Does Bactroban (mupirocin) cover Staphylococcus and Streptococcus?

Does Bactroban Cover Staph and Strep?

Yes, Bactroban (mupirocin) provides excellent coverage against both Staphylococcus aureus (including MRSA) and Streptococcus pyogenes, making it highly effective for treating superficial skin infections caused by these organisms. 1

Spectrum of Activity

Mupirocin demonstrates robust antibacterial activity against the key pathogens in skin infections:

• Staphylococcus aureus coverage: Mupirocin is active against a wide range of gram-positive bacteria, including methicillin-resistant S. aureus (MRSA), which is a critical advantage over many other topical agents 1, 2

• Streptococcus coverage: The drug has been shown to be active against most strains of Streptococcus pyogenes both in vitro and in clinical studies, as well as other beta-hemolytic streptococci 1, 3

• Additional gram-positive activity: Mupirocin is also active against most strains of Staphylococcus epidermidis and Staphylococcus saprophyticus 1

Clinical Guideline Recommendations

The Infectious Diseases Society of America (IDSA) explicitly recommends mupirocin as a first-line topical agent for impetigo:

• Mupirocin is designated as the best topical agent for treating impetigo caused by S. aureus and/or S. pyogenes (Grade A-I recommendation) 4

• Applied to lesions 2-3 times daily for patients with a limited number of lesions 4

• In clinical studies, both elimination of bacterial pathogens and clinical cure or improvement has been achieved in over 90% of patients 2

Mechanism and Efficacy

Mupirocin's unique mechanism provides several advantages:

• It inhibits bacterial protein synthesis by reversibly binding to bacterial isoleucyl transfer-RNA synthetase 1

• Due to this unique mode of action, mupirocin demonstrates no in vitro cross-resistance with other classes of antimicrobial agents 1

• Comparative studies show mupirocin cream is significantly more effective than oral erythromycin and similar in efficacy to oral flucloxacillin and cephalexin against both S. aureus and S. pyogenes 5

Important Caveats

Resistance considerations:

• Although resistance occurs rarely, mupirocin resistance has been described and can be problematic 4, 6

• High-level plasmid-mediated resistance (MIC >1024 mcg/mL) has been reported in some strains of S. aureus 1

• Unrestricted over-the-counter use and treatment of wounds with mupirocin are strongly associated with emergence of resistance 6

When to use systemic therapy instead:

• Patients with numerous lesions should receive oral antimicrobials effective against both S. aureus and S. pyogenes rather than relying solely on topical therapy 4

• Systemic therapy is preferred in outbreaks affecting several people to help decrease transmission 4