[Studies of epitope specificity of polyclonal antibodies against Proteus mirabilis R mutants].

The chemical structure of the following P. mirabilis R mutants lipopolysaccharide (LPS) were already established: R110/1959 (Ra), R4/028 (Rc) and R45/1959 (Re). In this report we focus on P. mirabilis R5/O28, R13/1959 and R14/1959 and R14/1959. The last one corresponds to Salmonella transient forms, and synthesis truncated core oligosaccharide lacking terminal DD-Hep and nevertheless substituted by T polysaccharide whose structure occurred to be similar to P. penneri 42 O-repeating unit. The knowledge of chemical structure of P. mirabilis R mutants lipopolysaccharides led us to the study of the epitope specificity of rabbit polyclonal R specific antisera. The results show strong structural and serological relatedness of LPS from P. mirabilis R110 and R13. Antibodies against P. mirabilis R4 recognize in homologous LPS an epitope sharing oligosaccharide Glc-Hep. The serological studies revealed also close similarities of LPS from P. mirabilis R14 and P. mirabilis S1959, O28 as well as P. penneri 42. These data indicate that polyclonal antibodies against P. mirabilis R14 are directed against four epitopes: two in T-polysaccharide (D-Glc-(beta 1,4)-D-Glc and terminal GalA residue) and two in core oligosaccharide (D-Glc-(alfa 1,6)-D-Glc and terminal GlcNAc residue) of lipopolysaccharide molecule.