(A) Representative flow cytometer fluorescence timecourse histograms of untreated cells and cells treated with spectinomycin, gentamicin, norfloxacin, ampicillin, 5-FU, or MMC. Increased FITC-Z-VD-FMK fluorescence indicates increased binding of this pan-caspase inhibitor to a bacterial protein with similar substrate specificity, identified as RecA. (B) Fold change in FITC-Z-VD-FMK fluorescence (mean ± SD at 4.5 hours post-treatment), relative to untreated wildtype cells. (C) Percent reduction in FITC-Z-VD-FMK fluorescence (mean ± SD at 4.5 hours post-treatment) when co-treated with norfloxacin and one of the protein synthesis inhibitors, chloramphenicol or spectinomycin.