Lipo-oligosaccharide profiles of Serpulina pilosicoli strains and their serological cross-reactivities

The purpose of this study was to determine the presence of lipopolysacchari de-like material in the intestinal spirochaete Serpulina pilosicoli and the extent of antigenic cross-reactivity of this material in different strains of the species. Hot water-phenol, aqueous-phase extracts from five porcine and three human strains of S, pilosicoli, and from seven strains of four o ther Serpulina spp,, were separated by SDS-PAGE and silver-stained profiles were obtained. All S, pilosicoli strains had a predominant band at c, 16 k Da, Some also had a partial ladder-like profile, consistent with the presen ce of semi-rough lipo-oligosaccharide (LOS); this was more obvious in Weste rn immunoblot analysis. LOS from each S, pilosicoli strain was serologicall y distinct in immunoblot analysis and there was no cross-reactivity with ot her Serpulina spp, The serological diversity found amongst the LOS of S, pi losicoli strains may help to explain why individual people and animals can suffer repeated infections with different strains of the organism.