Cefoxitin disk diffusion screen for confirmation of oxacillin-resistant Staphylococcus aureus isolates and utility in the clinical laboratory

Susan E Sharp; Julie A Warren; Richard B Thomson Jr

doi:10.1016/j.diagmicrobio.2004.09.003

Cefoxitin disk diffusion screen for confirmation of oxacillin-resistant Staphylococcus aureus isolates and utility in the clinical laboratory

Diagn Microbiol Infect Dis. 2005 Jan;51(1):69-71. doi: 10.1016/j.diagmicrobio.2004.09.003.

Authors

Susan E Sharp¹, Julie A Warren, Richard B Thomson Jr

Affiliation

¹ Kaiser Permenente, Department of Pathology, Regional Laboratory, Portland, OR, USA. susan.e.sharp@kp.org

PMID: 15629232
DOI: 10.1016/j.diagmicrobio.2004.09.003

Abstract

One hundred Vitek-2 identified oxacillin resistant S. aureus (ORSA) isolates were tested by oxacillin screen-plate (OXA-plate) and cefoxitin disk (FOX-disk) for confirmation of oxacillin resistance. Ninety-five of 100 confirmed oxacillin resistant by both, 3 of 5 were oxacillin susceptible by both and mecA negative, and 2 of 5 were oxacillin susceptible by OXA-plate, resistant by FOX-disk and mecA positive. The FOX-disk out-performed the OXA-plate for ORSA confirmation and can be performed using standard laboratory techniques.

MeSH terms

Cefoxitin / pharmacology*
Diffusion
Drug Resistance, Bacterial
Humans
Microbial Sensitivity Tests
Oxacillin / pharmacology*
Staphylococcus aureus / drug effects*

Substances

Cefoxitin
Oxacillin