Table 1.

MICs of β-lactams

β-Lactam(s)bMIC (μg/ml)a
P. aeruginosaGW-1P. aeruginosa PU21(pGW-1)P. aeruginosa PU21E. coli DH10B(pLAP-1)E. coli DH10B(pC1)E. coli DH10B
Amoxicillin>512>512>512>512>5124
Amoxicillin + CLA>512>512>51216>1284
Ticarcillin>512>5128256>5124
Ticarcillin + CLA>51225644644
Ticarcillin + TZB>512256842562
Piperacillin1286488641
Piperacillin + CLA64162181
Piperacillin + TZB1281616881
Cephalothin>512>512>512322562
Cefoxitin>512>512>512481
Ceftazidime3216181280.5
Ceftazidime + CLA161620.580.5
Ceftazidime + TZB8420.580.5
Cefotaxime1281288140.06
Cefotaxime + CLA256256160.060.50.06
Cefotaxime + TZB643280.520.06
Cefepime32160.50.120.250.03
Cefsulodin>512512232321
Aztreonam16840.510.12
Imipenem161620.250.060.06
Meropenem1620.50.060.060.06
Moxalactam16880.120.120.12
  • a β-Lactamases: GES-2, AmpC type, pI 7.5, for P. aeruginosa GW-1; GES-2, AmpC type for P. aeruginosa PU21(pGW-1); AmpC type for P. aeruginosaPU21; GES-2 for E. coli DH10B(pLAP-1); GES-1 for E. coli DH10B(pC1).

  • b CLA, clavulanic acid at a fixed concentration of 2 μg/ml; TZB, tazobactam at a fixed concentration of 4 μg/ml.