Relationship between mineral content of domestic hot water and microbial contamination.
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.
Borella
Paola
P
Department of Hygiene, Microbiology and Biostatistics, University of Modena, Modena, Italy. borella@unimore.it
Montagna
M Teresa
MT
Romano-Spica
Vincenzo
V
Stampi
Serena
S
Stancanelli
Giovanna
G
Triassi
Maria
M
Marchesi
Isabella
I
Bargellini
Annalisa
A
Neglia
Rachele
R
Paglionico
Natalia
N
Spilotros
Giovanna
G
Moscato
Umberto
U
Casati
Giulia
G
Legnani
Pier Paolo
PP
Sacchetti
Rossella
R
Ossi
Cristina
C
Moro
Matteo
M
Ribera
Gabriella
G
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
D014131:Trace Elements; D014867:Water; D008345:Manganese; D002713:Chlorine; D007501:Iron; D008274:Magnesium; D015032:Zinc; D002118:Calcium