Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum (MAIS) organisms were isolated and identified from waters, soils, aerosols, and droplets ejected from water collected from four geographically separate aquatic environments (Okefenokee Swamp, GA; Dismal Swamp, VA; Claytor Lake, VA; and Cranberry Glades, WV) during several seasons. Recovery of MAIS was significantly higher from waters, soils, and aerosols collected from the two acid, brown-water swamps located in the southeastern coastal plain. High MAIS numbers correlated with warmer temperature, low pH, low dissolved oxygen, high soluble zinc, high humic acid, and high fulvic acid. This research, in relation to previous findings for the geographic distribution and physiologic ecology of MAIS, supports the conclusion that waters, soils, and aerosols of the acid, brown-water swamps of the southeastern United States coastal plain represent major environmental sources likely connected with the higher incidence of human infection in this region.

Mycobacterium avium, an environmental, opportunistic pathogenic mycobacterium, has been isolated frequently and in high numbers from waters in Finland and from acid, brown water swamps of the southeastern coastal USA. M. avium has also been recovered in high numbers from Finnish drinking water and frequently isolated from Finnish AIDS patients. Boreal forests and brown water swamps are similar in that they are rich in humic and fulvic acids and of low pH and dissolved oxygen. Growth of representative isolates of M. avium in natural water was stimulated markedly by the addition of humic and fulvic acids. Further, the M. avium isolates grew at pH levels as low at 4.0 and at oxygen levels equal to 4% of atmospheric levels. The high numbers of M. avium in boreal waters and brown water swamps are likely due to their ability to proliferate in those humic- and fulvic-rich, acidic, micro-aerobic environments.

Mycobacterium avium, an environmental, opportunistic pathogenic mycobacterium, has been isolated frequently and in high numbers from waters in Finland and from acid, brown water swamps of the southeastern coastal USA. M. avium has also been recovered in high numbers from Finnish drinking water and frequently isolated from Finnish AIDS patients. Boreal forests and brown water swamps are similar in that they are rich in humic and fulvic acids and of low pH and dissolved oxygen. Growth of representative isolates of M. avium in natural water was stimulated markedly by the addition of humic and fulvic acids. Further, the M. avium isolates grew at pH levels as low at 4.0 and at oxygen levels equal to 4% of atmospheric levels. The high numbers of M. avium in boreal waters and brown water swamps are likely due to their ability to proliferate in those humic-and fulvic-rich, acidic, micro-aerobic environments. ß