(A) Resazurin assay for metabolic activity. Control, IC50, and 2×IC50 plumbagin treated cultures were used for assay with 10 μg/mL of resazurin, and the product (resorufin) formed in active cells was measured at 590 nm; NS indicates p>0.05; *indicates p<0.05, ** indicates p<0.005 in a paired t-test analysis. (B) The relative gene expression patterns of ClpX, MurAA and Hit calculated by taking the mean Ct values from triplicate runs (* indicates p<0.05 in a paired t-test analysis).