Fig. 6.
Phenotypic characterization of a S. sanguinis mutant expressing PilBD319A with an inactive MIDAS. (A) Piliation was quantified by purifying T4P from cultures adjusted to the same OD600. Purified T4P (identical volumes were loaded in each lane) were separated by SDS-PAGE and stained with Coomassie blue. A molecular weight marker (MW) was run in the first lane. MWs are indicated in kDa. (B) Twitching motility was assessed by a macroscopic motility assay. Bacteria were streaked on plates, which were incubated several days at 37 °C in a humid atmosphere and then photographed. Twitching motility is characterized by spreading zones around colonies. (C) Adhesion of S. sanguinis to eukaryotic cells was quantified by incubating bacteria (MOI = 10) with CHO cells for 1 h. After removing nonadherent bacteria by several washes, bacteria adhering to cells were enumerated by performing CFU counts. The results are expressed as adhesion relative to WT (set to 1) and are the average ± SDs from five independent experiments. For statistical analysis, one-way ANOVA followed by Dunnett’s multiple comparison tests were performed (****P < 0.0001).