Fig. 1

Reversible loss of SpeB is associated with tissue pathology and inflammation. A Distribution of SpeB⁺ and SpeB⁻ GAS clones directly isolated from NSTI patient tissue biopsies (n = 23). B Percentage of SpeB⁺ and SpeB⁻ GAS clones after the passage in THY media (p1, passage 1; p2, passage 2). Representative analysis of 2006 GAS patient isolate is shown. C–G Correlation analysis of bacterial load (left panel; n = 81 biopsies) or percentage of SpeB⁻ clones (right panel; n = 23 biopsies) with the presence of HMGB1 (C), IL-8 (D), infiltrating neutrophils (E), and resistin (F) in patient biopsies. Correlation was determined using Spearman test. Semiquantitative acquired computerized image analyses (ACIA) of immuno-histochemical staining were performed as described in the methods section. The cell area was defined by the hematoxylin counterstaining, and the results are presented as percent positively stained area × mean intensity of positive staining