Oxacillin susceptibility testing of Staphylococcus saprophyticus using disk diffusion, agar dilution, broth microdilution, and the Vitek GPS-105 card.
Eighty-three mecA negative isolates of S. saprophyticus had oxacillin zone diameters <or= 15 mm or MICs ranging from <or= 0.25-1.0 microg/ml when tested by either agar dilution, broth microdilution, or the Vitek GPS-105 card. Greater than 90% of these isolates would be considered resistant using NCCLS M7-A5, M100-S10 criteria. These results suggest that the current NCCLS MIC and zone diameter breakpoints for oxacillin resistance in coagulase-negative Staphylococci are not appropriate for S. saprophyticus as they do not correlate with the presence of the mecA gene.
Ramotar
K
K
Department of Pathology and Laboratory Medicine, Ottawa Hospital, University of Ottawa, Ottawa, Ontario, Canada.
Woods
W
W
Toye
B
B
D001426:Bacterial Proteins; D003470:Culture Media; D008826:Microbial Sensitivity Tests / Q000379:methods* / Q000592:standards; D010068:Oxacillin / Q000494:pharmacology*; D010403:Penicillin Resistance; D010406:Penicillins / Q000494:pharmacology*; D013210:Staphylococcus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*
D001426:Bacterial Proteins; D003470:Culture Media; D010406:Penicillins; C083616:mecA protein, Bacillus subtilis; D010068:Oxacillin