Table 1.

Microbiological activities of various antimicrobial agents against 109 carbapenem-resistant K. pneumoniae isolates

DrugMIC (μg/ml)a% susceptible
Range50%90%
Imipenem0.25–256321284.6
Meropenem0.5–>256641282.8
Ertapenem1–>256128>2560.0
Panipenem1–>51264256
Colistin0.5–1281296.3
Tigecycline0.25–81466.1
Minocycline0.06–12823274.3
Doxycycline0.06–6446464.2
Fosfomycin0.5–25612825645.0
Cefepime2–2562562561.8
Ceftazidime1–>256256>2561.8
Cefotaxime4–>256>256>2560.0
Cefoxitin0.06–>256128>2561.8
Cefoperazone-sulbactam2–2562562564.6
Piperacillin-tazobactam0.25–2562562561.8
Aztreonam16–>256>256>2560.0
Amikacin1–512>256>25614.7
Ciprofloxacin<0.06–2562562568.3
  • a 50% and 90%, MIC50 and MIC90, respectively. According to the British Society for Antimicrobial Chemotherapy (BSAC) criteria (1), a colistin MIC of ≤2 mg/liter indicates susceptible and >2 mg/liter indicates resistant and a tigecycline MIC of ≤1 mg/liter indicates susceptible, 2 mg/liter indicates intermediate, and >2 mg/liter indicates resistant.