Fig 3. P. aeruginosa tat mutants form defective biofilms with increased susceptibility to tobramycin.

CLSM images showing four-day-old biofilms formed in flow chambers of the gfp-tagged P. aeruginosa wild-type (a), tatA mutant (b) and genetically complemented tatA mutant (c). In (A) biofilms were stained for total biomass with Syto9 (green) and for eDNA with ethidium bromide (red). In (B) biofilms were treated with tobramycin and the medium was supplemented with propidium iodide prior to CLSM such that dead cells appear red while live cells appear green. Each panel shows one horizontal optical section two flanking vertical optical sections. Bars, 20 μm.