Extended Data Fig. 4: Adaptation to antibiotics by frequency of resistance assay.
From: ESKAPE pathogens rapidly develop resistance against antibiotics in development in vitro
(A) Changes in minimum inhibitory concentrations (MIC) in mutants isolated in frequency-of-resistance (FoR) assays. Each point represents the MICs of a mutant line and the corresponding ancestor (log10 scale). Control and recent antibiotics are indicated by blue and orange panels, respectively. The colour of the data points represents the bacterial species. The black dashed line indicated y = x (that is no changes in MIC in the mutants), whereas the red dashed line shows the antibiotic specific peak plasma concentration (Supplementary Table 3). For abbreviations, see Table 1. (B) Percentage of mutant lines reaching the clinical breakpoint in frequency of resistance assay and adaptive laboratory evolution. The heatmap shows the percentage of lines reaching the clinical breakpoint. Unavailable clinical breakpoints are indicated by white. For the antibiotic abbreviation and clinical breakpoints see Supplementary Table 3, for strain abbreviation see Supplementary Table 4. (C) Frequency of resistance of evolved lines adapted to different antibiotics. The frequency of resistance at 8 × MIC antibiotic concentrations was calculated for all antibiotics, shown as the number of mutations per cell per generation. Each data point represents the median MIC value of a distinct mutant line derived from the frequency of resistance assays (FoR), species are denoted by different colours. Median MIC values are based on 2 biological and 3 technical replicates for each bacterial strain-antibiotic combination. The label colour on the x-axis shows the generation of the different antibiotics (blue stands for control, orange for recent antibiotics). The boxplots show the median, first, and third quartiles, with whiskers showing the 5th and 95th percentiles of the median MIC values per each investigated group. There is highly significant heterogeneity in the frequency of resistance across antibiotics (Kruskal-Wallis test, P < 0.00001), but no statistical difference was found between control and recent antibiotics (Wilcoxon’s rank-sum-test, two-sided, P = 0.9) when all species and antibiotics were considered. For antibiotic abbreviations, see Table 1.
