Escherichia coli O25b lipopolysaccharide (O25b LPS)

Escherichia coli O25b lipopolysaccharide (LPS) is a major surface glycolipid and primary virulence factor of the ST131-O25b:H4 lineage, a globally dominant multidrug-resistant clone responsible for severe extraintestinal infections (Nicolas-Chanoine et al., 2014, Clinical Microbiology Reviews). The LPS molecule is composed of a conserved lipid A moiety, a core oligosaccharide, and a variable O-antigen polysaccharide, which in this case is the O25b serotype (Poolman & Wacker, 2015, Journal of Infectious Diseases). This O-antigen serves as a protective shield against the host's innate immune system, specifically preventing complement-mediated lysis and phagocytosis. Because of its surface exposure and high prevalence in antibiotic-resistant uropathogenic E. coli (UPEC), the O25b LPS is a high-priority target for the development of glycoconjugate vaccines like ExPEC9V and monoclonal antibodies such as JNJ-63871860 (Frenck et al., 2019, The Lancet Infectious Diseases). These therapeutic interventions aim to facilitate opsonophagocytic killing of the bacteria, providing a narrow-spectrum, resistance-proof approach to treating and preventing urosepsis and other invasive ExPEC diseases (Guachalla et al., 2017, Antimicrobial Agents and Chemotherapy).

Other names

O25b antigenO25b O-antigenST131-O25b LPSEscherichia coli O25b:H4 lipopolysaccharideE. coli O25b endotoxin

Induction of opsonophagocytic killing (OPK) and neutralization of bacterial virulence by targeting the O-specific polysaccharide chain of the lipopolysaccharide.