Taxonomic group: bacteria / Proteobacteria
(Phylum: Proteobacteria)
Associated disease: infection due to Escherichia coli [ICD11:
XN6P4 
]
NCBI PubMed ID: 19402104Publication DOI: 10.1002/jmr.955Journal NLM ID: 9004580Publisher: Chichester, Sussex, UK: John Wiley & Sons
Correspondence: terric

wpi.edu
Institutions: Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA
The O-antigen is a highly variable component of the lipopolysaccharide (LPS) among Escherichia coli strains and is useful for strain identification and assessing virulence. While the O-antigen has been chemically well characterized in terms of sugar composition, physical properties such as O-antigen length of E. coli LPS have not been well studied, even though LPS length is important for determining binding of bacteria to biomolecules and epithelial cells. Atomic force microscopy (AFM) was used to characterize the physicochemical properties of the LPS of eight E. coli strains. Steric repulsion between the AFM tip (silicon nitride) and the E. coli cells was measured and modeled, to determine LPS lengths for three O157 and two O113 E. coli strains, and three control (K12) strains that do not express the O-antigen. For strains with an O-antigen, the LPS lengths ranged from 17 +/- 10 to 37 +/- 9 nm, and LPS length was positively correlated with the force of adhesion (F(adh)). Longer lengths of LPS may have allowed for more hydrogen bonding between the O-antigen and silanol groups of the AFM silicon nitride tip, which controlled the magnitude of F(adh). For control strains, LPS lengths ranged from 3 +/- 2 to 5 +/- 3 nm, and there was no relationship between LPS length and adhesion force between the bacterium and the silicon nitride tip. In the absence of the O-antigen, we attributed F(adh) to electrostatic interactions with lipids in the bacterial membrane.
LPS, virulence, Bacterial Adhesion, AFM, adhesion force, E.coli
Structure type: oligomer
Location inside paper: p.353, table 3, O157:H16 R2
Aglycon: HepII
Compound class: core oligosaccharide
Contained glycoepitopes: IEDB_130693,IEDB_136906,IEDB_137340,IEDB_137472,IEDB_140529,IEDB_141794,IEDB_141807,IEDB_142488,IEDB_144998,IEDB_146664,IEDB_151528,IEDB_151531,IEDB_190606,IEDB_232584,IEDB_983931,SB_192,SB_7
Methods: atomic force microscopy, statistical analysis
Biological activity: adhesion force data
Related record ID(s): 23850, 24239, 24241, 24242
NCBI Taxonomy refs (TaxIDs): 626529,
930406Reference(s) to other database(s): GTC:G17527ZC, GlycomeDB:
27157
Show glycosyltransferases
There is only one chemically distinct structure: