Table 1.
Susceptibility of PAO1 and PAO1Δhfq toward different classes of antibiotics in SCFM medium.
| Classes/Subclass | Antibiotic | Mode of action | MIC | PAO1 | PAO1Δhfq | PAO1 | PAO1Δhfq |
|---|---|---|---|---|---|---|---|
| SCFM | High inoculuma | Low inoculumb | |||||
| β-LACTAM ANTIBIOTICS | |||||||
| Cephems/Cephalosporins IV | Cefepime | Cell wall | mg/L | 2/3 | 0.75/0.75 | 1/1 | 0.5/0.5 |
| Penems/Carbapenems | Imipenem | Cell wall | mg/L | 1/1 | 0.5/0.5 | 1/1 | 0.5/0.5 |
| NON-β-LACTAM ANTIBIOTICS | |||||||
| Aminoglycosides | Gentamicin | Protein synthesis | mg/L | 8/8 | 2/2 | 16/8 | 2/2 |
| Fluoroquinolones | Ciprofloxacin | DNA metabolism | mg/L | 0.25/0.25 | 0.12/0.12 | 0.12/0.12 | 0.06/0.12 |
| Fosfomycins | Fosfomycin | Cell wall | mg/L | >1024/>1024 | 64/64 | >1024/>1024 | 4/2 |
| Lipopeptides/Polymixins | Colistin | Cell membrane | mg/L | 3/4 | 2/3 | 6/4 | 3/2 |
| Tetracyclines | Tetracycline | Protein synthesis | mg/L | 128/128 | 32/32 | 16/16 | 8/8 |
/, Results of two independent experiments; >, more resistant than the highest concentration tested.
a
High inoculum, corresponds to 4 × 109 CFU/mL.
b
Low inoculum, corresponds to 2 × 106 CFU/mL.