Mupirocin ointment (Supirocin ointment) is a topical antimicrobial that contains an active substance called mupirocin. It is used in adults, adolescents, children and infants aged ≥4 weeks to treat infections on the skin such as infected hair follicles that form pimples containing pus (folliculitis), skin infection with blistering and crusting (impetigo) or recurring boils (furunculosis). Mupirocin (pseudomonic acid A), derived from the common Gram-neagtive bacteria, Pseudomonas fluorescens, inhibits bacterial protein and RNA synthesis by binding to bacterial isoleucyl-tRNA synthetase. Once the formation of the isoleucyl-tRNA synthetase is blocked, the cellular levels of the isoleucine charged transfer RNA are depleted, stopping protein and RNA synthesis in bacteria. It is a potent inhibitor against Gram-positive skin flora such as coagulase-negative Staphylococci and Staphylococcus aureus. Its rapid systemic metabolism means it can only be used topically which, combined with its novel chemical structure, should make cross-resistance less likely to occur than with other currently available antibiotics. It is available as topical preparations only and has no oral derivative, providing a lower risk of resistance and, therefore, may be beneficial in wound care management.
