FIGURE 5.

Attachment and DGC expression in PAO1-PA3177Ω in response to NaClO. (A) Attachment of P. aeruginosa mutant strain PAO1-PA3177Ω and wildtype PAO1 after 2 h incubation with half-MIC concentrations of NaClO (2 μg/ml) compared to untreated controls was assayed in 96-well microtiter plates by crystal violet staining. To show alterations in attachment caused by NaClO, A₅₉₅ of treated samples was normalized to A₅₉₅ of untreated controls for each strain (=relative biomass). Statistical significance was evaluated by the Mann–Whitney test (^∗∗∗p ≤ 0.001, n ≥ 12). Boxes include median (thick horizontal line), 25th and 75th percentiles. Dots indicate extreme values considered as outliers. (B) P. aeruginosa mutant strain PAO1-PA3177Ω was treated with 2 μg/ml NaClO and relative gene expression levels of genes encoding DGCs in comparison to untreated control cultures were analyzed by qRT-PCR. The figure shows mean averages and standard deviations calculated from three experiments, each analyzed in duplicate (n = 6). Ct values were normalized against the expression of housekeeping genes rpoD and fabD. The red line corresponds to a relative gene expression level of 1, which means no change in gene expression. Blue bars indicate relative gene expression values ≥ 3.