Supplementary Figure 2: PAS638 senses tetrathionate in a murine streptomycin-treated S. typhimurium colitis model

a) Timecourse of PAS638 switching during infection of C57Bl/6 mice with wt and ΔttrR S. typhimurium (S.tm) (n= 6 for control and 7 for S. typhimurium infected groups). Switching was only apparent in colonies from mice co-infected with S.typhimurium ΔttrR and on days 4 and/or 5 post administration. b) Enumeration of PAS638 E. coli and c) S. typhimurium variant levels by selective plating showed relatively consistent levels across experimental groups. d) LCN-2 quantification demonstrated inflammation in both S. typhimurium ΔttrR and wt administered mice. Graphs show individual mouse values and mean. * p=0.02, ** p=0.001 *** p<0.0001, F(2,17) = 25.96, using one way ANOVA with Tukey’s multiple comparisons test. e) Histology scoring of cecum, proximal and distal colon, showed inflammation in the presence of both S. typhimurium variants decreasingly apparent from the caecum to the distal colon. f) Scoring used a 0-4 point scale with example images of each score by histology provided. For cecal samples, only severity 3 and 4 were observed during S. typhimurium infection, characterized by accumulation of neutrophils (N) in epithelial tissues, edema (E), mucosal thickening and at times low-level presence of neutrophils in exudate at severity 3 and edema (E), extensive neutrophils present in exudate and/or epithelia (N), mucosal thickening and signs of crypt damage or regeneration (C) at severity 4. Proximal and distal colon showed signs of low-level inflammation (I) at severity 1, more extensive inflammation (I) and neutrophils in exudate (N) at severity 2. Severity 3 was noted in the proximal colon only and showed signs of ulceration (U), inflammatory cell migration (I), and neutrophils commonly present in exudate. Scale bars = 10μm.