FIG 2 .

Bactericidal activity of EsBPI2 and EsBPI4 against V. fischeri. (A and B) Survival of wild-type V. fischeri strain ES114 (Vf) following 1-h incubation with different concentrations of EsBPI2 (A) or EsBPI4 (B) compared to incubation with a chemical cell-permeant (SDS). Values are shown as means plus standard errors of the means (sem) (error bars) for three biological replicates, each with three technical replicates. Bars labeled with different letters are statistically significantly different (P < 0.001). (C and D) Effect of a pretreatment with either heat (70°C for 10 min; red) (C) or preincubation with the cognate antibody (Ab; blue) (D) on the killing of V. fischeri by a 30 nM concentration of either EsBPI2 or EsBPI4 after 1 h of incubation. Values are shown as means plus sem (error bars) for three biological replicates, each with three technical replicates. Pairwise comparisons of viability (CFU/milliliter) for untreated protein/heat-denatured protein (C) and untreated protein/preadsorbed with its cognate antibody protein (D) for each protein were tested by a one-way ANOVA, followed by a Tukey’s multiple-comparison test and are indicated as follows: **, P < 0.01; ***, P < 0.001. For each protein, heat or antibody treatment resulted in an activity not significantly different from that of the control (black).