Table 1.

MICs for P. mirabilis clinical isolates,E. coli K-12 C600, and the transconjugants producing TEM-89, TEM-3, and TEM-59

Strain (β-lactamase)MIC (μg/ml)a
AMZTICPIPCEFCTXCAZATM
Pm 631 (TEM-89) 256 (128, 128, 32) 64 (32, 16, 8)>128 (16, 32, 2)16 (16, 16, 8)0.06 (0.06, 0.06, ≤0.03)0.12 (0.12, 0.12, 0.06)0.06 (0.06, 0.06, 0.06)
E. coli Tc 631 (TEM-89) 512 (512, 256, 128) 256 (256, 256, 128) 64 (32, 16, 8) 8 (8, 8, 4)0.06 (0.06, ≤0.03, ≤0.03)0.25 (0.25, 0.12, 0.12)0.25 (0.25, 0.25, 0.12)
Pm 631SE (TEM-3)>512 (8, 4, 4)>512 (8, 2, 2) 64 (1, 1, 1)64 (8, 8, 8)4 (0.06, ≤0.03, ≤0.03)2 (0.12, 0.12, 0.12)0.12 (0.06, 0.03, 0.03)
E. coli Tc 631SE (TEM-3)>512 (8, 4, 2)>512 (16, 8, 8) 32 (1, 1, 1)32 (8, 4, 4)1 (0.06, 0.06, ≤0.03)2 (0.25, 0.25, 0.12)1 (0.25, 0.25, 0.25)
E. coli Tc 443 (TEM-59)>512 (512, 64, 128) 32 (32, 32, 8)>128 (>128, 16, >128)32 (16, 8, 4)0.06 (0.06, 0.06, ≤0.03)0.25 (0.25, 0.25, 0.12)0.25 (0.25, 0.25, 0.12)
E. coli K-12 C60042240.060.250.25
  • a AMZ, amoxicillin; TIC, ticarcillin; PIP, piperacillin; CEF, cephalothin; CTX, cefotaxime, CAZ, ceftazidime; ATM, aztreonam. The values in parentheses are MICs in the presence of 2 μg of clavulanic acid per ml, 4 μg of tazobactam per ml, and 8 μg of sulbactam per ml, respectively.