title: Probiotic bacteria reduce salmonella typhimurium intestinal colonization by competing for iron.
abstract: Host inflammation alters the availability of nutrients such as iron to limit microbial growth. However, Salmonella enterica serovar Typhimurium thrives in the inflamed gut by scavenging for iron with siderophores. By administering Escherichia coli strain Nissle 1917, which assimilates iron by similar mechanisms, we show that this nonpathogenic bacterium can outcompete and reduce S. Typhimurium colonization in mouse models of acute colitis and chronic persistent infection. This probiotic activity depends on E. coli Nissle iron acquisition, given that mutants deficient in iron uptake colonize the intestine but do not reduce S. Typhimurium colonization. Additionally, the ability of E. coli Nissle to overcome iron restriction by the host protein lipocalin 2, which counteracts some siderophores, is essential, given that S. Typhimurium is unaffected by E. coli Nissle in lipocalin 2-deficient mice. Thus, iron availability impacts S. Typhimurium growth, and E. coli Nissle reduces S. Typhimurium intestinal colonization by competing for this limiting nutrient.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697-4025, USA.
authors.forename: Elisa
authors.initials: E
authors.lastname: Deriu
authors.forename: Janet Z
authors.initials: JZ
authors.lastname: Liu
authors.forename: Milad
authors.initials: M
authors.lastname: Pezeshki
authors.forename: Robert A
authors.initials: RA
authors.lastname: Edwards
authors.forename: Roxanna J
authors.initials: RJ
authors.lastname: Ochoa
authors.forename: Heidi
authors.initials: H
authors.lastname: Contreras
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Libby
authors.forename: Ferric C
authors.initials: FC
authors.lastname: Fang
authors.forename: Manuela
authors.initials: M
authors.lastname: Raffatellu
mesh_terms: D000818:Animals; D003092:Colitis / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D004926:Escherichia coli / Q000378:metabolism*; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D007501:Iron / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D019936:Probiotics / Q000378:metabolism / Q000627:therapeutic use*; D012480:Salmonella Infections / Q000188:drug therapy / Q000378:metabolism / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D007501:Iron