FIG 6 .

UpaE mediates biofilm formation and adhesion to ECM proteins. (A) Polystyrene 96-well microtiter plates (Corning) were used to monitor biofilm formation. Overnight cultures were subcultured 1/100 into fresh M9 minimal medium supplemented with 1 mM IPTG and incubated with shaking at 37°C for 24 h. Biofilms were stained with a 0.1% crystal violet solution and quantified by dissolving the crystal violet with an acetone-ethanol mix and measuring the OD₅₉₅. MS427(pUpaE) was able to form a better biofilm than the vector control. Experiments were performed in triplicate. *, P < 0.05, unpaired Student’s t test. (B) MS427(pSU2718) vector control and MS427(pUpaE) were incubated in microtiter plates coated with ECM proteins. Nonadherent bacteria were washed off, and remaining bound cells were detected with a specific E. coli antiserum. MS427 overexpressing UpaE bound to fibronectin; laminin; collagens I, II, and V; and MaxGel. Experiments were performed in triplicate. *, P < 0.05, unpaired Student’s t test.