Salmonella Uses Energy Taxis to Benefit from Intestinal Inflammation

Fabian Rivera-Chávez is with University of California, Davis; Sebastian E. Winter is with University of California, Davis; Christopher A. Lopez is with University of California, Davis; Mariana N. Xavier is with University of California, Davis; Maria G. Winter is with University of California, Davis; Sean-Paul Nuccio is with University of California, Davis; Joseph M. Russell is with University of California, Davis; Richard C. Laughlin is with Texas A&M University; Sara D. Lawhon is with Texas A&M University; Torsten Sterzenbach is with University of California, Davis; Charles L. Bevins is with University of California, Davis; Renée M. Tsolis is with University of California, Davis; Rasika Harshey is with UT Austin; L. Garry Adams is with Texas A&M University; Andreas J. Bäumler is with University of California, Davis.Chemotaxis enhances the fitness of Salmonella enterica serotype Typhimurium (S. Typhimurium) during colitis. However, the chemotaxis receptors conferring this fitness advantage and their cognate signals generated during inflammation remain unknown. Here we identify respiratory electron acceptors that are generated in the intestinal lumen as by-products of the host inflammatory response as in vivo signals for methyl-accepting chemotaxis proteins (MCPs). Three MCPs, including Trg, Tsr and Aer, enhanced the fitness of S. Typhimurium in a mouse colitis model. Aer mediated chemotaxis towards electron acceptors (energy taxis) in vitro and required tetrathionate respiration to confer a fitness advantage in vivo. Tsr mediated energy taxis towards nitrate but not towards tetrathionate in vitro and required nitrate respiration to confer a fitness advantage in vivo. These data suggest that the energy taxis receptors Tsr and Aer respond to distinct in vivo signals to confer a fitness advantage upon S. Typhimurium during inflammation by enabling this facultative anaerobic pathogen to seek out favorable spatial niches containing host-derived electron acceptors that boost its luminal growth.We would like to acknowledge support by Public Health Service Grants AI088122 and AI096528 to AJB and AI076246 to AJB, CLB and LGA. CAL was supported by Public Health Service Grant AI060555. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Microbiolog