Fig 6.

Effect of LL7-37 on a GFP-tagged P. aeruginosa PAO1 biofilm stained with PI. The peptide LL7-37 at 0 μM (A), 25 μM (B), 50 μM (C), and 100 μM (D) (0, 95, 190, and 380 mg/liter) was exposed on a 24-h-old biofilm grown in a CDC reactor for 25 min. Live cells appear green by expression of the GFP, and the damaged cells appear red by the permeability of the dead cells to PI. The confocal laser scanning micrographs show a horizontal section with two flanking images representing sections in the xz and yz planes, respectively (left column). The right column represents a tridimensional view from the top of the biofilm.