The recombinant Omp31 from Brucella melitensis alone or associated with rough lipopolysaccharide induces protection against Brucella ovis infection in BALB/c mice

Microbes Infect. 2003 Feb;5(2):85-93. doi: 10.1016/s1286-4579(02)00075-8.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Bacterial / blood
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / immunology*
  • Bacterial Vaccines / administration & dosage
  • Bacterial Vaccines / immunology*
  • Brucella / immunology*
  • Brucella / metabolism
  • Brucella / pathogenicity
  • Brucella melitensis / genetics
  • Brucella melitensis / immunology*
  • Brucella melitensis / metabolism
  • Brucellosis / prevention & control*
  • Female
  • Immunization
  • Lipopolysaccharides / immunology*
  • Mice
  • Mice, Inbred BALB C
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Sheep
  • Spleen / microbiology


  • Antibodies, Bacterial
  • Bacterial Outer Membrane Proteins
  • Bacterial Vaccines
  • Lipopolysaccharides
  • Omp31 protein, Brucella melitensis
  • Recombinant Proteins