Salmonella Enteritidis O-polysaccharide (SE O-PS)

Salmonella Enteritidis O-polysaccharide is the distal, surface-exposed component of the lipopolysaccharide (LPS) found on the outer membrane of Salmonella enterica serovar Enteritidis. This polysaccharide consists of repeating oligosaccharide units—typically comprising tyvelose, mannose, rhamnose, and galactose—which define the O9 antigenic specificity of the Group D1 Salmonella serogroup (PubMed, PMID: 30213143). Biologically, the O-polysaccharide serves as a protective shield against the host's innate immune system, preventing complement-mediated killing and resisting phagocytosis (NCBI, Bookshelf NBK8435). In clinical medicine, it is a major target for vaccine development, particularly in the form of glycoconjugates where the polysaccharide is linked to a carrier protein to enhance immunogenicity in infants and young children (PubMed, PMID: 28433455). Antibodies directed against this target facilitate the clearance of the bacteria through opsonization and bactericidal activity. Consequently, it is a focal point for both diagnostic serotyping and the development of preventive strategies against salmonellosis and enteric fever (WHO, Salmonella Fact Sheet).

Other names

Salmonella Enteritidis O-antigenSalmonella Group D1 O-antigenLipopolysaccharide O-side chainO-specific polysaccharide

Induction of protective humoral immunity, specifically the production of opsonophagocytic and bactericidal antibodies that target the bacterial surface for destruction by the immune system.