From the Guidelines
Bactroban (mupirocin) topical ointment is not effective against Pseudomonas infections, and alternative antibiotics should be used for wound or skin infections with Pseudomonas, even with scant growth. For Pseudomonas skin infections, topical options like silver sulfadiazine cream, gentamicin ointment, or polymyxin B-containing products would be more appropriate 1. Bactroban primarily works against gram-positive bacteria like Staphylococcus and Streptococcus species, but has poor activity against gram-negative organisms like Pseudomonas aeruginosa.
Key Considerations
- The cell wall structure of Pseudomonas, as a gram-negative bacterium, has an outer membrane that prevents mupirocin from reaching its target site within the bacterial cell 1.
- Systemic antibiotics with anti-pseudomonal activity (such as ciprofloxacin, levofloxacin, or ceftazidime) may be necessary for more extensive infections.
- Proper wound cleaning and appropriate antibiotic selection based on culture results are essential for effective treatment.
Treatment Approach
- For mildly infected open wounds with minimal cellulitis, limited data support using topical antimicrobial therapy, but for severe infections, it is safest to promptly commence therapy with a broad-spectrum regimen 1.
- Clinicians should consider the results of culture and sensitivity testing in light of the clinical response of the infection to the empiric regimen.
- Isolating P. aeruginosa is a particularly problematic issue because it requires specifically targeted antibiotic coverage, and clinicians must decide if the preponderance of clinical and microbiologic evidence suggests they are pathogens that require targeted therapy 1.
From the Research
Effectiveness of Bactroban (Mupirocin) against Pseudomonas
- Bactroban (mupirocin) is a topical antibiotic commonly used to treat skin infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA) 2.
- However, its effectiveness against Pseudomonas aeruginosa is limited. A study from 1990 found that mafenide acetate and silver sulfadiazine had greater activity against Pseudomonas aeruginosa isolates compared to Bactroban (mupirocin) 2.
- The study also noted that Bactroban (mupirocin) showed in vitro activity against 71% of the gram-negative isolates tested, but its activity against Pseudomonas aeruginosa was significantly lower than that of mafenide acetate and silver sulfadiazine 2.
Treatment of Pseudomonas aeruginosa Infections
- Pseudomonas aeruginosa is a challenging pathogen to treat due to its limited susceptibility to antibiotics and the emergence of resistance 3, 4, 5.
- Various antibiotics, including ceftazidime, carbapenems, and piperacillin-tazobactam, have been used to treat Pseudomonas aeruginosa infections, but the optimal choice of antibiotic is still debated 4, 5.
- A systematic review and meta-analysis found no significant difference in clinical outcomes between different antipseudomonal monotherapies, including ceftazidime, carbapenems, and piperacillin-tazobactam 4.
- Another study found that ceftolozane/tazobactam, a newer antibiotic combination, demonstrated a favorable safety and tolerability profile in treating serious Pseudomonas aeruginosa infections, including those caused by multidrug-resistant strains 6.
Conclusion on Bactroban (Mupirocin) and Pseudomonas
- Based on the available evidence, Bactroban (mupirocin) is not the most effective topical antibiotic for treating Pseudomonas aeruginosa infections, particularly for scant growth on a wound or skin infection 2.
- Other antibiotics, such as mafenide acetate and silver sulfadiazine, may be more effective against Pseudomonas aeruginosa, but the choice of antibiotic should be guided by susceptibility testing and clinical judgment 2.