title: Relationship between mineral content of domestic hot water and microbial contamination.
abstract: The relationship between Legionella and Pseudomonas spp contamination and mineral content of domestic hot waters was investigated in a cross-sectional Italian survey. Pseudomonas spp contamination was associated with elevated Ca, but lower Fe and free chlorine content in the water. Waters with Cu concentrations > 50 microg/L prevented Legionella spp colonisation (OR = 0.14, 95% CI = 0.02-1.13), whereas the risk of legionellae occurrence increased in waters with Mn levels > 3 microg/L (OR = 2.37, 95% CI = 1.06-5.30). Furthermore, Mn was positively associated with the risk of colonisation by eterotrophic bacteria growing at either 22 and 36 degrees C. Legionella species and serogroups were differently distributed according to Cu and Mn concentrations, suggesting that Legionella strains may have a different sensibility/resistance to trace elements. A specific action of Cu as decontamination factor is suggested and the consideration of Mn as a risk indicator for bacterial colonisation and biofilm presence is proposed.
authors.affiliation: Department of Hygiene, Microbiology and Biostatistics, University of Modena, Modena, Italy. borella@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: Isabella
authors.initials: I
authors.lastname: Marchesi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Bargellini
authors.forename: Rachele
authors.initials: R
authors.lastname: Neglia
authors.forename: Natalia
authors.initials: N
authors.lastname: Paglionico
authors.forename: Giovanna
authors.initials: G
authors.lastname: Spilotros
authors.forename: Umberto
authors.initials: U
authors.lastname: Moscato
authors.forename: Giulia
authors.initials: G
authors.lastname: Casati
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Legnani
authors.forename: Rossella
authors.initials: R
authors.lastname: Sacchetti
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
mesh_terms: D002118:Calcium / Q000378:metabolism; D002713:Chlorine / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007501:Iron / Q000378:metabolism; D007875:Legionella / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D011549:Pseudomonas / Q000378:metabolism*; D012044:Regression Analysis; D013696:Temperature; D014131:Trace Elements; D014867:Water / Q000378:metabolism; D014871:Water Microbiology; D014881:Water Supply; D015032:Zinc / Q000378:metabolism
chemical_list: D014131:Trace Elements; D014867:Water; D008345:Manganese; D002713:Chlorine; D007501:Iron; D008274:Magnesium; D015032:Zinc; D002118:Calcium