Bacitracin exerts antibacterial effects by non-specifically blocking the phosphorylase reaction and inhibiting the synthesis of mucopeptides in bacteria. Bacitracin has good antibacterial activity against most Gram-positive bacteria such as Staphylococcus aureus, Streptococcus, Enterococcus, Clostridium and Corynebacterium, and is also effective against actinomycetes and spirochetes. Sensitive bacteria rarely develop drug resistance to it.