Table 2. MICs of selected antimicrobial agents tested against a representative isolate from an Elizabethkingia meningoseptica outbreak strain from an adult critical care unit, West London, UK, 2012–2013*.
| Antimicrobial agent | MIC, mg/L | Interpretation |
|---|---|---|
| Ceftazidime | 256 | Nonsusceptible |
| Piperacillin/tazobactam | 16 | Susceptible |
| Meropenem | >32 | Nonsusceptible |
| Imipenem | 64 | Nonsusceptible |
| Aztreonam | >64 | Nonsusceptible |
| Gentamicin | 16 | Nonsusceptible |
| Tobramycin | >32 | Nonsusceptible |
| Amikacin | 32 | Nonsusceptible |
| Colistin | >32 | Nonsusceptible |
| Ciprofloxacin | 1 | Intermediate |
| Minocycline | 0.5 | Unknown |
| Trimethoprim/sulfamethoxazole | 0.25 | Susceptible |
*MICs were determined by serial agar dilution by using established methods (24). Interpretation of MICs used established British Society of Chemotherapy breakpoints. The intrinsic metallo- and extended-spectrum-β-lactamases exhibited by E. meningoseptica mean the apparent in vitro susceptibility of the organism to piperacillin/tazobactam should be viewed with caution.