title: Legionella infection risk from domestic hot water.
abstract: We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <100 microg/L and copper levels of >50 microg/L appeared to be protective against Legionella colonization [corrected]. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches.
authors.affiliation: Dipartamento di Scienze Igienistiche, Microbiologiche e Biostatistiche, University of Modena and Reggio E., Via Campi 287, I-41100 Modena, Italy. borella.paola@unimore.it
authors.forename: Paola
authors.initials: P
authors.lastname: Borella
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Montagna
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Romano-Spica
authors.forename: Serena
authors.initials: S
authors.lastname: Stampi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Stancanelli
authors.forename: Maria
authors.initials: M
authors.lastname: Triassi
authors.forename: Rachele
authors.initials: R
authors.lastname: Neglia
authors.forename: Isabella
authors.initials: I
authors.lastname: Marchesi
authors.forename: Guglielmina
authors.initials: G
authors.lastname: Fantuzzi
authors.forename: Daniela
authors.initials: D
authors.lastname: Tatò
authors.forename: Christian
authors.initials: C
authors.lastname: Napoli
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Quaranta
authors.forename: Patrizia
authors.initials: P
authors.lastname: Laurenti
authors.forename: Erica
authors.initials: E
authors.lastname: Leoni
authors.forename: Giovanna
authors.initials: G
authors.lastname: De Luca
authors.forename: Cristina
authors.initials: C
authors.lastname: Ossi
authors.forename: Matteo
authors.initials: M
authors.lastname: Moro
authors.forename: Gabriella
authors.initials: G
authors.lastname: Ribera D'Alcalà
mesh_terms: D006801:Humans; D007558:Italy; D007875:Legionella / Q000302:isolation & purification*; D016952:Legionella pneumophila / Q000302:isolation & purification*; D007876:Legionellosis / Q000209:etiology*; D007877:Legionnaires' Disease / Q000209:etiology*; D008670:Metals / Q000032:analysis*; D011549:Pseudomonas / Q000302:isolation & purification*; D012307:Risk Factors; D014871:Water Microbiology; D014881:Water Supply / Q000032:analysis*
chemical_list: D008670:Metals