TABLE 3.
Agreement between BD and DD methods for CAS susceptibility testing
| Time of reading | Species (no. of strains) | BD methoda
|
% of isolates with DD inhibition zone diam ofb:
|
% Agreementc | ||
|---|---|---|---|---|---|---|
| MIC (μg/ml) | % of isolates | ≥12 mm | ≤11 mm | |||
| 24 h | C. albicans (50) | ≤1 | 92.0 | 76.1 | 23.9 | 78.0 |
| ≥2 | 8.0 | 0 | 100 | |||
| Non-C. albicans (50) | ≤1 | 94.0 | 74.4 | 25.6 | 76.0 | |
| ≥2 | 6.0 | 0 | 100 | |||
| Overall (100) | ≤1 | 93.0 | 75.2 | 24.2 | 77.0 | |
| ≥2 | 7.0 | 0 | 100 | |||
| 48 h | C. albicans (50) | ≤1 | 88.0 | 86.4 | 13.6 | 88.0 |
| ≥2 | 12.0 | 0 | 100 | |||
| Non-C. albicans (50) | ≤1 | 74.0 | 75.7 | 24.3 | 72.0 | |
| ≥2 | 26.0 | 38.5 | 61.5 | |||
| Overall (100) | ≤1 | 81.0 | 81.5 | 18.5 | 80.0 | |
| ≥2 | 19.0 | 26.3 | 73.7 | |||
a
CLSI M27-A2 microdilution method.
b
DD assay by the CLSI M44-A method with caspofungin at 2 mg per disk.
c
Percentages of inhibition zone diameters (in mm) compared with the reference MICs that were in agreement regarding a tentative breakpoint classification: susceptible, MIC of ≤1 mg/ml and inhibition zone diameters of ≥12 mm; resistant, MIC of ≥2 mg/ml and inhibition zone diameters of ≤11 mm.