Fig 1. PMS-mediated protection against norfloxacin is dependent on SoxR.
The E. coli wild type (wt) (BE1000) (A), ΔsoxR (AG035) (B), ΔmicF (YD002) (C) and ΔacrA (YD001) (D) strains were grown to mid-log phase in LB and then diluted to inoculate 96-well microplate wells containing LB liquid medium supplemented with norfloxacin at the indicated final concentration and supplemented or not (black bars) with PMS at 1/16 (grey bars) and 1/8 (white bars) of the MICPMS of each strain (MICPMS were 140 μM for wt, 40 μM for ΔsoxR, 100 μM for ΔmicF and 15 μM for ΔacrA). Cultures were incubated 18 hours at 37°C with shaking. Plates were read for OD600 in Tecan Infinite. The experiment was repeated at least three times. The means and standard deviations are shown. Asterisks represent the statistical significance calculated using the Bonferroni method (** p<0.01; * p<0.05; ns p>0.05).