Production and characterization of a monoclonal badger anti-immunoglobulin G and its use in defining the specificity of Mycobacterium bovis infection in badgers by western blot.

A mouse monoclonal anti-badger IgG antibody was produced to investigate the specificity of the antibody response of badgers infected with Mycobacterium bovis. The monoclonal antibody generated was directed against badger IgG heavy chain and appeared to be species restricted, reacting only with badger and dog IgGs but not cat, rabbit, mouse, guinea pig, bovine or ferret IgGs. This monoclonal antibody detection system functioned well in both ELISA and Western blot analyses and was successfully used to investigate the humoral response of the badger to M. bovis infection. Sera from infected badgers detected a 25 kDa antigen which was not detected by sera from M. bovis culture-negative animals. This antigen was conserved in all field strains of M. bovis tested and seroconversion to it was detected during experimental infection. The immunodominance of this antigen in the badger during infection with M. bovis suggests that this 25 kDa polypeptide is a suitable candidate on which to base an antibody detection test for M. bovis infection.