Structural and antigenic properties of Campylobacter coli lipopolysaccharide

Abstract

Lipopolysaccharides (LPSs) from O-serotype reference strains and from serotyped isolates of Campylobacter coli were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in combination with silver staining and immunoblotting to elucidate the molecular basis for the thermostable antigenic diversity in C. coli. Electrophoresed low-M(r) LPS was detectable by silver staining and immunoblotting, but high-M(r) LPS was demonstrated only by immunoblotting. Eight different antigenic specificities of low-M(r) LPS were defined among the 18 serotype reference strains. In some cases, the LPSs from serotype reference strains and from field isolates of the same serotype had virtually identical low-M(r) and high-M(r) molecules. In other cases, the high-M(r) molecules of the LPS were virtually the same for both the isolates and the corresponding serotype reference strains but low-M(r) LPS of the isolate differed in both its antigenicity and its structure. The antigenic specificities of high-M(r) LPS but not low-M(r) LPS are the serotypic markers of the species that are identified when serotyping is performed by passive hemagglutination.