Oxacillin susceptibility testing of coagulase-negative staphylococci using the disk diffusion method and the Vitek GPS-105 card.
One hundred and ninety-three isolates of coagulase-negative staphylococci (CoNS) were tested against oxacillin by agar dilution, disk diffusion, and Vitek (GPS-105 card), and the presence of the mecA gene determined by multiplex PCR. The results obtained by all testing methods were in agreement for 190 isolates. Two mecA-negative isolates (S. lugdunensis and S. haemolyticus) had MICs of < or = 0.25 microg/ml by agar dilution and Vitek but were resistant by disk diffusion. One mecA-positive isolate was resistant by Vitek and disk diffusion but had an agar dilution MIC of < or = 0.25 microg/ml. For the species of CoNS tested, oxacillin susceptibility results obtained with the Vitek GPS-105 card and disk diffusion correlated well with results obtained by National Committee for Clinical Laboratory Standards agar dilution and with the presence of the mecA gene.
Woods
Wendi
W
Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, Ontario K1H 8L6, Canada.
Ramotar
Karam
K
Lem
Paul
P
Toye
Baldwin
B
D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry; D024881:Drug Resistance, Bacterial; D006602:Hexosyltransferases; D006801:Humans; D008826:Microbial Sensitivity Tests; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics; D010068:Oxacillin / Q000378:metabolism / Q000494:pharmacology*; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism / Q000494:pharmacology*; D010458:Peptidyl Transferases; D016133:Polymerase Chain Reaction; D013203:Staphylococcal Infections / Q000188:drug therapy*; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D010068:Oxacillin