Figure 4.

Detailed efficacy assessment of compound 24 in cell‐based assay systems. A) Dose‐dependent inhibition of the QS autoinducer molecule PQS in PA strains PA14 and RP73. B) Dose‐dependent reduction of PA14 eDNA release as determined via propidium iodine staining. IC₅₀ 0.346 × 10⁻⁶ m (95%CI: 0.173–0.630). Mean ± SEM of at least three independent measurements are depicted. C) Combination of 24 and tobramycin (TOB) in the Calgary biofilm device. Biofilms were grown for 24 h in presence of 24/DMSO, followed by treatment of indicated samples with TOB for another 24 h. Viable cells were determined after 48 h via colony‐forming units (CFU) count. Means and SD of three independent measurements are depicted ^(* p < 0.05, ^*** p < 0.001 according to Tukey's range test). D) Inhibition of pyocyanin production in 14 PA clinical isolates from bronchiectasis patients and the laboratory strains PA14 and PAO1 (dashed lines) by compound 24. Each strain was grown in LB‐medium for 16 h in presence of either 2 × 10⁻⁶ m 24/DMSO or DMSO as control. Subsequently, pyocyanin was chloroform‐extracted from the supernatants and spectrophotometrically quantified by its absorbance at 520 nm. Means and SD of at least three independent measurements are depicted (^* p < 0.05, ^** p < 0.01, ^*** p < 0.001 according to unpaired Student's t tests).