Fluticasone proprionate

The Prestwick chemical library® (1280 FDA/EMA approved compounds, 10 µM in 96-well plates) was purchased from Prestwick chemicals. Avermectin B1a, bepridil, fluticasone proprionate, gliquidone, triclosan and nicardipine were purchased from Sigma-Aldrich.

For testing of primary bacterial strains, fresh overnight cultures grown aerobically in Luria broth (LB; Becton Dickinson) were inoculated into minimal (M9) medium plus 0.05% glucose with either 50 μM fluticasone proprionate or equivolume solvent (Tween 80; Sigma-Aldrich; final concentration, 0.25%) and then plated in sextuplicate in round-bottom 96-well plates. Plates were incubated at 37°C with shaking, and growth was assessed by determining the optical density at 600 nm hourly for up to 12 h; uninoculated media were plated as controls. For growth assays testing ATCC strains (Klebsiella pneumoniae ATCC 13883, Pseudomonas aeruginosa ATCC 27853, and Stenotrophomonas maltophilia ATCC 13637), overnight aerobic cultures in LB (37°C at 150 rpm) were inoculated into M9 medium plus 0.05% glucose with 50 μM fluticasone proprionate or equivolume solvent (DMSO; final concentration, 0.25%; Sigma-Aldrich). Serial dilutions were plated onto LB agar in triplicate at 4, 8, 12, and 24 h to yield 100 to 200 colonies per plate and counted the following day.