A New Look at the Enterobacterial Common Antigen Forms Obtained during Rough Lipopolysaccharides Purification.

Enterobacterial common antigen (ECA) is a conserved antigen expressed by enterobacteria. It is built by trisaccharide repeating units: →3)-α-D-Fuc4NAc-(1→4)-β-D-ManNAcA-(1→4)-α-D-GlcNAc-(1→ and occurs in three forms: as surface-bound linear polysaccharides linked to a phosphoglyceride (ECA) or lipopolysaccharide - endotoxin (ECA), and cyclic form (ECA). ECA maintains, outer membrane integrity, immunogenicity, and viability of enterobacteria.

Fractionation and analysis of lipopolysaccharide-derived oligosaccharides by zwitterionic-type hydrophilic interaction liquid chromatography coupled with electrospray ionisation mass spectrometry.

Lipopolysaccharide (LPS, endotoxin) is a main surface antigen and virulence factor of Gram-negative bacteria. Regardless of the source of LPS, this molecule, isolated from the smooth forms of bacteria, is characterised by a general structural layout encompassing three regions: (i) an O-specific polysaccharide (O-PS) - a polymer of repeating oligosaccharide units, (ii) core oligosaccharide (OS), and (iii) the lipid A anchoring LPS in the outer membrane of the cell envelope of Gram-negative bacteria. Structural analysis usually requires degradation of LPS and further efficient separation of various poly- and oligosaccharide glycoforms.

[The structure and significance of enterobacterial common antigen (ECA)].

The enterobacterial common antigen (ECA) is a carbohydrate-derived cell surface antigen present in all Gram-negative bacteria belonging to Enterobacteriaceae family. Biosynthetic pathways shared by ECA and LPS (endotoxin) suggest close connections between these antigens. ECA occurs in three different forms: a phosphatidyl-linked linear polysaccharide anchored on the cell surface (ECAPG), a cyclic form built of 4-6 repeating units localized in the periplasm (ECACYC) and as a linear polysaccharide covalently linked to LPS core oligosaccharide (ECALPS).

Occurrence of glycine in the core oligosaccharides of Hafnia alvei lipopolysaccharides--identification of disubstituted glycoform.

Endotoxins (lipopolysaccharides, LPS) are the main surface antigens and virulence factors of Gram-negative bacteria involved for example in the development of nosocomial infections and sepsis. They consist of three main regions: O-specific polysaccharide, core oligosaccharide, and lipid A. Bacteria modify LPS structure to escape the immune defence, but also to adapt to environmental conditions.

Diagnostic potential of monoclonal antibodies specific to the unique O-antigen of multidrug-resistant epidemic Escherichia coli clone ST131-O25b:H4.

The Escherichia coli lineage sequence type 131 (ST131)-O25b:H4 is a globally spread multidrug-resistant clone responsible for a great proportion of extraintestinal infections. Driven by the significant medical needs associated with this successful pathogenic lineage, we generated murine monoclonal antibodies (MAbs) against its lipopolysaccharide (LPS) O25b antigen in order to develop quick diagnostic tests. Murine monoclonal antibodies were generated by immunizing mice with whole killed nonencapsulated ST131-O25b E.

First evidence for a covalent linkage between enterobacterial common antigen and lipopolysaccharide in Shigella sonnei phase II ECALPS.

Enterobacterial common antigen (ECA) is expressed by Gram-negative bacteria belonging to Enterobacteriaceae, including emerging drug-resistant pathogens such as Escherichia coli, Klebsiella pneumoniae, and Proteus spp. Recent studies have indicated the importance of ECA for cell envelope integrity, flagellum expression, and resistance of enteric bacteria to acetic acid and bile salts. ECA, a heteropolysaccharide built from the trisaccharide repeating unit, →3)-α-D-Fucp4NAc-(1→4)-β-D-ManpNAcA-(1→4)-α-D-GlcpNAc-(1→, occurs as a cyclic form (ECA(CYC)), a phosphatidylglycerol (PG)-linked form (ECA(PG)), and an endotoxin/lipopolysaccharide (LPS)-associated form (ECA(LPS)).