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microbiHomes: a detailed investigation of the causes and consequences of bacterial growth in premise plumbing systems

English title microbiHomes: a detailed investigation of the causes and consequences of bacterial growth in premise plumbing systems
Applicant Hammes Frederik Albert
Number 163366
Funding scheme Project funding (Div. I-III)
Research institution Abteilung für Umweltmikrobiologie EAWAG
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Experimental Microbiology
Start/End 01.03.2016 - 29.02.2020
Approved amount 372'000.00
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All Disciplines (4)

Discipline
Experimental Microbiology
Other disciplines of Environmental Sciences
Ecology
Environmental Research

Keywords (8)

Building plumbing; Hygiene; Drinking water; Bacteria; Water quality; Growth; Pipe material; Microbiomes

Lay Summary (German)

Lead
Bakterien sind ein natürlicher Bestandteil von Trinkwassersystemen. Unter normalen Bedingungen reichen die Zellzahlen in der Wasserphase bis 100’000 Zellen pro Milliliter und in Biofilmen bis zu 100’000’000 Zellen pro Quadratzentimeter. Diese Zahlen setzten sich wiederrum aus tausenden unterschiedlichen Spezies zusammen. Trinkwasserverteilsysteme in Gebäuden stellen mit Blick auf die Mikrobiologie den unbeständigsten Bereich in der gesamten Trinkwasserverteilung dar. Die Mikrobiologie in Trinkwasserverteilsystemen von Gebäuden wird: (1) nicht routinemässig überwacht und (2) ist der Bereich nicht ausreichend durch Richtlinien abgedeckt.
Lay summary

Inhalt und Ziel des Forschungsprojekts

Die Trinkwasserverteilung in Gebäuden umfasst jeden Punkt der Installation, der mit Trinkwasser in Kontakt kommt - auch den Bereich Brauchwasser. Die Verteilung besteht aus unterschiedlichsten Rohr- und Dichtungsmaterialien. Komplexe bakterielle Gemeinschaften wachsen in den Leitungssystemen in einem  Temperaturbereich von kalt (5 °C) bis warm (55 °C) und nutzen vorallem Nährstoffe, die aus Kunststoffprodukten migrieren. Das Verhalten von Bakterien unter solchen Bedingungen wurde bis jetzt weder ausreichend charakterisiert, untersucht noch verstanden. Die Ziele des Projektes sind (1) die grundliegenden Ursachen und daraus resultierenden Wirkungen für das mikrobielle Wachstum  zu untersuchen, (2) die Folgen für das System und den Konsumenten zu beurteilen und (3) mögliche zukünftige innovative Management-Strategien zur Steuerung des Verhaltens der Mikrobiologie zu evaluieren.

Wissenschaftlicher und gesellschaftlicher Kontext

Im akademischen Sektor ist ein detailliertes Verständnis zum Wachstum natürlicher mikrobieller Gemeinschaften unter nährstoffarmen Bedingungen nicht vorhanden. Wir erwarten, dass diese Studie zu neuen Definitionen und Modellen im Gebiet der Biofilmbildung und -entwicklung führt.  Im angewandten Bereich soll diese Studie die Entscheidungsfindung bei der Wahl von Rohrmaterialien für Trinkwasserverteilsysteme unterstützen.

Direct link to Lay Summary Last update: 28.01.2016

Responsible applicant and co-applicants

Employees

Publications

Publication
Small-Scale Heterogeneity in Drinking Water Biofilms
Neu Lisa, Proctor Caitlin R., Walser Jean-Claude, Hammes Frederik (2019), Small-Scale Heterogeneity in Drinking Water Biofilms, in Frontiers in Microbiology, 10, 2446.
Ugly ducklings—the dark side of plastic materials in contact with potable water
Neu Lisa, Bänziger Carola, Proctor Caitlin R., Zhang Ya, Liu Wen-Tso, Hammes Frederik (2018), Ugly ducklings—the dark side of plastic materials in contact with potable water, in npj Biofilms and Microbiomes, 4(1), 7-7.
Biofilms in shower hoses
Proctor Caitlin R., Reimann Mauro, Vriens Bas, Hammes Frederik (2018), Biofilms in shower hoses, in Water Research, 131, 274-286.

Datasets

Ugly ducklings - The dark side of plastic materials in contact with potable water

Author Lisa, Neu
Persistent Identifier (PID) PRJEB24750
Repository European Nucleotide Archive
Abstract
Bath toys pose an interesting link between flexible plastic materials, potable water, external microbial and nutrient contamination, and potentially vulnerable end-users. Here, we characterized biofilm communities inside 19 bath toys used under real conditions. In addition, some determinants for biofilm formation were assessed, using six identical bath toys under controlled conditions with either clean water prior to bathing or dirty water after bathing. All examined bath toys revealed notable biofilms on their inner surface, with average total bacterial numbers of 5.5 x 106 cells/cm2 (clean water controls), 9.5 x 106 cells/cm2 (real bath toys), and 7.3 x 107 cells/cm2 (dirty water controls). Bacterial community compositions were diverse, showing many rare taxa in real bath toys and rather distinct communities in control bath toys, with a noticeable difference between clean and dirty water control biofilms. Fungi were identified in 58 % of all real bath toys and in all dirty water control toys. Based on the comparison of clean water and dirty water control bath toys, we argue that bath toy biofilms are influenced by (1) the organic carbon leaching from the flexible plastic material, (2) the chemical and biological tap water quality, (3) additional nutrients by care products and human body fluids in the bath water, as well as, (4) additional bacteria from dirt and/or the end-users’ microbiome. The present study gives a detailed characterization of bath toy biofilms and a better understanding of determinants for biofilm formation and development in systems comprising plastic materials in contact with potable water.

Small scale heterogeneity in biofilms

Author Neu, Lisa
Persistent Identifier (PID) PRJNA554997
Repository NCBI Sequence Read Archive (SRA)


Collaboration

Group / person Country
Types of collaboration
Ackermann group / Eawag / ETH Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
GDC, ETH Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Prof. Barth Smets / DTU Denmark Denmark (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Prof. Wen Tsu Liu United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
EPFL Environmental Engineering Seminar Series Talk given at a conference Managing unwanted bacterial colonization and growth in drinking water building plumbing systems 01.10.2019 Lausanne, Switzerland Hammes Frederik Albert;
Workshop for flow cytometry data usin Talk given at a conference Biofilms on flexible plastics - From measurement to management 04.09.2019 Lund, Sweden Neu Lisa;
Nordic Drinking Water Biofilm Symposium Talk given at a conference Biofilms in Drinking Water Building Plumbing Systems 25.04.2019 Horsens, Denmark Hammes Frederik Albert;
Swiss microbial ecology meeting Talk given at a conference Small-scale heterogeneity in drinking water biofilms 30.01.2019 Lausanne, Switzerland Neu Lisa;
Water Quality Technology Conference Talk given at a conference Heterogeneity in drinking water biofilms 11.11.2018 Toronto, Canada Neu Lisa;
Water Quality Technology Conference Talk given at a conference Material matters: Choosing your bacterial exposure at the hardware store 11.11.2018 Toronto, Canada Proctor Caitlin;
Lund University Seminar Individual talk Microbial Resource Management in New Buildings 25.10.2018 Lund, Sweden Hammes Frederik Albert;
ISME2018 Talk given at a conference Managing the drinking water microbiome in new buildings 12.08.2018 Leipzig, Germany Hammes Frederik Albert;
Biofilms8 Poster Small-scale heterogeneity in drinking water biofilms 19.06.2018 Aarhus, Denmark Neu Lisa;
IBP PhD Congress Talk given at a conference Heterogeneity in drinking water biofilms 06.04.2018 Zurich, Switzerland Neu Lisa;
IWA Sweden Biofilms in Drinking Water meeting Talk given at a conference Flow-cytometric assessment of biofilms in drinking water treatment and distribution systems 16.01.2018 Lund, Sweden Hammes Frederik Albert;
How Dead is Dead V Poster  Bacterial viability assessment - Advantages & challenges of using different methods 06.09.2017 Vienna, Austria Neu Lisa;
Swiss society for biomaterials and regenerative medicine annual conference Poster  Stable water until the point of use - towards a probiotic approach for plastic materials 17.05.2017 St Gallen, Switzerland Neu Lisa;
MEWE and Biofilms IWA Specialists Conference Poster  Ugly Ducklings The dark side of materials in contact with potable water 04.09.2016 Copenhagen, Denmark Neu Lisa; Hammes Frederik Albert;


Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
Sanitärtag - Kompetenz Trinkwasserinstallation Talk 23.10.2019 Bern, Switzerland Neu Lisa;
14. Schweizer Planertag, Warmwasserforum Talk 26.02.2019 Brugg, Switzerland Neu Lisa;
5. Schweizer Hygienetagung Talk 25.01.2019 Luzern, Switzerland Neu Lisa;
SVG-Hygienetagung Talk 18.06.2018 Zurich, Switzerland Neu Lisa;


Communication with the public

Communication Title Media Place Year
New media (web, blogs, podcasts, news feeds etc.) About ducks, pipes and microbiomes Nature Research Microbiology Community (Blog) International 2018
Media relations: print media, online media Bakterien im Bauch Tages Anzeiger German-speaking Switzerland 2018
Media relations: print media, online media Danger: a mucky rubber ducky is a haven for bacteria, says study The Guardian International 2018
Media relations: print media, online media Der Feind sammelt sich im Duschschlauch NZZ German-speaking Switzerland 2018
Print (books, brochures, leaflets) Der finale meter German-speaking Switzerland 2018
Media relations: print media, online media Eine Ente geht viral Tages Anzeiger German-speaking Switzerland 2018
Media relations: print media, online media Hässliche Seite der Badeente: Bakterien im Gummi-Spielze Süddeutsche Zeitung International 2018
Media relations: print media, online media Look at my yucky ducky! Parents cut open their children's bath toys to reveal the filthy grime insid The Daily Mail International 2018
Media relations: print media, online media RUBBER MUCKY This is why your kids’ bath toys could be KILLING them The Sun International 2018
Media relations: print media, online media The inside of rubber duckies are full of bacteria. You don't seem surprised CNN International 2018
Media relations: print media, online media There’s mold in your kids' bath toys (and that’s probably okay) The Washington Post International 2018

Awards

Title Year
Best presentation award; IBP PhD Congress 2018
ETH medal for PhD dissertation 2018
Best Poster Award; IBP PhD Congress 2017
Best Poster Award; MEWE and Biofilms IWA specialist conference 2016

Abstract

Three sobering facts about bacteria in our drinking water are that (1) building plumbing microbiology is not routinely monitored and (2) is essentially not covered by legislation, while (3) it is by far the most microbiologically volatile section of the entire drinking water distribution network. For example, the microbiome of stable non-chlorinated drinking water changes as much as 400% in numbers/composition at the customer’s tap due to overnight stagnation and regrowth in premise plumbing. Building plumbing microbiology is defined by (1) complex autochthonous communities, growing in (2) both biofilm and planktonic phases, (3) utilizing complex substrates under (4) dynamic oligotrophic conditions, where (5) carbonaceous nutrients migrate from the pipe surface (bottom-up supply), (6) intermittent loading of inorganic nutrients through stagnation-flushing (top-down supply) occurs, and (7) fluctuating temperatures and hydraulic conditions prevail. There exist a considerable knowledge gap in the most basic understanding of bacterial growth under the conditions described above. As a result, building plumbing microbiology is poorly understood, poorly managed, and ultimately the most critical point in the system - the point of consumption - is left extremely vulnerable. The overall goals of this project are:(1)To investigate the causes of premise plumbing microbial growth; (2)To assess the consequences that microbial growth holds for the system and for the consumers; (3)To assess potential innovative microbial management strategies for the future. This project proposes three complimentary work areas (WA) to deal with these different aspects. WA 1 (causes) will focus on the basics of bacterial growth under conditions unique to building plumbing systems. This will include a systematic investigation of planktonic and biofilm batch growth under mixed substrate and mixed community conditions, followed by modeling microbial community growth, and culminating in growth assessment in a realistic in pilot scale system. In WA 2 (consequences) we will demonstrate how selective growth on synthetic pipe materials influences community composition (richness/evenness) and subsequently the vulnerability of the microbial communities towards invasion from unwanted microbes. Moreover, we will investigate the impact of selective death (e.g., from copper pipes) on community composition and the critical question of whether this results in unwanted selection of multi-resistant bacteria. WA 3 (management) will investigate the exciting and provocative microbial management concept that a drinking water system can be purposefully pre-colonized with benign microbial communities as a so-called “probiotics”. The aim is to select and cultivate competitive “probiotic” organisms/communities, assess their ability to pre-colonize diverse plastic materials, and subsequently assess the long term stability of such bacteria during realistic operational conditions with exposure to autochthonous drinking water bacteria and invading organisms. The proposed work will have a clear academic and applied impact. A detailed understanding of autochthonous microbial community growth under low nutrient conditions with bottom-up nutrient supply does not exist and will have a broad benefit in both this specific field and related fields, leading to a new definitions and models of biofilm formation and development. The work on selection will reveal the importance of informed decision-making in the use of pipe materials for building plumbing systems. Although the “probiotics” section will not have immediate practical application - consumer acceptance may be a hindrance - it will demonstrate the extent to which communities can be managed and controlled to the benefit of the consumer, with multiple potential applications in the future.
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