FIG 3.
Recombinant human CP added to CF sputum and culture medium induces a zinc starvation response by P. aeruginosa. (A) P. aeruginosa strain PAO1 PrpmJ2-lacZ was grown in culture medium (Control), medium with 40 μM CP (CP), or medium with 40 μM CP and 1 mM ZnSO4 · 7 H2O [CP+Zn(II)], (NH4)2Fe(SO4)2 · 6 H2O [CP+Fe(II)], or MnCl2 · 4 H2O [CP+Mn(II)] for 3 h. The data shown represent the mean ± SD from three independent experiments. (B) P. aeruginosa strain PAO1 PrpmJ2-lacZ was inoculated into CF sputum from 11 different donors. The sputum was divided and left untreated (Control), treated with 100 μM ZnSO4 · 7 H2O (Zn), or treated with 40 μM CP and 100 μM ZnSO4 · 7 H2O (CP+Zn) for 3 h. Different-color dots represent samples from different donors. The same-color dots connected by a line are from the same CF sputum donor. Data were analyzed by RM one-way ANOVA with Tukey’s multiple-comparison test. (C) Representative growth curves of P. aeruginosa strain PAO1 PrpmJ2-lacZ grown in LB, LB containing 50 μM TPEN, or LB containing 40 μM CP. Data shown represent the mean ± SD from three technical replicates and are representative of three independent experiments. (D) OD600 at 16 h of P. aeruginosa strain PAO1 PrpmJ2-lacZ grown in LB, LB containing 50 μM TPEN, or LB containing 40 μM CP. Data shown represent the mean ± SD from three independent experiments. The data in panel A and panel D were analyzed by one-way ANOVA with Tukey’s multiple-comparison test. Samples marked with the same letter are not significantly different; samples marked with different letters are significantly different (P < 0.05).