The specificity of the fluorescent antibody test using the sera of rabbits inoculated with strains of myocobacteria.

Sera from experimentally infected rabbits were used to test the specificity of the fluorescent antibody test. It was possible using mono-specific sera to differentiate antigenically Mycobacterium phlei, M fortuitum, M smegmatis, M avium, M intracellulare, M bovis (BCG) and M johnei. The cross-reactivity within the M avium and M intracellulare group was such that one antigen from these groups would detect infection within that group and exclude M johnei infection. The M phlei growth factor independent strain M johnei 316F was shown to be antigenically distinct from a M phlei dependent strain 9N96. There was loss of specificity when M avium infection was superimposed on a previous M johnei infection and when M johnei infection was superimposed on M avium infection.