Examination of Bottled Water for Nontuberculous Mycobacteria

The objective of this study was to examine bottled water for the presence of nontuberculous mycobacteria as a potential source of infection in AIDS patients. Twenty brands of bottled water commonly used in the Los Angeles area were tested for the presence of nontuberculous mycobacteria. The three brands most commonly used in the Los Angeles area were tested most frequently. Sixty-nine samples were filtered and the filters were treated using cetylpyridinium chloride, sodium hydroxide, or oxalic acid (or a combination of these) as decontaminants to remove background flora. An aliquot of each sample was untreated. The filters were placed on selective Middlebrook 7H10 agar plates containing 500 μg of cycloheximide per ml. Plates were examined at 3 and 8 weeks. No acid-fast organisms were found. Although no nontuberculous mycobacteria were observed in any samples tested, before recommending the use of bottled water as an alternative to tap water by high-risk patients, the possible presence of other contaminants must be considered.