Pulmonary Mycobacteriosis:  Report of Seven Cases

Although the existence of acid-fast mycobacteria other than tubercle bacilli has long been known, the clinical significance was not important in the days of nonspecific therapy for tuberculosis. However, with the development of specific antituberculosis chemotherapeutic agents and with an appreciation of the significance of drug resistance in the mycobacteria, it is increasingly apparent that unclassified organisms have gradually become important as etiologic agents of disease. As bacteriologic techniques were developed to distinguish more closely the acid-fast mycobacteria from each other and to evaluate drug resistance in the various groups, a startling fact became apparent. It was soon discovered that these unclassified acid-fast mycobacteria which in the prechemotherapy years had been classified as harmless saprophytes were in fact pathogenic. Today there is no doubt that there are acid-fast mycobacteria which can be distinguished from Mycobacterium tuberculosis by standard bacteriologic techniques and which produce a disease in the lungs and elsewhere