FIG 8.

In vitro activity of the selected hits against biofilm preformed by the P. aeruginosa RP73 strain. Biofilm grown for 24 h was exposed to each hit or tobramycin at 2× and 4× MIC, and after 24 h of exposure, biofilm biomass was measured by crystal violet stain assay. Tirapazamine was not tested at 4× MIC due to its toxicity toward IB3-1 cells. Unexposed control samples were not exposed. Results are shown as individual data points and mean values ± SD (n = 6). Statistical significance: **, P < 0.01, and ****, P < 0.0001, versus unexposed sample, by one-way ANOVA plus Dunnett’s multiple-comparison posttest; °, P < 0.05, °°°, P < 0.001, and °°°°, P < 0.0001, by unpaired t test.