The seroagglutination test in the study of nontuberculous mycobacteria

The Schaefer seroagglutination test is useful in epidemiologic studies of nontuberculous mycobacteria, especially the Mycobacterium avium-intracellulare-scrofulaceum complex. Serovars 8, 16, 4, 19, 9, 42, and 1 were isolated most frequently from patients in the United States in the period 1976 to mid-1978. Several so-called double serovars were found serologically. It appears that this is an artifact due to cross-reacting antigens, because only one antigen is seen using chromatographic analyses. Further development of this system and its use in conjunction with other methods offer a valuable method for the study of nontuberculous mycobacteria.