Sheep anti-Bacitracin polyclonal antibody for EIA. Bacitracin is a mixture of related cyclic polypeptides produced by organisms of the licheniformis group of Bacillus subtilis var Tracy, isolation of which was first reported in 1945. As a toxic and difficult-to-use antibiotic, bacitracin does not work well orally. However, it is very effective topically, and is a common ingredient of eye and skin antibiotic preparations. Its action is on Gram-positive cell walls. It can cause contact dermatitis and cross-reacts with allergic sensitivity to sulfa-drugs.