Hospital water filters as a source of Mycobacterium avium complex

Bronchoscopes and the filters used for washing them were found to yield high numbers of Mycobacterium avium isolates sharing the same repetitive sequence-based PCR (rep-PCR) fingerprint pattern as M. avium isolates recovered from patient samples collected by bronchoscopy. Water and biofilm samples collected from the bronchoscopy preparation laboratory yielded M. avium, Mycobacterium intracellulare, Mycobacterium malmoense and Mycobacterium gordonae. Several M. avium and M. intracellulare isolates from water samples in the bronchoscopy laboratory had rep-PCR patterns matching those of patient bronchoscopy isolates. Five of the 22 (23 %) M. avium patient bronchoscopy isolates and 42 of the 56 (75 %) M. intracellulare patient bronchoscopy isolates could have been due to contamination from the water supply.