Low prevalence of borderline oxacillin resistant (BORSA) in a tertiary care hospital in South Carolina.

Prompt treatment for bloodstream infections is often dependent on known diagnostic testing modalities to differentiate between methicillin-susceptible (MSSA) and methicillin-resistant (MRSA). Borderline-oxacillin resistant S. aureus (BORSA), a rare, non-mecA mediated phenotype, has unclear resistance mechanisms but potentially significant consequences as it is frequently misidentified as MSSA but behaves more like MRSA.