MYCOBACTERIUM-AVIUM COMPLEX IN WATER, FOOD, AND SOIL SAMPLES COLLECTED FROM THE ENVIRONMENT OF HIV-INFECTED INDIVIDUALS

As part of an epidemiologic study of Mycobacterium avium complex (MAC) infection in San Francisco, water, food and soil samples were collect ed from the home environment of 290 persons with human immunodeficienc y virus (HIV) infection and cultured for mycobacteria. Isolates recove red from the environment were compared with isolates cultured from stu dy patients. Although mycobacteria were recovered from numerous enviro nmental samples, isolates reactive with MAC-specific DNA probes were r ecovered from only four of 528 (0.76%) water samples and one of 397 (0 .25%) food samples. The species M. avium was recovered from one water (0.19%) and one food sample. In contrast, MAC was recovered from 55% a nd M. avium from 27% of soil samples taken from potted plants in patie nts' home, Speciation of 76 MAC isolates from study patients showed al l isolates belonged to the species M. avium. With use of serotype and multilocus enzyme electrophoresis analysis, some of the soil isolates were found to be similar to isolates recovered from study patients. Th e results of this study suggest that soil, rather than water, may be a significant reservoir of organisms causing MAC infection in San Franc isco.