Legionella in drinking water: the detection method matters.

Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems (DWPS). The respective action levels differ at the international level. In Germany, the Federal Environment Agency (UBA) specifies the application of ISO 11731 for the detection of legionella in drinking water and gives a binding recommendation for the methods to be used for culturing and evaluation.

Comparison of the Legiolert™/Quanti-Tray MPN test for the enumeration of Legionella pneumophila from potable water samples with the German regulatory requirements methods ISO 11731-2 and ISO 11731.

Due to the promising results of a previous study of the performance of the novel MPN method (Legiolert™/Quanti-Tray) compared to ISO 11731-2, this study was performed to compare Legiolert for Legionella pneumophila with the German regulatory requirements methods ISO 11731-2 (100 ml membrane filtration) and ISO 11731 (1 ml direct plating) for the enumeration of L. pneumophila and Legionella spp. from potable water.