Staphylococcus aureus (MSSA)
General Susceptibility

General Susceptibility

Cloxacillin-susceptible isolates can be considered susceptible to cephalosporins and penicillin/beta-lactamase inhibitor combinations.

Optimal antibiotics:

  • ceFAZolin (preferred) and cloxacillin are optimal agents for intravenous therapy for severe MSSA infections.
  • Cephalexin or cefadroxil are preferred agents when oral therapy is appropriate (e.g., uncomplicated skin and soft tissue infections).
  • Vancomycin should ONLY be used if a beta-lactam cannot be used, higher mortality than beta-lactams.

Please Note:

  • Second and third generation cephalosporins (e.g., cefuroxime, cefixime, ceftazidime, cefotaxime, and cefTRIAXone) have limited activity against MSSA.
  • Once S. aureus is confirmed, these agents are NOT adequate for serious S. aureus infections.

Variable susceptibility to:

  • TMP-SMX
  • Tetracyclines
  • Clindamycin
  • Check local antibiogram

Do not use empirically or to treat serious infections.