Salmonella enterica lipopolysaccharide (LPS)

Salmonella enterica lipopolysaccharide (LPS) is a complex glycolipid that constitutes the major component of the outer leaflet of the bacterial outer membrane. It is composed of three distinct regions: the hydrophobic lipid A, which anchors the molecule and serves as a potent endotoxin; a core oligosaccharide; and the O-antigen, a repetitive glycan polymer that extends from the cell surface and determines serological specificity. LPS is essential for bacterial viability, providing a robust physical barrier against host defenses such as bile salts and certain antimicrobial agents. It plays a pivotal role in pathogenesis by facilitating immune evasion through the inhibition of phagocytosis and complement activation, while simultaneously acting as a primary pathogen-associated molecular pattern (PAMP) that triggers systemic inflammation via the TLR4 pathway. In therapeutic contexts, LPS is the primary target for polymyxin antibiotics, which bind to the negatively charged lipid A to disrupt membrane stability. Additionally, the O-antigen is a critical target for diagnostic serotyping and the development of conjugate vaccines against typhoid and non-typhoidal salmonellosis.

Other names

EndotoxinO-antigenSomatic antigenLipid AO-polysaccharideSalmonella LPS

Membrane disruption via binding to negatively charged Lipid A (polymyxins); Neutralization of bacterial surface antigens (antibodies); Activation of innate immune signaling (TLR4 agonism); Opsonization and complement activation (MBL and antibodies).