TABLE 3.

MICs of antimicrobial agents for the parental strain, transconjugant, and transformant

β-LactamaMIC (μg/ml)
K. pneumoniae KG525E. coli CSH-2(pKGC525)bE. coli CSH-2E. coli XL1-Blue(pKGB525)cE. coli XL1-Blue(pBCSK+)
Ampicillin>128>1284>1284
Ampicillin + sulbactam>1282222
Amoxicillin>128>1288>1284
Amoxicillin + clavulanate>128324324
Piperacillin128161161
Piperacillin + tazobactam1280.510.50.5
Cefotaxime6420.1320.13
Cefotaxime + clavulanate80.060.060.060.06
Cefotaxime + sulbactam320.060.060.060.06
Cefotaxime + tazobactam640.060.060.060.06
Ceftazidime>1,0241280.131280.13
Ceftazidime + clavulanate25640.1340.06
Ceftazidime + sulbactam>1280.250.130.50.13
Ceftazidime + tazobactam>1280.50.130.50.13
Cephaloridine>128162162
Cefminox80.50.510.5
Moxalactam40.250.130.50.13
Cefpirome>12810.0620.06
Cefepime160.130.060.250.06
Aztreonam6440.0640.06
Imipenem0.250.50.250.130.13
Gentamicin20.130.13<0.06<0.06
Amikacin6420.2540.25
Levofloxacin<0.060.130.13<0.06<0.06
Ciprofloxacin<0.06<0.06<0.06<0.06<0.06
  • a Clavulanate, tazobactam, and sulbactam were used at a fixed concentration of 4 μg/ml each.

  • b pKGC525 is a resident plasmid found in K. pneumoniae strain KG525, and it carries the blaGES-3 gene.

  • c pKGB525 is a recombinant plasmid that carries a 6.7-kb BamHI insert that mediates the blaGES-3 gene.