Salmonella Paratyphi A lipopolysaccharide (LPS (used generically; rarely abbreviated specifically for Paratyphi A))

Salmonella Paratyphi A lipopolysaccharide is a tripartite glycolipid structure embedded in the bacterial outer membrane, composed of lipid A, a nonrepeating oligosaccharide core, and a polymeric O-antigen polysaccharide (O2 antigen in Paratyphi A)[1][3][5][7]. LPS serves as a physical and immunological barrier, protecting bacteria from complement-mediated killing, opsonophagocytosis, and detergent or antibiotic assault[1][3]. The O-antigen component is both serotype-specific and highly variable in length, and is critical for immune recognition and pathogenicity[1][7]. LPS is a major target for host immune responses (notably via TLR4 signaling), diagnostic serotyping, and vaccine development for paratyphoid fever (caused by Salmonella Paratyphi A)[3][4][7]. Variations in the O-antigen structure influence serum resistance, complement evasion, and the overall virulence of Salmonella[1][3][7]. LPS is not currently directly targeted by small molecules in therapy, but is relevant in developing biologics and vaccines[3][4][7].

Other names

Paratyphi A LPSSalmonella enterica Paratyphi A LPSO-antigenO-polysaccharideOPSsurface polysaccharide

For antibodies or vaccines: neutralization, opsonization, and promotion of immune clearance; for innate immune sensors: induction of cytokine response via pattern recognition