Table 4. Determination and interpretation of the MIC values of the antibiotics tested for Pseudomonas aeruginosa ** (n = 153).
Antibiotic | MIC range | MIC50 (µg/ml) | Interpretation* | MIC90 (µg/ml) | Interpretation* |
Pip/tazo | 0.5–>128 | 8/4 | S | >128/4 | R |
Cefminox | 64–>128 | >128 | No criteria | >128 | No criteria |
Cefmetazole | 64–>128 | >128 | No criteria | >128 | No criteria |
Ceftazidime | 0.25–>64 | 8 | S | >64 | R |
Ceftriaxone | 1–>128 | 64 | No criteria | >128 | No criteria |
Aztreonam | 0.12–>128 | 4 | S | >128 | R |
Fosfomycin | 1–>256 | 32 | No criteria | 256 | No criteria |
Imipenem | 0.25- >64 | 8 | R | >64 | R |
Meropenem | ≤0.06–>128 | 4 | I | >128 | R |
Doripenem | ≤0.03–>64 | 2 | S | >64 | R |
Biapenem | ≤0.06–>128 | 2 | No criteria | 128 | No criteria |
Amikacin | 0.25–>128 | 4 | S | >128 | R |
Arbekacin | 0.12–>128 | 1 | No criteria | 32 | No criteria |
Gentamicin | ≤0.06–>128 | 2 | S | >128 | R |
Colistin | 0.12–16 | 1 | S | 2 | S |
*The interpretation of the MIC50 and MIC90 of all antibiotics tested for all pathogens was performed using the Clinical and Laboratory Standards Institute (CLSI) 2012 guidelines.
**Pseudomonas aeruginosa is intrinsically resistant to ampicillin/sulbactam and thus, MIC testing was not performed for this antibiotic.
Abbreviations: S: susceptible, R: resistant, I: intermediate, pip/taz: piperacillin/tazobactam, MIC: minimum inhibition concentration.