A Retrospective Analysis of Treatment and Clinical Outcomes among Patients with Methicillin-Susceptible Staphylococcus aureus Bloodstream Isolates Possessing Detectable mecA by a Commercial PCR Assay Compared to Patients with Methicillin-Resistant Staphylococcus aureus Bloodstream Isolates

Abstract

ABSTRACT mecA -positive Staphylococcus aureus isolates phenotypically susceptible to cefoxitin ( mecA -methicillin-sensitive S. aureus [MSSA]) have been identified. We describe the treatment and outcomes among patients with mecA -MSSA bloodstream infections (BSI) and MRSA BSI matched 1:1 for age, BSI origin, and BSI type ( n = 17 per group). Compared to MRSA BSI patients, mecA -MSSA BSI patients more often experienced clinical failure (58.8% and 11.8%, P = 0.010), driven largely by persistent bacteremia (35.3% and 11.8%). mecA -MSSA BSI patients may be at higher risk for poor clinical outcomes.