Table 4. Antimicrobial susceptibility of carbapenemase-producing K. pneumoniae isolates.
| Antimicrobial agent | KPC-2-producing K. pneumoniae isolates (n=24) | OXA-232-producing K. pneumoniae isolates (n = 45) | ||||||
|---|---|---|---|---|---|---|---|---|
| MIC (µg/mL) | % R | MIC (µg/mL) | % R | |||||
| Range | MIC50 | MIC90 | Range | MIC50 | MIC90 | |||
| Cefotetan | 128– > 256 | > 256 | > 256 | 100 | 1– > 256 | 128 | 256 | 89 |
| Cefotaxime | > 32 | > 32 | > 32 | 100 | 1– > 32 | > 32 | > 32 | 98 |
| Ceftazidime | 128– > 256 | 256 | > 256 | 100 | 0.25– > 256 | > 256 | > 256 | 96 |
| Cefepime | 128– > 256 | > 256 | > 256 | 100 | 0.25– > 256 | > 256 | > 256 | 93 |
| Aztreonam | > 256 | > 256 | > 256 | 100 | < 0.125– > 256 | > 256 | > 256 | 93 |
| Ertapenem | > 32 | > 32 | > 32 | 100 | 1– > 32 | > 32 | > 32 | 96 |
| Imipenem | 32– > 32 | > 32 | > 32 | 100 | 0.5– > 32 | 4 | 16 | 69 |
| Meropenem | > 32 | > 32 | > 32 | 100 | 0.5– > 32 | 16 | > 32 | 96 |
| Amikacin | > 256 | > 256 | > 256 | 100 | 2– > 256 | > 256 | > 256 | 84 |
| Ciprofloxacin | > 32 | > 32 | > 32 | 100 | < 0.125– > 32 | > 32 | > 32 | 93 |
| Tigecycline | 0.25–2 | 0.5 | 1 | 0 | 0.5–4 | 2 | 4 | 22 |
| Colistin | 0.126–16 | 0.25 | 0.5 | 8 | 0.125–32 | 0.5 | 4 | 11 |
Abbreviations: KPC, Klebsiella pneumoniae carbapenemase; OXA, oxacillinase; MIC, minimum inhibitory concentration; MIC50, minimum inhibitory concentration for 50% of isolates; MIC90, minimum inhibitory concentration for 90% of isolates; % R, % of resistance.