Metabolomics Reveals Phospholipids as Important Nutrient Sources during Salmonella Growth in Bile In Vitro and In Vivo

During the colonization of hosts, bacterial pathogens are presented with many challenges that must be overcome for colonization to occur successfully. This requires the bacterial sensing of the surroundings and adaptation to the conditions encountered. One of the major impediments to the pathogen colonization of the mammalian gastrointestinal tract is the antibacterial action of bile.Salmonella enterica serovar Typhimurium has specific mechanisms involved in resistance to bile. Additionally,Salmonella can successfully multiply in bile, using it as a source of nutrients. This accomplishment is highly relevant to pathogenesis, asSalmonella colonizes the gallbladder of hosts, where it can be carried asymptomatically and promote further host spread and transmission. To gain insights into the mechanisms used bySalmonella to grow in bile, we studied the changes elicited bySalmonella in the chemical composition of bile during growthin vitro andin vivo through a metabolomics approach. Our data suggest that phospholipids are an important source of carbon and energy forSalmonella during growth in the laboratory as well as during gallbladder infections of mice. Further studies in this area will generate a better understanding of howSalmonella exploits this generally hostile environment for its own benefit.