Table 2.

MICs of β-lactams for A. baumannii RYC 52763/97 and recipient strain E. coli TG1 harboring various β-lactamases

β-LactamMIC (μg/ml) for strain (enzyme[s])a
A. baumannii RYC 52763/97 (AmpC, OXA-24 enzyme, and TEM-1)E. coli TG1E. coli TG1 with pGER1 (AmpC)bE. coli TG1 (TEM-1)E. coli TG1 with pBMB-1 (OXA-24)
Ampicillin>1,0244128>1,024128
Ampicillin + clavulanic acidc 5124641664
Ticarcillin>1,024432>1,024256
Cefazolin>2568>2561632
Cefuroxime>2564>25644
Cefoxitin>2564444
Cefotaxime>2560.0640.060.06
Ceftazidime>2560.125160.1250.25
Cefepime2560.060.250.060.125
Aztreonam>2560.0610.060.125
Imipenem1280.1250.1250.1251
Meropenem2560.030.030.030.125
  • a All the β-lactamase genes were cloned into the same pBGS18 plasmid.

  • b See reference 7.

  • c Concentration of the inhibitor was 4 μg/ml.