FIG 4 .

Requirement of ubiE for bacterial coaggregation, biofilm formation, and pilus assembly. (A) Coaggregation of A. oris strains and S. oralis So34 was determined as described in the legend to Fig. 2. (B) Biofilms were obtained by growing the indicated strains in HIB containing 1% sucrose for 48 h. Harvested biofilms were subjected to crystal violet staining and optical density measurement at 580 nm using a microplate reader. The results are shown as representatives of 3 independent experiments performed in triplicate. **, P < 0.0025, calculated using a one-way ANOVA (Duncan’s method, nonparametric) with GraphPad Prism. (C to N) A. oris cells were immobilized in nickel grids and stained with anti-FimA (C to F), anti-CafA (G to J), or anti-type 1 (K to N) antibodies, followed by staining with IgG conjugated to 18-nm gold particles. Samples were stained with 1% uranyl acetate prior to being analyzed by electron microscopy. Scale bars indicate 0.5 µm.