Mupirocin (BACTROBAN®) is an antibiotic from a strain of Pseudomonas fluorescens. It has shown excellent activity against gram-positive staphylococci and streptococci. The antibiotic is used primarily for the treatment of primary and secondary skin disorders, nasal infections, and wound healing. Mupirocin inhibits bacterial protein synthesis by reversibly and specifically binding to bacterial isoleucyltransfer RNA (tRNA) synthetase. It also severely inhibits RNA synthesis. DNA and cell wall peptidoglycan synthesis are inhibited to a lesser extent and interference with these processes is considered to be a secondary effect. Mupirocin is bactericidal at concentrations achieved by topical administration.