Fig. S1. The role of tetrathionate reductase activity in virulence of S. marcescens. A. Survivorship curves of the wild type, S. marcescens PDL100 (blue line) and the ttr mutant CK7A11 (red line). Data for infections with 108 cfu ml−1 are shown and differences in survivorship were significant (χ2 = 6.0204, P = 0.0141). No mortality was observed at lower doses.

B. Mutant screen details. A library of Mariner transposon mutants of S. marcescens was screened for those defective to use tetrathionate as a respiration electron acceptor as in Hensel and colleauges’ (1999). The test tubes on the bottom left are controls (S. enterica sv. Typhimurium 14 028 wild type, bottom row, and the isogenic ttrS and ttrA mutant, top and middle rows. Notice the difference in color of the tubes due to the changes in the pH). Right panels show wild type S. marcescens PDL100 (top row) and six ttr mutants. CK7A11 (bottow row) was selected for the infections.

Fig. S2. Survival of A. pallida in the presence of S. marcescens PDL100 culture filtrates. A. pallida was placed in the medium containing 2× (brown line), 1/5× (blue line), 1/50× (green line) extracellular components of S. marcescens PDL100 spent medium.

Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.