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dc.contributor.authorRhoads, William J.en_US
dc.contributor.authorJi, Panen_US
dc.contributor.authorPruden, Amyen_US
dc.contributor.authorEdwards, Marc A.en_US
dc.date.accessioned2017-03-08T19:38:09Z
dc.date.available2017-03-08T19:38:09Z
dc.date.issued2015-12-01en_US
dc.identifier.issn2049-2618en_US
dc.identifier.urihttp://hdl.handle.net/10919/75496
dc.description.abstractBackground Lowering water heater temperature set points and using less drinking water are common approaches to conserving water and energy; yet, there are discrepancies in past literature regarding the effects of water heater temperature and water use patterns on the occurrence of opportunistic pathogens, in particular Legionella pneumophila. Our objective was to conduct a controlled, replicated pilot-scale investigation to address this knowledge gap using continuously recirculating water heaters to examine five water heater set points (39–58 °C) under three water use conditions. We hypothesized that L. pneumophila levels at the tap depend on the collective influence of water heater temperature, flow frequency, and the resident plumbing ecology. Results We confirmed temperature setting to be a critical factor in suppressing L. pneumophila growth both in continuously recirculating hot water lines and at distal taps. For example, at 51 °C, planktonic L. pneumophila in recirculating lines was reduced by a factor of 28.7 compared to 39 °C and was prevented from re-colonizing biofilm. However, L. pneumophila still persisted up to 58 °C, with evidence that it was growing under the conditions of this study. Further, exposure to 51 °C water in a low-use tap appeared to optimally select for L. pneumophila (e.g., 125 times greater numbers than in high-use taps). We subsequently explored relationships among L. pneumophila and other ecologically relevant microbes, noting that elevated temperature did not have a general disinfecting effect in terms of total bacterial numbers. We documented the relationship between L. pneumophila and Legionella spp., and noted several instances of correlations with Vermamoeba vermiformis, and generally found that there is a dynamic relationship with this amoeba host over the range of temperatures and water use frequencies examined. Conclusions Our study provides a new window of understanding into the microbial ecology of potable hot water systems and helps to resolve past discrepancies in the literature regarding the influence of water temperature and stagnation on L. pneumophila, which is the cause of a growing number of outbreaks. This work is especially timely, given society’s movement towards “green” buildings and the need to reconcile innovations in building design with public health.
dc.format.extent? - ? (13) page(s)en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherBiomed Central Ltden_US
dc.relation.urihttp://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000366352500002&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=930d57c9ac61a043676db62af60056c1en_US
dc.rightsCreative Commons Attribution 4.0 International*
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/*
dc.subjectMicrobiologyen_US
dc.subjectLegionella pneumophilaen_US
dc.subjectHot wateren_US
dc.subjectStagnationen_US
dc.subjectWater useen_US
dc.subjectTemperatureen_US
dc.subjectMODEL PLUMBING SYSTEMen_US
dc.subjectDOMESTIC HOT-WATERen_US
dc.subjectFREE-LIVING AMEBASen_US
dc.subjectDRINKING-WATERen_US
dc.subjectLEGIONNAIRES-DISEASEen_US
dc.subjectPSEUDOMONAS-AERUGINOSAen_US
dc.subjectNONTUBERCULOUS MYCOBACTERIAen_US
dc.subjectUNITED-STATESen_US
dc.subjectRISK-FACTORSen_US
dc.subjectGROWTHen_US
dc.titleWater heater temperature set point and water use patterns influence Legionella pneumophila and associated microorganisms at the tapen_US
dc.typeArticle - Refereed
dc.description.versionPublished (Publication status)en_US
dc.rights.holderRhoads et al.
dc.title.serialMICROBIOMEen_US
dc.identifier.doihttps://doi.org/10.1186/s40168-015-0134-1
dc.identifier.volume3en_US
dc.type.dcmitypeText
pubs.organisational-group/Virginia Tech
pubs.organisational-group/Virginia Tech/All T&R Faculty
pubs.organisational-group/Virginia Tech/Engineering
pubs.organisational-group/Virginia Tech/Engineering/Civil & Environmental Engineering
pubs.organisational-group/Virginia Tech/Engineering/COE T&R Faculty


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Creative Commons Attribution 4.0 International
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