Comparison of filtering methods, filter processing and DNA extraction kits for detection of mycobacteria in water.

Introduction And Objective: Mycobacteria have been isolated from almost all types of natural waters, as well as from man-made water distribution systems. Detection of mycobacteria using PCR has been described in different types of water; however, currently, there is no standardised protocol for the processing of large volumes of water.

Material And Methods: In the present study, different filtering methods are tested and optimised for tap or river water filtration up to 10 L, as well as filter processing and DNA isolation using four commercially available kits.

Results: The PowerWater DNA isolation kit (MoBio, USA), together with a kit used for soil and other environmental samples (PowerSoil DNA isolation kit, MoBio), had the highest efficiency. Filtration of 10 L of water and elution of the filter in PBS with the addition of 0.05% of Tween 80 is suggested.

Conclusions: The described protocol for filter elution is recommended, and the use of the PowerWater DNA isolation kit for the highest mycobacterial DNA yield from water samples. The described protocol is suitable for parallel detection of mycobacteria using cultivation.