Fig 4. Hyaluronic acid capsule expression by Streptococcus pyogenes promotes skin infection in B6_HLA mice.

B6_HLA mice were administered ~5 × 10⁷ CFUs of wildtype S. pyogenes MGAS8232, or the hasA mutant, or the ΔhasA + hasA complemented strain by intradermal injections in each hind flank. (A) Weights of B6_HLA mice at 24, 48, and 72 h following skin challenge. Data is represented as a percentage of day 0 weight. Data points represent the weight means ± SEM (n ≥ 5). (B) Skin lesion areas of mice at 24, 48, and 72 h after skin challenge. Data points represent individual lesion areas (2 per mouse), and the bars represent the mean. Significance was determined by two-way ANOVA with Geisser’s Greenhouse correction and Dunnett’s multiple comparisons test (*, P < 0.05, **, P < 0.01, ***, P < 0.001;) for panels A and B. (C) Data points represent CFUs from individual infected skin lesions from mice at 72 h. Horizontal bars represent the geometric mean. Significance was determined by one-way ANOVA with Kruskal-Wallis test (****, P < 0.0001; **, P < 0.01). The horizontal dotted line indicates the theoretical limit of detection. (D) Representative skin lesion images from B6_HLA mice 72 h following skin challenge.