Mupirocin (DB00410): A Comprehensive Monograph on its Chemistry, Pharmacology, and Clinical Utility

Executive Summary

Mupirocin is a topical antibiotic with a unique structure and mechanism of action that has established it as a cornerstone therapy for superficial bacterial skin infections and a critical tool in public health infection control strategies. Derived from the fermentation of Pseudomonas fluorescens, Mupirocin is not a single chemical entity but a mixture of related pseudomonic acids, with pseudomonic acid A being the principal active component. Its defining pharmacological feature is the specific inhibition of bacterial isoleucyl-tRNA synthetase (IleRS), a mechanism distinct from all other major antibiotic classes. This distinction confers the significant clinical advantage of no inherent cross-resistance, allowing Mupirocin to remain effective against pathogens that have developed resistance to other antimicrobials, most notably methicillin-resistant Staphylococcus aureus (MRSA).

The clinical utility of Mupirocin is twofold. It is a first-line treatment for primary skin infections such as impetigo and folliculitis, as well as secondarily infected traumatic skin lesions, caused by susceptible strains of S. aureus and Streptococcus pyogenes. Beyond treating active infections, its role in public health has been profound, particularly through the use of a dedicated nasal formulation for the eradication of MRSA carriage. This application is central to infection control programs aimed at reducing transmission and preventing invasive infections in high-risk settings like hospitals and long-term care facilities.