Mupirocin inhibits bacterial RNA and protein synthesis. It is available only as a 2% topical preparation, which is bactericidal against staphylococci Staphylococcal Infections Staphylococci are gram-positive aerobic organisms. Staphylococcus aureus is the most pathogenic; it typically causes skin infections and sometimes pneumonia, endocarditis, and osteomyelitis... read more 
and beta-hemolytic streptococci Streptococcal Infections Streptococci are gram-positive aerobic organisms that cause many disorders, including pharyngitis, pneumonia, wound and skin infections, sepsis, and endocarditis. Symptoms vary with the organ... read more 
. Systemic absorption of topical mupirocin is negligible.
Mupirocin is used for
Minor superficial secondarily infected skin lesions
Eradication of Staphylococcus aureus nasal carriage, although relapse rates may be high
Chronic therapy leads to mupirocin-resistant staphylococci.
Mupirocin is nontoxic but, when applied to denuded skin or mucous membranes, may cause itching and burning.
