The CLSI document M100 is the definitive resource for all standard susceptibility interpretative criteria.
Oxacillin is the standard antibiotic incorporated into MIC testing algorithms to predict resistance to beta-lactam antibiotics. Breakpoints for oxacillin as defined by the CLSI are defined as follows:
Interpretative criteria for oxacillin and S. aureus:
Antibiotic | Susceptible | Intermediate | Resistant |
Oxacillin | ≤ 2µg/mL | -- | ≥ 4 µg/mL |