TABLE 3.

Antibiotic susceptibilitiesa and carbapenemase activities of clinical isolates of K. pneumoniae

AntibioticbInhibitorMIC (μg/ml)
CL 5761CL 5762ACL 5762BCL 5763CL 15245
Imipenem1621616≤0.125
+ CLAc80.588≤0.25
Meropenem811616≤0.125
+ CLA823216≤0.125
Ertapenemd>320.25>32>32NTe
Aztreonam>256256>256>256≤0.25
+ CLA25664>256>256≤0.25
Ceftazidime256256>256>256≤0.25
+ CLA12832256>256≤0.25
Ceftriaxone256>256>256>256≤0.25
+ CLA6432128256≤0.25
Cefepime32128128128≤0.25
+ CLA3286464≤0.25
Cefoxitin128322562562
+ CLA25632256256<1
Piperacillind+ Tazo- bactam>256>256>256>256NT
Amikacin163232320.5
Gentamicin881616≤0.25
Chloramphenicol12864641284
Ciprofloxacin42416≤0.06
Polymyxin B0.250.25640.1250.25
Tetracycline41441
  • a Antibiotic susceptibility determined by broth microdilution method except where noted.

  • b Specific activities for CL 5761, CL 5762A, CL 5762B, and CL 5763 were 0.22, 0.46, 0.50, and 0.53, nmol of imipenem hydrolyzed/min/mg of protein, respectively. The specific activity for CL 15245 was not tested.

  • c + CLA, MIC determined in presence of 4 μg of clavulanic acid/ml; −, no inhibitor.

  • d Antibiotic susceptibility determined by E test.

  • e NT, not tested.