FIG. 5.

Role of the OmpU protein in adherence of Vibrio vulnificus to immobilized fibronectin. (A) Adherence of various V. vulnificus strains to fibronectin. V. vulnificus cells (wild-type V. vulnificus MO6-24/O [open bar], ompU mutant strain DK1 [closed bar], DK1 carrying pJH0311 [gray bar], and DK1 carrying a complementation plasmid, pSM1 [hatched bar]) were added to a 96-well plate coated with fibronectin. The percentage of bacterial cells that adhered to fibronectin-coated wells was determined by plating bound bacteria onto LBS agar. Error bars represent the means ± standard deviations from three independent experiments. Assay of the binding of each V. vulnificus strain to fibronectin was performed in quadruplicate for each experiment. Asterisks indicate binding levels that were significantly different from that of wild-type V. vulnificus by the Student's t test. Data with P values of <0.01 are indicated with two asterisks, whereas data with P values of between 0.01 and 0.05 are indicated with one asterisk. (B) Inhibition of fibronectin binding of wild-type V. vulnificus by anti-OmpU. The percentage of bacterial cells that adhered to fibronectin-coated wells was determined for wild-type V. vulnificus preincubated with mouse preimmune serum (dotted bar) or with anti-OmpU (cross-hatched bar) at 20 μg ml⁻¹. Error bars represent the means ± standard deviations from three independent experiments. Assay of binding of V. vulnificus to fibronectin was performed in quadruplicate for each experiment. The asterisk indicates a binding level that was significantly different from that of wild-type V. vulnificus pretreated with mouse preimmune serum by Student's t test (0.01 < P < 0.05). Ab, antibody.