Table 1.

MICs of β-lactams for clinical isolate K. oxytoca KER, wild OXY-producing K. oxytoca strains, and mutant strains of K. oxytoca overproducing OXY enzymes

Strain (enzyme)MIC (μg/ml)a
AmoxicillinTicarcillinPiperacillinCephalo- thinCefo- taximeCeftazi- dimeAztreo- nam
AloneWith CAAloneWith CAAloneWith CAWith SULWith TAZ
K. oxytoca KER (IRKO-1)512256   168128128128640.50.010.030.03
K. oxytoca producing OXY enzymes (n = 14)32–1281–232–1281–22–81–20.25–21–24b 0.03b 0.12b 0.12b
K. oxytoca overproducing OXY enzymes (n = 3)>4,09664–2564,09632–128128–1,02416–32128–512128–512512–1,0240.5–10.258–32
  • a CA, clavulanic acid (2 μg/ml); SUL, sulbactam (8 μg/ml); TAZ, tazobactam (4 μg/ml).

  • b Mode MICs.