Fig 2.

Categorical agreement between the KeyPath MRSA/MSSA blood culture test and cefoxitin disk test for prediction of oxacillin susceptibility. Two S. aureus isolates judged to be cefoxitin resistant using the disk test were misclassified as susceptible by the KeyPath MRSA/MSSA blood culture test (very major error). One cefoxitin susceptible isolate was misclassified as susceptible by KeyPath MRSA/MSSA blood culture test (major error). Repeat testing on two of the isolates (one incorrectly classified as susceptible and one incorrectly classified as resistant) yielded results concordant with those of cefoxitin disk testing.