FIG 3.

MgrB inactivation manifests as reduced capsule amount and an increased mucin association. (A) Comparison of capsule production between WT, MgrB⁻, and MgrB⁺ using a uronic acid assay from stationary-phase culture samples. (B) Comparison of the association of WT, MgrB⁻, MgrB⁺, and CPS⁻ (Δwcaj) to immobilized semipurified bovine submaxillary gland mucin. Shown are the CFU counts of each strain that adhered to the immobilized mucin. Boxes and whiskers indicate the means and minimum to maximum values, respectively. Three independent assays were carried out for both capsule amount (in duplicate) and mucin binding (in sextuplicate). Statistical differences were calculated using Kruskal-Wallis tests with Dunn’s test of multiple comparisons across strains. *, P < 0.05; **, P < 0.01; n.s., not significant.