Do you treat with antibiotics active against methicillin-resistant staphylococci when a patient's culture grows non-lugdunensis, coagulase-negative staphylococci that tests susceptible to oxacillin by phenotypic testing, given the low constitutive PbP2A production of most CoNS?

What is your approach when a patient's culture grows non-lugdunensis, coagulase-negative staphylococci, which tests susceptible to oxacillin by phenotypic testing?

• Treat as methicillin-sensitive.  
• Treat as methicillin-resistant.
• Ask Microbiology to test for PbP2A (protein-based assay)
• Ask Microbiology to test for mecA (DNA-based assay)
• Ask Microbiology to test with cefoxitin or oxacillin disk diffusion (Induction assay). 
• Assume the isolate is a contaminant.
• Other