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MYCOBACTERIUM AVIUM AND DRINKING WATER WHAT ARE THE CONNECTIONS?
HILBORN, E. D., M. A. YAKRUS, T. C. COVERT, S. HARRIS, S. F. DONNELY, E. W. RICE, M. T. SCHMITT, S. TONEY, S. BAILEY, AND G. N. STELMA. MYCOBACTERIUM AVIUM AND DRINKING WATER WHAT ARE THE CONNECTIONS? Presented at American Society for Microbiology General Meeting, Toronto, ON, CANADA, May 01 - 02, 2007.
Background: Human Mycobacterium avium infections are only known to be acquired from environmental sources such as water and soil. We compared M. avium isolates from clinical and drinking water sources using molecular tools. Methods: M. avium was isolated from water samples collected from a municipal drinking water system. Clinical isolates of nontuberculous mycobacteria (NTM) derived from patients with residential zip codes in the county served by the drinking water system were collected during 1999 - 2002. Clinical M. avium isolates were compared among themselves and to drinking water isolates using multilocus enzyme electrophoresis (MEE) as a screening tool. Isolates with similar MEE patterns were then compared using pulsed-field gel electrophoresis (PFGE). Results: Thirty M. avium isolates from four drinking water sample sites and 74 clinical isolates derived from persons living within zip codes served by the drinking water utility were compared. Four clinical isolates were potentially related by PFGE to environmental isolates. However, only one of these clinical isolates was indistinguishable from a drinking water isolate and was collected from a patient whose residential zip code was adjacent to the drinking water sample site. Five PFGE groups were identified among 15 clinical isolates. Isolates within these PFGE groups were collected over a 2 ¿ 41 month period. Conclusion: Given the genetic heterogeneity of M. avium, our results suggest that we were able to identify a clinical infection associated with a drinking water exposure. The discovery of five PFGE groups of clinical isolates collected over a period of months, suggests either persistence of a common source of exposure or delayed detection of infection among patients exposed to a transitory common source of exposure. Molecular techniques are useful to identify specific environmental sources of human M. avium infections and clusters of infections. These methods are most efficient when used to identify sources of exposure after cases of human infection have been detected. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.