First isolation of Mycobacterium canariasense from municipal water supplies in Tenerife, Canary Islands, Spain.

BACKGROUND

Nontuberculous mycobacteria (NTM) are common bacteria in water and especially water supply distribution systems. Some species can cause infections, especially in immunocompromised patients and other risk groups. This study examined the frequency of occurrence of NTM in 135 household potable water samples collected from household water taps in Tenerife Island.

METHODS

Mycobacteria species were identified by polymerase chain reaction targeting the 16S rRNA and 16S-23S rRNA regions, and by double-reverse hybridization on a dipstick using colloidal gold-bound and membrane-bound probes (Speed-Oligo(®) Mycobacteria). Some species were identified by sequencing the gene that encodes the 16S rRNA region.

RESULTS

NTM were present in 47.4% of the samples. Mycobacterium fortuitum was the NTM isolated most frequently (70.3%), followed by Mycobacterium canariasense (6.3%) and Mycobacterium chelonae (6.3%). Other species were isolated at lower percentage frequencies.

CONCLUSION

We isolated and identified the species M. canariasense in water supplies for public consumption. This species has previously been reported only in hospital settings. The elevated presence of NTM in the water supply indicates that it may be a reservoir for infections caused by recently described species of mycobacteria.