Figure 1

Distribution of results from the MS-AFST assay for the 80 C. glabrata isolates according to the MIC values as determined by the reference CLSI method. The isolates were tested against the antifungal drugs anidulafungin (a) and fluconazole (b). For each isolate, the MIC value (x-axis) was plotted against the CCI_max/CCI_null ratio (y-axis). The latter was calculated as the maximum CCI value (i.e. the value obtained by matching the breakpoint spectrum with the spectrum at maximal drug concentration) divided by the null CCI value (i.e. the value obtained by matching the breakpoint spectrum with the spectrum at null drug concentration). Isolates were called susceptible if the CCI_max/CCI_null ratio was higher than 1, whereas isolates were called resistant if the CCI_max/CCI_null ratio was lower than 1. In the (a) and (b) graphs, solid lines indicate the MIC breakpoints for resistance to anidulafungin (≥0.5 µg/mL) and fluconazole (≥64 µg/mL), whereas the dotted line indicates the MIC breakpoint for the intermediate (0.25 µg/mL) susceptibility to anidulafungin. In (a) the red circle denotes isolates with MICs in the intermediate (n = 4) or resistance (n = 7) range to anidulafungin, whereas in (b) red arrows indicate single isolates with MICs in the dose-dependently susceptibility (n = 1) or resistance (n = 2) range to fluconazole; all the 11 isolates (8 for anidulafungin and 3 for both anidulafungin and fluconazole) had classification results by the MS-AFST assay that did not agree with the categorization results obtained by the reference CLSI method.