ANTIGENIC POLYMORPHISM OF THE LIPOPOLYSACCHARIDES FROM HUMAN AND ANIMAL ISOLATES OF BORDETELLA-BRONCHISEPTICA

Six monoclonal antibodies (mAbs) against lipopolysaccharides (LPS) fro m Bordetella pertussis (P1P3, 60.5), B. parapertussis (PPZ, PP6, PP8) and B. bronchiseptica (BRg1) were used to examine the presence of anti genic determinants of LPS on B. bronchiseptica cells. Forty-eight clin ical isolates of this Cram-negative bacterium (4 canine, 3 equine, 6 p orcine, 4 rabbit and 31 human) were examined. Significant cross-reacti vities with the heterologous anti-pertussis and anti-parapertussis mAb s were observed. The isolates also exhibited marked antigenic polymorp hism. The 48 isolates could be classified in six immunogroups. Purifie d LPS preparations extracted from some isolates were analysed by ELISA , thin-layer chromatography, and tricine-SDS-PAGE. The results show th at four main types of antigenic polymorphism of B. bronchiseptica LPSs exist: (a) heterogeneity of the care, (b) presence or absence of O-ch ains, (c) differences in the hinge region between O-chain and core, an d (d) differences in interactions of LPS with other cell-surface const ituents. Smooth-type LPS molecules, detectable with mAb PP6, were more frequently observed in animal isolates (94%) than in human isolates ( 52 %). Reverse frequencies were found with mAb 60.5 (48 % of human iso lates, 18 % of animal isolates), which is unable to react with long-ch ain LPSs. This observation could be due to the general absence of some lectin-like receptor, specific to the O-chain, on human bronchoalveol ar tissues.