Effect of PIP and RES on 48 h biofilm levels of <i>E. coli</i> CFT073 (white bars) and the flagellar mutant <i>E. coli</i> Δ<i>fli</i>C (black bars) in (A) 96 well plates and (B) polystyrene tubes.

<p>The biofilm values (OD₅₇₀) were normalized with respect to growth (OD₆₀₀). Abbreviations: PIP 0.5 or RES 0.5, piperine or reserpine at 0.5 µg/mL (<i>e.g.</i>, PIP 0.5 indicates piperine at 0.5 µg/mL). Values shown denote the mean + SD for three experiments. * and ** indicate statistically significant differences with respect to the control with values <i>p</i><0.05 and <i>p</i><0.01, respectively.