Bacitracin

Bacitracin is a polypeptide antibiotic obtained from a strain of a bacterium (Bacillus subtilis) and used as a topical ointment in the treatment of certain bacterial infections, especially those caused by cocci. Since it is toxic, bacitracin is widely used for topical therapy such as for skin and eye infections. It is effective against gram-positive bacteria, including strains of staphylococcus that are resistant to penicillin.