FIG. 2.

Survival of logarithmic-phase (A) and stationary-phase (B) E. coli UB1005 in MH broth after addition of fourfold the MIC of peptide, gentamicin, or ceftazidime. This corresponds to 2 μg of CP26, CP29, and ceftazadime per ml, 4 μg of CEME and CEMA per ml, and 0.5 μg of gentamicin per ml. Actual initial concentrations of bacteria ranged from 0.5 × 10⁸ to 2.5 × 10⁸/ml but were corrected to an initial concentration of 1 × 10⁸/ml for clarity. A typical experiment out of three trials is shown. Symbols: ▵, no peptide; ▴, CP26; ▾, CP29; ●, CEME; ○, CEMA; ■, ceftazidime; □, gentamicin. Results for CP26 in panel A were almost superimposable with the ceftazidime results and were thus omitted for clarity. No evidence of bacterial aggregation was observed when viewed under a light microscope or in light-scattering experiments.