FIGURE 2.

Resistance and fitness of the wild type and evolved strains. For the wild type and evolved strains, the relative fitness is shown as a function of the minimum inhibitory concentration (MIC) for colistin. Each box symbol represents one strain. The relative fitness was determined by measuring the growth rate in MH medium at OD600. The growth rate was calculated from the OD₆₀₀ values during exponential growth by an R script. (A–D) Four colonies of A. baumannii strains evolved in solid agar plates. (E) The strain evolved in liquid media.