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Stallard MA, Mulhern R, Greenwood E, Franklin T, Engel LS, Fisher MB, Sobsey MD, Zanib H, Noble RT, Stewart JR, Sozzi E. Occurrence of male-specific and somatic coliphages and relationship with rainfall in privately-owned wells from peri‑urban and rural households. WATER RESEARCH X 2021; 12:100102. [PMID: 34027379 PMCID: PMC8131969 DOI: 10.1016/j.wroa.2021.100102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/19/2021] [Accepted: 04/25/2021] [Indexed: 06/12/2023]
Abstract
Privately-owned drinking water wells serving fewer than 25 people (private wells) are prevalent and understudied across most of the US. Private wells primarily serve rural households located outside of municipal drinking water and sewerage service coverage areas. These wells are not regulated by United States Environmental Protection Agency (EPA) under the Safe Drinking Water Act, are not regularly monitored by any public agency or utility, and generally do not undergo disinfection treatment. Coliphages are a group of viruses that infect coliform bacteria and are useful viral surrogates for fecal contamination in water systems in much the same way that fecal indicator bacteria (FIB), such as E. coli and to a lesser extent total coliforms, are used to quantify fecal contamination. Coliphages are approved by the EPA for regulatory monitoring in groundwater wells in the USA, but are not routinely used for this purpose. The present study characterizes the occurrence of male-specific and somatic coliphages, along with FIB, in private wells (n = 122) across two different counties in North Carolina. While occurrences of E. coli were rare and frequency of total coliform was generally low (~20%), male-specific and somatic coliphages were detectable in 66% and 54% of samples, respectively. Concentrations of male-specific coliphages were higher than somatics at each county and on a monthly basis. Rainfall appears to be partly influencing higher coliphage concentrations in December, January and February. This research underscores the need for increased surveillance in private wells and consideration of using coliphages in order to better characterize occurrence of fecal contamination at the time of sampling, especially during rainier months.
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Affiliation(s)
- Megan A Stallard
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Riley Mulhern
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Emily Greenwood
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Taylor Franklin
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Lawrence S Engel
- Gillings School of Global Public Health, Department of Epidemiology, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7435, Chapel Hill, NC 27599, USA
| | - Michael B Fisher
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Mark D Sobsey
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Hania Zanib
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Rachel T Noble
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, 3431 Arendell St., Morehead City, NC 28557, USA
| | - Jill R Stewart
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
| | - Emanuele Sozzi
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, 135 Dauer Drive, CB #7431, Chapel Hill, NC 27599, USA
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Méndez J, Toribio-Avedillo D, Mangas-Casas R, Martínez-González J. Bluephage, a method for efficient detection of somatic coliphages in one hundred milliliter water samples. Sci Rep 2020; 10:2977. [PMID: 32076096 PMCID: PMC7031265 DOI: 10.1038/s41598-020-60071-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 02/07/2020] [Indexed: 11/09/2022] Open
Abstract
Emerging water quality guidelines and regulations require the absence of somatic coliphages in 100 mL of water, yet the efficiency of standardized methods to test this volume of sample is questionable. A recently described procedure, Bluephage, using a modified E. coli host strain, overcomes some of the methodological limitations of standardized methods. In a maximum of 6.5 hours (2.5 hours for pre-growing the host strain and 4 hours for the presence/absence test), Bluephage allows the direct detection of one plaque-forming unit (PFU) in a 100 mL water sample. The test shows high levels of specificity for somatic coliphages and comparable accuracy with standardized methods.
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Affiliation(s)
- Javier Méndez
- Department of Genetics, Microbiology and Statistics. Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
| | - Daniel Toribio-Avedillo
- Department of Genetics, Microbiology and Statistics. Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Raquel Mangas-Casas
- Department of Genetics, Microbiology and Statistics. Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Judit Martínez-González
- Department of Genetics, Microbiology and Statistics. Faculty of Biology, University of Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
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Muniesa M, Ballesté E, Imamovic L, Pascual-Benito M, Toribio-Avedillo D, Lucena F, Blanch AR, Jofre J. Bluephage: A rapid method for the detection of somatic coliphages used as indicators of fecal pollution in water. WATER RESEARCH 2018; 128:10-19. [PMID: 29078067 DOI: 10.1016/j.watres.2017.10.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 10/09/2017] [Accepted: 10/14/2017] [Indexed: 05/04/2023]
Abstract
The use of somatic coliphages as indicators of fecal and viral pollution in water and food has great potential due to the reliability, reproducibility, speed and cost effectiveness of methods for their detection. Indeed, several countries already use this approach in their water management policies. Although standardized protocols for somatic coliphage detection are available, user-friendly commercial kits would facilitate their routine implementation in laboratories. The new method presented here allows detection of up to 1 somatic coliphage in under 3.5 h, well within one working day. The method is based on a modified Escherichia coli strain with knocked-out uidB and uidC genes, which encode the transport of glucuronic acid inside cells, and overexpressing uidA, which encodes the enzyme β-glucuronidase. The enzyme accumulated in the bacterial cells only has contact with its substrate after cell lysis, such as that caused by phages, since the strain cannot internalize the substrate. When the enzyme is released into the medium, which contains a chromogen analogous to glucuronic acid, it produces a change of color from yellow to dark blue. This microbiological method for the determination of fecal pollution via the detection of culturable microorganisms can be applied to diverse sample types and volumes for qualitative (presence/absence) and quantitative analysis and is the fastest reported to date.
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Affiliation(s)
- M Muniesa
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain.
| | - E Ballesté
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - L Imamovic
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - M Pascual-Benito
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - D Toribio-Avedillo
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - F Lucena
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - A R Blanch
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
| | - J Jofre
- Department of Genetics, Microbiology and Statistics, Microbiology Section, Faculty of Biology, University of Barcelona, Diagonal 643, E-08028, Barcelona, Spain
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