Salmonella Uses Energy Taxis to Benefit from Intestinal Inflammation

Abstract

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.

Osmotaxis in Escherichia coli through changes in motor speed

“…This behavior, called taxis [Krell et al, 2011, Purcell, 1977, has long been a subject of scientific investigation, as it serves a variety of purposes: seeking out nutrients and avoiding toxic substances Armitage, 2004, Adler, 1969], identifying thermal [Paster and Ryu, 2007] and oxygen [Adler et al, 2012] gradients, as well as aiding pathogenic species in infecting their hosts [Rivera-Chávez et al, 2013, Cullender et al, 2013. The understanding of bacterial taxis is not only important when it comes to bacterial motility and accumulation; it also serves as a model for biological signal processing.…”

Curcumin Reduces the Motility of Salmonella enterica Serovar Typhimurium by Binding to the Flagella, Thereby Leading to Flagellar Fragility and Shedding

“…Flagella contribute to the virulence of the pathogen by aiding motility, adherence, and invasion of the host cells (4,5). With the help of flagellar and chemotaxis machinery, the pathogen can cross the mucus barrier and gain access to the epithelial layer (6). Salmonella clings onto the epithelial cells with the help of flagella and fimbriae, inducing its uptake into the cells (4,(7)(8)(9)(10).…”

Use of Attenuated but Metabolically Competent Salmonella as a Probiotic To Prevent or Treat Salmonella Infection

“…These mice are Nramp1 ϩ/ϩ , they tend to carry Salmonella for long periods in their intestinal tract, and their intestinal tract becomes inflamed by day 10 postinfection (27,38). With no need for disruption of the microbiota with antibiotics, this model may have the most realistic microbiota composition during inflammation.…”

“…However, these mice have the unusual attribute of allowing persistent intestinal colonization by Salmonella. It was recently discovered that the gastrointestinal tracts of these mice are becoming inflamed during these persistent infections, starting at 10 days postinfection (27,38). Since this inflammation requires no streptomycin-mediated disruption of the microbiota, it has the most realistic microbial community composition of the Salmonella inflammation models.…”