TABLE 1

Checkerboard assay of S. cerevisiae strains overexpressing multidrug efflux pumps CaCDR1 and CaMDR1a

Strain and compoundCompound concn (μg/ml)FLC concn (μg/ml)FICIOutcome
MIC1*MIC2*FICMIC1MIC2FIC
AD/CaCDR1
    1690.540.008300750.250.26Synergy
    2700.140.002300750.250.25Synergy
    3730.070.001300750.250.25Synergy
    4750.590.008300750.250.26Synergy
AD/CaMDR1
    1690.130.002153.80.250.25Synergy
    2700.270.004153.80.250.25Synergy
    3731.130.016153.80.250.27Synergy
    4750.140.002153.80.250.25Synergy
    5800.630.008153.80.250.26Synergy
  • a MIC values were determined by a broth microdilution assay according to CLSI protocol M27-A3 (2008) using 50% growth reduction as the cutoff for the reported MIC values. MIC1, MIC of compound or FLC alone; MIC2, MIC of compound or FLC in the presence of FLC or compound, respectively. FIC, fractional inhibitory concentration; FICI, fractional inhibitory concentration index. *, values were converted from μM to μg/ml.