FIGURE 3.

S. sanguinis mutants exhibiting a reduction in platelet binding are deficient in aggregating platelets. Ability of mutant strains to induce platelet aggregation in platelet-rich plasma (PRP). The concentration of bacterial strains was normalized to an OD₆₀₀ of 10, and 10 μL of each culture was added to the wells of a microtiter plate. 90 μL of PRP was quickly added to the bacterial solution and the microtiter plate transferred to a pre-warmed plate reader, where the initial OD at 595 nm was measured. The plate reader was set to shake constantly and read the OD every 2.5 min. (A) Platelet aggregation was determined by the decrease in OD over time and set relative to the maximum aggregation observed in WT. Strains labeled with stars and in brackets were indistinguishable from baseline. (B) Total area of platelet aggregation over the experimental time course. Assays were performed in triplicate and three experiments were performed. Statistical analysis was performed using two-way ANOVA for the time course and one-way ANOVA for Area Under Curve, both corrected for multiple comparisons against the WT mean using Dunnett’s test. ^∗p < 0.05. Error bars represent the standard error.