Osmoregulated periplasmic glucans of Salmonella enterica serovar Typhimurium are required for optimal virulence in mice.
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.
Bhagwat
Arvind A
AA
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.
Jun
Won
W
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.
Liu
Liu
L
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.
Kannan
Porteen
P
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.
Dharne
Mahesh
M
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.
Pheh
Benedict
B
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.
Tall
Ben D
BD
Food and Drug Administration, Division of Virulence Assessment, Laurel, MD 20708, USA.
Kothary
Mahendra H
MH
Food and Drug Administration, Division of Virulence Assessment, Laurel, MD 20708, USA.
Gross
Kenneth C
KC
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.
Angle
Scott
S
College of Agriculture, University of Maryland, College Park, MD 20742-7521, USA.
Meng
Jianghong
J
Department of Food Science and Nutrition, University of Maryland, College Park, MD 20742-7521, USA.
Smith
Allen
A
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.
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
D003470:Culture Media; D005936:Glucans; D005947:Glucose