CLSM images of <i>P</i>. <i>aeruginosa</i> PA01 biofilms after 24 hours growth treated with PBS or nitroxoline or colistin for 3.5 hours.

<p>(A) PBS treatment; (B) 160 μg/mL nitroxoline; (C) 160 μg/mL colistin; (D) 320 μg/mL nitroxoline; (E) 320 μg/mL colistin (F) 640 μg/mL nitroxoline; (G) 640 μg/mL colistin. Viable cells are visible in green (SYTO 9) and dead cells in red (propidium iodide). All images present only sections of approximately 50 x 50 μm (X x Y) and variable Z-sizes (depending on biofilm thickness).