To the Editor.
—In the October Archives Greenberger and Katzenstein1 described an interesting case of Mycobacterium chelonei colonization in a patient's bronchi. I would like to make an addition to this article concerning this Runyon group IV mycobacteria and its pharmacologic management.Runyon's group IV classification comprises the rapidly growing mycobacteria irrespective of their pigmentation. Although two separate species within this group, Mycobacterium fortuitum, Mycobacterium chelonei subspecies chelonei, and M chelonei subspecies abscessus are often identified in combination (M fortuitum-chelonei complex) due to production of similar clinical diseases, however, M chelonei is the more important pathogen. These organisms can be differentiated by taxonomic characteristics and are found widely distributed in water and soil, although the reservoir for human disease is unknown. The two strains of M chelonei are noted in the sputum of apparently healthy humans and infection usually occurs nosocomially or secondary to trauma. As far as can