TABLE 1.
Susceptibility profile of the studied S. aureus strains and TO-resistant mutants selected after serial passage in the presence of TO or FC04-100
| Strain or clonesa | MIC (μg/ml)b |
|||
|---|---|---|---|---|
| TO | FcM | Fcm | GEN | |
| S. aureus Newbould | >128 | 2 | 8 | 0.25 |
| S. aureus Newbould ΔhemB | 0.06 | 0.06 | 2 | 8 |
| P07intR-1, -2, and -3* | 0.25 | 0.5–1 | 4 | 8 |
| P11intR-1, -2, and -3* | 0.25–0.5 | 0.5–1 | 4 | 8 |
| P20intR-1, -2, and -3* | 0.25–1 | 1 | 4 | 8 |
| SaR1-1, -2, and -3# | >64 | 2 | 8 | 8 |
| SaR2-1, -2, and -3§ | >64 | 2 | 8 | 8 |
| SaR3-1, -2, and -3# | >64 | 2 | 8 | 8 |
| SaR4-1, -2, and -3# | >64 | 2 | 8 | 8 |
| SaR5-1, -2, and -3† | >64 | 2 | 8–16 | 8–16 |
| SaR6-1, -2, and -3† | >64 | 2 | 8 | 8 |
a
Clones of S. aureus Newbould ΔhemB are indicated as follows: *, clones selected after 7, 11, or 20 passages, respectively, in the presence of TO; #, clones selected after 30 passages in the presence of TO; §, clones from a clone of S. aureus Newbould ΔhemB with low-level of resistance to TO (P07intR-1) after an additional 30 passages in the presence of TO; †, clones selected after 30 passages in the presence of FC04-100.
b
TO, tomatidine; FcM, FC04-100 major stereoisomer; Fcm, FC04-100 minor stereoisomer; GEN, gentamicin. For the MIC, the “>” sign denotes the highest concentration tested.