title: Biotin sulfoxide reductase contributes to oxidative stress tolerance and virulence in Salmonella enterica serovar Typhimurium.
abstract: Oxidative stress converts sulfur residues of molecules like biotin and methionine into their oxidized forms. Here we show that the biotin sulfoxide reductase BisC of Salmonella enterica serovar Typhimurium (S. Typhimurium) repairs both oxidized biotin and oxidized methionine. Exposure to H2O2 in vitro reduced survival of a S. Typhimurium ΔbisC mutant. Furthermore, replication of the ΔbisC mutant inside IFN-γ activated macrophages was reduced. In vitro tolerance of the mutant to H2O2 was restored by plasmids carrying either bisC or msrA; the latter encodes a methioinine sulfoxide reductase. In contrast, the proliferation defect inside IFN-γ activated macrophages was rescued by bisC but not by msrA. Thus growth of the ΔbisC mutant in IFN-γ activated macrophages required repair of oxidized biotin. Both the ΔbisC and a biotin auxotrophic (ΔbioB) mutant were attenuated in mice, suggesting that besides biotin biosynthesis, biotin repair was essential for virulence of S. Typhimurium in vivo. Attenuation of the ΔbisC mutant was more pronounced in 129 mice that produce a stronger oxidative response. These results show that BisC is essential for full virulence of Salmonella by contributing to the defence of S. Typhimurium against host-derived stress, and provides an attractive drug target since it is not present in mammals.
authors: Dept. of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hannover, Germany.
authors: Luisa A
authors: LA
authors: Denkel
authors: Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, 17177 Stockholm, Sweden.
authors: Mikael
authors: M
authors: Rhen
authors: Dept. of Medical Microbiology and Hospital Epidemiology, Medical School Hannover, 30625 Hannover, Germany.
authors: Franz-Christoph
authors: FC
authors: Bange
mesh_terms: D000818:Animals; D001710:Biotin / Q000378:metabolism; D002460:Cell Line; D005260:Female; D018869:Heat-Shock Response; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D008807:Mice, Inbred BALB C; D018384:Oxidative Stress / Q000502:physiology; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D012480:Salmonella Infections / Q000382:microbiology; D012486:Salmonella typhimurium / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D014774:Virulence
chemical_list: D001710:Biotin; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C019792:biotin sulfoxide reductase