title: Osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium are required for optimal virulence in mice.
abstract: We purified osmoregulated periplasmic glucans (OPGs) from Salmonella enterica serovar Typhimurium and found them to be composed of 100 % glucose with 2-linked glucose as the most abundant residue, with terminal glucose, 2,3-linked and 2,6-linked glucose also present in high quantities. The two structural genes for OPG biosynthesis, opgG and opgH, form a bicistronic operon, and insertion of a kanamycin resistance gene cassette into this operon resulted in a strain devoid of OPGs. The opgGH mutant strain was impaired in motility and growth under low osmolarity conditions. The opgGH mutation also resulted in a 2 log increase in the LD50 in mice compared to the wild-type strain SL1344. Inability to synthesize OPGs had no significant impact on the organism's lipopolysaccharide pattern or its ability to survive antimicrobial peptides-, detergent-, pH- and nutrient-stress conditions. We observed that the opgGH-defective strain respired at a reduced rate under acidic growth conditions (pH 5.0) and had lower ATP levels compared to the wild-type strain. These data indicate that OPGs of S. Typhimurium contribute towards mouse virulence as well as growth and motility under low osmolarity growth conditions.
authors.affiliation: Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Arvind A
authors.initials: AA
authors.lastname: Bhagwat
authors.affiliation: Department of Plant Science & Landscape Architecture, University of Maryland, College Park, MD 20742-7521, USA.|Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Won
authors.initials: W
authors.lastname: Jun
authors.affiliation: Department of Food Science and Nutrition, University of Maryland, College Park, MD 20742-7521, USA.|Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Liu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Porteen
authors.initials: P
authors.lastname: Kannan
authors.affiliation: Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Mahesh
authors.initials: M
authors.lastname: Dharne
authors.affiliation: Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Benedict
authors.initials: B
authors.lastname: Pheh
authors.affiliation: Food and Drug Administration, Division of Virulence Assessment, Laurel, MD 20708, USA.
authors.forename: Ben D
authors.initials: BD
authors.lastname: Tall
authors.affiliation: Food and Drug Administration, Division of Virulence Assessment, Laurel, MD 20708, USA.
authors.forename: Mahendra H
authors.initials: MH
authors.lastname: Kothary
authors.affiliation: Produce Quality and Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-235, USA.
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Gross
authors.affiliation: College of Agriculture, University of Maryland, College Park, MD 20742-7521, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Angle
authors.affiliation: Department of Food Science and Nutrition, University of Maryland, College Park, MD 20742-7521, USA.
authors.forename: Jianghong
authors.initials: J
authors.lastname: Meng
authors.affiliation: Diet Genomics and Immunology Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research Service, USDA, 10300 Baltimore Avenue, Bldg. 002, BARC-W, Beltsville, MD 20705-2350, USA.
authors.forename: Allen
authors.initials: A
authors.lastname: Smith
mesh_terms: D000818:Animals; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D005936:Glucans / Q000737:chemistry / Q000378:metabolism*; D005947:Glucose / Q000032:analysis; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D019897:Periplasm / Q000378:metabolism*; D010641:Phenotype; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity* / Q000502:physiology; D014774:Virulence; D014882:Water-Electrolyte Balance
chemical_list: D003470:Culture Media; D005936:Glucans; D005947:Glucose