FIG 6 .

Effects of MntE on Sda1 expression, survival of GAS in a neutrophil killing assay, and virulence in a murine model of infection. (A) Wild-type 5448, 5448ΔmntE, 5448ΔmntE::mntE, 5448ΔperR, and 5448Δsda1 were grown in THY broth alone or THY broth supplemented with 0.5 mM manganese, and supernatant was harvested at mid-exponential growth phase. Cell supernatant proteins were trichloroacetic acid precipitated, run on an SDS-PAGE gel, and subjected to immunoblotting using anti-Sda1. MW, molecular weights in thousands. (B) Percent survival of 5448 wild type, 5448ΔmntE, and 5448ΔmntE::mntE following coculture with human neutrophils in vitro. One-way ANOVA was performed comparing 5448 wild type versus 5448ΔmntE (***, P < 0.001). The graph is representative of three independent experiments. (C) Survival of mice (WT and 5448ΔmntE::mntE, n = 20; 5448ΔmntE, n = 19) after subcutaneous challenge of transgenic humanized plasminogen AlbPLG1 C57BL/J6 mice with 5448 wild type (circles), 5448ΔmntE (triangles, dashed line), and 5448ΔmntE::mntE (squares). Infecting dose, 2 × 10⁷ to 4 × 10⁷ CFU. The Mantel-Cox log rank test was performed comparing 5448ΔmntE to 5448 wild type (P = 0.067) and 5448ΔmntE::mntE (P = 0.3369).