Gut Gas Gives Salmonella A Boost

Salmonella enterica, a pathogenic bacterium responsible for serious digestive illness and even death, gets a source of energy from a sulfur compound generated by the gut inflammation that the bacterium causes (Nature 2010, 467, 426). Andreas J. Bäumler and Sebastian E. Winter of the University of California, Davis, and colleagues show that in mice the gut can produce tetrathionate (S₄O₆ ^2–), which is synthesized from thiosulfate (S₂O₃ ^2–) in the gut and oxygen radicals produced during the gut’s inflammatory response. Tetrathionate serves as an electron acceptor for Salmonella, providing an energy source that allows the bacterium to flourish more vigorously than normal gut microbes. Although scientists have known since the 1920s that Salmonella uses S₄O₆ ^2– as an energy source, only recently had researchers entertained the notion that vertebrate intestinal tracts could produce this compound. The new experiments establish this mechanistic link between inflammation and colonization that gives Salmonella its deadly edge.