Table 2.
In vitro antibiotic susceptibilities for KPC-producing Enterobacteriaceae
| Antibiotic | Disk Diffusion Susceptibility % S / % I / % R |
E-test MICs | |
|---|---|---|---|
| MIC50 | MIC90 | ||
| Amikacin | 100% / 0% / 0% | ||
| Ampicillin | 0% / 0% / 100% | ||
| Ampicillin/sulbactam | 0% / 0% / 100% | ||
| Aztreonam | 0% / 0% / 100% | ||
| Cefazolin | 0% / 0% / 100% | ||
| Cefepime | 0% / 40% / 60% | ||
| Cefoxitin | 0% / 0% / 100% | ||
| Chloramphenicol | 256 | 256 | |
| Ciprofloxacin | 5% / 33% / 62% | ||
| Colistin | 100% / 0% / 0% | ||
| Ceftriaxone | 0% / 0% / 100% | ||
| Doripenem | 32 | 32 | |
| Doxycycline | 100% / 0% / 0% | ||
| Ertapenem | 32 | 32 | |
| Fosfomycina | 16 | 205 | |
| Gentamicin | 81% / 19% / 0% | ||
| Imipenem | 32 | 32 | |
| Meropenem | 32 | 32 | |
| Minocycline | 4 | 22 | |
| Nitrofurantoin | 19% / 24% / 57% | ||
| Piperacillin/tazobactam | 0% / 0% / 100% | ||
| Tetracycline | 6 | 18 | |
| Ticarcillin/clavulanate | 0% / 0% / 100% | ||
| Tigecyclineb | 1 | 2 | |
| Tobramycin | 54% / 31% / 15% | ||
| Trimethoprim/sulfamethoxazole | 0% / 0% / 100% | ||
Abbreviation: S, sensitive; I, intermediate; R, resistant
a
Clinical and Laboratory Standards Institute susceptibility breakpoints for fosfomycin: susceptible – ≤64 mg/L; intermediate – 128 mg/L; resistant – ≥256 mg/L
b
US Food and Drug Administration susceptibility breakpoints for tigecycline: susceptible – ≤2 mg/L; intermediate – 4 mg/L; resistant – ≥8 mg/L