Role of bgsB in biofilm formation and bacterial adherence to Caco-2 cells. A Biofilm formation on polystyrene. Microtiter plates were incubated with bacteria for 18 h, non-adherent bacteria removed by washing with PBS, and biofilms stained with crystal violet. Data represent the means ± SEM. *** P < Tukey's multiple comparison test. B Development of biofilm on polystyrene of E. faecalis 12030 wt, 12030ΔbgsB, and 12030ΔbgsA over time. After incubation periods of ≥ 4 h, E. faecalis 12030 wt elaborated significantly more biofilm than the deletion mutants (P < 0.001, Tukey's multiple comparison test). Bars represent means ± SEM. C Bacterial adherence to Caco-2 cells. Caco-2 cells were incubated at a multiple of infection of 100:1 for 2 h with the respective strain grown to mid-log phase. Data represent the means ± SEM. *** P < 0.001, Dunn's multiple comparison test.