TABLE 1.
Intralaboratory agreement between test methodsa
| Species (no. of isolates) | Median (range) MIC (mg/liter) by: |
Mean (range) difference (% of isolates with differences of >2 2-fold dilutions) |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| EUCAST | CLSI | Etest (24 h) | Etest (48 h) | EU vs CL | EU vs Et24 | EU vs Et48 | CL vs Et24 | CL vs Et48 | |
| C. albicans (50) | 0.016 (0.004–0.016) | 0.004 (≤0.002–0.016) | 0.008 (0.004–0.016) | 0.012 (0.008–0.016) | 1.1 (−1 to 3)* (4) | 0.3 (−1 to 2) (0) | 0 (−2 to 1) (0) | 0.8 (−1 to 3)* (6) | −1.1 (−3 to 1)* (8) |
| C. glabrata (40) | 0.016 (0.008–0.016) | 0.016 (0.016–0.031) | 0.008 (0.004–0.008) | 0.008 (0.004–0.016) | −0.3 (−1 to 0)* (0) | 0.9 (0 to 2)* (0) | 0.8 (0 to 2)* (0) | −0.8 (−2 to 6)* (5) | 1 (0 to 2)* (0) |
| C. tropicalis (40) | 0.063 (0.016–0.125) | 0.031 (0.008–0.031) | 0.016 (0.008–0.032) | 0.016 (0.016–0.032) | 0.5 (−1 to 2) (0) | 1.3 (0 to 3)* (3) | 0.9 (0 to 2)* (0) | −0.8 (−2 to 1)* (0) | 0.4 (−1 to 1)* (0) |
| C. parapsilosis (40) | 1 (1–4) | 1 (0.25–1) | 0.5 (0.25–1) | 1 (0.5–2) | 0.9 (0 to 2)* (0) | 1.3 (0 to 3)* (3) | 0.7 (0 to 2)* (0) | −0.4 (−2 to 2) (0) | −0.2 (−2 to 1) (0) |
| C. krusei (30) | 0.125 (0.063–0.25) | 0.125 (0.031–0.25) | 0.063 (0.032–0.125) | 0.063 (0.032–0.125) | 0.2 (−1 to 2) (0) | 1.2 (0 to 2)* (0) | 1 (0 to 2)* (0) | −0.9 (−3 to 1)* (3) | 0.8 (−1 to 2)* (0) |
| All (200) | 0.016 (0.004–4) | 0.016 (0.002–1) | 0.016 (0.004–1) | 0.016 (0.004–2) | 0.5 (−1 to 3)* (1) | 0.9 (−1 to 3)* (1) | 0.6 (−2 to 2)* (0) | 0.1 (−3 to 2) (2) | −0.3 (−3 to 6)* (3) |
a
Comparison of results obtained by the EUCAST method (EU), the CLSI method (CL), and the Etest read after 24 h (Et24) or 48 h (Et48) in one laboratory. Median (range) MICs are presented for each method, whereas for the comparison, the average (range) 2-fold-dilution difference is shown (together with the percentage of isolates with differences of >2 2-fold dilutions). Asterisks indicate a P value of <0.001 by a paired t test.