Patient variability in denatonium-induced Pseudomonas killing. (A) Example plate with Pseudomonas CFUs when bacteria were mixed with ASL from ALI cultures stimulated with PBS, 0.1, 1.0, and 10.0 mM denatonium. (B) Pseudomonas percentage survival after bacteria were mixed with ASL from ALIs stimulated with different concentrations of denatonium (normalized to number of CFUs after PBS stimulation for each individual culture). Average percentage survival after stimulation with 0.1, 1.0, and 10.0 mM denatonium were 93.84 ± 25.31, 76.98 ± 41.67, and 8.652 ± 13.43, respectively (n = 46 patients). Box and whiskers plot shows mean ± SD (box) with whiskers from minimum to maximum and circles indicating individual patient percentage survivals. ALI = air-liquid interface; ASL = airway surface liquid; CFUs = colony forming units; SD = standard deviation.