FIG 3.
Time-kill experiments evaluating bacterial killing activity of polymyxin B and azithromycin combinations versus the P. aeruginosa wild-type PAO1 (row A) and the rhlR/lasR knockout (row B) strains. Comparative pharmacodynamic responses between PAO1 (black) and the rhlR/lasR knockout (blue) at increasing azithromycin concentrations in combination with polymyxin B and data fit with linear (C1 to 3) or Hill-type (C4) functions. Data for polymyxin B monotherapy are not shown for C1 to C4. Activity is defined as the log10 ratio of the AUCFU of treatment to the AUCFU of growth control (log ratio area) based on observed response throughout the 48-h time-kill experiments.