FIG. 4.

Inhibition of biofilm formation by S. epidermidis strains 10b (A) and 1457 (B) and a sesC-negative biofilm-positive clinical isolate of S. warneri (C) with increasing concentrations of preimmune and anti-SesC IgGs. Overnight cultures were diluted to an OD₆₀₀ of 0.005, mixed with the indicated concentrations of IgGs, and incubated for 2 h at 4°C and then overnight at 37°C. The formation of biofilms was measured using the stain crystal violet. The error bars indicate standard errors. For each concentration of IgGs at least nine independent measurements from three independent experiments were assessed. One hundred percent adherence was defined as biofilm formation in TSB without any IgG.