Fig. 4

Ursolic acid inhibits efflux pump in colistin resistant clinical isolates K. pneumoniae BC936 and E. coli U3790. The deenergized cells of K. pneumoniae BC936 and E. coli U3790 were treated with ursolic acid (UR) for 1 h. The cells were then reenergized with glucose and residual fluorescence of EtBr was measured for a time period of 0–20 min. Phenyl arginine beta naphthylamide (PABN) and Carbonyl cyanide m-chlorophenylhydrazine (CCCP) were maintained as positive controls (Filled diamonds—untreated cells; Empty circles—cells + EtBr; Empty triangles—PABN treated; Filled triangles—CCCP treated; Filled squares—ursolic acid treated). The experiment was performed in triplicates