Figure 5. Lysozyme resistance is incurred through Rgg2/3-SHP induction.

(A) Effect of peptide treatment on bacterial aggregation. (B–E) Survival of GAS during challenge with 2 mg mL⁻¹ lysozyme after (B) pre-treatment of wild-type NZ131 and isogenic rgg mutants with 100 nM synthetic C8 or reverse peptide; (C) pre-growth in metal-deplete (50 μM CaCl₂, 1000 μM MgSO₄) or replete (50 μM CaCl₂, 1000 μM MgSO₄, 20 μM FeSO₄, 30 μM MnSO₄) CxCDM; (D) pre-growth in CDM containing 1% glucose or 1% mannose; (E) pre-treatment with 10 nM synthetic C8, 10 nM cyclosporin A (CsA), or a combination of the two (1:1, 10 nM CsA + 10 nM C8; 10:1,100 nM CsA + 10 nM C8; 100:1, 1000 nM CsA + 10 nM C8). (F) Lysozyme challenge of different GAS serotypes after pre-treatment with 100 nM C8 or reverse peptide. Concentrations of lysozyme used were 10 mg mL⁻¹, MGAS5005; 20 mg mL⁻¹, MGAS10394, HSC5; or 50 mg mL⁻¹, MGAS315. The mean and SD of duplicate (A) or triplicate (B–F) samples is shown, and data are representative of experiments performed at least twice.