MSSA

Medical abbreviation · Infectious Disease

MSSA
Stands forMethicillin-susceptible Staphylococcus aureus
CategoriesMedical

MSSA stands for Methicillin-susceptible Staphylococcus aureus, an infectious disease abbreviation.

Staph aureus strains that remain susceptible to anti-staphylococcal beta-lactams. Serious MSSA infections, such as bacteremia, are best treated with nafcillin, oxacillin or cefazolin, which outperform vancomycin.

Example: Blood cultures MSSA 2 of 2; switch vancomycin to cefazolin 2 g q8h, TEE ordered.

Usage notes

MSSA causes more infections overall than MRSA. Continuing vancomycin after MSSA is identified is linked to worse outcomes, so prompt de-escalation is a stewardship priority. Any S. aureus in blood requires repeat cultures, a search for endocarditis and usually infectious disease consultation.

More infectious disease abbreviations

  • MDR-TB – Multidrug-resistant tuberculosis
  • MDRO – Multidrug-resistant organism
  • MERS – Middle East respiratory syndrome
  • MIC – Minimum inhibitory concentration
  • MRSA – Methicillin-resistant Staphylococcus aureus
  • MSM – Men who have sex with men
  • N95 – N95 filtering facepiece respirator
  • NHSN – National Healthcare Safety Network
  • NSTI – Necrotizing soft tissue infection
  • NTM – Nontuberculous mycobacteria
  • OI – Opportunistic infection
  • OPAT – Outpatient parenteral antimicrobial therapy

See all 92 infectious disease abbreviations →

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.