TABLE 3.
Characteristics of selected isolates by echinocandin agent
| Factor | Echinocandin selection plate |
||
|---|---|---|---|
| Anidulafungin (n = 74) | Caspofungin (n = 159) | Micafungin (n = 14) | |
| Median drug concn (range) for selection | 0.5 (0.25–8) | 2 (0.5–8) | 0.25 (0.25–4) |
| No. (%) | |||
| >2-Fold anidulafungin MIC increase | 62 (84)a | 43 (27) | 14 (100) |
| >2-Fold caspofungin MIC increase | 48 (65) | 116 (73)b | 14 (100) |
| >2-Fold micafungin MIC increase | 30 (41) | 43 (27) | 14 (100) |
| FKS hot spot mutation | 23 (31)c | 47 (30) | 12 (86)d |
a
Colonies selected from anidulafungin-containing agar were more likely to have >2-fold MIC increases to anidulafungin than >2-fold MIC increases to caspofungin (P = 0.002) or micafungin (P = 0.0001).
b
Colonies selected from caspofungin-containing agar were more likely to have >2-fold MIC increases to caspofungin than >2-fold MIC increases to anidulafungin or micafungin (P < 0.0001 for both).
c
One additional isolate harbored a non-hot spot mutation in FKS2 (E655K).
d
All 14 isolates harbored mutations in FKS; two isolates harbored mutations outside the hot spot region (E655G and E655K) in FKS2.