Figure 5

For mcr-negative E. coli probability of target attainment (PTA) for the pharmacodynamic targets (PDT) fAUC_{(PK 0–24 h)}/MIC of: (A) ≥ 26.20 h for combined population, (B) ≥ 8.39 h for the highly susceptible dominant S1 (approx. 99.95% of the initial total population) population, or (C) ≥ 38.10 h for the less-susceptible sub-dominant S2 (approx. 0.05% of initial total population) population. PTA was determined in 500 simulated broiler chickens for four doses of colistin (75,000, 100,000, and 150,000 IU/kg via drinking water and 75,000 via 6 h pulse-dose drinking water). The horizontal dotted line signifies the PTA of 90%. The relative frequency of the MIC distribution of E. coli strains is taken from European Committee for Antimicrobial Susceptibility Testing (EUCAST, 2022).