Fig. 2
The purR-dependent clumping phenotype requires fibronectin binding proteins and host fibronectin. In a, cultures were grown in TSB or TSB-S for 3.5 h and then imaged on a wide field microscope at ×40 magnification. White boxes define the region of interest that is depicted in the insets. Scale bars = 40 µm. Representative images are shown. In b, cultures were grown as in a and OD600 was measured as described in the legend to Fig. 1 and in the Methods section. Data shown are mean ± SEM of four independent experiments. ***p-value < 0.001, based on a one-way ANOVA with a Bonferroni post-test. In c, WT and the purR::ΦNΣ mutant were grown in TSB, TSB-S, TSB containing 10% v/v of various levels of Fn-depleted horse serum or Fn-depleted horse serum with the addition of eluted fibronectin (Fn depletion 3+Fn). Measurement of OD600 of cultures to evaluate clumping was performed as described above. Data shown are mean ± SEM of five independent experiments and two different Fn purifications. ***p-value < 0.001, based on a one-way ANOVA with a Bonferroni post-test. In d, biofilm forming ability of indicated strains was measured after growth in TSB in a standard 96-well plate biofilm assay (see the Methods section). Data shown are mean ± SEM of four experiments. **p-value < 0.01, ***p-value < 0.001, based on a one-way ANOVA with a Bonferroni post-test. Source data are provided as a Source Data file
