Table 2.

Antibiotic susceptibility of E. coli ATCC 25922 as a planktonic population (MIC) and as a biofilm population (MBEC) as derived by the NCCLS assay and an assay with the CBD

AntibioticMIC (μg/ml)aMBEC (μg/ml)
NCCLS assayaAssay with CBDaA650a0 CFU/pegb
Ampicillin24>1,024>1,024
Piperacillin143232
Cefazolin14>1,024>1,024
Cefotaxime0.061256256
Ciprofloxacin0.0040.00888
Gentamicin241616
Tobramycin1422
Trimethoprim-sulfa-methoxazole0.06/1.140.12/2.2864/1,21632/608
  • a The values were obtained by measuring the turbidity at 650 nm (A650) on a 96-well plate reader.

  • b The values were obtained by determination of plate counts.