Fig. 7. Gentamicin penetration through MPAO1 WT and ΔflgE biofilms observed by confocal laser scanning microscopy.

Seventy-two hours-old biofilms were exposed to M9 medium supplemented with 2 µg/mL of TR-gentamicin for 20 min. Biofilms were then washed with 0.9% NaCl and living cells were stained with SYTO9. The green and red fluorescence correspond to the SYTO9 staining and the gentamicin, respectively. Two orthogonal views (labeled as “1” and “2”) are shown from left to right with an overlay of SYTO9 and TR-gentamicin, SYTO9 alone and TR-gentamicin fluorescence alone. Images are representative of two independent experiments.