Table 2.

MICs of β-lactams for P. aeruginosa COL-1,E. coli DH10B harboring recombinant plasmid pNOR-2001, and E. coli reference strain DH10B

β-Lactam(s)aMIC (μg/ml)
P. aeruginosa COL-1E. coliDH10B (pNOR-2001)bE. coli DH10B
Amoxicillin>512>5124
Amoxicillin + CLA>5125124
Ticarcillin>512>5124
Ticarcillin + CLA>5125124
Piperacillin6441
Piperacillin + TZB1641
Cephalothin>5122562
Cefoxitin>5121281
Ceftazidime256160.5
Cefotaxime>51280.06
Cefepime640.060.03
Aztreonam0.250.120.12
Meropenem1280.250.06
Imipenem12810.12
  • a CLA, clavulanic acid at a fixed concentration of 2 μg/ml; TZB, tazobactam at a fixed concentration of 4 μg/ml.

  • b E. coli DH10B(pNOR-2001) expressed the carbapenem-hydrolyzing β-lactamase VIM-2.