Table 1.

Representative isogenic E. coli strains: standard- and high-inoculum MICs

StrainEnzymeMIC (μg/ml) of drug at indicated inoculum (CFU/ml)a
MEMCTTCTXCAZCROFEPATMTZP
105107105107105107105107105107105107105107105107
PAB-C14SHV-20.030.030.250.5165121632325128>1288644256
PAB-CS7SHV-70.030.030.25132>1,0242561,02464>1,0248>1281,0241,024264
PAB-C43TEM-430.030.060.250.250.58641,0241321321612824
PAB-C12TEM-120.030.060.250.250.258325120.2584>12821628
PAB-C10TEM-100.030.030.251232256>1,0244644>12812851222
PAB-C-4TEM-40.030.031132>1,0243212832>1,0244>128326424
PAB-C3TEM-30.030.060.50.516>1,0243225616>1,0244>128163224
  • a Abbreviations: MEM, meropenem; CTT, cefoteten; CTX, cefotaxime; CAZ, ceftazidime; CRO, ceftriaxone; FEP, cefepime; ATM, aztreonam; TZP, piperacillin-tazobactam.