title: Legionella spp. isolation and quantification from greywater.
abstract: Legionella, an opportunistic human pathogen whose natural environment is water, is transmitted to humans through inhalation of contaminated aerosols. Legionella has been isolated from a high diversity of water types. Due its importance as a pathogen, two ISO protocols have been developed for its monitoring. However, these two protocols are not suitable for analyzing Legionella in greywater (GW). GW is domestic wastewater excluding the inputs from toilets and kitchen. It can serve as an alternative water source, mainly for toilet flushing and garden irrigation; both producing aerosols that can cause a risk for Legionella infection. Hence, before reuse, GW has to be treated and its quality needs to be monitored. The difficulty of Legionella isolation from GW strives in the very high load of contaminant bacteria. Here we describe a modification of the ISO protocol 11731:1998 that enables the isolation and quantification of Legionella from GW samples. The following modifications were made:•To enable isolation of Legionella from greywater, a pre-filtration step that removes coarse matter is recommended.•Legionella can be isolated after a combined acid-thermic treatment that eliminates the high load of contaminant bacteria in the sample.
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel.
authors.forename: Sara
authors.initials: S
authors.lastname: Rodríguez-Martínez
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion, Haifa, Israel.
authors.forename: Marina
authors.initials: M
authors.lastname: Blanky
authors.affiliation: Faculty of Civil and Environmental Engineering, Technion, Haifa, Israel.
authors.forename: Eran
authors.initials: E
authors.lastname: Friedler
authors.affiliation: Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel; Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon, Israel.
authors.forename: Malka
authors.initials: M
authors.lastname: Halpern
keywords: Acid-thermic treatment; Culture; Greywater; ISO 11731:1998; Legionella isolation; Pre-filtration