TABLE 3.
Fold increase in the MICs of terbinafine, itraconazole, amorolfine, and ciclopirox for drug-resistant T. rubrum mutants compared to their parental strainsa
| Mutant and drug susceptibility | Fold MIC increase |
|||
|---|---|---|---|---|
| Terbinafine | Itraconazole | Amorolfine | Ciclopirox | |
| ATCC 28188 | ||||
| TRB-S (n = 1) | 50 | ns | ns | ns |
| ITC-S (n = 5) | 4–8 | 4–8 | 4–8 | ns |
| AMF-S (n = 3) | 4–8 | ns | 16–32 | ns |
| TRB-I (n = 3) | 500–1,000 | ns | ns | ns |
| ITC-I (n = 5) | 8 | 4–8 | 32 | ns |
| AMF-I (n = 3) | 8–16 | ns | 64 | ns |
| CI-1 | ||||
| ITC-S (n = 5) | 4–8 | 4–8 | 4–8 | ns |
| AMF-S (n = 1) | 4 | ns | 16 | ns |
| TRB-I (n = 5) | 500 | ns | ns | ns |
| ITC-I (n = 5) | 8 | 4–8 | 32 | ns |
| AMF-I (n = 5) | 8–16 | ns | 32–64 | ns |
| CI-2 | ||||
| TRB-S (n = 2) | 500–1,000 | ns | ns | ns |
| ITC-S (n = 5) | 4–8 | 4–8 | 4–8 | ns |
| AMF-S (n = 4) | 4–8 | ns | 8–16 | ns |
a
Mutants were obtained following direct selection on plates containing inhibitory drug concentrations on the basis of selection (TBR, terbinafine; ITC, itraconazole; AMF, amorolfine) and the parental strain from which they derived. n, number of strains; ns, not significant (MIC differences of ±1 2-fold dilution were considered not significant).