—I thank Dr Holdiness for his interest and kind words concerning our brief review. Our review was not intended to be exhaustive, but was targeted towards mycobacteria most likely to be encountered by the practicing physician. Mycobacterium bovis (including the BCG strain) is frequently classified in the tuberculosis complex. We did not include M szulgai because of its low incidence. We also did not include Mycobacterium ulcerans for similar reasons. Dr Holdiness' comments concerning these mycobacteria are well taken. I would also like to emphasize that since the original submission of our manuscript, Mycobacterium avium-intracellulare has become an important pathogen in the treatment of patients with the acquired immune deficiency syndrome.