Fig 2.

Dispersal of mature biofilms by sub-MICs of nitroxoline (NIT). (A) Dosage dependence. Biofilms of strain BK6695-10 were grown in polystyrol tubes (1-ml bathing volume exposed to approximately 5-cm² tube surface, CELLSTAR polystyrene tubes; Greiner Bio-One GmbH, Kremsmünster, Austria) washed and subsequently exposed to the indicated agents or phosphate-buffered saline (PBS) alone (control) for 1.5 h. Viable cell numbers in the supernatant and, after dislodgment by sonication (17), in the biofilm layer were determined by serial dilution and plating. Data represent means ± SD of five independent experiments, and significant differences to controls are indicated (*, P < 0.05; **, P < 0.01; ***, P < 0.001). (B) Kinetics of dispersal. Biofilms were exposed over a period of 12 h and subsequently stained with crystal violet. Results are representative of three independent experiments, with three replicate tubes per experiment.