Figure 3.

The response of P. aeruginosa to GaPPIX depends on intracellular iron carryover. (A) P. aeruginosa PAO1 cells from an inoculum with 100 μM FeCl₃ (black bars) and without FeCl₃ (white bars) were grown in DCAA supplemented with increasing concentrations of GaPPIX for 24 h at 37°C. The values are expressed as the percentage relative to the untreated cultures, and represent the mean of four independent experiments, each one performed at least in duplicate ± the standard deviation. Asterisks indicate statistically significant differences relative to a culture derived from cells grown in the presence of 100 μM FeCl₃ (^***P < 0.001). (B) P. aeruginosa PAO1 (white bars), ΔpchD (light gray bars), ΔpvdA (dark gray bars), and ΔpvdAΔpchD (black bars) were grown in DCAA supplemented with increasing concentrations of GaPPIX for 24 h at 37°C. Values are the mean of two independent experiments, each one performed in duplicate ± the standard deviation.