Oxazolidinone Antibiotics: MIC Determination

The oxazolidinone antibiotics (linezolid, radezolid, and contezolid) and other antibiotics used in this experiment were purchased from MedChemExpress (MCE, Shanghai, China). The minimum inhibitory concentration (MIC) of these antimicrobial agents was determined using the agar dilution method based on Clinical and Laboratory Standards Institute (CLSI) guidelines as described in our previous study (Zheng J. et al., 2020 (link)). While no standard breakpoint was recommended for radezolid against S. aureus in CLSI, in order to analyze the MIC distribution of radezolid, the MICs of radezolid against S. aureus were categorized into three levels, namely, ≤0.125, 0.25, and 0.5 mg/L, and those of linezolid were divided into ≤0.5, 1, 2, and 4 mg/L.