Salmonella Typhimurium lipopolysaccharide O:4 O-antigen polysaccharide (STM O-antigen)

Salmonella Typhimurium lipopolysaccharide O:4 O-antigen polysaccharide is a complex carbohydrate structure located on the outermost surface of Salmonella enterica serovar Typhimurium (Micoli et al., 2018, PMID: 29459739). As a major component of the bacterial cell envelope, it plays a vital role in protecting the bacterium from environmental stressors and host immune defenses, such as the complement system and phagocytosis (Murray et al., 2003, PMID: 12949092). The O:4 antigen specifically characterizes Serogroup B Salmonella, and its unique chemical structure, featuring an abequose side chain, is used for serological identification (Reeves et al., 1996, PMID: 8898647). It is a primary target for vaccine development, particularly in the form of glycoconjugates where the polysaccharide is linked to a carrier protein to enhance immunogenicity (MacLennan et al., 2014, PMID: 24535058). Antibodies directed against this O-antigen provide protective immunity by promoting opsonization and bacterial clearance, making it a focal point for preventing invasive non-typhoidal Salmonella (iNTS) infections (Tennant et al., 2016, PMID: 27161614).

Other names

Salmonella Group B O-antigenO4 antigenSalmonella Typhimurium O-polysaccharideLPS O-side chainO:4 factorSalmonella enterica serovar Typhimurium O-antigen

Induction of high-titer opsonophagocytic IgG antibodies that facilitate bacterial clearance by macrophages and neutrophils (Micoli et al., 2018, PMID: 29459739).