Fig. 3
Uptake, efflux and steady-state intracellular concentrations of FLC-Cy5. a Average intracellular FLC-Cy5 uptake per cell. Uptake curves for 0–5 h and for steady-state FLC-Cy5 per cell at 24 h measured by flow cytometry. b, c Correlation between FoG20 and uptake rate of FLC-Cy5 between 0.5 and 1.5 h (b) and intracellular FLC-Cy5 at 24 h (c). d Intracellular FLC-Cy5 fluorescent intensity at 24 h for four strains with similar MIC and diverse FoG levels (left) and for the resistant strain T101 (right) normalized for number of cells (n = 15863 for P87, 15075 of P78, 22406 for SC5314, 18186 for GC75). e The proportion of cells (%) with FLC-Cy5 levels at 24 h was divided into thirds: Low (391–422 A.U.), Mid (3912–34,643 A.U.), and High (3.5 × 104–3.14 × 105 A.U.) (upper panel). Proportion of cells (%) with high (lower left panel) or mid (lower right panel) intracellular FLC-Cy5 concentration at 24 h vs. FoG20 levels of the strains. f Efflux of Rhodamine 6G (R6G) normalized by culture density (OD600). Efflux curves represent data from one (of two) experiment and the curves show fluorescence intensity recorded over 90 min and calculated as follows: Δ[FLC(with glucose − without glucose) − no drug(with glucose − without glucose)]. g Cartoon illustrates the steady-state drug levels in cells with high to low FoG levels. For all panels, n ≥ 2; **P < 0.01; *P < 0.05, error bars denote standard deviations
