Table 2.

MICs of different antibiotics for bacterial strains

Strain Plasmid β-Lactamase(s) MIC (μg/ml)a
PIPPIP/CLAbCEF CMZ CTM CTXFEP IPM PAM MEM ATM
S. marcescensKU3838 pKU501 TEM-1, IMP-6 >128 >128 >128 >128 >128 >128>128 32 >128 >128 128
E. coliKU3999 pKU501 TEM-1, IMP-6 >128 32 >128 >128128 >128 16 8 32 64 0.25
E. coli KU4866 pKU502 TEM-1, IMP-6 >128 1 >128>128 >128 >128 16 2 8 64 0.25
E. coli KU4867 pKU503 IMP-6 1 0.5>128 >128 >128 >128 32 2 4 640.06
E. coli KU1917 pMS361 IMP-1 4 4>128 128 128 64 0.5 2 2 0.5 0.06
E. coli ML49010c 0d 2 0.5 40.25 0.03 0.13 0.13 0.25 0.5 0.250.06
  • a Abbreviations: PIP, piperacillin; CLA, clavulanic acid; CEF, cephalothin; CMZ, cefmetazole; CTM, cefotiam; CTX, cefotaxime; FEP, cefepime; IPM, imipenem; PAM, panipenem; MEM, meropenem; ATM, aztreonam.

  • b MICs were determined in the presence of clavulamic acid (5 μg/ml).

  • c Contains no plasmid.

  • d Does not produce TEM-1, IMP-1, and IMP-6.