Structures of the O-specific polysaccharides and a serological cross-reactivity of the lipopolysaccharides of Proteus mirabilis O24 and O29

Strains of Proteus mirabilis belonging to serogroups O24 and O29 are freque nt in clinical specimens. Anti-P. mirabilis O24 serum cross-reacted with th e lipopolysaccharide (LPS) of P, mirabilis O29 and vice versa, The structur es of the O-specific polysaccharides (OPSs, O-antigens) of both LPSs were e stablished using sugar analysis and one- and two-dimensional H-1- and C-13- NMR spectroscopy and found to be different. SDS-PAGE and Western immunoblot ting suggested that the serological cross-reactivity of the LPSs is due to a common epitope(s) on the core-lipid A moiety, rather than on the OPS. The refore, the epitope specificity and the structures of the O-antigens studie d are unique among Proteus serogroups. (C) 1999 Federation of European Bioc hemical Societies.