Fig. 4. Bacterial virulence factors determine the extent and consequences of lymphatic-dissemination.

a–c Recovery of a panel of isogenic S. pyogenes isolates from the hindlimb infection site, lymph nodes, and systemic organs of FVB/n mice at 0.5 h (a), 3 h (b), or 24 h (c) after intramuscular infection with 10⁸ CFU. Isogenic strains were: wildtype (H584); acapsular mutant, Δcapsule (H1454); high-capsule ΔP2 (H1458); and high-capsule CovR^mutant (H1565). Symbols represent individual mice, n = 6 per group, black lines indicate geometric means. *p ≤ 0.05; **p ≤ 0.005; ***p ≤ 0.001; ns, p > 0.5: one-way ANOVA followed by Tukey’s multiple comparisons post-tests were performed on log10-transformed data. CFU are per ml of blood, per g of liver, per leg, or per organ.