NHSN doesn’t encourage assumptions; the lab report must identify the isolate as ‘MRSA’ [or some form of the name] or have a susceptibility pattern which meets the definition to qualify for event reporting. MRSA includes S. aureus cultured from any specimen that tests oxacillin-resistant, cefoxitin-resistant, or methicillin-resistant by standard susceptibility testing methods, or any laboratory finding of MRSA (includes but not limited to PCR or other molecular based detection methods).