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Growth kinetics and gene transfer of enteric and environmental E. coli in domestic settings

English title Growth kinetics and gene transfer of enteric and environmental E. coli in domestic settings
Applicant Julian Timothy
Number 157065
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 Environmental Research
Start/End 01.07.2015 - 30.06.2018
Approved amount 397'000.00
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All Disciplines (3)

Discipline
Environmental Research
Other disciplines of Environmental Sciences
Civil Engineering

Keywords (5)

source tracking; E. coli; environmental microbiology; gene transfer; fecal indicator bacteria

Lay Summary (German)

Lead
Oberflächen, Bodenoberflächen und Wasser in Haushalten in Entwicklungsländern weisen häufig eine sehr hohe E. coli Kontamination auf. Unser Forschungsprojekt prüft, inwieweit diese E. coli Kolonien in Haushalten ein Gesundheitsrisiko für den Menschen darstellen. Das Ziel der Studie besteht darin, Massnahmen zur Verringerung der Exposition durch pathogene E. coli zu verbessern.
Lay summary

Inhalt und Ziele des Forschungsprojekts

Unsere bisherige Forschung zeigt, dass Haushalte in Entwicklungsländern (z.B. Bangladesch, Peru und Tansania) grundsätzlich deutlich höhere Kontaminationen durch E. coli Bakterien (einschließlich pathogener E. coli Stämme) auf Händen und Böden, im Trinkwasser und in Nahrungsmitteln aufweisen als Haushalte in Industriestaaten (z.B. USA). Diese höheren E. coli Konzentrationen tragen mutmasslich zur höheren Zahl von Durchfallerkrankungen bei.

Ziel dieses Projekts ist es, die Ökologie von pathogenen E. coli Stämmen in Haushalten zu verstehen und daraus Massnahmen zur Verringerung des menschlichen Kontakts mit fäkalen Verunreinigungen zu entwickeln.

Spezifische Forschungsfragen:

  1. Sind die in den Haushalten beobachteten E. coli Kolonien fäkalen Ursprungs oder natürlicher Teil der Umwelt?

     

  2. Inwiefern können E. coli Bakterien auch ausserhalb des Verdauungstrakts des Wirts überleben, bzw. welche Faktoren beeinflussen Überlebensfähigkeit und Wachstumsrate?

     

  3. Kann durch Einführung pathogener E. coli in die Umwelt eine Virulenz in vorher apathogenen E. coli Stämmen induziert werden?

 

Wissenschaftlicher und gesellschaftlicher Kontext des Forschungsprojekts

Das wissenschaftliche Ziel dieses Forschungsprojekts ist, den Einfluss der Umwelt auf die Amplifikation pathogener E. coli - durch Vermehrung oder Gentransfer - in Wachstumsexperimenten zu bestimmen. Das Projekt überprüft das existierende Forschungsparadigma, das die Umwelt als Sammelbecken und nicht als Quelle pathogener E. coli Stämme identifiziert, mit Hilfe fundamentaler Analysen der E. coli-Ökologie in Haushalten.

Das gesellschaftliche Ziel dieses Forschungsprojektes liegt darin, einen Beitrag zur Verbesserung von Massnahmen zu leisten, die das menschliche Gesundheitsrisiko durch fäkale Kontaminationen in Haushalten von Entwicklungsländern verringern sollen. 

 

Direct link to Lay Summary Last update: 17.06.2015

Responsible applicant and co-applicants

Employees

Publications

Publication
Safely Managed Hygiene: A Risk-Based Assessment of Handwashing Water Quality
Verbyla Matthew E., Pitol Ana K., Navab-Daneshmand Tala, Marks Sara J., Julian Timothy R. (2019), Safely Managed Hygiene: A Risk-Based Assessment of Handwashing Water Quality, in Environmental Science & Technology, 53(5), 2852-2861.
Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh
Montealegre Maria Camila, Roy Subarna, Böni Franziska, Hossain Muhammed Iqbal, Navab-Daneshmand Tala, Caduff Lea, Faruque A. S. G., Islam Mohammad Aminul, Julian Timothy R. (2018), Risk Factors for Detection, Survival, and Growth of Antibiotic-Resistant and Pathogenic Escherichia coli in Household Soils in Rural Bangladesh, in Applied and Environmental Microbiology, 84(24), e01978-18.
Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors
Julian Timothy R., Mosler Hans-Joachim, Friedrich Max N. D., Navab-Daneshmand Tala, Montealegre Maria Camila, Gächter Marja, Nhiwatiwa Tamuka, Mlambo Linn S. (2018), Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors, in The American Journal of Tropical Medicine and Hygiene, 98(3), 803-813.
Environmental transmission of diarrheal pathogens in low and middle income countries
Julian Timothy R (2016), Environmental transmission of diarrheal pathogens in low and middle income countries, in Environmental Science: Processes & Impacts, 18(8), 944-955.

Collaboration

Group / person Country
Types of collaboration
Hospital Universitario Ramón y Cajal (Dr. Val F. Lanza) Spain (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
icddr,b (Dr. Mohammad Aminul Islam) Bangladesh (Asia)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel
University of San Diego (Dr. Matt Verbyla) United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Eawag (Dr. Hans-Joachim Mosler) Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Stanford University (Dr. Amy Pickering) United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
University of Zimbabwe (Dr. Tamuka Nhiwatiwa) Zimbabwe (Africa)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Water Microbiology 2018 Talk given at a conference Are Soils in Households Plots Reservoirs for Antimicrobial Resistant and Diarrheagenic Escherichia coli in Bangladesh? 22.05.2018 Chapel Hill, NC, United States of America Julian Timothy;
Water Microbiology 2018 Talk given at a conference Genomic Diversity of Escherichia Coli Isolated from Soil and Fecal Sources in Domestic Environments in Bangladesh 22.05.2018 Chapel Hill, NC, United States of America Montealegre Camila;
Annual Congress of the Swiss Society for Microbiology 2017 Talk given at a conference Detection, Growth, and Survival of Enteropathogenic Escherichia coli (EPEC) in Soils 30.08.2017 Basel, Switzerland Montealegre Camila;
Association of Environmental Engineering and Science Professors Conference Poster Hands, soil and water as reservoirs for enteric pathogens transmission in Harare, Zimbabwe, 20.06.2017 Ann Arbor, MI, United States of America Navab Daneshmand Tala;
Water Microbiology 2017 Poster Fate and persistence in soil microcosms of environmental and fecal Escherichia coli isolated from low-income countries 15.05.2017 Chapel Hill, NC, United States of America Montealegre Camila;
7th Annual Pacific Northwest Water Research Symposium Talk given at a conference Water for unity 06.03.2017 Corvallis, Oregon, United States of America Navab Daneshmand Tala;
Water Microbiology Conference 2016 (University of North Carolina, North Carolina, USA) Talk given at a conference Impact of environmental fecal contamination on hand hygiene in urban Harare 17.05.2016 Chapel Hill, North Carolina, USA, United States of America Navab Daneshmand Tala;


Knowledge transfer events



Self-organised

Title Date Place
Environmental Transmission of Infectious Diseases - Talk at World Health Organization 18.07.2016 Geneva, Switzerland, Switzerland

Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Escherichia coli in Harare - Wie gelangt das Bakterium in die Haushalte und woher stammt es? Aqua & Gas German-speaking Switzerland 2018

Associated projects

Number Title Start Funding scheme
192763 Risk Factors for Pathogenic and Antimicrobial Resistant Escherichia coli in Drinking Water based on Nationally representative Household-Level Surveys 01.07.2020 Project funding (Div. I-III)

Abstract

The goal of this project is to understand the in situ growth kinetics and potential for gene transfer between enteric and environmental strains of E. coli in domestic settings of low income countries. My previous research has demonstrated substantially higher fecal bacteria and pathogen concentrations on the hands, soils, and surfaces in low income countries (i.e., Bangladesh, Peru, Tanzania) than in high income countries (i.e., United States, European Union). Exposure to higher concentrations of fecal bacteria and pathogens is linked to multiple acute and chronic adverse health outcomes, including diarrheal disease, reduced nutrient absorption, reduced vaccine efficacy, stunting, and death. In light of the high levels of contamination of fecal source E. coli in domestic settings, fundamental concerns arise about the nature of the observed E. coli. Concerns include: the extent to which E. coli in these environments are fecal-source versus autochthonous; the ability of the E. coli to persist and thrive in these environments; and the potential for fecal source pathogenic E. coli to induce pathogenicity in autochthonous bacteria through gene transfer.Specifically, I propose to address these emerging concerns through a series of field- and laboratory-based experiments focused on the following questions: -Are there distinctions (genotypic and/or phenotypic) between enteric E. coli strains and the environmental E. coli strains found in the domestic environment (i.e., hands, soils, and surfaces)? -Are E. coli found in domestic environments persistent and/or able to regrow in the environment of domestic settings in tropical climates? If there are distinctions between enteric and environmental E. coli strains, do these disintctions influence persistence and/or regrowth? -Are pathogenic E. coli from enteric sources contributors of pathogenicity islands (e.g., hemolysin production, P-related fimbrie) to autochthonous or naturalized soil microbiota (including environmental E. coli strains) via horizontal gene transfer?The proposed study aims to identify whether or not the detection of E. coli in environmental reservoirs indicates risks for human health from fecal contamination exposures. Increasingly, the presence/absence of E. coli is used as an indicator of the quality of water and sanitation infrastructure in low resource settings. Therefore, the high concentrations of E. coli we have previously detected are currently interpreted to imply high risks to human health in domestic, low-income settings. However, further research in the following areas is needed to improve interpretation of E. coli detection assays: relative prevalence of enteric and environmental E. coli strains, mechanistic differences in enteric and environmental E. coli strains, in situ growth kinetics of E. coli, and potential for horizontal gene transfer between diarrheagenic E. coli and autochthonous bacteria including environmental E. coli strains. The work proposed here will inform fecal contamination exposure remediation efforts and quantitative microbial risk assessment studies intended to improve health and well-being of families exposed to fecal-source E. coli.
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