Table 3.
Genetic changes in C. difficile upon selection with LFF571a
| Strain | Nucleotide/amino acid change |
MIC (μg/ml)b |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| tufa | tufB | LFF571 | VAN | MET | FDX | TET | CLI | ERY | MOX | LNZ | |
| NB95009 | NCc | NC | 0.25 | 1 | 0.5 | 0.03 | 64 | 2 | 1 | 2 | 2 |
| NB95002 | NC | NC | 0.5 | 0.5 | 1 | 0.125 | 32 | 4 | 1 | 1 | 2 |
| NB95002–JAL0777 | NC | G782A/G260E | >128 | 0.5 | 1 | 0.03 | 64 | 4 | 0.5 | 0.5 | 2 |
| NB95002–JAL0783 | NC | G782A/G260E | >128 | 0.5 | 1 | 0.03 | 32 | 4 | 0.5 | 0.5 | 2 |
| NB95013 | NC | NC | 0.25 | 0.5 | 0.5 | 0.03 | 0.06 | 4 | 1 | 0.5 | 2 |
| NB95013–JAL0758 | NC | G782A/G260E | >128 | 0.5 | 0.5 | 0.03 | 0.06 | 4 | 1 | 0.5 | 2 |
| NB95013–JAL0759 | G782A/G260E | G782A/G260E | >128 | 1 | 0.5 | 0.03 | 0.06 | 4 | 1 | 0.5 | 2 |
| NB95026 | NC | NC | 0.25 | 0.5 | 0.5 | 0.06 | 0.06 | 2 | 1 | 32 | 2 |
| NB95026–JAL0792 | NC | G782A/G260E | >128 | 0.5 | 0.5 | 0.06 | 0.125 | 2 | 1 | 32 | 2 |
a
All strains were selected on 0.5 μg/ml LFF571, except NB95002-JAL0783, which was selected on 1 μg/ml.
b
MICs were determined by agar dilution methods according to Clinical and Laboratory Standards Institute (CLSI) guidelines (5). VAN, vancomycin; MET, metronidazole; FDX, fidaxomicin; TET, tetracycline; CLI, clindamycin; ERY, erythromycin; MOX, moxifloxacin; LNZ, linezolid.
c
NC, no change.