Treatment of Methicillin-Sensitive Staphylococcus Aureus Infections
Efficacy and Preferred Agents
- The Infectious Diseases Society of America (IDSA) recommends piperacillin-tazobactam as an option for empiric coverage of MSSA infections, particularly in hospital-acquired pneumonia, in patients without risk factors for MRSA 1, 2, 3, 4, 5
- The IDSA lists oxacillin, nafcillin, or cefazolin as preferred first-line agents for treatment of proven MSSA infections, due to better outcomes 6, 7, 8
Clinical Scenarios for Piperacillin-Tazobactam
- Piperacillin-tazobactam is appropriate for empiric therapy in suspected polymicrobial infections where MSSA might be one of the pathogens, and for treatment of necrotizing fasciitis where both aerobic and anaerobic coverage is needed 1, 6
- The American Heart Association, as referenced in Circulation, suggests de-escalating to a more targeted agent, such as oxacillin, nafcillin, or cefazolin, when MSSA is identified as the sole pathogen 7
Treatment Algorithm
- For empiric therapy, piperacillin-tazobactam is suitable when a polymicrobial infection is suspected, and vancomycin or linezolid should be added if MRSA is a concern 1, 6
- For definitive therapy, de-escalation to nafcillin, oxacillin, or cefazolin is recommended when MSSA is the only pathogen, and piperacillin-tazobactam may be continued for polymicrobial infections with MSSA and gram-negatives/anaerobes 6, 8
Antibiotic Regimen Optimization for MSSA Joint Infection with Pseudomonas Wound Infection
Rationale for De-escalation from Vancomycin
- The Infectious Diseases Society of America (IDSA) recommends that oxacillin, nafcillin, or cefazolin are preferred agents for treatment of proven MSSA, as they are superior to vancomycin 9, 10
Optimal Regimen for Dual Pathogen Coverage
- The IDSA suggests that once susceptibilities are known, MSSA should be treated with cefazolin or an antistaphylococcal penicillin, and cefepime can be continued for Pseudomonas coverage 9, 10
Management of Polymicrobial Infections with MSSA and Pseudomonas
Rationale for De-escalation from Vancomycin
- The Infectious Diseases Society of America (IDSA) explicitly states that oxacillin, nafcillin, or cefazolin are preferred agents for treatment of proven MSSA due to superior outcomes 11