Salmonella enterica serovar Typhimurium and Enteritidis outer membrane and O-antigen epitopes (S. Typhimurium/Enteritidis O-antigen/OMP)

Salmonella enterica serovar Typhimurium and Enteritidis outer membrane and O-antigen epitopes are primary targets for the development of vaccines and therapeutics against non-typhoidal Salmonella (NTS). The O-antigen is a repetitive glycan polymer found on the surface lipopolysaccharide (LPS) that determines the serovar identity; S. Typhimurium typically expresses O-antigens 1, 4, [5], and 12, while S. Enteritidis expresses 1, 9, and 12 (PubMed: 26251142). These surface structures are critical for bacterial survival within the host, providing protection against complement-mediated killing and facilitating environmental fitness (PubMed: 25135637). In the context of disease, these epitopes are the focus of bivalent glycoconjugate vaccines designed to prevent invasive non-typhoidal Salmonella (iNTS) disease, which causes significant mortality in sub-Saharan Africa and among immunocompromised individuals (NIH: PMC5576495). Therapeutic strategies involve inducing high titers of bactericidal antibodies that target these specific epitopes to neutralize the pathogen and promote its clearance by the immune system. Additionally, outer membrane proteins (OMPs) such as OmpA and OmpC are explored as conserved protein targets to provide broader protection across different Salmonella strains (PubMed: 23935143).

Other names

Salmonella O-antigenSalmonella lipopolysaccharide (LPS)Salmonella outer membrane proteins (OMPs)iNTS antigensSalmonella surface antigens

Induction of protective humoral immunity through the production of O-antigen-specific IgG antibodies that facilitate serum bactericidal activity and opsonophagocytosis. Vaccines often utilize glycoconjugation (linking O-antigen to a carrier protein like CRM197) to induce T-cell dependent immune responses and long-term memory.