title: The recombinant Omp31 from Brucella melitensis alone or associated with rough lipopolysaccharide induces protection against Brucella ovis infection in BALB/c mice.
abstract: Immunogenicity and protective activity against Brucella ovis of detergent-extracted recombinant Omp31 (rOmp31 extract) from Brucella melitensis produced in Escherichia coli, purified rough lipopolysaccharide from B. ovis (R-LPS) and a mixture of rOmp31 extract and R-LPS (rOmp31 extract + R-LPS) were assessed in BALB/c mice. The experimental vaccines were compared with a hot saline extract (HS extract) from B. ovis mainly composed of outer membrane proteins (OMPs) and R-LPS, and known to be protective in mice against a B. ovis infection. Serum antibodies to Omp31 and R-LPS were detected in the corresponding mice using Western blotting with B. ovis whole-cell lysates and ELISA with purified antigens. Protection was evaluated by comparing the levels of infection in the spleens of vaccinated mice challenged with B. ovis. A significantly lower number of B. ovis colony-forming units in spleens relative to unimmunized (saline injected) controls were considered as protection. Mice immunized with rOmp31 extract or rOmp31 extract mixed with R-LPS developed antibodies that bound to the B. ovis surface with similar titers. Vaccination with rOmp31 extract plus R-LPS provided the best protection level, which was comparable with that given by HS extract. Similar protection was also obtained with rOmp31 extract alone and, to a lesser degree, with R-LPS. Comparisons between groups showed that an extract from E. coli-pUC19 (devoid of Omp31) provided no protection relative to either HS extract, rOmp31 extract or rOmp31 extract mixed with R-LPS. In conclusion, the recombinant Omp31 associated or not with B. ovis R-LPS, could be an interesting candidate for a subcellular vaccine against B. ovis infection.
authors.affiliation: Laboratorio de Inmunoquímica y Biotecnología, Departamento de Sanidad Animal y Medicina Preventiva, Facultad de Ciencias Veterinarias, UNICEN, 7000 Tandil, Argentina.
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Estein
authors.forename: Juliana
authors.initials: J
authors.lastname: Cassataro
authors.forename: Nieves
authors.initials: N
authors.lastname: Vizcaíno
authors.forename: Michel S
authors.initials: MS
authors.lastname: Zygmunt
authors.forename: Axel
authors.initials: A
authors.lastname: Cloeckaert
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Bowden
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002002:Brucella / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D017347:Brucella melitensis / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D002006:Brucellosis / Q000517:prevention & control*; D005260:Female; D007114:Immunization; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D012756:Sheep; D013154:Spleen / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D008070:Lipopolysaccharides; C101108:Omp31 protein, Brucella melitensis; D011994:Recombinant Proteins