O-antigen polysaccharide of Escherichia coli serotype O6A (O-antigen (E. coli O6A))

The O-antigen of Escherichia coli serotype O6A is a variable surface polysaccharide located at the distal end of the bacterial lipopolysaccharide (LPS) molecule, composed of repeating sugar units that differ among serogroups. Its sequence and branching pattern determine serotype identity, immune recognition, and pathogenic features. The O-antigen is highly immunogenic and forms the structural basis for O-serotyping of E. coli, critical for epidemiologic tracing, diagnostic discrimination, and vaccine development. In the O6A variant, the O-antigen confers unique serological properties and influences interactions with the host immune system, phages, and environmental pressures. While not a protein receptor, it is an established target for diagnostics and experimental therapeutics.

Other names

O-antigenO-specific polysaccharideO-polysaccharideEscherichia coli O6 (sometimes O6:K-:H-)E. coli O6A LPS

Experimental monoclonal antibodies: Bind specific O-antigen epitopes, opsonize bacteria, promote immune clearance. Conjugate vaccines: Induce protective antibody response using O-antigen as immunogen. Bacteriophage: Recognize and bind O-antigen as receptor for infection.