O-antigen polysaccharide of Salmonella typhimurium lipopolysaccharide (O-antigen)

The O-antigen polysaccharide is the outermost, highly variable component of the lipopolysaccharide (LPS) complex located on the surface of Salmonella enterica serovar Typhimurium. It consists of repeating oligosaccharide units—typically comprising D-galactose, L-rhamnose, and D-mannose with an abequose side chain—that determine the bacterium's O-serogroup identity (Raetz & Whitfield, 2002). Biologically, the O-antigen serves as a critical virulence factor by protecting the pathogen from host innate immune defenses, such as complement-mediated lysis and phagocytosis, and by providing resistance to environmental stressors like bile (Hajra et al., 2021). In the context of drug development, the O-antigen is a primary target for glycoconjugate vaccines and therapeutic monoclonal antibodies designed to combat non-typhoidal Salmonella (NTS) infections (Micoli et al., 2018). These therapeutic strategies aim to elicit high-affinity antibodies that promote opsonophagocytosis and bacterial killing. However, the structural diversity of O-antigens across different serovars remains a significant challenge for creating broad-spectrum protective interventions (MacLennan et al., 2014).

Other names

O-polysaccharideO-side chainSomatic O-antigenLPS O-antigenSalmonella Typhimurium O-antigen

Induction of opsonophagocytic and bactericidal antibodies that facilitate bacterial clearance by the immune system; neutralization of bacterial attachment and colonization.