Rapid detection of methicillin resistance in Staphylococcus aureus isolates; evaluation of colorimetric Quicolor ES agar and determination of breakpoint inhibition zone diameters of cefoxitin

Abstract

In this study, it was aimed to evaluate colorimetric Quicolor ES agar for the rapid detection of methicillin resistance and to determine susceptibility and resistance breakpoint zone diameters for cefoxitin by using 51 methicillin susceptible Staphylococcus aureus (MSSA) and 63 methicillin resistant S. aureus (MRSA) isolates. In the study, while oxacillin and cefoxitin results were obtained within 4-7 h (5.5 h in average) for MSSA isolates, the results of MRSA isolates were obtained within 5.5-9 h (6.6 h in average) for both antibiotics on QC ES agar. QC ES agar is an inexpensive medium for rapid detection (4-9 h) of methicillin resistance by disc diffusion method using oxacillin or cefoxitin. Additional studies for further evaluation of the efficiency of QC-ES agar in rapid determination of methicillin resistance in S. aureus may be beneficial.