Evaluation of the AutoMicrobic system Gram-Positive Susceptibility-MIC card for detection of oxacillin-resistant coagulase-negative staphylococci.

A total of 398 consecutive clinical staphylococcus isolates, of which 205 were coagulase negative and 193 were coagulase positive, were tested in parallel by using AutoMicrobic system Gram-Positive Susceptibility-MIC cards and modified Mueller-Hinton agar containing 4% NaCl and oxacillin (6 micrograms/ml). The AutoMicrobic system cards correctly detected 103 of 104 (99%) oxacillin-resistant coagulase-negative isolates with no reports of false resistance.