Abstract: Chimeric polypeptides useful as immunogens for inducing protective immune responses and neutralizing antibodies against Shiga toxin (Stx) in mammals. More specifically, chimeric polypeptides having a monomer of the homopentameric B subunit of the Shiga 2 toxin fused to the N-terminus of a monomer of Brucella lumazine synthase, and to oligomeric protein complexes formed from said chimeric polypeptides. Polynucleotides and vectors encoding said chimeric polypeptides, transgenic cells having said polynucleotides and vectors, pharmaceutical compositions, such as a vaccine, having said chimeric polypeptides and chimeric polynucleotides, antibodies which bind to the chimeric polypeptides, a method for obtaining antibodies which bind specifically to the subunit B of the Shiga 2 toxin and methods of lowering the bacterial load of enterohemorrhagic Escherichia coli in mammals, which can be used for prevention of inter alia, hemolytic-ureic syndrome (HUS), are also provided.

Abstract: Chimeric polypeptides useful as immunogens for inducing protective immune responses and neutralizing antibodies against Shiga toxin (Stx) in mammals. More specifically, chimeric polypeptides having a monomer of the homopentameric B subunit of the Shiga 2 toxin fused to the N-terminus of a monomer of Brucella lumazine synthase, and to oligomeric protein complexes formed from said chimeric polypeptides. Polynucleotides and vectors encoding said chimeric polypeptides, transgenic cells having said polynucleotides and vectors, pharmaceutical compositions, such as a vaccine, having said chimeric polypeptides and chimeric polynucleotides, antibodies which bind to the chimeric polypeptides, a method for obtaining antibodies which bind specifically to the subunit B of the Shiga 2 toxin and methods of lowering the bacterial load of enterohemorrhagic Escherichia coli in mammals, which can be used for prevention of inter cilia, hemolytic-ureic syndrome (HUS), are also provided.

Abstract: Isolated chimeric proteins including up to ten copies of peptides, polypeptides or protein domains inserted in the amino termini of the Brucella spp. Lumazine synthase enzyme. Isolated nucleotide sequences codifying the chimeric proteins. Vectors, plasmids and transformed cells used for expressing the proteins. Monoclonal and polyclonal antibodies induced by the chimeric proteins. Hybridomas producing the monoclonal antibodies. Vaccines and pharmaceutical compounds including the chimeric proteins, nucleotide sequences and antibodies. A method to induce an immune response in higher organisms including the administration of effective amounts of the vaccines and pharmaceutical compounds. Biosensors including the chimeric proteins. Protein conjugates formed by the chimeric proteins and a ligand bound by means of covalent and noncovalent bonds.