Fig 1. Flowchart showing sample selection.

The grey boxes show results that have been published previously [18]. Audit cases were defined as those cases that were identified according to the public healthcare sector Corporate Data Warehouse (CDW) (which houses records of patient details and laboratory results) but not received for processing in the laboratory. * One isolate did not contain mecA or mecC and did not harbour a SCCmec element although it was phenotypically non-susceptible (oxacillin >2, cefoxitin screen positive). This is possible as explained previously [19] possibly due to excision of the cassette (SCCmec) and/or mecA/C gene drop-out.