) in infants.
The bacitracin-producing bacterium was isolated in 1945 from a contaminated wound on the knee of a child named Margaret Tracy. The bacillus was named after her.