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Paar J, Willis JR, Sette L, Wood SA, Bogomolni A, Dulac M, Sivaganesan M, Shanks OC. Occurrence of recreational water quality monitoring general fecal indicator bacteria and fecal source identification genetic markers in gray seal scat. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 934:173220. [PMID: 38761521 DOI: 10.1016/j.scitotenv.2024.173220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 05/11/2024] [Accepted: 05/11/2024] [Indexed: 05/20/2024]
Abstract
The number of gray seals (Halichoerus grypus) observed along the United States Northwest Atlantic region has been increasing for decades. These colonial animals often haul-out on beaches seasonally in numbers ranging from a few individuals to several thousands. While these larger aggregations are an important part of gray seal behavior, there is public concern that haul-outs could lead to large amounts of fecal waste in recreational areas, potentially resulting in beach closures. Yet, data to confirm whether these animals contribute to beach closures is lacking and minimal information is available on the occurrence of key water quality monitoring genetic markers in gray seal scat. This study evaluates the concentration of E. coli (EC23S857), enterococci (Entero1a), and fecal Bacteroidetes (GenBac3) as well as six fecal source identification genetic markers (HF183/BacR287, HumM2, CPQ_056, Rum2Bac, DG3, and GFD) measured by qPCR in 48 wild gray seal scat samples collected from two haul-out areas in Cape Cod (Massachusetts, U.S.A.). Findings indicate that FIB genetic markers are shed in gray seal scat at significantly different concentrations with the Entero1a genetic marker exhibiting the lowest average concentration (-0.73 log10 estimated mean copies per nanogram of DNA). In addition, systematic testing of scat samples demonstrated that qPCR assays targeting host-associated genetic markers indicative of human, ruminant, and canine fecal pollution sources remain highly specific in waters frequented by gray seals (>97 % specificity).
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Affiliation(s)
- Jack Paar
- U.S. Environmental Protection Agency, New England Regional Laboratory, North Chelmsford, MA 01863, USA
| | - Jessica R Willis
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Cincinnati, OH 45268, USA
| | - Lisa Sette
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA 02657, USA
| | - Stephanie A Wood
- University of Massachusetts, Boston, Biology Department, 100 Morrissey Blvd., Boston, MA 02125, USA
| | - Andrea Bogomolni
- Massachusetts Maritime Academy, Marine Science, Safety and Environmental Protection, 101 Academy Drive, Buzzards Bay, MA 02532, USA
| | - Monique Dulac
- U.S. Environmental Protection Agency, New England Regional Laboratory, North Chelmsford, MA 01863, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Cincinnati, OH 45268, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling, Cincinnati, OH 45268, USA.
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Shanks OC, Diedrich A, Sivaganesan M, Willis JR, Sharifi A. Quantitative fecal source characterization of urban municipal storm sewer system outfall 'wet' and 'dry' weather discharges. WATER RESEARCH 2024; 259:121857. [PMID: 38851116 DOI: 10.1016/j.watres.2024.121857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/27/2024] [Accepted: 05/29/2024] [Indexed: 06/10/2024]
Abstract
Urban areas are built environments containing substantial amounts of impervious surfaces (e.g., streets, sidewalks, roof tops). These areas often include elaborately engineered drainage networks designed to collect, transport, and discharge untreated stormwater into local surface waters. When left uncontrolled, these discharges may contain unsafe levels of fecal waste from sources such as sanitary sewage and wildlife even under dry weather conditions. This study evaluates paired measurements of host-associated genetic markers (log10 copies per reaction) indicative of human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), canine (DG3), and avian (GFD) fecal sources, 12-hour cumulative precipitation (mm), four catchment land use metrics determined by global information system (GIS) mapping, and Escherichia coli (MPN/100 ml) from seven municipal separate storm sewer system outfall locations situated at the southern portion of the Anacostia River Watershed (District of Columbia, U.S.A.). A total of 231 discharge samples were collected twice per month (n = 24 sampling days) and after rain events (n = 9) over a 13-month period. Approximately 50 % of samples (n = 116) were impaired, exceeding the local E. coli single sample maximum of 2.613 log10 MPN/100 ml. Genetic quality controls indicated the absence of amplification inhibition in 97.8 % of samples, however 14.7 % (n = 34) samples showed bias in DNA recovery. Of eligible samples, quantifiable levels were observed for avian (84.1 %), human (57.4 % for HF183/BacR287 and 40 % for HumM2), canine (46.7 %), and ruminant (15.9 %) host-associated genetic markers. Potential links between paired measurements are explored with a recently developed Bayesian qPCR censored data analysis approach. Findings indicate that human, pet, and urban wildlife all contribute to storm outfall discharge water quality in the District of Columbia, but pollutant source contributions vary based on 'wet' and 'dry' conditions and catchment land use, demonstrating that genetic-based fecal source identification methods combined with GIS land use mapping can complement routine E. coli monitoring to improve stormwater management in urban areas.
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Affiliation(s)
- Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
| | - Adam Diedrich
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Jessica R Willis
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Amirreza Sharifi
- Department of Energy and Environment, 1200 First St NE, Washington, D.C., USA
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Hill E, Chun CL, Hamilton K, Ishii S. High-Throughput Microfluidic Quantitative PCR Platform for the Simultaneous Quantification of Pathogens, Fecal Indicator Bacteria, and Microbial Source Tracking Markers. ACS ES&T WATER 2023; 3:2647-2658. [PMID: 37593240 PMCID: PMC10428101 DOI: 10.1021/acsestwater.3c00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/19/2023]
Abstract
Contamination of water with bacterial, viral, and protozoan pathogens can cause human diseases. Both humans and nonhumans can release these pathogens through their feces. To identify the sources of fecal contamination in the water environment, microbial source tracking (MST) approaches have been developed; however, the relationship between MST markers and pathogens is still not well understood most likely due to the lack of comprehensive datasets of pathogens and MST marker concentrations. In this study, we developed a novel microfluidic quantitative PCR (MFQPCR) platform for the simultaneous quantification of 37 previously validated MST markers, two fecal indicator bacteria (FIB), 22 bacterial, 11 viral, and five protozoan pathogens, and three internal amplification/process controls in many samples. The MFQPCR chip was applied to analyze pathogen removal rates during the wastewater treatment processes. In addition, multiple host-specific MST markers, FIB, and pathogens were successfully quantified in human and avian-impacted surface waters. While the genes for pathogens were relatively infrequently detected, positive correlations were observed between some potential pathogens such as Clostridium perfringens and Mycobacterium spp., and human MST markers. The MFQPCR chips developed in this study, therefore, can provide useful information to monitor and improve water quality.
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Affiliation(s)
- Elizabeth
R. Hill
- Water
Resource Science Graduate Program, University
of Minnesota, 173 McNeal
Hall, 1985 Buford Avenue, St. Paul, Minnesota 55108, United States
| | - Chan Lan Chun
- Water
Resource Science Graduate Program, University
of Minnesota, 173 McNeal
Hall, 1985 Buford Avenue, St. Paul, Minnesota 55108, United States
- Natural
Resources Research Institute, University
of Minnesota, 5013 Miller
Trunk Highway, Duluth, Minnesota 55811, United States
- Department
of Civil Engineering, University of Minnesota, 221 Swenson Civil Engineering, 1405
University Drive, Duluth, Minnesota 55812, United States
| | - Kerry Hamilton
- School
of Sustainable Engineering and the Built Environment, Arizona State University, 660 S. College Avenue, Tempe, Arizona 85281, United States
- Biodesign
Center for Environmental Health Engineering, Arizona State University, 727 E. Tyler Street, Tempe, Arizona 85281, United States
| | - Satoshi Ishii
- Water
Resource Science Graduate Program, University
of Minnesota, 173 McNeal
Hall, 1985 Buford Avenue, St. Paul, Minnesota 55108, United States
- BioTechnology
Institute, University of Minnesota, 140 Gortner Laboratory, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, United States
- Department
of Soil, Water, and Climate, University
of Minnesota, 439 Borlaug
Hall, 1991 Upper Buford Circle, St. Paul, Minnesota 55108, United States
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Derx J, Kılıç HS, Linke R, Cervero-Aragó S, Frick C, Schijven J, Kirschner AKT, Lindner G, Walochnik J, Stalder G, Sommer R, Saracevic E, Zessner M, Blaschke AP, Farnleitner AH. Probabilistic fecal pollution source profiling and microbial source tracking for an urban river catchment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159533. [PMID: 36270368 DOI: 10.1016/j.scitotenv.2022.159533] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
We developed an innovative approach to estimate the occurrence and extent of fecal pollution sources for urban river catchments. The methodology consists of 1) catchment surveys complemented by literature data where needed for probabilistic estimates of daily produced fecal indicator (FIBs, E. coli, enterococci) and zoonotic reference pathogen numbers (Campylobacter, Cryptosporidium and Giardia) excreted by human and animal sources in a river catchment, 2) generating a hypothesis about the dominant sources of fecal pollution and selecting a source targeted monitoring design, and 3) verifying the results by comparing measured concentrations of the informed choice of parameters (i.e. chemical tracers, C. perfringensspores, and host-associated genetic microbial source tracking (MST) markers) in the river, and by multi-parametric correlation analysis. We tested the approach at a study area in Vienna, Austria. The daily produced microbial particle numbers according to the probabilistic estimates indicated that, for the dry weather scenario, the discharge of treated wastewater (WWTP) was the primary contributor to fecal pollution. For the wet weather scenario, 80-99 % of the daily produced FIBs and pathogens resulted from combined sewer overflows (CSOs) according to the probabilistic estimates. When testing our hypothesis in the river, the measured concentrations of the human genetic fecal marker were log10 4 higher than for selected animal genetic fecal markers. Our analyses showed for the first-time statistical relationships between C. perfringens spores (used as conservative microbial tracer for communal sewage) and a human genetic fecal marker (i.e. HF183/BacR287) with the reference pathogen Giardia in river water (Spearman rank correlation: 0.78-0.83, p < 0.05. The developed approach facilitates urban water safety management and provides a robust basis for microbial fate and transport models and microbial infection risk assessment.
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Affiliation(s)
- Julia Derx
- Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Austria.
| | - H Seda Kılıç
- Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Austria
| | - Rita Linke
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Microbiology and Molecular Diagnostics 166/5/3, TU Wien, Austria
| | - Sílvia Cervero-Aragó
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Christina Frick
- Vienna City Administration, Municipal Department 39, Division of Hygiene, Vienna, Austria
| | - Jack Schijven
- Utrecht University, Faculty of Geosciences, Department of Earth Sciences, Utrecht, the Netherlands; National Institute for Public Health and the Environment, Department of Statistics, Informatics and Modelling, Bilthoven, the Netherlands
| | - Alexander K T Kirschner
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria; Division Water Quality and Health, Department of Pharmacology, Physiology, and Microbiology, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
| | - Gerhard Lindner
- Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Austria
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Gabrielle Stalder
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Regina Sommer
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Austria
| | - Ernis Saracevic
- Institute for Water Quality and Resource Management, TU Wien, Vienna, Austria
| | - Matthias Zessner
- Institute for Water Quality and Resource Management, TU Wien, Vienna, Austria
| | - Alfred P Blaschke
- Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Austria
| | - Andreas H Farnleitner
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Microbiology and Molecular Diagnostics 166/5/3, TU Wien, Austria.; Division Water Quality and Health, Department of Pharmacology, Physiology, and Microbiology, Karl Landsteiner University of Health Sciences, Krems an der Donau, Austria
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5
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Diedrich A, Sivaganesan M, Willis JR, Sharifi A, Shanks OC. Genetic fecal source identification in urban streams impacted by municipal separate storm sewer system discharges. PLoS One 2023; 18:e0278548. [PMID: 36701383 PMCID: PMC9879488 DOI: 10.1371/journal.pone.0278548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/17/2022] [Indexed: 01/27/2023] Open
Abstract
Municipal stormwater systems are designed to collect, transport, and discharge precipitation from a defined catchment area into local surface waters. However, these discharges may contain unsafe levels of fecal waste. Paired measurements of Escherichia coli, precipitation, three land use metrics determined by geographic information system (GIS) mapping, and host-associated genetic markers indicative of human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), dog (DG3), and avian (GFD) fecal sources were assessed in 231 urban stream samples impacted by two or more municipal stormwater outfalls. Receiving water samples were collected twice per month (n = 24) and after rain events (n = 9) from seven headwaters of the Anacostia River in the District of Columbia (United States) exhibiting a gradient of impervious surface, residential, and park surface areas. Almost 50% of stream samples (n = 103) were impaired, exceeding the local E. coli single sample maximum assessment level (410 MPN/100 ml). Fecal scores (average log10 copies per 100 ml) were determined to prioritize sites by pollution source and to evaluate potential links with land use, rainfall, and E. coli levels using a recently developed censored data analysis approach. Dog, ruminant, and avian fecal scores were almost always significantly increased after rain or when E. coli levels exceeded the local benchmark. Human fecal pollution trends showed the greatest variability with detections ranging from 9.1% to 96.7% across sites. Avian fecal scores exhibited the closest connection to land use, significantly increasing in catchments with larger residential areas after rain events (p = 0.038; R2 = 0.62). Overall, results demonstrate that combining genetic fecal source identification methods with GIS mapping complements routine E. coli monitoring to improve management of urban streams impacted by stormwater outfalls.
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Affiliation(s)
- Adam Diedrich
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
| | - Jessica R. Willis
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
| | - Amirreza Sharifi
- Department of Energy and Environment, Government of the District of Columbia, Washington, DC, United States of America
| | - Orin C. Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
- * E-mail:
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Sivaganesan M, Willis JR, Karim M, Babatola A, Catoe D, Boehm AB, Wilder M, Green H, Lobos A, Harwood VJ, Hertel S, Klepikow R, Howard MF, Laksanalamai P, Roundtree A, Mattioli M, Eytcheson S, Molina M, Lane M, Rediske R, Ronan A, D'Souza N, Rose JB, Shrestha A, Hoar C, Silverman AI, Faulkner W, Wickman K, Kralj JG, Servetas SL, Hunter ME, Jackson SA, Shanks OC. Interlaboratory performance and quantitative PCR data acceptance metrics for NIST SRM® 2917. WATER RESEARCH 2022; 225:119162. [PMID: 36191524 PMCID: PMC9932931 DOI: 10.1016/j.watres.2022.119162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Surface water quality quantitative polymerase chain reaction (qPCR) technologies are expanding from a subject of research to routine environmental and public health laboratory testing. Readily available, reliable reference material is needed to interpret qPCR measurements, particularly across laboratories. Standard Reference Material® 2917 (NIST SRM® 2917) is a DNA plasmid construct that functions with multiple water quality qPCR assays allowing for estimation of total fecal pollution and identification of key fecal sources. This study investigates SRM 2917 interlaboratory performance based on repeated measures of 12 qPCR assays by 14 laboratories (n = 1008 instrument runs). Using a Bayesian approach, single-instrument run data are combined to generate assay-specific global calibration models allowing for characterization of within- and between-lab variability. Comparable data sets generated by two additional laboratories are used to assess new SRM 2917 data acceptance metrics. SRM 2917 allows for reproducible single-instrument run calibration models across laboratories, regardless of qPCR assay. In addition, global models offer multiple data acceptance metric options that future users can employ to minimize variability, improve comparability of data across laboratories, and increase confidence in qPCR measurements.
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Affiliation(s)
- Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Jessica R Willis
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Mohammad Karim
- Environmental Services Laboratory, City of Santa Cruz, Santa Cruz, CA, USA
| | - Akin Babatola
- Environmental Services Laboratory, City of Santa Cruz, Santa Cruz, CA, USA
| | - David Catoe
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
| | - Maxwell Wilder
- Department of Environmental Biology, SUNY-ESF, Syracuse, NY, USA
| | - Hyatt Green
- Department of Environmental Biology, SUNY-ESF, Syracuse, NY, USA
| | - Aldo Lobos
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Stephanie Hertel
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Regina Klepikow
- U.S. Environmental Protection Agency, Region 7 Laboratory, Kansas City, KS, USA
| | | | | | - Alexis Roundtree
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Mia Mattioli
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Stephanie Eytcheson
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Marirosa Molina
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Molly Lane
- Annis Water Resources Institute, Grand Valley State University, Muskegon, MI, USA
| | - Richard Rediske
- Annis Water Resources Institute, Grand Valley State University, Muskegon, MI, USA
| | - Amanda Ronan
- U.S. Environmental Protection Agency, Region 2 Laboratory, Edison, NJ, USA
| | - Nishita D'Souza
- Department of Fisheries and Wildlife, Michigan State University, E. Lansing, MI, USA
| | - Joan B Rose
- Department of Fisheries and Wildlife, Michigan State University, E. Lansing, MI, USA
| | - Abhilasha Shrestha
- Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL, USA
| | - Catherine Hoar
- Department of Civil and Urban Engineering, New York University Tandon School of Engineering, Brooklyn, NY, USA
| | - Andrea I Silverman
- Department of Civil and Urban Engineering, New York University Tandon School of Engineering, Brooklyn, NY, USA
| | | | | | - Jason G Kralj
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Stephanie L Servetas
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Monique E Hunter
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Scott A Jackson
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
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Williams NLR, Siboni N, Potts J, Campey M, Johnson C, Rao S, Bramucci A, Scanes P, Seymour JR. Molecular microbiological approaches reduce ambiguity about the sources of faecal pollution and identify microbial hazards within an urbanised coastal environment. WATER RESEARCH 2022; 218:118534. [PMID: 35537251 DOI: 10.1016/j.watres.2022.118534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 06/14/2023]
Abstract
Urbanised beaches are regularly impacted by faecal pollution, but management actions to resolve the causes of contamination are often obfuscated by the inability of standard Faecal Indicator Bacteria (FIB) analyses to discriminate sources of faecal material or detect other microbial hazards, including antibiotic resistance genes (ARGs). We aimed to determine the causes, spatial extent, and point sources of faecal contamination within Rose Bay, a highly urbanised beach within Sydney, Australia's largest city, using molecular microbiological approaches. Sampling was performed across a network of transects originating at 9 stormwater drains located on Rose Bay beach over the course of a significant (67.5 mm) rainfall event, whereby samples were taken 6 days prior to any rain, on the day of initial rainfall (3.8 mm), three days later after 43 mm of rain and then four days after any rain. Quantitative PCR (qPCR) was used to target marker genes from bacteria (i.e., Lachnospiraceae and Bacteroides) that have been demonstrated to be specific to human faeces (sewage), along with gene sequences from Heliobacter and Bacteriodes that are specific to bird and dog faeces respectively, and ARGs (sulI, tetA, qnrS, dfrA1 and vanB). 16S rRNA gene amplicon sequencing was also used to discriminate microbial signatures of faecal contamination. Prior to the rain event, low FIB levels (mean: 2.4 CFU/100 ml) were accompanied by generally low levels of the human and animal faecal markers, with the exception of one transect, potentially indicative of a dry weather sewage leak. Following 43 mm of rain, levels of both human faecal markers increased significantly in stormwater drain and seawater samples, with highest levels of these markers pinpointing several stormwater drains as sources of sewage contamination. During this time, sewage contamination was observed up to 1000 m from shore and was significantly and positively correlated with often highly elevated levels of the ARGs dfrA1, qnrS, sulI and vanB. Significantly elevated levels of the dog faecal marker in stormwater drains at this time also indicated that rainfall led to increased input of dog faecal material from the surrounding catchment. Using 16S rRNA gene amplicon sequencing, several indicator taxa for stormwater contamination such as Arcobacter spp. and Comamonadaceae spp. were identified and the Bayesian SourceTracker tool was used to model the relative impact of specific stormwater drains on the surrounding environment, revealing a heterogeneous contribution of discrete stormwater drains during different periods of the rainfall event, with the microbial signature of one particular drain contributing up to 50% of bacterial community in the seawater directly adjacent. By applying a suite of molecular microbiological approaches, we have precisely pinpointed the causes and point-sources of faecal contamination and other associated microbiological hazards (e.g., ARGs) at an urbanised beach, which has helped to identify the most suitable locations for targeted management of water quality at the beach.
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Affiliation(s)
- Nathan L R Williams
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Nachshon Siboni
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Jaimie Potts
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Meredith Campey
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Colin Johnson
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Shivanesh Rao
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Anna Bramucci
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Peter Scanes
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Justin R Seymour
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
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8
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Willis JR, Sivaganesan M, Haugland RA, Kralj J, Servetas S, Hunter ME, Jackson SA, Shanks OC. Performance of NIST SRM® 2917 with 13 recreational water quality monitoring qPCR assays. WATER RESEARCH 2022; 212:118114. [PMID: 35091220 PMCID: PMC10786215 DOI: 10.1016/j.watres.2022.118114] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Fecal pollution remains a significant challenge for recreational water quality management worldwide. In response, there is a growing interest in the use of real-time quantitative PCR (qPCR) methods to achieve same-day notification of recreational water quality and associated public health risk as well as to characterize fecal pollution sources for targeted mitigation. However, successful widespread implementation of these technologies requires the development of and access to a high-quality standard control material. Here, we report a single laboratory qPCR performance assessment of the National Institute of Standards and Technology Standard Reference Material 2917 (NIST SRM® 2917), a linearized plasmid DNA construct that functions with 13 recreational water quality qPCR assays. Performance experiments indicate the generation of standard curves with amplification efficiencies ranging from 0.95 ± 0.006 to 0.99 ± 0.008 and coefficient of determination values (R2) ≥ 0.980. Regardless of qPCR assay, variability in repeated measurements at each dilution level were very low (quantification threshold standard deviations ≤ 0.657) and exhibited a heteroscedastic trend characteristic of qPCR standard curves. The influence of a yeast carrier tRNA added to the standard control material buffer was also investigated. Findings demonstrated that NIST SRM® 2917 functions with all qPCR methods and suggests that the future use of this control material by scientists and water quality managers should help reduce variability in concentration estimates and make results more consistent between laboratories.
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Affiliation(s)
- Jessica R Willis
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Richard A Haugland
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Jason Kralj
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Stephanie Servetas
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Monique E Hunter
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Scott A Jackson
- National Institute of Standards and Technology, Biosystems and Biomaterials Division, Complex Microbial Systems Group, Gaithersburg, MD, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
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9
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Green H, Wilder M, Wiedmann M, Weller D. Integrative Survey of 68 Non-overlapping Upstate New York Watersheds Reveals Stream Features Associated With Aquatic Fecal Contamination. Front Microbiol 2021; 12:684533. [PMID: 34475855 PMCID: PMC8406625 DOI: 10.3389/fmicb.2021.684533] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/05/2021] [Indexed: 12/03/2022] Open
Abstract
Aquatic fecal contamination poses human health risks by introducing pathogens in water that may be used for recreation, consumption, or agriculture. Identifying fecal contaminant sources, as well as the factors that affect their transport, storage, and decay, is essential for protecting human health. However, identifying these factors is often difficult when using fecal indicator bacteria (FIB) because FIB levels in surface water are often the product of multiple contaminant sources. In contrast, microbial source-tracking (MST) techniques allow not only the identification of predominant contaminant sources but also the quantification of factors affecting the transport, storage, and decay of fecal contaminants from specific hosts. We visited 68 streams in the Finger Lakes region of Upstate New York, United States, between April and October 2018 and collected water quality data (i.e., Escherichia coli, MST markers, and physical–chemical parameters) and weather and land-use data, as well as data on other stream features (e.g., stream bed composition), to identify factors that were associated with fecal contamination at a regional scale. We then applied both generalized linear mixed models and conditional inference trees to identify factors and combinations of factors that were significantly associated with human and ruminant fecal contamination. We found that human contaminants were more likely to be identified when the developed area within the 60 m stream buffer exceeded 3.4%, the total developed area in the watershed exceeded 41%, or if stormwater outfalls were present immediately upstream of the sampling site. When these features were not present, human MST markers were more likely to be found when rainfall during the preceding day exceeded 1.5 cm. The presence of upstream campgrounds was also significantly associated with human MST marker detection. In addition to rainfall and water quality parameters associated with rainfall (e.g., turbidity), the minimum distance to upstream cattle operations, the proportion of the 60 m buffer used for cropland, and the presence of submerged aquatic vegetation at the sampling site were all associated based on univariable regression with elevated levels of ruminant markers. The identification of specific features associated with host-specific fecal contaminants may support the development of broader recommendations or policies aimed at reducing levels of aquatic fecal contamination.
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Affiliation(s)
- Hyatt Green
- Department of Environmental Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, NY, United States
| | - Maxwell Wilder
- Department of Environmental Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, NY, United States
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, United States
| | - Daniel Weller
- Department of Environmental Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, NY, United States
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10
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Zimmer-Faust AG, Steele JA, Xiong X, Staley C, Griffith M, Sadowsky MJ, Diaz M, Griffith JF. A Combined Digital PCR and Next Generation DNA-Sequencing Based Approach for Tracking Nearshore Pollutant Dynamics Along the Southwest United States/Mexico Border. Front Microbiol 2021; 12:674214. [PMID: 34421839 PMCID: PMC8377738 DOI: 10.3389/fmicb.2021.674214] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/25/2021] [Indexed: 12/27/2022] Open
Abstract
Ocean currents, multiple fecal bacteria input sources, and jurisdictional boundaries can complicate pollution source tracking and associated mitigation and management efforts within the nearshore coastal environment. In this study, multiple microbial source tracking tools were employed to characterize the impact and reach of an ocean wastewater treatment facility discharge in Mexico northward along the coast and across the Southwest United States- Mexico Border. Water samples were evaluated for fecal indicator bacteria (FIB), Enterococcus by culture-based methods, and human-associated genetic marker (HF183) and Enterococcus by droplet digital polymerase chain reaction (ddPCR). In addition, 16S rRNA gene sequence analysis was performed and the SourceTracker algorithm was used to characterize the bacterial community of the wastewater treatment plume and its contribution to beach waters. Sampling dates were chosen based on ocean conditions associated with northern currents. Evidence of a gradient in human fecal pollution that extended north from the wastewater discharge across the United States/Mexico border from the point source was observed using human-associated genetic markers and microbial community analysis. The spatial extent of fecal contamination observed was largely dependent on swell and ocean conditions. These findings demonstrate the utility of a combination of molecular tools for understanding and tracking specific pollutant sources in dynamic coastal water environments.
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Affiliation(s)
- Amity G Zimmer-Faust
- Southern California Coastal Water Research Project, Costa Mesa, CA, United States
| | - Joshua A Steele
- Southern California Coastal Water Research Project, Costa Mesa, CA, United States
| | - Xianyi Xiong
- BioTechnology Institute, University of Minnesota Twin Cities, Saint Paul, MN, United States
| | - Christopher Staley
- BioTechnology Institute, University of Minnesota Twin Cities, Saint Paul, MN, United States
| | - Madison Griffith
- Southern California Coastal Water Research Project, Costa Mesa, CA, United States
| | - Michael J Sadowsky
- Department of Soil, Water, and Climate, University of Minnesota Twin Cities, Saint Paul, MN, United States
| | - Margarita Diaz
- Proyecto Fronterizo de Educación Ambiental, A.C., Tijuana, Mexico
| | - John F Griffith
- Southern California Coastal Water Research Project, Costa Mesa, CA, United States
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11
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Li X, Kelty CA, Sivaganesan M, Shanks OC. Variable fecal source prioritization in recreational waters routinely monitored with viral and bacterial general indicators. WATER RESEARCH 2021; 192:116845. [PMID: 33508720 PMCID: PMC8186395 DOI: 10.1016/j.watres.2021.116845] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 05/03/2023]
Abstract
Somatic and F+ coliphage methods are under consideration as potential routine surface water quality monitoring tools to identify unsafe levels of fecal pollution in recreational waters. However, little is known about the cooccurrence of these virus-based fecal indicators and host-associated genetic markers used to prioritize key pollution sources for remediation. In this study, paired measurements of cultivated coliphage (somatic and F+) and bacterial (E. coli and enterococci) general fecal indicators and genetic markers indicative of human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), canine (DG3), and avian (GFD) fecal pollution sources were assessed in 365 water samples collected from six Great Lakes Basin beach and river sites over a 15-week recreational season. Water samples were organized into groups based on defined viral and bacterial fecal indicator water quality thresholds and average log10 host-associated genetic marker fecal score ratios were estimated to compare pollutant source inferences based on variable routine water quality monitoring practices. Eligible log10 fecal score ratios ranged from -0.051 (F+ coliphage, GFD) to 2.08 (enterococci, Rum2Bac). Using a fecal score ratio approach, findings suggest that general fecal indicator selection for routine water quality monitoring can influence the interpretation of host-associated genetic marker measurements, in some cases, prioritizing different pollutant sources for remediation. Variable trends were also observed between Great Lake beach and river sites suggesting disparate management practices may be useful for each water type.
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Affiliation(s)
- Xiang Li
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China 518055
| | - Catherine A Kelty
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA.
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12
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Brumfield KD, Cotruvo JA, Shanks OC, Sivaganesan M, Hey J, Hasan NA, Huq A, Colwell RR, Leddy MB. Metagenomic Sequencing and Quantitative Real-Time PCR for Fecal Pollution Assessment in an Urban Watershed. FRONTIERS IN WATER 2021; 3:626849. [PMID: 34263162 PMCID: PMC8274573 DOI: 10.3389/frwa.2021.626849] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Microbial contamination of recreation waters is a major concern globally, with pollutants originating from many sources, including human and other animal wastes often introduced during storm events. Fecal contamination is traditionally monitored by employing culture methods targeting fecal indicator bacteria (FIB), namely E. coli and enterococci, which provides only limited information of a few microbial taxa and no information on their sources. Host-associated qPCR and metagenomic DNA sequencing are complementary methods for FIB monitoring that can provide enhanced understanding of microbial communities and sources of fecal pollution. Whole metagenome sequencing (WMS), quantitative real-time PCR (qPCR), and culture-based FIB tests were performed in an urban watershed before and after a rainfall event to determine the feasibility and application of employing a multi-assay approach for examining microbial content of ambient source waters. Cultivated E. coli and enterococci enumeration confirmed presence of fecal contamination in all samples exceeding local single sample recreational water quality thresholds (E. coli, 410 MPN/100 mL; enterococci, 107 MPN/100 mL) following a rainfall. Test results obtained with qPCR showed concentrations of E. coli, enterococci, and human-associated genetic markers increased after rainfall by 1.52-, 1.26-, and 1.11-fold log10 copies per 100 mL, respectively. Taxonomic analysis of the surface water microbiome and detection of antibiotic resistance genes, general FIB, and human-associated microorganisms were also employed. Results showed that fecal contamination from multiple sources (human, avian, dog, and ruminant), as well as FIB, enteric microorganisms, and antibiotic resistance genes increased demonstrably after a storm event. In summary, the addition of qPCR and WMS to traditional surrogate techniques may provide enhanced characterization and improved understanding of microbial pollution sources in ambient waters.
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Affiliation(s)
- Kyle D. Brumfield
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, United States
| | | | - Orin C. Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincin nati, OH, United States
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincin nati, OH, United States
| | - Jessica Hey
- U.S. Environmental Protection Agency, Office of Research and Development, Cincin nati, OH, United States
| | - Nur A. Hasan
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, United States
| | - Anwar Huq
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States
| | - Rita R. Colwell
- Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States
- University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD, United States
- CosmosID Inc., Rockville, MD, United States
- Correspondence: Rita R. Colwell , Menu B. Leddy
| | - Menu B. Leddy
- Essential Environmental and Engineering Systems, Huntington Beach, CA, United States
- Correspondence: Rita R. Colwell , Menu B. Leddy
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13
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Zimmer-Faust AG, Steele JA, Griffith JF, Schiff K. The challenges of microbial source tracking at urban beaches for Quantitative Microbial Risk Assessment (QMRA). MARINE POLLUTION BULLETIN 2020; 160:111546. [PMID: 32898736 DOI: 10.1016/j.marpolbul.2020.111546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/27/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Urban beaches are frequently impacted from multiple sources of fecal contamination. This along with high beach usage underscores the importance of appropriate management that protects swimmer health. The USEPA has enabled the use of QMRA as a tool for quantifying swimmer health risk and setting site-specific water quality objectives. This study illustrates the challenges associated with human and non-human source identification and how these challenges influence the decision of whether QMRA at typical urban beaches for water quality management is appropriate. In this study, a similar and correlated spatial relationship with elevated Enterococcus and avian-specific markers was observed, suggesting shorebirds as a primary source of FIB. However, human-associated markers were also detected frequently but at low concentrations. Ultimately, a QMRA was not conducted because pathogen loading from potential human sources could not be confidently quantified, having consequences for health risk in receiving waters where recreational contact occurs.
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Affiliation(s)
- Amity G Zimmer-Faust
- Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America.
| | - Joshua A Steele
- Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America
| | - John F Griffith
- Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America
| | - Ken Schiff
- Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America
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14
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Shrestha A, Kelty CA, Sivaganesan M, Shanks OC, Dorevitch S. Fecal pollution source characterization at non-point source impacted beaches under dry and wet weather conditions. WATER RESEARCH 2020; 182:116014. [PMID: 32622131 PMCID: PMC8220998 DOI: 10.1016/j.watres.2020.116014] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/01/2020] [Accepted: 06/02/2020] [Indexed: 05/09/2023]
Abstract
Though Lake Michigan beaches in Chicago are not impacted by stormwater or wastewater outfalls, several of those beaches often exceed USEPA Beach Action Values (BAVs). We investigated the role of microbial source tracking (MST) as a complement to routine beach monitoring at Chicago beaches. In summer 2016, water samples from nine Chicago beaches were analyzed for E. coli by culture and enterococci by qPCR. A total of 195 archived samples were then tested for human (HF183/BacR287, HumM2), canine (DG3, DG37), and avian (GFD) microbial source tracking (MST) markers. Associations between MST and general fecal indicator bacteria (FIB) measures were evaluated and stratified based on wet and dry weather definitions. Among the 195 samples, HF183/BacR287 was quantifiable in 4%, HumM2 in 1%, DG3 in 6%, DG37 in 2%, and GFD in 23%. The one beach with a dog area was far more likely to have DG3 present in the quantifiable range than other beaches. Exceedance of general FIB BAVs increased the odds of human, dog and avian marker detection. MST marker weighted-average fecal scores for DG3 was 2.4 times, DG37 was 2.1 times, and GFD was 1.6 times higher during wet compared to dry weather conditions. HF183/BacR287 weighted-average fecal scores were not associated with precipitation. Associations between FIB BAV exceedance and MST marker detection were generally stronger in wet weather. Incorporating MST testing into routine beach water monitoring can provide information that beach managers can use when developing protection plans for beaches not impacted by point sources.
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Affiliation(s)
- Abhilasha Shrestha
- Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL, USA.
| | - Catherine A Kelty
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Samuel Dorevitch
- Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL, USA; Institute for Environmental Science and Policy, University of Illinois at Chicago, Chicago, IL, USA
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15
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Gyawali P, Hamilton K, Joshi S, Aster D, Ahmed W. Identification of reliable marker genes for the detection of canine fecal contamination in sub-tropical Australia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:137246. [PMID: 32105941 DOI: 10.1016/j.scitotenv.2020.137246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/09/2020] [Accepted: 02/09/2020] [Indexed: 06/10/2023]
Abstract
Animal fecal contamination in aquatic environments is a major source of zoonotic diseases in humans. While concerns are focused on livestock, companion animals such as dogs can also be a source of a wide range of zoonotic pathogens. Therefore, detection of dog or canine fecal contamination in aquatic environments is important for mitigating risks. In this study, host-sensitivity and specificity of four canine fecal-associated marker genes were evaluated by analyzing 30 canine and 240 non-canine fecal samples. The application of these markers was also tested in water from an urban river under dry weather conditions. The host sensitivity values of the Bacteroides BacCan-UCD, DogBact, DF113 and DF418 were 1.00, 0.90, 0.83, and 0.90, respectively. The host specificity value of the BacCan-UCD, DogBact, DF113 and DF418 were 0.87, 0.98, 0.83, and 0.41, respectively. The mean concentrations of DF418 were highest (7.82 ± 1.13 log10 gene copies (GC)/g of feces) followed by BacCan-UCD (7.61 ± 1.06 log10 GC/g) and DogBact (7.15 ± 0.92 log10 GC/g). The mean concentration of DF113 (5.80 ± 1.25 log10 GC/g) was 1.5 to 2.5 orders of magnitude lower than the other marker genes. The DogBact marker gene was not detected in any other animal feces other than a small number of untreated sewage samples. The BacCan-UCD marker gene cross-reacted with cat, chicken, and pig fecal samples, while the DF113 marker gene cross-reacted with cat, chicken, cattle fecal and untreated sewage samples. The DF418 marker gene was detected in all sewage and animal feces and deemed not suitable for canine fecal contamination tracking in sub-tropical Australia. Canine fecal contamination was infrequently detected in environmental water samples. Based on the results obtained in this study, we recommend that at least two canine feces-associated marker genes should be used in field studies.
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Affiliation(s)
- Pradip Gyawali
- Institute of Environmental Science and Research Ltd (ESR), Porirua 5240, New Zealand
| | - Kerry Hamilton
- The School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, USA; The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, 1001 S McAlister Ave, Tempe, AZ 85281, USA
| | - Sayalee Joshi
- The School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, USA; The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, 1001 S McAlister Ave, Tempe, AZ 85281, USA
| | - David Aster
- Department of Agriculture and Fisheries, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia.
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16
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McKee BA, Molina M, Cyterski M, Couch A. Microbial source tracking (MST) in Chattahoochee River National Recreation Area: Seasonal and precipitation trends in MST marker concentrations, and associations with E. coli levels, pathogenic marker presence, and land use. WATER RESEARCH 2020; 171:115435. [PMID: 31927096 PMCID: PMC8188702 DOI: 10.1016/j.watres.2019.115435] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 12/17/2019] [Accepted: 12/21/2019] [Indexed: 05/14/2023]
Abstract
Escherichia coli levels in recreational waters are often used to predict when fecal-associated pathogen levels are a human health risk. The reach of the Chattahoochee River that flows through the Chattahoochee River National Recreation Area (CRNRA), located in the Atlanta-metropolitan area, is a popular recreation area that frequently exceeds the U.S. Environmental Protection Agency beach action value (BAV) for E. coli. A BacteriALERT program has been implemented to provide real-time E. coli estimates in the reach and notify the public of potentially harmful levels of fecal-associated pathogens as indicated by surrogate models based on real-time turbidity measurements from continuous water quality monitoring stations. However, E. coli does not provide information about the sources of fecal contamination and its accuracy as a human health indicator is questionable when sources of contamination are non-human. The objectives of our study were to investigate, within the Park and surrounding watersheds, seasonal and precipitation-related patterns in microbial source tracking marker concentrations of possible sources (human, dog, and ruminant), assess correlations between source contamination levels and culturable E. coli levels, determine which sources best explained model-based E. coli estimates above the BAV and detection of esp2 (a marker for the esp gene associated with pathogenic strains of Enterococcus faecium and Enterococcus faecalis), and investigate associations between source contamination levels and land use features. Three BacteriALERT sites on the Chattahoochee River were sampled six times per season in the winter and summer from December 2015 through September 2017, and 11 additional stream sites (synoptic sites) from the CRNRA watershed were sampled once per season. Samples were screened with microbial source tracking (MST) quantitative PCR (qPCR) markers for humans (HF183 Taqman), dogs (DogBact), and ruminants (Rum2Bac), the esp2 qPCR marker, and culturable E. coli. At the BacteriALERT sites, HF183 Taqman concentrations were higher under wet conditions DogBact concentrations were greater in the winter and under wet conditions, and Rum2Bac concentrations were comparatively low throughout the study with no difference across seasons or precipitation conditions. Concentrations of HF183 Taqman, DogBact, and Rum2Bac were positively correlated with culturable E. coli concentrations; however, DogBact had the largest R2 value among the three markers, and the forward stepwise regression indicated it was the best predictor of culturable E. coli concentrations at the BacteriALERT sites. Recursive partitioning indicated that BAV exceedances of model-based E. coli estimates were best explained by DogBact concentrations ≥3 gene copies per mL (CN/mL). Detections of esp2 at BacteriALERT sites were best explained by DogBact concentrations ≥11 CN/mL, while detections of esp2 at synoptic sites were best explained by HF183 Taqman ≥29 CN/mL. At the synoptic sites, HF183 Taqman levels were associated with wastewater treatment plant density. However, this relationship was driven primarily by a single site, suggesting possible conveyance issues in that catchment. esp2 detections at synoptic sites were positively associated with development within a 2-km radius and negatively associated with development within the catchment, suggesting multiple sources of esp2 in the watershed. DogBact and Rum2Bac were not associated with the land use features included in our analyses. Implications for Park management include: 1) fecal contamination levels were highest during wet conditions and in the off season when fewer visitors are expected to be participating in water-based recreation, 2) dogs are likely contributors to fecal contamination in the CRNRA and may be sources of pathogenic bacteria indicating further investigation of the origins of this contamination may be warranted as would be research to understand the human health risks from exposure to dog fecal contamination, and 3) high levels of the human marker at one site in the CRNRA watershed suggests more extensive monitoring in that catchment may locate the origin of human fecal contamination detected during this study.
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Affiliation(s)
- By Anna McKee
- U.S. Geological Survey, South Atlantic Water Science Center, 1770 Corporate Drive Suite 500, Norcross, GA, 30093, USA.
| | - Marirosa Molina
- U.S. Environmental Protection Agency, Office of Research and Development, 960 College Station Road, Athens, GA, 30605, USA
| | - Mike Cyterski
- U.S. Environmental Protection Agency, Office of Research and Development, 960 College Station Road, Athens, GA, 30605, USA
| | - Ann Couch
- National Park Service, Chattahoochee River National Recreation Area, 1978 Island Ford Parkway, Sandy Springs, GA, 30350, USA
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17
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Ahmed W, Payyappat S, Cassidy M, Harrison N, Besley C. Sewage-associated marker genes illustrate the impact of wet weather overflows and dry weather leakage in urban estuarine waters of Sydney, Australia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 705:135390. [PMID: 31838427 DOI: 10.1016/j.scitotenv.2019.135390] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/03/2019] [Accepted: 11/04/2019] [Indexed: 05/18/2023]
Abstract
This study investigates the impact of wet weather overflows (WWOs) at three estuarine locations in Sydney, NSW, Australia. WWOs can occur when infiltration of stormwater leads to an excess volume of flow within the sewerage system, resulting in the release of diluted sewage into the environment. Sewage contamination poses a risk to human health due to the presence of pathogens. The magnitude of sewage contamination was monitored using established and novel sewage-associated marker genes, Bacteroides HF183, pepper mild mottle virus (PMMoV), crAssphage CPQ_056, Lachnospiraceae (Lachno3) marker genes along with culturable fecal indicator bacteria (FIB) Escherichia coli (E. coli) and enterococci. Water samples were collected at two water depths (0.5 m below the water surface and 1 m above the bottom surface) during one dry weather and two storm events. Analysis of sewage-associated marker genes showed greater (i.e., 3-5 orders of magnitude) concentrations in water samples collected during the storm events compared to dry weather event. Water samples were also analysed for four animal feces-associated marker genes targeting avian (GFD), dog (BacCan-UCD), cow (cowM2) and horse (HoF597) species to determine the extent of animal fecal contamination. Among the four marker genes, cowM2 and HoF597 could not be detected, while GFD marker gene was consistently present and BacCan-UCD was occasionally detected. Overall results suggested that after rainfall, untreated sewage from WWOs was present at sampling locations. In addition, microbial source tracking (MST) monitoring was able to distinguish the presence of a leaking sewer impacting on the recreational area during dry weather condition. This study demonstrated the capability of the MST monitoring approach to understand sources (sewage or animal) of fecal contamination. This capability will greatly enhance management decisions assisting in the prioritisation of remediation efforts of the sewerage system to improve estuarine bathing water quality and diminish human health risk.
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Affiliation(s)
- Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, QLD 4102, Australia.
| | - Sudhi Payyappat
- Sydney Water, 1 Smith Street, Parramatta, NSW 2150, Australia
| | - Michele Cassidy
- Sydney Water, 1 Smith Street, Parramatta, NSW 2150, Australia
| | - Nathan Harrison
- Sydney Water, 1 Smith Street, Parramatta, NSW 2150, Australia
| | - Colin Besley
- Sydney Water, 1 Smith Street, Parramatta, NSW 2150, Australia
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18
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Weller D, Belias A, Green H, Roof S, Wiedmann M. Landscape, Water Quality, and Weather Factors Associated With an Increased Likelihood of Foodborne Pathogen Contamination of New York Streams Used to Source Water for Produce Production. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2020; 3:124. [PMID: 32440656 PMCID: PMC7241490 DOI: 10.3389/fsufs.2019.00124] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There is a need for science-based tools to (i) help manage microbial produce safety hazards associated with preharvest surface water use, and (ii) facilitate comanagement of agroecosystems for competing stakeholder aims. To develop these tools an improved understanding of foodborne pathogen ecology in freshwater systems is needed. The purpose of this study was to identify (i) sources of potential food safety hazards, and (ii) combinations of factors associated with an increased likelihood of pathogen contamination of agricultural water Sixty-eight streams were sampled between April and October 2018 (196 samples). At each sampling event separate 10-L grab samples (GS) were collected and tested for Listeria, Salmonella, and the stx and eaeA genes. A 1-L GS was also collected and used for Escherichia coli enumeration and detection of four host-associated fecal source-tracking markers (FST). Regression analysis was used to identify individual factors that were significantly associated with pathogen detection. We found that eaeA-stx codetection [Odds Ratio (OR) = 4.2; 95% Confidence Interval (CI) = 1.3, 13.4] and Salmonella isolation (OR = 1.8; CI = 0.9, 3.5) were strongly associated with detection of ruminant and human FST markers, respectively, while Listeria spp. (excluding Listeria monocytogenes) was negatively associated with log10 E. coli levels (OR = 0.50; CI = 0.26, 0.96). L. monocytogenes isolation was not associated with the detection of any fecal indicators. This observation supports the current understanding that, unlike enteric pathogens, Listeria is not fecally-associated and instead originates from other environmental sources. Separately, conditional inference trees were used to identify scenarios associated with an elevated or reduced risk of pathogen contamination. Interestingly, while the likelihood of isolating L. monocytogenes appears to be driven by complex interactions between environmental factors, the likelihood of Salmonella isolation and eaeA-stx codetection were driven by physicochemical water quality (e.g., dissolved oxygen) and temperature, respectively. Overall, these models identify environmental conditions associated with an enhanced risk of pathogen presence in agricultural water (e.g., rain events were associated with L. monocytogenes isolation from samples collected downstream of dairy farms; P = 0.002). The information presented here will enable growers to comanage their operations to mitigate the produce safety risks associated with preharvest surface water use.
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Affiliation(s)
- Daniel Weller
- Department of Food Science, Cornell University, Ithaca, NY, United States
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, United States
| | - Alexandra Belias
- Department of Food Science, Cornell University, Ithaca, NY, United States
| | - Hyatt Green
- Department of Environmental and Forest Biology, SUNY College of Environmental Science and Forestry, Syracuse, NY, United States
| | - Sherry Roof
- Department of Food Science, Cornell University, Ithaca, NY, United States
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, NY, United States
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Abstract
Fecal contamination of waterbodies due to poorly managed human and animal waste is a pervasive problem that can be particularly costly to address, especially if mitigation strategies are ineffective at sufficiently reducing the level of contamination. Identifying the most worrisome sources of contamination is particularly difficult in periurban streams with multiple land uses and requires the distinction of municipal, agricultural, domestic pet, and natural (i.e., wildlife) wastes. Microbial source-tracking (MST) methods that target host-specific members of the bacterial order Bacteroidales and others have been used worldwide to identify the origins of fecal contamination. We conducted a dry-weather study of Onondaga Creek, NY, where reducing fecal contamination has been approached mainly by mitigating combined sewer overflow events (CSOs). Over three sampling dates, we measured in-stream concentrations of fecal indicator bacteria; MST markers targeting human, ruminant, and canine sources; and various physical–chemical parameters to identify contaminants not attributable to CSOs or stormwater runoff. We observed that despite significant ruminant inputs upstream, these contaminants eventually decayed and/or were diluted out and that high levels of urban bacterial contamination are most likely due to failing infrastructure and/or illicit discharges independent of rain events. Similar dynamics may control other streams that transition from agricultural to urban areas with failing infrastructure.
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Senkbeil JK, Ahmed W, Conrad J, Harwood VJ. Use of Escherichia coli genes associated with human sewage to track fecal contamination source in subtropical waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 686:1069-1075. [PMID: 31200304 DOI: 10.1016/j.scitotenv.2019.05.201] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 06/09/2023]
Abstract
Escherichia coli (E. coli) is frequently used in assessment and regulation of recreational water quality, but it is a general fecal indicator that provides no information about fecal contamination source. Sewage-associated microorganisms and related marker genes have proven useful for microbial source tracking (MST) applications that link fecal contamination to host sources, but many MST marker genes are carried in taxa not used in regulatory contexts. A more direct connection with regulatory concerns, including human health risk and total maximum daily load (TMDL) assessments, could be accomplished with tools such as the human-associated marker genes of E. coli. We evaluated the performance of E. coli H8, H12, H14, and H24 marker genes for detection of domestic sewage at the E. coli isolate level in Florida. E. coli isolates (n = 1, 380) from reference fecal and wastewater samples were first tested by binary PCR for the presence of each H marker gene. H8 and H12 were >90% specific and sensitive for domestic sewage, while H14 and H24 were ≤86% specific. Therefore, quantitative PCR (qPCR) assays were used to quantify H8 and H12 marker genes at the sample level. Specificity values for the H8 and H12 qPCR assays were 96 and 93%, respectively, while both marker genes showed 100% sensitivity. H12 concentrations were tenfold lower in wastewater than H8 (~6-7 log10 gene copies (GC)/100 mL). H8 concentrations in wastewater and contaminated environmental water samples were correlated with the sewage-associated Bacteroides HF183 marker gene. This study suggests that E. coli H genes, and H8 in particular, can be useful for sewage contamination tracking and TMDL development in subtropical waters.
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Affiliation(s)
- Jacob K Senkbeil
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, United States of America
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Qld 4102, Australia.
| | - James Conrad
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, United States of America
| | - Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, United States of America
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Zhang Q, Gallard J, Wu B, Harwood VJ, Sadowsky MJ, Hamilton KA, Ahmed W. Synergy between quantitative microbial source tracking (qMST) and quantitative microbial risk assessment (QMRA): A review and prospectus. ENVIRONMENT INTERNATIONAL 2019; 130:104703. [PMID: 31295713 DOI: 10.1016/j.envint.2019.03.051] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 05/20/2023]
Abstract
The use of microbial source tracking (MST) marker genes has grown in recent years due to the need to attribute point and non-point fecal contamination to specific sources. Quantitative microbial risk assessment (QMRA) is a modeling approach used to estimate health risks from exposure to feces-contaminated water and associated pathogens. A combination of these approaches [quantitative MST (qMST) and QMRA] can provide additional pathogen-related information for prioritizing and addressing health risks, compared to reliance on conventional fecal indicator bacteria (FIB). To inform expansion of this approach, a review of published qMST-QMRA studies was conducted to summarize the state of the science and to identify research needs. The reviewed studies primarily aimed to identify what levels of MST marker genes in hypothetical recreational waterbodies would exceed the United States Environmental Protection Agency (USEPA) risk benchmarks for primary contact recreators. The QMRA models calculated relationships between MST marker gene(s) and reference pathogens based on published data in the literature. The development of a robust, accurate relationship was identified as an urgent research gap for qMST-QMRA. This metric requires additional knowledge to quantify the relationship between MST marker genes and the degree of variability in decay of pathogens as a dynamic function of environmental conditions and combinations of fecal sources at multiple spatial and temporal scales. Improved characterization of host shedding rates of host-associated microorganisms (i.e., MST marker genes), as well as fate and transport of these microorganisms and their nucleic acids, would facilitate expansion of this approach to other exposure pathways. Incorporation of information regarding the recovery efficiency, and host-specificity of MST marker genes into QMRA model parameters, and the sensitivity analysis, would greatly improve risk management and site-specific water monitoring criteria.
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Affiliation(s)
- Qian Zhang
- BioTechnology Institute, University of Minnesota, 1479 Gortner Ave, St. Paul, MN 55108, USA
| | - Javier Gallard
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Baolei Wu
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an, Shaanxi 710055, PR China
| | - Valerie J Harwood
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Michael J Sadowsky
- BioTechnology Institute, University of Minnesota, 1479 Gortner Ave, St. Paul, MN 55108, USA; Department of Soil, Water & Climate and Department of Plant & Microbial Biology, University of Minnesota, 1991 Upper Buford Ave, St. Paul, MN 55108, USA
| | - Kerry A Hamilton
- School for Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, USA; The Biodesign Institute Center for Environmental Health Engineering, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85281, USA
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, QLD 4102, Australia.
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22
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Host Specificity and Sensitivity of Established and Novel Sewage-Associated Marker Genes in Human and Nonhuman Fecal Samples. Appl Environ Microbiol 2019; 85:AEM.00641-19. [PMID: 31076423 DOI: 10.1128/aem.00641-19] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/02/2019] [Indexed: 12/13/2022] Open
Abstract
Microbial source tracking (MST) methods measure fecal contamination levels and identify possible sources using quantitative PCR (qPCR) that targets host-associated fecal microorganisms. To date, most established MST assays for human sources, especially bacterial markers, have shown some nonhuman host cross-reactions. Recently developed assays, such as the crAssphage CPQ_056, Lachnospiraceae Lachno3, and Bacteroides BacV6-21, have more limited information on host sensitivity and host specificity for human or sewage sources, particularly in countries other than the United States. In this study, we rigorously evaluated six sewage-associated MST assays (i.e., Bacteroides HF183, human adenovirus [HAdV], human polyomavirus [HPyV], crAssphage CPQ_056, Lachno3, and BacV6-21) to show advantages and disadvantages of their applications for MST. A total of 29 human and 3 sewage samples and 360 nonhuman fecal samples across 14 hosts collected from a subtropical region of Australia were tested for marker host specificity, host sensitivity, and concentrations. All sewage samples were positive for all six marker genes tested in this study. Bacterial markers were more prevalent than viral markers in human feces. Testing against animal hosts showed human feces (or sewage)-associated marker gene specificity was HAdV (1.00) > HPyV (0.99) > crAssphage CPQ_056 (0.98) > HF183 (0.96) > Lachno3 (0.95) > BacV6-21 (0.90), with marker concentrations in some animal fecal samples being 3 to 5 orders of magnitude lower than those in sewage. When considering host specificity, sensitivity, and concentrations in source samples, the HF183, Lachno3, and crAssphage CPQ_056 tests were the most suitable assays in this study for sewage contamination tracking in subtropical waters of Australia.IMPORTANCE Large financial investments are required to remediate fecal contamination sources in waterways, and accurate results from field studies are crucial to build confidence in MST approaches. Host specificity and sensitivity are two main performance characteristics for consideration when choosing MST assays. Ongoing efforts for marker assay validation will improve interpretation of results and could shed light on patterns of occurrence in nontarget hosts that might explain the underlying drivers of cross-reaction of certain markers. For field applications, caution should be taken to choose appropriate MST marker genes and assays based on available host specificity and sensitivity data and background knowledge of the contaminating sources in the study area. Since many waterborne pathogens are viruses, employing both viral and bacterial markers in investigations could provide insight into contamination dynamics and ecological behavior in the environment. Therefore, combined usage of marker assays is recommended for more accurate and informative sewage contamination detection and fecal source resolution.
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23
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Li X, Sivaganesan M, Kelty CA, Zimmer-Faust A, Clinton P, Reichman JR, Johnson Y, Matthews W, Bailey S, Shanks OC. Large-scale implementation of standardized quantitative real-time PCR fecal source identification procedures in the Tillamook Bay Watershed. PLoS One 2019; 14:e0216827. [PMID: 31170166 PMCID: PMC6553688 DOI: 10.1371/journal.pone.0216827] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 04/29/2019] [Indexed: 12/24/2022] Open
Abstract
Fecal pollution management remains one of the biggest challenges for water quality authorities worldwide. Advanced fecal pollution source identification technologies are now available that can provide quantitative information from many animal groups. As public interest in these methodologies grows, it is vital to use standardized procedures with clearly defined data acceptance metrics and conduct field studies demonstrating the use of these techniques to help resolve real-world water quality challenges. Here we apply recently standardized human-associated qPCR methods with custom data acceptance metrics (HF183/BacR287 and HumM2), along with established procedures for ruminant (Rum2Bac), cattle (CowM2 and CowM3), canine (DG3 and DG37), and avian (GFD) fecal pollution sources to (i) demonstrate the feasibility of implementing standardized qPCR procedures in a large-scale field study, and (ii) characterize trends in fecal pollution sources in the research area. A total of 602 water samples were collected over a one-year period at 29 sites along the Trask, Kilchis, and Tillamook rivers and tributaries in the Tillamook Bay Watershed (OR, USA). Host-associated qPCR results were combined with high-resolution geographic information system (GIS) land use and general indicator bacteria (E. coli) measurements to elucidate water quality fecal pollution trends. Results demonstrate the feasibility of implementing standardized fecal source identification qPCR methods with established data acceptance metrics in a large-scale field study leading to new investigative leads suggesting that elevated E. coli levels may be linked to specific pollution sources and land use activities in the Tillamook Bay Watershed.
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Affiliation(s)
- Xiang Li
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
| | - Catherine A. Kelty
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
| | - Amity Zimmer-Faust
- Southern California Coastal Water Research Project, Costa Mesa, CA, United States of America
| | - Pat Clinton
- U.S. Environmental Protection Agency, Office of Research and Development, Newport, OR, United States of America
| | - Jay R. Reichman
- U.S. Environmental Protection Agency, Office of Research and Development, Corvallis, OR, United States of America
| | - York Johnson
- Oregon Department of Environmental Quality & Tillamook Estuaries Partnership, Garibaldi, Oregon, United States of America
| | - William Matthews
- Oregon Department of Agriculture, Salem, Oregon, United States of America
| | - Stephanie Bailey
- U.S. Environmental Protection Agency, Region 10 Manchester Laboratory, Port Orchard, WA, United States of America
| | - Orin C. Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, United States of America
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Mrdjen I, Fennessy S, Schaal A, Dennis R, Slonczewski JL, Lee S, Lee J. Tile Drainage and Anthropogenic Land Use Contribute to Harmful Algal Blooms and Microbiota Shifts in Inland Water Bodies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8215-8223. [PMID: 29952549 DOI: 10.1021/acs.est.8b03269] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Freshwater harmful algal blooms (HABs), driven by nutrient inputs from anthropogenic sources, pose unique risks to human and ecological health worldwide. A major nutrient contributor is agricultural land use, specifically tile drainage discharge. Small lakes and ponds are at elevated risk for HAB appearance, as they are uniquely sensitive to nutrient input. HABs introduce exposure risk to microcystin (MC), hepatotoxic and potentially carcinogenic cyanotoxins. To investigate the impact of anthropogenic land use on small lakes and ponds, 24 sites in central Ohio were sampled over a 3-month period in late summer of 2015. MC concentration, microbial community structure, and water chemistry were analyzed. Land use intensity, including tile drainage systems, was the driver of clustering in principle component analysis, ultimately contributing to nutrient deposition, a driver of HABs. Relative abundance of HAB-forming genera was correlated with elevated concentrations of nitrate and soluble reactive phosphate. One location (FC) showed MC concentrations exceeding 875 μg/L and large community shifts in ciliates (Oligohymenophorea) associated with hypoxic conditions. The prokaryotic community at FC was dominated by Planktothrix sp. These results demonstrate the impact of HABs in small lakes and ponds, and that prevailing issues extend beyond cyanotoxins, such as cascading impacts on other trophic levels.
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Affiliation(s)
- Igor Mrdjen
- Division of Environmental Health Sciences, College of Public Health , The Ohio State University , 1841 Neil Avenue , Columbus , Ohio 43210 , United States
| | - Siobhan Fennessy
- Department of Biology , Kenyon College , 202 North College Road , Gambier , Ohio 43022 , United States
| | - Alex Schaal
- Department of Biology , Kenyon College , 202 North College Road , Gambier , Ohio 43022 , United States
| | - Richard Dennis
- Department of Biology , Kenyon College , 202 North College Road , Gambier , Ohio 43022 , United States
| | - Joan L Slonczewski
- Department of Biology , Kenyon College , 202 North College Road , Gambier , Ohio 43022 , United States
| | - Seungjun Lee
- Division of Environmental Health Sciences, College of Public Health , The Ohio State University , 1841 Neil Avenue , Columbus , Ohio 43210 , United States
| | - Jiyoung Lee
- Division of Environmental Health Sciences, College of Public Health , The Ohio State University , 1841 Neil Avenue , Columbus , Ohio 43210 , United States
- Department of Food Science and Technology , The Ohio State University , Columbus , Ohio 43210 , United States
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25
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Stachler E, Akyon B, de Carvalho NA, Ference C, Bibby K. Correlation of crAssphage qPCR Markers with Culturable and Molecular Indicators of Human Fecal Pollution in an Impacted Urban Watershed. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7505-7512. [PMID: 29874457 DOI: 10.1021/acs.est.8b00638] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Environmental waters are monitored for fecal pollution to protect public health. Many previously developed human-specific fecal pollution indicators lack adequate sensitivity to be reliably detected in environmental waters or do not correlate well with viral pathogens. Recently, two novel human sewage-associated source tracking qPCR markers were developed based on the bacteriophage crAssphage, CPQ_056 and CPQ_064. These assays are highly human specific, abundant in sewage, and are viral-based, suggesting great promise for environmental application as human fecal pollution indicators. A 30-day sampling study was conducted in an urban stream impacted by combined sewer overflows to evaluate the crAssphage markers' performance in an environmental system. The crAssphage markers were present at concentrations of 4.02-6.04 log10 copies/100 mL throughout the study period, indicating their high abundance and ease of detection in polluted environmental waters. In addition, the crAssphage assays were correlated with rain events, molecular markers for human polyomavirus and HF183, as well as culturable E. coli, enterococci, and somatic coliphage. The CPQ_064 assay correlated strongly to a greater number of biological indicators than the CPQ_056 assay. This study is the first to evaluate both crAssphage qPCR assays in an extended environmental application of crAssphage markers for monitoring of environmental waters. It is also the first study to compare crAssphage marker concentration with other viral-based indicators.
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Affiliation(s)
- Elyse Stachler
- Department of Civil and Environmental Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Benay Akyon
- Department of Civil and Environmental Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Nathalia Aquino de Carvalho
- Department of Civil and Environmental Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Christian Ference
- Department of Civil and Environmental Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Kyle Bibby
- Department of Civil and Environmental Engineering , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
- Department of Civil and Environmental Engineering and Earth Sciences , University of Notre Dame , South Bend , Indiana 46556 , United States
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26
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Steele JA, Blackwood AD, Griffith JF, Noble RT, Schiff KC. Quantification of pathogens and markers of fecal contamination during storm events along popular surfing beaches in San Diego, California. WATER RESEARCH 2018; 136:137-149. [PMID: 29501758 DOI: 10.1016/j.watres.2018.01.056] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 01/19/2018] [Accepted: 01/24/2018] [Indexed: 05/08/2023]
Abstract
Along southern California beaches, the concentrations of fecal indicator bacteria (FIB) used to quantify the potential presence of fecal contamination in coastal recreational waters have been previously documented to be higher during wet weather conditions (typically winter or spring) than those observed during summer dry weather conditions. FIB are used for management of recreational waters because measurement of the bacterial and viral pathogens that are the potential causes of illness in beachgoers exposed to stormwater can be expensive, time-consuming, and technically difficult. Here, we use droplet digital Polymerase Chain Reaction (digital PCR) and digital reverse transcriptase PCR (digital RT-PCR) assays for direct quantification of pathogenic viruses, pathogenic bacteria, and source-specific markers of fecal contamination in the stormwater discharges. We applied these assays across multiple storm events from two different watersheds that discharge to popular surfing beaches in San Diego, CA. Stormwater discharges had higher FIB concentrations as compared to proximal beaches, often by ten-fold or more during wet weather. Multiple lines of evidence indicated that the stormwater discharges contained human fecal contamination, despite the presence of separate storm sewer and sanitary sewer systems in both watersheds. Human fecal source markers (up to 100% of samples, 20-12440 HF183 copies per 100 ml) and human norovirus (up to 96% of samples, 25-495 NoV copies per 100 ml) were routinely detected in stormwater discharge samples. Potential bacterial pathogens were also detected and quantified: Campylobacter spp. (up to 100% of samples, 16-504 gene copies per 100 ml) and Salmonella (up to 25% of samples, 6-86 gene copies per 100 ml). Other viral human pathogens were also measured, but occurred at generally lower concentrations: adenovirus (detected in up to 22% of samples, 14-41 AdV copies per 100 ml); no enterovirus was detected in any stormwater discharge sample. Higher concentrations of avian source markers were noted in the stormwater discharge located immediately downstream of a large bird sanctuary along with increased Campylobacter concentrations and notably different Campylobacter species composition than the watershed that had no bird sanctuary. This study is one of the few to directly measure an array of important bacterial and viral pathogens in stormwater discharges to recreational beaches, and provides context for stormwater-based management of beaches during high risk wet-weather periods. Furthermore, the combination of culture-based and digital PCR-derived data is demonstrated to be valuable for assessing hydrographic relationships, considering delivery mechanisms, and providing foundational exposure information for risk assessment.
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Affiliation(s)
- Joshua A Steele
- Southern California Coastal Water Research Project, 3535 Harbor Blvd. Ste 110, Costa Mesa, CA 92626, USA.
| | - A Denene Blackwood
- UNC Institute of Marine Science, 3431 Arendell Street, Morehead City, NC 28557, USA
| | - John F Griffith
- Southern California Coastal Water Research Project, 3535 Harbor Blvd. Ste 110, Costa Mesa, CA 92626, USA
| | - Rachel T Noble
- UNC Institute of Marine Science, 3431 Arendell Street, Morehead City, NC 28557, USA
| | - Kenneth C Schiff
- Southern California Coastal Water Research Project, 3535 Harbor Blvd. Ste 110, Costa Mesa, CA 92626, USA
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Zhuang FF, Li H, Zhou XY, Zhu YG, Su JQ. Quantitative detection of fecal contamination with domestic poultry feces in environments in China. AMB Express 2017; 7:80. [PMID: 28411348 PMCID: PMC5392188 DOI: 10.1186/s13568-017-0379-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 03/31/2017] [Indexed: 11/25/2022] Open
Abstract
Poultry are an important source of fecal contamination in environments. However, tools for detecting and tracking this fecal contamination are in the early stages of development. In practice, we have found that source tracking methods targeting the 16S rRNA genes of poultry-specific microbiota are not sufficiently sensitive. We therefore developed two quantitative PCR assays for detection of poultry fecal contamination, by targeting chicken and duck mitochondrial genes: NADH dehydrogenase subunit 5 (ND5) and cytochrome b (cytb). The sensitivity of both assays was 100% when tested on 50 chicken and duck fecal samples from 10 provinces of China. These assays were also tested in field samples, including soil and water collected adjacent to duck farms, and soils fertilized with chicken manure. Poultry mitochondrial DNA was detected in most of these samples, indicating that the assays are a robust method for monitoring environmental contamination with poultry feces. Complemented with existing indicators of fecal contamination, these markers should improve the efficiency and accuracy of microbial source tracking.
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28
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Prahlow JA, Cameron T, Arendt A, Cornelis K, Bontrager A, Suth MS, Black L, Tobey R, Pollock S, Stur S, Cotter K, Gabrielse J. DNA testing in homicide investigations. MEDICINE, SCIENCE, AND THE LAW 2017; 57:179-191. [PMID: 28776465 DOI: 10.1177/0025802417721790] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Objectives With the widespread use of DNA testing, police, death investigators, and attorneys need to be aware of the capabilities of this technology. This review provides an overview of scenarios where DNA evidence has played a major role in homicide investigations in order to highlight important educational issues for police, death investigators, forensic pathologists, and attorneys. Methods This was a nonrandom, observational, retrospective study. Data were obtained from the collective files of the authors from casework during a 15-year period, from 2000 through 2014. Results A series of nine scenarios, encompassing 11 deaths, is presented from the standpoint of the police and death investigation, the forensic pathology autopsy performance, the subsequent DNA testing of evidence, and, ultimately, the final adjudication of cases. Details of each case are presented, along with a discussion that focuses on important aspects of sample collection for potential DNA testing, especially at the crime scene and the autopsy. The presentation highlights the diversity of case and evidence types in which DNA testing played a valuable role in the successful prosecution of the case. Conclusions By highlighting homicides where DNA testing contributed to the successful adjudication of cases, police, death investigators, forensic pathologists, and attorneys will be better informed regarding the types of evidence and situations where such testing is of potential value.
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Affiliation(s)
- Joseph A Prahlow
- 1 Western Michigan University Homer Stryker M.D. School of Medicine, USA
| | - Thomas Cameron
- 2 Metro Homicide Unit, USA
- 3 South Bend Police Department, USA
| | | | - Kenneth Cornelis
- 2 Metro Homicide Unit, USA
- 5 St. Joseph County Sheriff Department, USA
| | | | | | - Lisa Black
- 6 Indiana State Police Laboratory, Forensic Biology Unit, USA
| | - Rebbecca Tobey
- 6 Indiana State Police Laboratory, Forensic Biology Unit, USA
| | - Sharon Pollock
- 6 Indiana State Police Laboratory, Forensic Biology Unit, USA
| | - Shawn Stur
- 6 Indiana State Police Laboratory, Forensic Biology Unit, USA
| | | | - Joel Gabrielse
- 7 St. Joseph County Prosecutors Office, USA
- 8 United States Department of Justice, Northern District of Indiana, USA
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29
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Staley ZR, Grabuski J, Sverko E, Edge TA. Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls. Appl Environ Microbiol 2016; 82:6357-6366. [PMID: 27542934 DOI: 10.1128/aem.01675-01616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/11/2016] [Indexed: 05/20/2023] Open
Abstract
UNLABELLED Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log10 CFU/100 ml, and 7.65 log10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. IMPORTANCE Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can potentially degrade water quality and pose risks to human and ecosystem health. Therefore, identifying fecal contamination in storm water runoff and outfalls is essential for remediation efforts to reduce risks to public health. This study employed multiple methods of identifying levels and sources of fecal contamination in both river and storm water outfall sites, evaluating the efficacy of using culture-based enumeration of E. coli, molecular methods of determining the source(s) of contamination, and CST markers as indicators of fecal contamination. The results identified pervasive human sewage contamination in storm water outfalls and throughout an urban watershed and highlight the utility of using both MST and CST to identify raw sewage contamination.
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Affiliation(s)
- Zachery R Staley
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - Josey Grabuski
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - Ed Sverko
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada
| | - Thomas A Edge
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, Ontario, Canada
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Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls. Appl Environ Microbiol 2016; 82:6357-6366. [PMID: 27542934 DOI: 10.1128/aem.01675-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/11/2016] [Indexed: 12/26/2022] Open
Abstract
Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log10 CFU/100 ml, and 7.65 log10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. IMPORTANCE Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can potentially degrade water quality and pose risks to human and ecosystem health. Therefore, identifying fecal contamination in storm water runoff and outfalls is essential for remediation efforts to reduce risks to public health. This study employed multiple methods of identifying levels and sources of fecal contamination in both river and storm water outfall sites, evaluating the efficacy of using culture-based enumeration of E. coli, molecular methods of determining the source(s) of contamination, and CST markers as indicators of fecal contamination. The results identified pervasive human sewage contamination in storm water outfalls and throughout an urban watershed and highlight the utility of using both MST and CST to identify raw sewage contamination.
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Staley ZR, Edge TA. Comparative microbial source tracking methods for identification of fecal contamination sources at Sunnyside Beach in the Toronto region area of concern. JOURNAL OF WATER AND HEALTH 2016; 14:839-850. [PMID: 27740549 DOI: 10.2166/wh.2016.296] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Several beaches within the Toronto region area of concern have persistent issues with fecal contamination, causing a beach beneficial use impairment (BUI). In this study, Escherichia coli, including ampicillin-resistant strains, were enumerated via culturable and quantitative polymerase chain reaction (qPCR) methods. Microbial source tracking (MST) markers (for general Bacteroidales, human, ruminant/cow, gull, and dog) were detected and enumerated via PCR and qPCR to identify sources of fecal contamination at Sunnyside Beach and in the Humber River. Human, cow, and dog markers had good host-specificity, while gull markers sometimes amplified a few other bird species. The ruminant endpoint PCR marker amplified a variety of other animal species rendering it less useful. Both human and gull fecal contamination were prevalent in the Humber River, while Sunnyside Beach was predominantly impacted by gull fecal contamination. Human sewage impacts were more prevalent in the lower Humber River, particularly in Black Creek. However, to reduce Sunnyside beach postings, reducing bird fecal contamination in the river and at the beach would be necessary. When there are high levels of E. coli throughout a beachshed, an MST toolbox approach can add value to discriminate source(s) of E. coli contamination and guide decisions relating to public health risk and remediation strategies.
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Affiliation(s)
- Zachery R Staley
- Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada E-mail:
| | - Thomas A Edge
- Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada E-mail:
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Shanks OC, Kelty CA, Oshiro R, Haugland RA, Madi T, Brooks L, Field KG, Sivaganesan M. Data Acceptance Criteria for Standardized Human-Associated Fecal Source Identification Quantitative Real-Time PCR Methods. Appl Environ Microbiol 2016; 82:2773-2782. [PMID: 26921430 PMCID: PMC4836407 DOI: 10.1128/aem.03661-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/23/2016] [Indexed: 11/20/2022] Open
Abstract
There is growing interest in the application of human-associated fecal source identification quantitative real-time PCR (qPCR) technologies for water quality management. The transition from a research tool to a standardized protocol requires a high degree of confidence in data quality across laboratories. Data quality is typically determined through a series of specifications that ensure good experimental practice and the absence of bias in the results due to DNA isolation and amplification interferences. However, there is currently a lack of consensus on how best to evaluate and interpret human fecal source identification qPCR experiments. This is, in part, due to the lack of standardized protocols and information on interlaboratory variability under conditions for data acceptance. The aim of this study is to provide users and reviewers with a complete series of conditions for data acceptance derived from a multiple laboratory data set using standardized procedures. To establish these benchmarks, data from HF183/BacR287 and HumM2 human-associated qPCR methods were generated across 14 laboratories. Each laboratory followed a standardized protocol utilizing the same lot of reference DNA materials, DNA isolation kits, amplification reagents, and test samples to generate comparable data. After removal of outliers, a nested analysis of variance (ANOVA) was used to establish proficiency metrics that include lab-to-lab, replicate testing within a lab, and random error for amplification inhibition and sample processing controls. Other data acceptance measurements included extraneous DNA contamination assessments (no-template and extraction blank controls) and calibration model performance (correlation coefficient, amplification efficiency, and lower limit of quantification). To demonstrate the implementation of the proposed standardized protocols and data acceptance criteria, comparable data from two additional laboratories were reviewed. The data acceptance criteria proposed in this study should help scientists, managers, reviewers, and the public evaluate the technical quality of future findings against an established benchmark.
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Affiliation(s)
- Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio, USA
| | - Catherine A Kelty
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio, USA
| | - Robin Oshiro
- U.S. Environmental Protection Agency, Office of Water, Washington DC, USA
| | - Richard A Haugland
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio, USA
| | - Tania Madi
- Source Molecular Corporation, Miami, Florida, USA
| | - Lauren Brooks
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Katharine G Field
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | - Mano Sivaganesan
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio, USA
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Staley ZR, Robinson C, Edge TA. Comparison of the occurrence and survival of fecal indicator bacteria in recreational sand between urban beach, playground and sandbox settings in Toronto, Ontario. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 541:520-527. [PMID: 26432162 DOI: 10.1016/j.scitotenv.2015.09.088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
While beach sands are increasingly being studied as a reservoir of fecal indicator bacteria (FIB), less is known about the occurrence of FIB in other recreational sands (i.e., sandboxes and playgrounds). In this study, different culture-based FIB enumeration techniques were compared and microbial source tracking assays were conducted on recreational sand samples from beaches, playgrounds and sandboxes around Toronto, ON. FIB were detected in every sand sample (n=104) with concentrations not changing significantly over the five month sampling period. Concentrations of FIB and a gull-specific DNA marker were significantly higher in foreshore beach sands, and indicated these were a more significant reservoir of FIB contamination than sandbox or playground sands. Human- and dog-specific contamination markers were not detected. All culture-based FIB enumeration techniques were consistent in identifying the elevated FIB concentrations associated with foreshore beach sands. However, significant differences between differential agar media, IDEXX and Aquagenx Compartment Bag Test were observed, with DC media and Enterolert being the most sensitive methods to detect Escherichia coli and enterococci, respectively. To better understand the elevated occurrence of E. coli in foreshore sands, microcosm survival experiments were conducted at two different temperatures (15 °C and 28 °C) using non-sterile saturated foreshore beach sands collected from two urban freshwater beaches with different sand type (fine grain and sand-cobble). Microcosms were inoculated with a mixture of eight sand-derived E. coli strains and sampled over a 28-day period. E. coli levels were found to decline in all microcosms, although survival was significantly greater in the finer sand and at the cooler temperature (15 °C). These results indicate that FIB can be widespread in any type of recreational sand and, while E. coli can survive for many weeks, it is most likely to accumulate in cooler fine-grain sand as occurs below the foreshore sand surface.
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Affiliation(s)
- Zachery R Staley
- Department of Civil and Environmental Engineering, Western University, London, ON, Canada; Environment Canada, Canada Centre for Inland Waters, Burlington, ON, Canada.
| | - Clare Robinson
- Department of Civil and Environmental Engineering, Western University, London, ON, Canada
| | - Thomas A Edge
- Environment Canada, Canada Centre for Inland Waters, Burlington, ON, Canada
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Identification of Specialists and Abundance-Occupancy Relationships among Intestinal Bacteria of Aves, Mammalia, and Actinopterygii. Appl Environ Microbiol 2015; 82:1496-1503. [PMID: 26712546 DOI: 10.1128/aem.02456-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/16/2015] [Indexed: 11/20/2022] Open
Abstract
The coalescence of next-generation DNA sequencing methods, ecological perspectives, and bioinformatics analysis tools is rapidly advancing our understanding of the evolution and function of vertebrate-associated bacterial communities. Delineation of host-microbe associations has applied benefits ranging from clinical treatments to protecting our natural waters. Microbial communities follow some broad-scale patterns observed for macroorganisms, but it remains unclear how the specialization of intestinal vertebrate-associated communities to a particular host environment influences broad-scale patterns in microbial abundance and distribution. We analyzed the V6 region of 16S rRNA genes amplified from 106 fecal samples spanning Aves, Mammalia, and Actinopterygii (ray-finned fish). We investigated the interspecific abundance-occupancy relationship, where widespread taxa tend to be more abundant than narrowly distributed taxa, among operational taxonomic units (OTUs) within and among host species. In a separate analysis, we identified specialist OTUs that were highly abundant in a single host and rare in all other hosts by using a multinomial model without excluding undersampled OTUs a priori. We show that intestinal microbes in humans and other vertebrates display abundance-occupancy relationships, but because intestinal host-associated communities have undergone intense specialization, this trend is violated by a disproportionately large number of specialist taxa. Although it is difficult to distinguish the effects of dispersal limitations, host selection, historical contingency, and stochastic processes on community assembly, results suggest that intestinal bacteria can be shared among diverse hosts in ways that resemble the distribution of "free-living" bacteria in the extraintestinal environment.
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