Salmonella Typhimurium O-polysaccharide (O-PS) (O-PS)

Salmonella Typhimurium O-polysaccharide is the highly immunogenic, outermost component of the lipopolysaccharide (LPS) found on the cell 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 O-antigenic specificity (serogroup B) of the bacterium (Micoli et al., 2018). Biologically, this polysaccharide acts as a protective shield against the host's innate immune system, specifically preventing the membrane attack complex of the complement system from reaching the bacterial outer membrane (MacLennan et al., 2014). It also serves as a receptor for various bacteriophages and plays a role in biofilm formation and environmental survival. In clinical medicine, the O-polysaccharide is a major target for vaccine development, particularly glycoconjugate vaccines where the polysaccharide is chemically linked to a carrier protein to enhance T-cell dependent immune responses (Baliban et al., 2017). Therapeutic strategies focusing on this target aim to elicit bactericidal antibodies that promote opsonophagocytosis and neutralize the pathogen during infection (Rondini et al., 2013). Challenges in targeting this molecule include its high structural diversity across different serovars and the necessity of removing the toxic Lipid A component during the manufacturing of polysaccharide-based therapeutics (Micoli et al., 2018).

Other names

Salmonella Typhimurium O-antigenSalmonella enterica serovar Typhimurium O-antigenGroup B O-antigenLPS O-side chain

Induction of opsonophagocytic and bactericidal antibodies