Biofilm formation by APEC χ7503 and its derivatives.

<p>Bacteria were grown in either LB or DMEM media at 28°C for 48 hours. Biofilm-associated cells were visualized by crystal violet staining. The data represent means and standard deviations of three independent experiments. Asterisks show significant difference versus the wild-type strain (*, <i>P</i><0.05; **, <i>P</i><0.005).