TABLE 1.

MICs of β-lactams for K. pneumoniae YC, the transconjugant strain, and the reference strain

β-Lactam(s)aMIC (μg/ml) for:
K. pneumoniae YCTc E. coli J53E. coli J53
Amoxicillin>256>2564
Amoxicillin + CLA32324
Ticarcillin>256>2562
Ticarcillin + CLA>2562562
Piperacillin>256>2561
Piperacillin + TZB256641
Cephalothin>256>2564
Cefoxitin6421
Cefotaxime6440.06
Cefotaxime + CLA1620.06
Ceftazidime6440.06
Aztreonam>256160.03
Aztreonam + CLA>25680.03
Imipenem480.12
Imipenem + CLA220.12
Meropenem220.03
Meropenem + CLA10.250.03
  • a CLA, clavulanic acid at a fixed concentration of 2 μg/ml; TZB, tazobactam at a fixed concentration of 4 μg/ml.