title: Structure of a capsular polysaccharide isolated from Salmonella enteritidis.
abstract: Salmonella enteritidis is a food-borne enteric human pathogen that can form a complex protective extracellular matrix. We describe here a component of this matrix which is distinct from other known salmonella extracellular polysaccharides such as cellulose and colanic acid. We have used glycosyl composition and linkage analysis, as well as 1D and 2D NMR spectroscopy to determine the structure of this polysaccharide. We propose that the primary saccharide in the S. enteritidis capsule has a branched tetrasaccharide repeating unit having the following structure: -->3)-alpha-D-Galp-(1-->2)-[alpha-Tyvp-(1-->3)]-alpha-D-Manp-(1-->4)-alpha-L-Rhap-(1-->. This structure is partially substituted on both tyvelose and galactose with a glucose-containing side chain. It further bears considerable similarity to the O antigen from this organism, a feature found in a number of other capsules from Gram-negative bacteria. In addition, we have detected fatty acids at levels that indicate the presence of a lipid anchor.
authors.affiliation: Complex Carbohydrate Research Center, Athens, GA 30602-4712, USA.
authors.forename: David Scott
authors.initials: DS
authors.lastname: Snyder
authors.forename: Deanna
authors.initials: D
authors.lastname: Gibson
authors.forename: Christian
authors.initials: C
authors.lastname: Heiss
authors.forename: William
authors.initials: W
authors.lastname: Kay
authors.forename: Parastoo
authors.initials: P
authors.lastname: Azadi
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005109:Extracellular Matrix / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D006031:Glycosylation; D009682:Magnetic Resonance Spectroscopy; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification*; D012477:Salmonella enteritidis / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D011135:Polysaccharides, Bacterial