Comparative Quantitative Evaluation of Legiolert and the ISO 11731:2017 Method in Drinking Water

Presentation by Maria Luisa Ricci PhD of the Department of Infectious Diseases, Istituto Superiore di Sanità

The European Directive (DWD) 2020/2184 on the quality of water for human consumption includes for the first time among water pathogens to be controlled in domestic water systems Legionella that can be detected also by molecular and other rapid culture-based methods. Legiolert, a bacterial enzyme technology, detects Legionella pneumophila (Lp) in a liquid culture, providing the result as Most Probable Number of Lp in the sample. This study compares Legiolert and the ISO 11731:2017 methodology for Lp quantification. 709 potable water samples collected throughout Italy were analysed by 33 laboratories and data provided were analysed statistically, according to ISO 17994:2014.