RESUMO
Antigen extracts obtained by sonication of 22 strains of Mycobacterium bovis from cattle and badgers together with extracts of strains of M. tuberculosis, M. paratuberculosis, M. avium, M. africanum, M. kansasi, M. leprae and BCG were examined with a panel of 10 monoclonal antibodies to M. tuberculosis or M. leprae. Antigen extracts were coated in aqueous solution (wet coating) and the extracts were also dried on to the polyvinyl plates (dry coating). When dry coating was compared to wet coating, there was a major increase in the binding of monoclonal antibody ML03 to M. avium and M. paratuberculosis, monoclonal antibody ML02 to M. paratuberculosis, and monoclonal antibodies TB71 and TB72 to the majority of M. bovis isolates. The study confirmed that on wet-coated plates, monoclonal antibodies TB71 and TB72 bind poorly or not at all to M. bovis and that monoclonal antibodies TB68, TB78, TB77 and TB23 each bind to field strains of M. bovis while TB23 binds poorly to BCG in wet-coating conditions. Antibodies TB72 and TB71, originally thought to be specific for M. tuberculosis, each reacted with M. africanum. Antibody TB78 bound to M. paratuberculosis but did not react with M. avium, and M. avium and M. paratuberculosis were distinguished from M. bovis and M. tuberculosis by the binding of antibody ML03 to dry-coated plates. When wet-coated plates were used, ML03 bound strongly only to M. leprae. The panel of monoclonal antibodies did not demonstrate distinct serotype differences between the field isolates of M. bovis.