Escherichia coli O2 antigen (O2 antigen)

The Escherichia coli O2 antigen is a specific O-polysaccharide component of the lipopolysaccharide (LPS) located on the outer membrane of certain pathogenic E. coli strains. It serves as a key surface-exposed structure that facilitates bacterial survival by providing resistance to the host's complement-mediated killing and preventing phagocytosis (PubMed: 30201686). The O2 serotype is one of the most prevalent antigens found in extra-intestinal pathogenic E. coli (ExPEC), which are major contributors to urinary tract infections, bacteremia, and neonatal meningitis (PubMed: 29158483). Due to its high immunogenicity and prevalence in clinical isolates, the O2 antigen is a primary target for glycoconjugate vaccines, such as ExPEC9V, and therapeutic monoclonal antibodies (PubMed: 32814658). These interventions aim to elicit or supply opsonophagocytic antibodies that enhance the clearance of the bacteria by the host's immune system.

Other names

O2 lipopolysaccharideO2-polysaccharideE. coli O2 LPSO2-specific side chain

Induction of serotype-specific opsonophagocytic antibodies that facilitate the clearance of bacteria by immune cells.