title: Epitope mapping of the Brucella melitensis BP26 immunogenic protein: usefulness for diagnosis of sheep brucellosis.
abstract: Sequencing of bp26, the gene encoding the Brucella sp. immunogenic BP26 periplasmic protein, was performed in the reference strains of Brucella abortus, B. suis, and B. ovis. The three bp26 sequences were almost identical to that published for B. melitensis 16M bp26, and only minor nucleotide substitutions, without modifying the amino acid sequence, were observed between species. The bp26 genes of the seven B. abortus biovar reference strains and B. abortus S19 and RB51 vaccine strains were also sequenced. Again, only minor differences were found. Surprisingly, the bp26 nucleotide sequence for B. abortus S19 was almost identical to that found for B. melitensis 16M and differed from the sequence described previously by others (O. L. Rossetti, A. I. Arese, M. L. Boschiroli, and S. L. Cravero, J. Clin. Microbiol. 34:165-169, 1996) for the same B. abortus strain. The epitope mapping of BP26, performed by using a panel of monoclonal antibodies and recombinant DNA techniques, allowed the identification of an immunodominant region of the protein interesting for the diagnosis of B. melitensis and B. ovis infection in sheep. A recombinant fusion protein containing this region of BP26 reacted indeed, in Western blotting, as the entire recombinant BP26 against sera from B. melitensis- or B. ovis-infected sheep while it avoided false-positive reactions observed with sera from Brucella-free sheep when using the entire recombinant BP26. Thus, use of this recombinant fusion protein instead the entire recombinant BP26 could improve the specific serological diagnosis of B. melitensis or B. ovis infection in sheep.
authors.affiliation: Departamento de Microbiología y Genética, Universidad de Salamanca, 37007 Salamanca, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Seco-Mediavilla
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Verger
authors.forename: Maggy
authors.initials: M
authors.lastname: Grayon
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
authors.forename: Clara M
authors.initials: CM
authors.lastname: Marín
authors.forename: Michel S
authors.initials: MS
authors.lastname: Zygmunt
authors.forename: Luis
authors.initials: L
authors.lastname: Fernández-Lago
authors.forename: Nieves
authors.initials: N
authors.lastname: Vizcaíno
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D017347:Brucella melitensis / Q000235:genetics / Q000276:immunology*; D042061:Brucella ovis / Q000276:immunology; D041021:Brucella suis / Q000276:immunology; D002006:Brucellosis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D018604:Epitope Mapping; D005798:Genes, Bacterial; D016056:Immunodominant Epitopes / Q000235:genetics / Q000276:immunology*; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000276:immunology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D012757:Sheep Diseases / Q000175:diagnosis* / Q000382:microbiology; D013045:Species Specificity
chemical_list: D000942:Antigens, Bacterial; C106040:BP26 protein, Brucella; D001426:Bacterial Proteins; D016056:Immunodominant Epitopes; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins