Isolation and automated ribotyping of Mycobacterium lentiflavum from drinking water distribution system and clinical specimens.

Automated ribotyping as a tool for identifying of nontuberculous mycobacteria was evaluated. We created a database comprising of riboprints of 60 strains, representing 32 species of nontuberculous mycobacteria. It was shown that combined ribopatterns generated after digestion with EcoRI and PvuII were distinguishable between species of both slow-growing and rapid-growing mycobacteria. The findings were in good agreement with the 16S rRNA gene sequencing results, allowing correct identification of Mycobacterium lentiflavum isolated from clinical specimens and from biofilms growing in public water distribution system. The automated ribotyping was powerful in discriminating between M. lentiflavum and closely related species M. simiae and M. palustre. Mycobacterium lentiflavum strains from drinking water biofilms were resistant to two to four antimycobacterial drugs. The drinking water distribution system may, thus, be a source of nontuberculous mycobacteria resistant to multiple drugs.