Salmonella Enteritidis lipopolysaccharide O-antigen (LPS O-antigen (sometimes abbreviated as O-Ag); no unique, widely accepted abbreviation specific to Salmonella Enteritidis found)

The Salmonella Enteritidis lipopolysaccharide O-antigen is the highly variable, distal polysaccharide segment of the LPS molecule found on the outer membrane of Salmonella Enteritidis. It consists of repeating oligosaccharide units (typically four sugars in Salmonella Enteritidis: rhamnose, mannose, galactose, and tyvelose), which confer strain-specific antigenicity and allow differentiation between serovars. The O-antigen protects the bacterium from host immune defenses, particularly the complement system, and supports virulence by enabling bacterial survival, colonization, airbags resistance to environmental stresses. Its variable structure underlies most of the antigenic diversity among Salmonella strains, making it a critical target for diagnostics, serotyping, and the development of vaccines and immunotherapies. Structural and compositional variation in the O-antigen is a major therapeutic and research challenge, as it impacts both host-pathogen interactions and the design of broad-spectrum interventions.

Other names

O-antigenO-polysaccharideO-specific polysaccharide (O-Ag)LPS O-antigenSalmonella Enteritidis O-antigen

Antibody-mediated neutralization and opsonization (for vaccines and immunotherapies); Potential phage attachment (some bacteriophages recognize O-antigen as binding targets); Inhibition of biosynthetic enzymes (preclinical models for antibiotics disrupting LPS assembly)