Lipopolysaccharide from Shigella flexneri serotype-specific strain (LPS from S. flexneri (serotype X, 2a, etc., if specified))

Lipopolysaccharide from *Shigella flexneri* is a complex glycolipid located in the outer membrane of this Gram-negative bacterium. LPS consists of three main domains: lipid A (the toxic component), a core oligosaccharide, and a highly variable O-antigen polysaccharide responsible for serotype specificity. The O-antigen undergoes various modifications—such as glucosylation, O-acetylation, and phosphoethanolamine addition—which create different serotypes and enable immune evasion. LPS protects *S. flexneri* from acid stress, bile salts, and antibiotics, and plays a key role in pathogenesis and the host immune response. Although LPS is central to infection and immunity, it is not a classical therapeutic target (e.g. receptor or enzyme); instead, it represents a molecular signature used for bacterial serotyping and epidemiological tracking, and is considered in vaccine development as an immunodominant antigen.

Other names

S. flexneri LPSShigella flexneri lipopolysaccharideS. flexneri O-antigen (when focusing on the serotype-specific component)

Disruption of bacterial outer membrane integrity (e.g., polymyxin mechanism) Neutralization of endotoxin effect (e.g., LPS-binding peptides for sepsis; not serotype-specific)