Enhancement activity of anti-brucella sera in experimental Brucella abortus infection in mice

The passive transfer of rabbit anti-brucella sera promotes the multiplication of Brucella abortus in the spleen of mice infected intravenously with a low dose of this bacteria. The enhancement activity of the anti-brucella sera is related to their modes of preparation in rabbits. The agglutinin titers of all these antisera were relatively high, while there was some discrepancies in their content in haemagglutinating, immune adherence and complement fixing antibodies.