Water and nontuberculous mycobacteria

The atypical mycobacteria or nontuberculous mycobacteria differ from tuberc ulous mycobacteria (M. tuberculosis, M. bovis, M. africanum) because most o f them are ubiquitous and saprophytic. A few are considered potential human pathogens: M. avium, M. intracellulare, M. chelonae, M. kansasii, M. marin um, M. fortuituma and M. ulcerans. The immunological status of a person det ermines the advance of disease. disseminated or localizated (lung disease, lymphadenitis. skin or soft tissue involve ment). Over the last decades the incidence of mycobacteriosis has increased in account of Sida. M. avium-M. intracellulare complex (MAC) are predominant species. In contrast to M. tu berculosis per son-to-person transmission does not occur with nontuberculou s mycobacteria. These bacteria are ubiquitous and may be found in the envir onment especially in water. It is difficult to isolate mycobacteria from na ture thus published results certainly under estimate reality. Several studi es indicated that the fluctuation in the occurrence of environmental mycoba cteria was in relation to chemical and physical characteristics of the wate r: pH. ions concentration, temperature, organic matter. Among water species, scotochromogen M. gordonae or M. flavescens are the mo st common. Rapidly growing species M. fortuitum or M. chelonae are also com mon water contaminants. On account of their resistance to decontaminating a gents they cause abscesses or postsurgical infections. M. marinum, isolated from aquariums or swimming pools, is the agent of inflammatory cutaneous n odules. M. kansasii, M. xenopi are especially found in drinking water distr ibution, they are responsible for pulmonary diseases. The majority of human mycobacteriosis are due to species of the complex MAC which are isolated m ore frequently in warm water. Epidemiologic studies suggest that natural or drinking water are the principal source of human contamination. Recently r esults obtained using molecular biology techniques as pulsed field gel elec trophoresis demonstrated a relation beta een environmental and human specie s. The eradication of nontuberculous in water is not possible so preventive measure could be a good strategy to limit mycobacteria. (C) 1999 Elsevier Science Ltd. All rights reserved.