Structural variability and originality of the Bordetella endotoxins

Structural studies of Bordetella endotoxins (LPSs) have revealed remarkable differences: (i) between their LPSs and those of other bacterial pathogens ; (ii) among the LPSs of the seven identified Bordetella species; and (iii) among the LPSs of some Bordetella strains. The lipid As have the 'classica l' bisphosphorylated diglucosamine backbone but tend to have fewer and spec ies-specific fatty acid components compared to those of other genera. Never theless, three strains of B. bronchiseptica have at least three different f atty acid distributions; however, the recently identified B. hinzii and B. trematum LPSs had identical lipid A structures. The B. pertussis core is a dodecasaccharide multi-branched structure bearing amino and carboxylic grou ps. Another unusual feature is the presence of free amino sugars in the cen tral core region and a complex distal trisaccharide unit containing five am ino groups of which four are acetylated and one is methylated. The B. pertu ssis LPS does not have O-chains and that of B. trematum had only a single O -unit, unlike the LPSs of all the other species of the smooth-type. The O-c hain-free cores of non-B. pertussis LPSs were always built on the B. pertus sis core model but most were species-specifically incomplete. The LPS struc tures of three B. bronchiseptica strains were found to be different from ea ch other. The O-chains of B. bronchiseptica and B, parapertussis were almos t identical and had some features in common with B. hinzii O-chain. Serolog ical analyses are consistent with the determined LPS structures.