Fig. 3: Bioenergetic stress accelerates resistance evolution by enhancing ROS production.
From: Bioenergetic stress potentiates antimicrobial resistance and persistence
a Basal mutation rates in pEmpty, pF1, (p = 0.8267) and pNOX (p = 0.1025) cells in untreated cells as determined by Luria-Delbrück fluctuation assays68,69 (n = 10). Statistical testing by one-way ANOVA (p < 0.0001) with Šídák’s multiple comparisons test versus pEmpty. b Mutation rates in pEmpty (n = 48), pF1 (n = 41; p = 0.0505), and pNOX (n = 42; p = 0.0006) cells following overnight growth in 8 ng/mL ciprofloxacin (Cip) (left). Statistical testing by one-way ANOVA (p = 0.0013) with Dunnett’s multiple comparisons test versus pEmpty. Fold-change in ciprofloxacin-treated mutation rates relative to mutation rates from untreated cells (right). Statistical testing by one-way ANOVA (p < 0.0001) with Dunnett’s multiple comparisons test versus pEmpty (pF1 p = 0.0104, pNOX p < 0.0001). c Exponential phase oxygen consumption rates (OCR) for wildtype MG1655 (n = 12), ΔatpA (n = 8; p = 0.0068), and ΔcyoA ΔcydB ΔappB (ΔETC; n = 4; p < 0.0001) E. coli cells. Statistical testing by one-way ANOVA (p < 0.0001) with Dunnett’s multiple comparisons test versus MG1655. d Integrated H2O2 for ∆HPX and ∆HPX ∆atpA cells at mid-exponential phase (OD600 ≈ 0.5) (p = 0.0286 by two-sided Mann-Whitney test). e Carbonylated proteins in exponential phase MG1655, ∆atpA (p < 0.0001), and ∆HPX (p < 0.0001) cells. Statistical testing by one-way ANOVA (p < 0.0001) with Dunnett’s multiple comparisons test versus MG1655. f Oxidized deoxyguanosine in exponential phase MG1655, ∆atpA (p = 0.0002), and ∆HPX (p = 0.0001) cells. Statistical testing by Welch’s ANOVA (p < 0.0001) with Dunnett’s T3 multiple comparisons test versus MG1655. g Ciprofloxacin resistance evolution for MG1655, ΔatpA, and ΔETC cells. h Ciprofloxacin resistance evolution for pEmpty, pF1, and pNOX cells in the presence (left) or absence (right) of 12.5 µM respiratory inhibitor piceatannol (PA). Data on untreated cells are replicated from Fig. 1 for comparison. i Ciprofloxacin resistance evolution for MG1655 and ΔHPX cells. j Ciprofloxacin resistance evolution for pEmpty, pF1, and pNOX cells in the presence (left) or absence (right) of 15 µ/mL catalase (CAT). Data on untreated cells are replicated from Fig. 1 for comparison. Data reported as change in the minimum concentration for 50% growth inhibition (MIC50) relative to Cycle 1 for all resistance evolution experiments. All experiments performed in MOPS-rich media. n = 4 for all experiments unless otherwise indicated. All data represent biological replicates (independent cultures) and are depicted as mean ± SEM unless otherwise indicated. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001. p ≥ 0.1 not shown. Source data are provided within the ‘Source Data.xlsx’ file.
