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Kahler AM, Hofstetter J, Arrowood M, Peterson A, Jacobson D, Barratt J, da Silva ALBR, Rodrigues C, Mattioli MC. Sources and Prevalence of Cyclospora cayetanensis in Southeastern U.S. Growing Environments. J Food Prot 2024; 87:100309. [PMID: 38815808 DOI: 10.1016/j.jfp.2024.100309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/01/2024]
Abstract
Recent cyclosporiasis outbreaks associated with fresh produce grown in the United States highlight the need to better understand Cyclospora cayetanensis prevalence in U.S. agricultural environments. In this study, C. cayetanensis occurrence was assessed in municipal wastewater sludge, on-farm portable toilets, irrigation pond water, and spent packing house dump tank water in a Southeastern Georgia growing region over two years. Detection of the C. cayetanensis 18S rRNA qPCR gene target in pond samples was 0%, 28%, and 42% (N = 217) depending on the detection definition used, and ≤1% in dump tank samples (N = 46). However, no qPCR detections were confirmed by sequencing, suggesting false detection occurred due to cross-reactions. C. cayetanensis qPCR detections were confirmed in 9% of wastewater sludge samples (N = 76). The human-specific fecal markers HF183 and crAssphage were detected in 33% and 6% of pond samples, respectively, and 4% and 0% of dump tank samples, respectively. Despite community Cyclospora shedding and evidence of human fecal contamination in irrigation water, there was no correlation between C. cayetanensis and HF183 qPCR detections, further supporting that 18S gene target qPCR amplifications were due to cross-reactions. When evaluating C. cayetanensis qPCR environmental detection data, the impact of assay specificity and detection criteria should be considered. Moreover, additional sequence-based testing may be needed to appropriately interpret Cyclospora qPCR environmental data.
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Affiliation(s)
- Amy M Kahler
- Centers for Disease Control and Prevention (CDC), Division of Foodborne, Waterborne, and Environmental Diseases, Atlanta, GA 30329, USA
| | - Jessica Hofstetter
- Chenega Enterprise Systems & Solutions, LLC, Chesapeake, VA 23320, USA; Auburn University, Department of Horticulture, Auburn, AL 36849, USA
| | - Michael Arrowood
- Centers for Disease Control and Prevention (CDC), Division of Foodborne, Waterborne, and Environmental Diseases, Atlanta, GA 30329, USA
| | - Anna Peterson
- Centers for Disease Control and Prevention (CDC), Division of Parasitic Diseases and Malaria, Atlanta, GA 30329, USA
| | - David Jacobson
- Centers for Disease Control and Prevention (CDC), Division of Parasitic Diseases and Malaria, Atlanta, GA 30329, USA
| | - Joel Barratt
- Centers for Disease Control and Prevention (CDC), Division of Parasitic Diseases and Malaria, Atlanta, GA 30329, USA
| | | | - Camila Rodrigues
- Auburn University, Department of Horticulture, Auburn, AL 36849, USA
| | - Mia C Mattioli
- Centers for Disease Control and Prevention (CDC), Division of Foodborne, Waterborne, and Environmental Diseases, Atlanta, GA 30329, USA.
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2
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Jordan MA, Ojeda AS, Larson EA, Rogers SR. Investigating the Relationship between Surface Water Pollution and Onsite Wastewater Treatment Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17042-17050. [PMID: 37878501 DOI: 10.1021/acs.est.2c09590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Onsite wastewater treatment systems (OWTSs) are important nonpoint sources (NPSs) of pollution to consider in watershed management. However, limited OWTS data availability makes it challenging to account for them as an NPS of water pollution. In this study, we succeeded in obtaining OWTS permits and integrated them with environmental data to model the pollution potential from OWTSs at the watershed scale using GIS-based multicriteria decision analysis. Then, in situ water quality parameters─Escherichia coli (E. coli), total nitrogen, total phosphorus, temperature, and pH─were measured along the main tributary at base-flow conditions. Three general linear models were developed to relate E. coli to water quality parameters and OWTS pollution indicators. It was found that the model with the OWTS pollution potential had the lowest corrected Akaike information criterion (AICc) value (35.01) compared to the models that included classified OWTS pollution potential input criteria (AICc = 36.76) and land cover (AICc = 36.74). These results demonstrate that OWTSs are a significant contributor to surface water pollution, and future efforts should be made to improve access to OWTS data (i.e., location and age) to account for these systems as an NPS of water pollution.
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Affiliation(s)
- Mallory A Jordan
- Department of Geosciences, Auburn University, Auburn, Alabama 36849, United States
| | - Ann S Ojeda
- Department of Geosciences, Auburn University, Auburn, Alabama 36849, United States
| | - Eleanore A Larson
- Department of Geosciences, Auburn University, Auburn, Alabama 36849, United States
| | - Stephanie R Rogers
- Department of Geosciences, Auburn University, Auburn, Alabama 36849, United States
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3
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Flores ME, Jafarzadeh A, Moghadam SV, Vadde KK, Dhar DA, Nunu RR, Kapoor V. Occurrence and removal of fecal bacteria and microbial source tracking markers in a stormwater detention basin overlying the Edwards Aquifer recharge zone in Texas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:103836-103850. [PMID: 37691063 DOI: 10.1007/s11356-023-29636-w] [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: 04/19/2023] [Accepted: 08/28/2023] [Indexed: 09/12/2023]
Abstract
The Edwards Aquifer is the primary water resource for over 2 million people in Texas and faces challenges including fecal contamination of water recharging the aquifer, while effectiveness of best management practices (BMPs) such as detention basins in mitigating fecal pollution remains poorly understood. For this study, the inlet and outlet of a detention basin overlying the aquifer's recharge zone were sampled following storm events using automated samplers. Microbial source tracking and culture-based methods were used to determine the occurrence and removal of fecal genetic markers and fecal coliform bacteria in collected water samples. Markers included E. coli (EC23S857), Enterococcus (Entero1), human (HF183), canine (BacCan), and bird (GFD). Fecal coliforms, EC23S857, and Entero1 were detected following each storm event. GFD was the most frequent host-associated marker detected (91% of samples), followed by BacCan (46%), and HF183 (17%). Wilcoxon signed rank tests indicated significantly lower outlet concentrations for fecal coliforms, EC23S857, and Entero1, but not for HF183, GFD, and BacCan. Higher GFD and BacCan outlet concentrations may be due to factors independent of basin design, such as the non-point source nature of bird fecal contamination and domestic dog care practices in neighborhoods contributing to the basin. Mann-Whitney tests showed marker concentrations were not significantly higher during instances of fecal coliform water quality criterion exceedance, except for E. coli, and that fecal coliform concentrations were not significantly different based on marker detection. Overall, results suggest that the detention basin is effective in attenuating fecal contamination associated with fecal coliforms and the general markers, but not for host-associated markers. Consequently, management efforts should focus on mitigating dog and bird-associated fecal pollution in the study region.
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Affiliation(s)
- Mauricio Eduardo Flores
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
- Southwest Research Institute, 6220 Culebra Rd, San Antonio, TX, 78238, USA
| | - Arash Jafarzadeh
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Sina Vedadi Moghadam
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Kiran Kumar Vadde
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Dipti Anik Dhar
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Rebecca R Nunu
- Southwest Research Institute, 6220 Culebra Rd, San Antonio, TX, 78238, USA
| | - Vikram Kapoor
- School of Civil & Environmental Engineering, and Construction Management, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
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Hart JJ, Jamison MN, McNair JN, Woznicki SA, Jordan B, Rediske RR. Using watershed characteristics to enhance fecal source identification. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 336:117642. [PMID: 36907065 DOI: 10.1016/j.jenvman.2023.117642] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/17/2022] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Fecal pollution is one of the most prevalent forms of pollution affecting waterbodies worldwide, threatening public health and negatively impacting aquatic environments. Microbial source tracking (MST) applies polymerase chain reaction (PCR) technology to help identify the source of fecal pollution. In this study, we combine spatial data for two watersheds with general and host-associated MST markers to target human (HF183/BacR287), bovine (CowM2), and general ruminant (Rum2Bac) sources. Concentrations of MST markers in samples were determined with droplet digital PCR (ddPCR). The three MST markers were detected at all sites (n = 25), but bovine and general ruminant markers were significantly associated with watershed characteristics. MST results, combined with watershed characteristics, suggest that streams draining areas with low-infiltration soil groups and high agricultural land use are at an increased risk for fecal contamination. Microbial source tracking has been applied in numerous studies to aid in identifying the sources of fecal contamination, but these studies usually lack information on the involvement of watershed characteristics. Our study combined watershed characteristics with MST results to provide more comprehensive insight into the factors that influence fecal contamination in order to implement the most effective best management practices.
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Affiliation(s)
- John J Hart
- Robert B. Annis Water Resources Institute, 740 West Shoreline Dr, Muskegon, MI, 49441, USA.
| | - Megan N Jamison
- Oakland University, Department of Chemistry, 146 Library Dr., Rochester, MI, 48309, USA.
| | - James N McNair
- Robert B. Annis Water Resources Institute, 740 West Shoreline Dr, Muskegon, MI, 49441, USA.
| | - Sean A Woznicki
- Oakland University, Department of Chemistry, 146 Library Dr., Rochester, MI, 48309, USA.
| | - Ben Jordan
- Ottawa Conservation District, 16731 Ferris St, Grand Haven, MI, 49417, USA.
| | - Richard R Rediske
- Robert B. Annis Water Resources Institute, 740 West Shoreline Dr, Muskegon, MI, 49441, USA.
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Sresung M, Paisantham P, Ruksakul P, Kongprajug A, Chyerochana N, Gallage TP, Srathongneam T, Rattanakul S, Maneein S, Surasen C, Passananon S, Mongkolsuk S, Sirikanchana K. Microbial source tracking using molecular and cultivable methods in a tropical mixed-use drinking water source to support water safety plans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162689. [PMID: 36898534 DOI: 10.1016/j.scitotenv.2023.162689] [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: 12/10/2022] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Microbial contamination deteriorates source water quality, posing a severe problem for drinking water suppliers worldwide and addressed by the Water Safety Plan framework to ensure high-quality and reliable drinking water. Microbial source tracking (MST) is used to examine different microbial pollution sources via host-specific intestinal markers for humans and different types of animals. However, the application of MST in tropical surface water catchments that provide raw water for drinking water supplies is limited. We analyzed a set of MST markers, namely, three cultivable bacteriophages and four molecular PCR and qPCR assays, together with 17 microbial and physicochemical parameters, to identify fecal pollution from general, human-, swine-, and cattle-specific sources. Seventy-two river water samples at six sampling sites were collected over 12 sampling events during wet and dry seasons. We found persistent fecal contamination via the general fecal marker GenBac3 (100 % detection; 2.10-5.42 log10 copies/100 mL), with humans (crAssphage; 74 % detection; 1.62-3.81 log10 copies/100 mL) and swine (Pig-2-Bac; 25 % detection; 1.92-2.91 log10 copies/100 mL). Higher contamination levels were observed during the wet season (p < 0.05). The conventional PCR screening used for the general and human markers showed 94.4 % and 69.8 % agreement with the respective qPCR results. Specifically, in the studied watershed, coliphage could be a screening parameter for the crAssphage marker (90.6 % and 73.7 % positive and negative predictive values; Spearman's rank correlation coefficient = 0.66; p < 0.001). The likelihood of detecting the crAssphage marker significantly increased when total and fecal coliforms exceeded 20,000 and 4000 MPN/100 mL, respectively, as Thailand Surface Water Quality Standards, with odds ratios and 95 % confidence intervals of 15.75 (4.43-55.98) and 5.65 (1.39-23.05). Our study confirms the potential benefits of incorporating MST monitoring into water safety plans, supporting the use of this approach to ensure high-quality drinking water supplies worldwide.
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Affiliation(s)
- Montakarn Sresung
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Phongsawat Paisantham
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Pacharaporn Ruksakul
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Akechai Kongprajug
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Natcha Chyerochana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Tharindu Pollwatta Gallage
- Program in Environmental Toxicology, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Thitima Srathongneam
- Program in Applied Biological Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Surapong Rattanakul
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Siriwara Maneein
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Chatsinee Surasen
- Water Resources and Environment Department, Metropolitan Waterworks Authority, Bangkok 10210, Thailand
| | - Somsak Passananon
- Line of Deputy Governor (Water Production), Metropolitan Waterworks Authority, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailand.
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6
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Digaletos M, Ptacek CJ, Thomas J, Liu Y. Chemical and biological tracers to identify source and transport pathways of septic system contamination to streams in areas with low permeability soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:161866. [PMID: 36709906 DOI: 10.1016/j.scitotenv.2023.161866] [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: 09/10/2022] [Revised: 01/13/2023] [Accepted: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Septic systems are widely used in rural areas that lack centralized sewage treatment systems. Incomplete removal of domestic wastewater contaminants in septic systems can lead to leaching of nutrients (P and N), bacteria/viruses, and trace contaminants to surrounding groundwater and surface water. This study focuses on delineating the fate of wastewater contaminants in localities where septic systems are installed in moderate to fine-grained overburden materials to assess potential impacts on groundwater and surface water quality in these settings. Nutrients and a suite of anthropogenic tracers, including host-specific fecal indicator bacteria (bovine- and human-specific Bacteroides), pharmaceutical compounds (caffeine, carbamazepine, gemfibrozil, ibuprofen, naproxen, and sulfamethoxazole), and an artificial sweetener (acesulfame-K), were selected to evaluate differences in transport properties. Surface water samples (n = 103) were collected from streams upstream (US) and downstream (DS) of three rural hamlets up to two times monthly over one year. Results indicate the presence of wastewater indicators in the streams, with DS locations showing significantly elevated concentrations of both chemical and biological anthropogenic tracers. Human-specific Bacteroides, caffeine, and acesulfame-K were consistently observed at elevated concentrations at all DS sites. Nutrients exhibited varied concentrations between US and DS locations at three study sites. The occurrence of human-specific Bacteroides in the surface water samples suggests the presence of preferential flow pathways within the silt/clay overburden. These results demonstrate the advantages of using a combined tracer approach, involving a conservative tracer such as acesulfame-K coupled with the human-specific biological indicator Bacteroides (BacHum), to understand not only impacting sources but also potential transport pathways of septic system contamination to nearby streams. Septic systems may be an underappreciated contaminant source in rural hamlets located in fine-grained overburden materials; although, a distinction of specific nutrient sources (septic systems vs. agriculture) remains challenging.
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Affiliation(s)
- Maria Digaletos
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - Carol J Ptacek
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - Janis Thomas
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd., Toronto, Ontario M9P 3V6, Canada; Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada
| | - YingYing Liu
- Department of Earth and Environmental Sciences, University of Waterloo, 200 University Ave. W, Waterloo, Ontario N2L 3G1, Canada.
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Christenson E, Wickersham L, Jacob M, Stewart J. A watershed study assessing effects of commercial hog operations on microbial water quality in North Carolina, USA. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156085. [PMID: 35605858 DOI: 10.1016/j.scitotenv.2022.156085] [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: 03/12/2022] [Revised: 05/10/2022] [Accepted: 05/16/2022] [Indexed: 05/31/2023]
Abstract
Commercial Hog Operations (CHOs) produce large amounts of fecal waste, which is often treated in lagoons and sprayed onto fields as fertilizer. The effects of these systems on proximal water quality compared to ambient conditions have not been well-studied, and are particularly important for understanding the dissemination of fecal bacteria and antimicrobial resistance. A longitudinal, case-control watershed study was designed to study effects of CHOs on microbial water quality among watersheds with similar soil, land use, human population, and area. We compared watersheds with (n = 13) and without (n = 9) CHOs over one year measuring fecal indicator bacteria (FIB), microbial source tracking (MST) fecal markers, and antimicrobial resistance in isolated Escherichia coli. E. coli concentrations were higher (p < 0.001) at sites downstream of CHOs (1284 CFU/100 mL, n = 103) compared to background sites (687 CFU/100 mL, n = 74). The human MST marker HF183 was detected at similarly low concentrations (PR = 1.3 (0.91, 1.8), p = 0.30). However, the swine MST marker pig-2-bac was found at more sites downstream of CHOs (PR = 3.5 (0.98, 12), p = 0.035) and at a significantly higher (p = 0.003) mean concentration at sites downstream of CHOs (283 copies/mL) compared to background sites (0.76 copies/mL). The presence of any antimicrobial resistance was observed more often for E. coli isolated downstream from CHOs (19%, n = 556) than background sites (6%, n = 356), with tetracycline resistance observed most often. Nine isolates from four sites downstream of CHOs and one isolate from a background site were confirmed β-lactamase-producing E. coli. Overall, these results show that fecal microbes and antimicrobial resistance from CHOs may be transported off-site, however more research is needed to characterize timing and conditions of off-site transport. Mitigation strategies such as optimizeation of waste treatment, buffers, and antibiotic stewardship could help reduce the contributions of microbial contaminants to surface water.
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Affiliation(s)
- Elizabeth Christenson
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, USA.
| | - Lindsay Wickersham
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, USA
| | - Megan Jacob
- Population Health & Pathobiology, North Carolina State University, Raleigh, NC, USA
| | - Jill Stewart
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, NC, USA
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Sources and Drivers of ARGs in Urban Streams in Atlanta, Georgia, USA. Microorganisms 2022; 10:microorganisms10091804. [PMID: 36144405 PMCID: PMC9503305 DOI: 10.3390/microorganisms10091804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/01/2022] [Accepted: 09/01/2022] [Indexed: 11/16/2022] Open
Abstract
The spread of antibiotic resistance genes (ARGs) in the aquatic environment is an emerging concern in the interest of protecting public health. Stemming the environmental dissemination of ARGs will require a better understanding of the sources and drivers of ARGs in the water environment. In this study, we used direct measurement of sewage-associated molecular markers, the class 1 integron gene, standard water quality parameters, and watershed characteristics to evaluate the sources and drivers of ARGs in an urban watershed impacted by a gradient of human activities. Quantitative polymerase chain reaction (qPCR) was used to quantify the abundance of the sewage-associated HF183, the E. coli fecal indicator, class 1 integron gene (int1), and the ARGs sulI, sulII, tetW, tetM, ampC, and blaSHV in stream water samples collected from the Proctor Creek watershed in Atlanta, Georgia. Our findings show that ARGs were widely distributed, with detection frequencies of 96% (sulI and sulII), 82% (tetW and tetM), and 49% (ampC and blaSHV). All the ARGs were positively and significantly correlated (r > 0.5) with the HF183 and E. coli markers. Non-linear machine learning models developed using generalized boosting show that more than 70% of the variation in ARG loads in the watershed could be explained by fecal source loading, with other factors such as class 1 integron, which is associated with acquired antibiotic resistance, and environmental factors contributing < 30% to ARG variation. These results suggest that input from fecal sources is a more critical driver of ARG dissemination than environmental stressors or horizontal gene transfer in aquatic environments highly impacted by anthropogenic pollution. Finally, our results provide local watershed managers and stakeholders with information to mitigate the burden of ARGs and fecal bacteria in urban streams.
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Damashek J, Westrich JR, McDonald JMB, Teachey ME, Jackson CR, Frye JG, Lipp EK, Capps KA, Ottesen EA. Non-point source fecal contamination from aging wastewater infrastructure is a primary driver of antibiotic resistance in surface waters. WATER RESEARCH 2022; 222:118853. [PMID: 35870389 DOI: 10.1016/j.watres.2022.118853] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 07/06/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Antibiotic resistance is a global threat to human health. Many surface water resources are environmental hotspots of antibiotic resistant gene (ARG) transfer, with agricultural runoff and human waste highlighted as common sources of ARGs to aquatic systems. Here we quantified fecal marker genes and ARGs in 992 stream water samples collected seasonally during a 5-year period from 115 sites across the Upper Oconee watershed (Georgia, USA), an area characterized by gradients of agricultural and urban development. Widespread fecal contamination was found from humans (48% of samples), ruminants (55%), and poultry (19%), and 73% of samples tested positive for at least one of the six targeted ARGs (ermB, tet(B), blaCTX-M-1, blaKPC, blaSHV, and qnrS). While ARGs were strongly correlated with human fecal markers, many highly contaminated samples were not associated with sewage outfalls, an expected source of fecal and ARG pollution. To determine sources of contamination, we synthesized ARG and fecal marker data with geospatial data on land use/land cover and wastewater infrastructure across the watershed. This novel analysis found strong correlations between ARGs and measures of sewer density, sewer length, and septic system age within sample watersheds, indicating non-point sources of fecal contamination from aging wastewater infrastructure can be critical disseminators of anthropogenic ARGs in the environment.
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Affiliation(s)
- Julian Damashek
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA 30602, USA
| | - Jason R Westrich
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA 30602, USA
| | - Jacob M Bateman McDonald
- Lewis F. Rogers Institute for Environmental and Spatial Analysis, University of North Georgia, 2636 Mathis Drive, Oakwood, GA 30566, USA
| | - Morgan E Teachey
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA 30602, USA
| | - Charlene R Jackson
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, USDA-ARS, 950 College Station Road, Athens, GA 30605, USA
| | - Jonathan G Frye
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, USDA-ARS, 950 College Station Road, Athens, GA 30605, USA
| | - Erin K Lipp
- Department of Environmental Health Science, University of Georgia, 150 East Green Street, Athens, GA 30602, USA
| | - Krista A Capps
- Odum School of Ecology, University of Georgia, 140 East Green Street, Athens, GA 30602, USA; Savannah River Ecology Laboratory, University of Georgia, SRS Building 737A, Aiken, SC 29808, USA
| | - Elizabeth A Ottesen
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA 30602, USA.
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10
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Flood MT, Hernandez-Suarez JS, Nejadhashemi AP, Martin SL, Hyndman D, Rose JB. Connecting microbial, nutrient, physiochemical, and land use variables for the evaluation of water quality within mixed use watersheds. WATER RESEARCH 2022; 219:118526. [PMID: 35598465 DOI: 10.1016/j.watres.2022.118526] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/15/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
As non-point sources of pollution begin to overtake point sources in watersheds, source identification and complicating variables such as rainfall are growing in importance. Microbial source tracking (MST) allows for identification of fecal contamination sources in watersheds; when combined with data on land use and co-occuring variables (e.g., nutrients, sediment runoff) MST can provide a basis for understanding how to effectively remediate water quality. To determine spatial and temporal trends in microbial contamination and correlations between MST and nutrients, water samples (n = 136) were collected between April 2017 and May of 2018 during eight sampling events from 17 sites in 5 mixed-use watersheds. These samples were analyzed for three MST markers (human - B. theta; bovine - CowM2; porcine - Pig2Bac) along with E. coli, nutrients (nitrogen and phosphorus species), and physiochemical paramaters. These water quality variables were then paired with data on land use, streamflow, precipitation and management practices (e.g., tile drainage, septic tank density, tillage practices) to determine if any significant relationships existed between the observed microbial contamination and these variables. The porcine marker was the only marker that was highly correlated (p value <0.05) with nitrogen and phosphorus species in multiple clustering schemes. Significant relationships were also identified between MST markers and variables that demonstrated temporal trends driven by precipitation and spatial trends driven by septic tanks and management practices (tillage and drainage) when spatial clustering was employed.
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Affiliation(s)
- Matthew T Flood
- Department of Fisheries and Wildlife, Michigan State University, East Lansing MI 48824, USA.
| | | | - A Pouyan Nejadhashemi
- Department of Biosystems and Agricultural Engineering, Michigan State University, East Lansing MI 48824, USA
| | - Sherry L Martin
- Department of Earth and Environmental Sciences, Michigan State University, East Lansing MI
| | - David Hyndman
- Department of Geosciences, School of Natural Sciences and Mathematics, University of Texas at Dallas, Richardson TX, 75080, USA
| | - Joan B Rose
- Department of Fisheries and Wildlife, Michigan State University, East Lansing MI 48824, USA
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Wiesner-Friedman C, Beattie RE, Stewart JR, Hristova KR, Serre ML. Characterizing Differences in Sources of and Contributions to Fecal Contamination of Sediment and Surface Water with the Microbial FIT Framework. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:4231-4240. [PMID: 35298143 DOI: 10.1021/acs.est.2c00224] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Surface water monitoring and microbial source tracking (MST) are used to identify host sources of fecal pollution and protect public health. However, knowledge of the locations of spatial sources and their relative impacts on the environment is needed to effectively mitigate health risks. Additionally, sediment samples may offer time-integrated information compared to transient surface water. Thus, we implemented the newly developed microbial find, inform, and test framework to identify spatial sources and their impacts on human (HuBac) and bovine (BoBac) MST markers, quantified from both riverbed sediment and surface water in a bovine-dense region. Dairy feeding operations and low-intensity developed land-cover were associated with 99% (p-value < 0.05) and 108% (p-value < 0.05) increases, respectively, in the relative abundance of BoBac in sediment, and with 79% (p-value < 0.05) and 39% increases in surface water. Septic systems were associated with a 48% increase in the relative abundance of HuBac in sediment and a 56% increase in surface water. Stronger source signals were observed for sediment responses compared to water. By defining source locations, predicting river impacts, and estimating source influence ranges in a Great Lakes region, this work informs pollution mitigation strategies of local and global significance.
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Affiliation(s)
- Corinne Wiesner-Friedman
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
| | - Rachelle E Beattie
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Jill R Stewart
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
| | - Krassimira R Hristova
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Marc L Serre
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
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12
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Wiesner-Friedman C, Beattie RE, Stewart JR, Hristova KR, Serre ML. Microbial Find, Inform, and Test Model for Identifying Spatially Distributed Contamination Sources: Framework Foundation and Demonstration of Ruminant Bacteroides Abundance in River Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:10451-10461. [PMID: 34291905 DOI: 10.1021/acs.est.1c01602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Microbial pollution in rivers poses known ecological and health risks, yet causal and mechanistic linkages to sources remain difficult to establish. Host-associated microbial source tracking (MST) markers help to assess the microbial risks by linking hosts to contamination but do not identify the source locations. Land-use regression (LUR) models have been used to screen the source locations using spatial predictors but could be improved by characterizing transport (i.e., hauling, decay overland, and downstream). We introduce the microbial Find, Inform, and Test (FIT) framework, which expands previous LUR approaches and develops novel spatial predictor models to characterize the transported contributions. We applied FIT to characterize the sources of BoBac, a ruminant Bacteroides MST marker, quantified in riverbed sediment samples from Kewaunee County, Wisconsin. A 1 standard deviation increase in contributions from land-applied manure hauled from animal feeding operations (AFOs) was associated with a 77% (p-value <0.05) increase in the relative abundance of ruminant Bacteroides (BoBac-copies-per-16S-rRNA-copies) in the sediment. This is the first work finding an association between the upstream land-applied manure and the offsite bovine-associated fecal markers. These findings have implications for the sediment as a reservoir for microbial pollution associated with AFOs (e.g., pathogens and antibiotic-resistant bacteria). This framework and application advance statistical analysis in MST and water quality modeling more broadly.
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Affiliation(s)
- Corinne Wiesner-Friedman
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
| | - Rachelle E Beattie
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Jill R Stewart
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
| | - Krassimira R Hristova
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin 53233, United States
| | - Marc L Serre
- Gillings School of Global Public Health, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7400, United States
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13
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Saraceno M, Gómez Lugo S, Ortiz N, Gómez BM, Sabio Y García CA, Frankel N, Graziano M. Unraveling the ecological processes modulating the population structure of Escherichia coli in a highly polluted urban stream network. Sci Rep 2021; 11:14679. [PMID: 34282205 PMCID: PMC8289912 DOI: 10.1038/s41598-021-94198-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 07/07/2021] [Indexed: 02/06/2023] Open
Abstract
Escherichia coli dynamics in urban watersheds are affected by a complex balance among external inputs, niche modulation and genetic variability. To explore the ecological processes influencing E. coli spatial patterns, we analyzed its abundance and phylogenetic structure in water samples from a stream network with heterogeneous urban infrastructure and environmental conditions. Our results showed that environmental and infrastructure variables, such as macrophyte coverage, DIN and sewerage density, mostly explained E. coli abundance. Moreover, main generalist phylogroups A and B1 were found in high proportion, which, together with an observed negative relationship between E. coli abundance and phylogroup diversity, suggests that their dominance might be due to competitive exclusion. Lower frequency phylogroups were associated with sites of higher ecological disturbance, mainly involving simplified habitats, higher drainage infrastructure and septic tank density. In addition to the strong negative relationship between phylogroup diversity and dominance, the occurrence of these phylogroups would be associated with increased facilitated dispersal. Nutrients also contributed to explaining phylogroup distribution. Our study proposes the differential contribution of distinct ecological processes to the patterns of E. coli in an urban watershed, which is useful for the monitoring and management of fecal pollution.
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Affiliation(s)
- Martín Saraceno
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET - Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
| | - Sebastián Gómez Lugo
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
| | - Nicolás Ortiz
- Instituto Nacional del Agua, 1804, Ezeiza, Argentina
| | | | - Carmen A Sabio Y García
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
| | - Nicolás Frankel
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET - Universidad de Buenos Aires, 1428, Buenos Aires, Argentina
| | - Martín Graziano
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), CONICET - Universidad de Buenos Aires, 1428, Buenos Aires, Argentina.
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428, Buenos Aires, Argentina.
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14
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Soueidan J, Warren A, Pearson M, Montie EW. A changing estuary: Understanding historical patterns in salinity and fecal coliform levels in the May River, SC. MARINE POLLUTION BULLETIN 2021; 168:112384. [PMID: 33901906 DOI: 10.1016/j.marpolbul.2021.112384] [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: 11/10/2020] [Revised: 04/02/2021] [Accepted: 04/11/2021] [Indexed: 06/12/2023]
Abstract
The May River, South Carolina watershed has undergone rapid increases in population and development from 1999 to 2017. This study aimed to understand the factors that influence salinity and fecal coliform levels in this estuary and how these levels changed from 1999 to 2017. This analysis revealed that salinity levels decreased in the headwaters, while variability increased. Additionally, fecal coliform increased from 1999 to 2017 throughout the hydrological network, with drastic changes occurring in the headwaters. Salinity and fecal coliform were influenced by spatial (distance from the mouth of the river), temporal (year, season, and tidal cycles), environmental (El Niño Southern Oscillation and rainfall), and anthropogenic parameters (population). This analysis suggests that the synergistic nature of climate change, resulting in more intense and frequent El Niño events, and watershed development may lead to further decreases in salinity and increases in fecal coliform levels in the May River estuary.
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Affiliation(s)
- Jamileh Soueidan
- Graduate Programs in Environmental and Sustainability Studies and Public Administration, College of Charleston, Charleston, SC, United States of America; Department of Natural Sciences, University of South Carolina Beaufort, Bluffton, SC, United States of America
| | - Alan Warren
- Department of Nursing and Health Professions, University of South Carolina Beaufort, Bluffton, SC, United States of America
| | - Mike Pearson
- South Carolina Department of Health and Environmental Control, Columbia, SC, United States of America
| | - Eric W Montie
- Department of Natural Sciences, University of South Carolina Beaufort, Bluffton, SC, United States of America; Graduate Program in Marine Biology, College of Charleston, Charleston, SC, United States of America.
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15
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Paruch L, Paruch AM. Cross-tracking of faecal pollution origins, macronutrients, pharmaceuticals and personal care products in rural and urban watercourses. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:610-621. [PMID: 33600365 DOI: 10.2166/wst.2020.603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study describes microbial and chemical source tracking approaches for water pollution in rural and urban catchments. Culturable faecal indicator bacteria, represented by Escherichia coli, were quantified. Microbial source tracking (MST) using host-specific DNA markers was applied to identify the origins of faecal contamination. Chemical source tracking (CST) was conducted to determine contaminants of emerging concern (CEC) of human/anthropogenic origin, including pharmaceuticals and personal care products (PPCPs) and endocrine-disrupting chemicals (EDCs). In addition, the eutrophication-causing macronutrients nitrogen and phosphorus were studied. MST tests revealed both anthropogenic and zoogenic faecal origins, with a dominance of human sources in the urban stream; non-human/environmental sources were prevalent in the rural creek. CST analyses revealed a higher number of CECs in the urban stream than in the rural watercourse. Positive correlations between PPCPs and both E. coli and the human DNA marker were uncovered in the urban stream, while in the rural creek, PPCPs were only highly correlated with the anthropogenic marker. Interestingly, macronutrients were strongly associated with primary faecal pollution origins in both watercourses. This correlation pattern determines the main pollutant contributors (anthropogenic or zoogenic) to eutrophication.
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Affiliation(s)
- Lisa Paruch
- Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research (NIBIO), Oluf Thesens vei 43, 1433 Ås, Norway E-mail:
| | - Adam M Paruch
- Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research (NIBIO), Oluf Thesens vei 43, 1433 Ås, Norway E-mail:
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16
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Mattioli MC, Benedict KM, Murphy J, Kahler A, Kline KE, Longenberger A, Mitchell PK, Watkins S, Berger P, Shanks OC, Barrett CE, Barclay L, Hall AJ, Hill V, Weltman A. Identifying septic pollution exposure routes during a waterborne norovirus outbreak - A new application for human-associated microbial source tracking qPCR. J Microbiol Methods 2020; 180:106091. [PMID: 33137355 DOI: 10.1016/j.mimet.2020.106091] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/13/2020] [Accepted: 10/27/2020] [Indexed: 11/18/2022]
Abstract
In June 2017, the Pennsylvania Department of Health (PADOH) was notified of multiple norovirus outbreaks associated with 179 ill individuals who attended separate events held at an outdoor venue and campground over a month period. Epidemiologic investigations were unable to identify a single exposure route and therefore unable to determine whether there was a persistent contamination source to target for exposure mitigation. Norovirus was detected in a fresh recreational water designated swimming area and a drinking water well. A hydrogeological site evaluation suggested a nearby septic leach field as a potential contamination source via ground water infiltration. Geological characterization revealed a steep dip of the bedrock beneath the septic leach field toward the well, providing a viral transport pathway in a geologic medium not previously documented as high risk for viral ground water contamination. The human-associated microbial source tracking (MST) genetic marker, HF183, was used as a microbial tracer to demonstrate the hydrogeological connection between the malfunctioning septic system, drinking water well, and recreational water area. Based on environmental investigation findings, venue management and local public health officials implemented a series of outbreak prevention strategies including discontinuing the use of the contaminated well, issuing a permit for a new drinking water well, increasing portable toilet and handwashing station availability, and promoting proper hand hygiene. Despite the outbreaks at the venue and evidence of ground water contamination impacting nearby recreational water and the drinking water well, no new norovirus cases were reported during a large event one week after implementing prevention practices. This investigation highlights a new application for human-associated MST methods to trace hydrological connections between multiple fecal pollutant exposure routes in an outbreak scenario. In turn, pollutant source information can be used to develop effective intervention practices to mitigate exposure and prevent future outbreaks associated with human fecal contaminated waters.
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Affiliation(s)
- Mia C 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, USA.
| | - Katharine M Benedict
- 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, USA
| | - Jennifer Murphy
- 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, USA
| | - Amy Kahler
- 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, USA
| | - Kelly E Kline
- Pennsylvania Department of Health, Division of Infectious Disease Epidemiology, USA
| | - Allison Longenberger
- Pennsylvania Department of Health, Division of Infectious Disease Epidemiology, USA
| | - Patrick K Mitchell
- Pennsylvania Department of Health, Division of Infectious Disease Epidemiology, USA; Epidemic Intelligence Service, Division of Scientific Education and Professional Development, Center for Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Sharon Watkins
- Pennsylvania Department of Health, Division of Infectious Disease Epidemiology, USA
| | - Philip Berger
- U.S. Environmental Protection Agency, Office of Ground Water and Drinking Water, Washington, DC, USA
| | - Orin C Shanks
- U.S. Environmental Protection Agency, Office of Research and Development, Cincinnati, OH, USA
| | - Catherine E Barrett
- 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, USA
| | - Leslie Barclay
- Viral Gastroenteritis Branch, Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, USA
| | - Aron J Hall
- Viral Gastroenteritis Branch, Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, USA
| | - Vincent Hill
- 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, USA
| | - Andre Weltman
- Pennsylvania Department of Health, Division of Infectious Disease Epidemiology, USA
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17
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Hinojosa J, Green J, Estrada F, Herrera J, Mata T, Phan D, Pasha ABMT, Matta A, Johnson D, Kapoor V. Determining the primary sources of fecal pollution using microbial source tracking assays combined with land-use information in the Edwards Aquifer. WATER RESEARCH 2020; 184:116211. [PMID: 32721766 DOI: 10.1016/j.watres.2020.116211] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/18/2020] [Accepted: 07/20/2020] [Indexed: 06/11/2023]
Abstract
The Edwards Aquifer serves as a primary source of drinking water to more than 2 million people in south-central Texas, and as a karst aquifer, is vulnerable to human and animal fecal contamination which poses a serious risk to human and environmental health. A one-year study (Jan 2018 - Feb 2019) was conducted to determine the primary sources of fecal pollution along the Balcones and Leon Creek within the Edwards Aquifer recharge and contributing zones using general (E. coli, enterococci, and universal Bacteriodales) and host-associated (human-, dog-, cow- and chicken/duck-associated Bacteriodales) microbial source tracking (MST) assays. Additionally, sites were classified based on surrounding land use as a potential source predictor and marker levels were correlated with rain events and water quality parameters. Levels for the three general indicators were highest and exhibited similar trends across the sampling sites, suggesting that the sole use of these markers is not sufficient for specific fecal source identification. Among the host-associated markers, highest concentrations were observed for the dog marker (BacCan) in the Leon Creek area and the cow marker (BacCow) in the Balcones Creek area. Additionally, Chicken/Duck-Bac, BacCan and BacCow all exhibited higher concentrations during the spring season and the end of fall/early winter. Relatively lower concentrations were observed for the human-associated markers (HF183 and BacHum), however, levels were higher in the Leon Creek area and highest following rainfall events. Additionally, relatively higher levels in HF183 and BacHum were observed at sites having greater human population and septic tank density and may be attributed to leaks or breaks in these infrastructures. This study is the first to examine and compare fecal contamination at rural and urban areas in the recharge and contributing zones of the Edwards Aquifer using a molecular MST approach targeting Bacteroidales 16S rRNA gene-based assays. The Bacteroidales marker assays, when combined with land use and weather information, can allow for a better understanding of the sources and fluxes of fecal contamination, which can help devise effective mitigation measures to protect water quality.
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Affiliation(s)
- Jessica Hinojosa
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jemima Green
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Fabiola Estrada
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Jonathan Herrera
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Troy Mata
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Duc Phan
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - A B M Tanvir Pasha
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Akanksha Matta
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Drew Johnson
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Vikram Kapoor
- Department of Civil and Environmental Engineering, University of Texas at San Antonio, San Antonio, TX 78249, USA.
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18
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Ballesté E, Demeter K, Masterson B, Timoneda N, Sala-Comorera L, Meijer WG. Implementation and integration of microbial source tracking in a river watershed monitoring plan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 736:139573. [PMID: 32474276 DOI: 10.1016/j.scitotenv.2020.139573] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 05/20/2023]
Abstract
Fecal pollution of water bodies poses a serious threat for public health and ecosystems. Microbial source tracking (MST) is used to track the source of this pollution facilitating better management of pollution at the source. In this study we tested 12 MST markers to track human, ruminant, sheep, horse, pig and gull pollution to assess their usefulness as an effective management tool of water quality. First, the potential of the selected markers to track the source was evaluated using fresh fecal samples. Subsequently, we evaluated their performance in a catchment with different impacts, considering land use and environmental conditions. All MST markers showed high sensitivity and specificity, although none achieved 100% for both. Although some of the MST markers were detected in hosts other than the intended ones, their abundance in the target group was always several orders of magnitude higher than in the non-target hosts, demonstrating their suitability to distinguish between sources of pollution. The MST analysis matched the land use in the watershed allowing an accurate assessment of the main sources of pollution, in this case mainly human and ruminant pollution. Correlating environmental parameters including temperature and rainfall with MST markers provided insight into the dynamics of the pollution in the catchment. The levels of the human marker showed a significant negative correlation with rainfall in human polluted areas suggesting a dilution of the pollution, whereas at agricultural areas the ruminant marker increased with rainfall. There were no seasonal differences in the levels of human marker, indicating human pollution as a constant pressure throughout the year, whereas the levels of the ruminant marker was influenced by the seasons, being more abundant in summer and autumn. MST analysis integrated with land use and environmental data can improve the management of fecal polluted areas and set up best practice.
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Affiliation(s)
- Elisenda Ballesté
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Katalin Demeter
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Bartholomew Masterson
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Natàlia Timoneda
- Computational Genomics Laboratory, Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
| | - Laura Sala-Comorera
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland
| | - Wim G Meijer
- UCD School of Biomolecular and Biomedical Science, UCD Earth Institute, UCD Conway Institute, University College Dublin, Dublin, Ireland.
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19
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Faecal pollution affects abundance and diversity of aquatic microbial community in anthropo-zoogenically influenced lotic ecosystems. Sci Rep 2019; 9:19469. [PMID: 31857659 PMCID: PMC6923421 DOI: 10.1038/s41598-019-56058-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 11/15/2019] [Indexed: 12/14/2022] Open
Abstract
The aquatic microbiota is known to be an important factor in the sustainability of the natural water ecosystems. However, the microbial community also might include pathogens, which result in very serious waterborne diseases in humans and animals. Faecal pollution is the major cause of these diseases. Therefore, it is of immense importance to assess the potential impact of faecal pollution, originating from both anthropogenic and zoogenic sources, on the profile of microbial communities in natural water environments. To this end, the microbial taxonomic diversity of lotic ecosystems in different regions of Norway, representing urban and rural areas, exposed to various levels of faecal pollution, was investigated over the course of a 1-year period. The highest microbial diversity was found in rural water that was the least faecally polluted, while the lowest was found in urban water with the highest faecal contamination. The overall diversity of the aquatic microbial community was significantly reduced in severely polluted water. In addition, the community compositions diverged between waters where the dominant pollution sources were of anthropogenic or zoogenic origin. The results provide new insight into the understanding of how faecal water contamination, specifically that of different origins, influences the microbial diversity of natural waters.
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20
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Buckerfield SJ, Quilliam RS, Waldron S, Naylor LA, Li S, Oliver DM. Rainfall-driven E. coli transfer to the stream-conduit network observed through increasing spatial scales in mixed land-use paddy farming karst terrain. WATER RESEARCH X 2019; 5:100038. [PMID: 31660535 PMCID: PMC6807365 DOI: 10.1016/j.wroa.2019.100038] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/19/2019] [Accepted: 10/03/2019] [Indexed: 06/01/2023]
Abstract
Karst aquifers have distinctive hydrology and supply 25% of the world's population with drinking water, making them a critical geological setting for understanding and managing microbial water pollution. Rainfall causes elevated concentrations and loading of faecal microorganisms, e.g. E. coli, in catchment surface and groundwater systems, increasing the risk of human exposure to faecally-contaminated water. However, effective management of microbial water quality in complex karst catchments is constrained by limited understanding of E. coli - discharge responses to rainfall. We analysed how rainfall events of varying magnitude (2.4-100 mm) control E. coli-discharge dynamics at increasing spatial scales in a mixed land-use karst catchment in southwest China. During the wet season, hourly water sampling was undertaken throughout five storm events to characterise in high detail E. coli emergence with resulting flow across multiple sites of varying catchment area, stream order, and land-use. E. coli concentration was found to increase by 1-3 orders of magnitude following rainfall events. Maximum E. coli concentration and speed of E. coli recession were influenced by rainfall (amount, intensity), timing of agricultural activities, and position in the hydrological system. For high intensity events ∼90% of the cumulative E. coli export occurred within 48 h. E. coli concentration increased with increasing discharge at all sites. E. coli concentration at low discharge was higher in the headwaters than at the catchment outlet, while the rate of increase in E. coli concentration with increasing discharge appears to follow the opposite trend, being higher at the catchment outlet than the headwaters. This was attributed to the decreasing flow path gradient and increasing degree of development of the fissure network, but further event monitoring at varying catchment scales is required to confirm this relationship. The results provide novel insight into how rainfall characteristics combine with land-use and catchment hydrology to control E. coli export in karst landscapes.
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Affiliation(s)
- Sarah J. Buckerfield
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, United Kingdom
| | - Richard S. Quilliam
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, United Kingdom
| | - Susan Waldron
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - Larissa A. Naylor
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - Siliang Li
- Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
| | - David M. Oliver
- Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, FK9 4LA, United Kingdom
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21
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Paruch L, Paruch AM, Sørheim R. DNA-based faecal source tracking of contaminated drinking water causing a large Campylobacter outbreak in Norway 2019. Int J Hyg Environ Health 2019; 224:113420. [PMID: 31748129 DOI: 10.1016/j.ijheh.2019.113420] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/07/2019] [Accepted: 11/14/2019] [Indexed: 12/24/2022]
Abstract
During June 2019, an outbreak of campylobacteriosis occurred in Askøy, an island northwest of Bergen, Norway. According to the publicly available records, over 2000 residents fell ill and 76 were hospitalised, and two deaths were suspected to be associated with Campylobacter infection. By investigating the epidemic pattern and scope, an old caved drinking water holding pool was identified that had been faecally contaminated as indicated by the presence of Escherichia coli (E. coli). Furthermore, Campylobacter bacteria were found at several points in the water distribution system. In the escalated water health crisis, tracking down the infectious source became pivotal for the local municipality in order to take prompt and appropriate action to control the epidemic. A major task was to identify the primary faecal pollution source, which could further assist in tracking down the epidemic origin. Water from the affected pool was analysed using quantitative microbial source tracking (QMST) applying host-specific Bacteroidales 16S rRNA genetic markers. In addition, Campylobacter jejuni, Enterococcus faecalis, Clostridium perfringens and Shiga toxin-producing E. coli were detected. The QMST outcomes revealed that non-human (zoogenic) sources accounted predominantly for faecal pollution. More precisely, 69% of the faecal water contamination originated from horses.
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Affiliation(s)
- Lisa Paruch
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Environment and Natural Resources, Fredrik A. Dahls Vei 20, 1433, Aas, Norway
| | - Adam M Paruch
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Environment and Natural Resources, Fredrik A. Dahls Vei 20, 1433, Aas, Norway.
| | - Roald Sørheim
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Environment and Natural Resources, Fredrik A. Dahls Vei 20, 1433, Aas, Norway
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22
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Paruch L, Paruch AM, Eiken HG, Sørheim R. Aquatic microbial diversity associated with faecal pollution of Norwegian waterbodies characterized by 16S rRNA gene amplicon deep sequencing. Microb Biotechnol 2019; 12:1487-1491. [PMID: 31290258 PMCID: PMC6801177 DOI: 10.1111/1751-7915.13461] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/25/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022] Open
Abstract
Faecal contamination is one of the major factors affecting biological water quality. In this study, we investigated microbial taxonomic diversity of faecally polluted lotic ecosystems in Norway. These ecosystems comprise tributaries of drinking water reservoirs with moderate and high faecal contamination levels, an urban creek exposed to extremely high faecal pollution and a rural creek that was the least faecally polluted. The faecal water contamination had both anthropogenic and zoogenic origins identified through quantitative microbial source tracking applying host-specific Bacteroidales 16S rRNA genetic markers. The microbial community composition revealed that Proteobacteria and Bacteroidetes (70-90% relative abundance) were the most dominant bacterial phyla, followed by Firmicutes, especially in waters exposed to anthropogenic faecal contamination. The core archaeal community consisted of Parvarchaeota (mainly in the tributaries of drinking water reservoirs) and Crenarchaeota (in the rural creek). The aquatic microbial diversity was substantially reduced in water with severe faecal contamination. In addition, the community compositions diverge between waters with dominant anthropogenic or zoogenic pollution origins. These findings present novel interpretations of the effect of anthropo-zoogenic faecal water contamination on microbial diversity in lotic ecosystems.
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MESH Headings
- Archaea/classification
- Archaea/genetics
- Bacteria/classification
- Bacteria/genetics
- Cluster Analysis
- DNA, Archaeal/chemistry
- DNA, Archaeal/genetics
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Feces
- Genes, rRNA
- High-Throughput Nucleotide Sequencing
- Microbiota
- Norway
- Phylogeny
- RNA, Ribosomal, 16S/genetics
- Sequence Analysis, DNA
- Water Microbiology
- Water Pollution
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Affiliation(s)
- Lisa Paruch
- Division of Environment and Natural ResourcesNorwegian Institute of Bioeconomy Research (NIBIO)Fredrik A. Dahls vei 201433AasNorway
| | - Adam M. Paruch
- Division of Environment and Natural ResourcesNorwegian Institute of Bioeconomy Research (NIBIO)Fredrik A. Dahls vei 201433AasNorway
| | - Hans Geir Eiken
- Division of Environment and Natural ResourcesNorwegian Institute of Bioeconomy Research (NIBIO)Fredrik A. Dahls vei 201433AasNorway
| | - Roald Sørheim
- Division of Environment and Natural ResourcesNorwegian Institute of Bioeconomy Research (NIBIO)Fredrik A. Dahls vei 201433AasNorway
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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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Enterococcal Concentrations in a Coastal Ecosystem Are a Function of Fecal Source Input, Environmental Conditions, and Environmental Sources. Appl Environ Microbiol 2018; 84:AEM.01038-18. [PMID: 30006393 DOI: 10.1128/aem.01038-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/23/2018] [Indexed: 02/01/2023] Open
Abstract
Fecal pollution at coastal beaches requires management efforts to address public health and economic concerns. Feces-borne bacterial concentrations are influenced by different fecal sources, environmental conditions, and ecosystem reservoirs, making their public health significance convoluted. In this study, we sought to delineate the influences of these factors on enterococcal concentrations in southern Maine coastal recreational waters. Weekly water samples and water quality measurements were conducted at freshwater, estuarine, and marine beach sites from June through September 2016. The samples were analyzed for total and particle-associated enterococcal concentrations, total suspended solids, and microbial source tracking markers (PCR: Bac32, HF183, CF128, DF475, and Gull2; quantitative PCR [qPCR]: AllBac, HF183, and GFD). Water, soil, sediment, and marine sediment samples were also subjected to 16S rRNA sequencing and SourceTracker analysis to determine the influence from these environmental reservoirs on water sample microbial communities. Enterococcal and particle-associated enterococcal concentrations were elevated in freshwater, but the concentrations of suspended solids were relatively similar. Mammal fecal contamination was significantly elevated in the estuary, with human and bird fecal contaminant levels similar between sites. A partial least-squares regression model indicated particle-associated enterococcal and mammal marker concentrations had the most significant positive relationships with enterococcal concentrations across marine, estuary, and freshwater environments. Freshwater microbial communities were significantly influenced by underlying sediment, while estuarine/marine beach communities were influenced by freshwater, high tide height, and estuarine sediment. Elevated enterococcal levels were reflective of a combination of increased fecal source input, environmental sources, and environmental conditions, highlighting the need for encompassing microbial source tracking (MST) approaches for managing water quality issues.IMPORTANCE Enterococci have long been the federal standard in determining water quality at estuarine and marine environments. Although enterococci are highly abundant in the intestines of many animals, they are not exclusive to that environment and can persist and grow outside fecal tracts. This presents a management problem for areas that are largely impaired by nonpoint source contamination, as fecal sources might not be the root cause of contamination. This study employed different microbial source tracking methods for delineating the influences from fecal source input, environmental sources, and environmental conditions to determine which combination of variables are influencing enterococcal concentrations in recreational waters at a historically impaired coastal town. The results showed that fecal source input, environmental sources, and conditions all play roles in influencing enterococcal concentrations. This highlights the need to include an encompassing microbial source tracking approach to assess the effects of all important variables on enterococcal concentrations.
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Olds HT, Corsi SR, Dila DK, Halmo KM, Bootsma MJ, McLellan SL. High levels of sewage contamination released from urban areas after storm events: A quantitative survey with sewage specific bacterial indicators. PLoS Med 2018; 15:e1002614. [PMID: 30040843 PMCID: PMC6057621 DOI: 10.1371/journal.pmed.1002614] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/15/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Past studies have demonstrated an association between waterborne disease and heavy precipitation, and climate change is predicted to increase the frequency of these types of intense storm events in some parts of the United States. In this study, we examined the linkage between rainfall and sewage contamination of urban waterways and quantified the amount of sewage released from a major urban area under different hydrologic conditions to identify conditions that increase human risk of exposure to sewage. METHODS AND FINDINGS Rain events and low-flow periods were intensively sampled to quantify loads of sewage based on two genetic markers for human-associated indicator bacteria (human Bacteroides and Lachnospiraceae). Samples were collected at a Lake Michigan estuary and at three river locations immediately upstream. Concentrations of indicators were analyzed using quantitative polymerase chain reaction (qPCR), and loads were calculated from streamflow data collected at each location. Human-associated indicators were found during periods of low flow, and loads increased one to two orders of magnitude during rain events from stormwater discharges contaminated with sewage. Combined sewer overflow (CSO) events increased concentrations and loads of human-associated indicators an order of magnitude greater than heavy rainfall events without CSO influence. Human-associated indicator yields (load per km2 of land per day) were related to the degree of urbanization in each watershed. Contamination in surface waters were at levels above the acceptable risk for recreational use. Further, evidence of sewage exfiltration from pipes threatens drinking water distribution systems and source water. While this study clearly demonstrates widespread sewage contamination released from urban areas, a limitation of this study is understanding human exposure and illness rates, which are dependent on multiple factors, and gaps in our knowledge of the ultimate health outcomes. CONCLUSIONS With the prediction of more intense rain events in certain regions due to climate change, sewer overflows and contamination from failing sewer infrastructure may increase, resulting in increases in waterborne pathogen burdens in waterways. These findings quantify hazards in exposure pathways from rain events and illustrate the additional stress that climate change may have on urban water systems. This information could be used to prioritize efforts to invest in failing sewer infrastructure and create appropriate goals to address the health concerns posed by sewage contamination from urban areas.
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Affiliation(s)
- Hayley T. Olds
- School of Freshwater Sciences, UW-Milwaukee, Milwaukee, Wisconsin, United States of America
- United States Geological Survey, Upper Midwest Water Science Center, Middleton, Wisconsin, United States of America
| | - Steven R. Corsi
- United States Geological Survey, Upper Midwest Water Science Center, Middleton, Wisconsin, United States of America
| | - Deborah K. Dila
- School of Freshwater Sciences, UW-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Katherine M. Halmo
- School of Freshwater Sciences, UW-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Melinda J. Bootsma
- School of Freshwater Sciences, UW-Milwaukee, Milwaukee, Wisconsin, United States of America
| | - Sandra L. McLellan
- School of Freshwater Sciences, UW-Milwaukee, Milwaukee, Wisconsin, United States of America
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Ahmed W, Lobos A, Senkbeil J, Peraud J, Gallard J, Harwood VJ. Evaluation of the novel crAssphage marker for sewage pollution tracking in storm drain outfalls in Tampa, Florida. WATER RESEARCH 2018; 131:142-150. [PMID: 29281808 DOI: 10.1016/j.watres.2017.12.011] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/05/2017] [Accepted: 12/07/2017] [Indexed: 05/25/2023]
Abstract
CrAssphage are recently-discovered DNA bacteriophages that are prevalent and abundant in human feces and sewage. We assessed the performance characteristics of a crAssphage quantitative PCR (qPCR) assay for quantifying sewage impacts in stormwater and surface water in subtropical Tampa, Florida. The mean concentrations of crAssphage in untreated sewage ranged from 9.08 to 9.98 log10 gene copies/L. Specificity was 0.927 against 83 non-human fecal reference samples and the sensitivity was 1.0. Cross-reactivity was observed in DNA extracted from soiled poultry litter but the concentrations were substantially lower than untreated sewage. The presence of the crAssphage marker was monitored in water samples from storm drain outfalls during dry and wet weather conditions in Tampa, Florida. In dry weather conditions, 41.6% of storm drain outfalls samples were positive for the crAssphage marker and the concentrations ranged from 3.60 to 4.65 log10 gene copies/L of water. After a significant rain event, 66.6% of stormwater outlet samples were positive for the crAssphage marker and the concentration ranged from 3.62 to 4.91 log10 gene copies/L of water. The presence of the most commonly used Bacteroides HF183 marker in storm drain outfalls was also tested along with the crAssphage. Thirteen samples (55%) were either positive (i.e., both markers were present) or negative (i.e., both markers were absent) for both the markers. Due to the observed cross-reactivity of this marker with DNA extracted from poultry litter samples, it is recommended that this marker should be used in conjunction with additional markers such as HF183. Our data indicate that the crAssphage marker is highly sensitive to sewage, is adequately specific, and will be a valuable addition to the MST toolbox.
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Affiliation(s)
- Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Qld 4102, Australia.
| | - Aldo Lobos
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Jacob Senkbeil
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Jayme Peraud
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Javier Gallard
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
| | - Valerie J Harwood
- Department of Integrative Biology, SCA 110, University of South Florida, 4202 East Fowler Ave, Tampa, FL 33620, USA
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Cross-Comparison of Human Wastewater-Associated Molecular Markers in Relation to Fecal Indicator Bacteria and Enteric Viruses in Recreational Beach Waters. Appl Environ Microbiol 2017; 83:AEM.00028-17. [PMID: 28159789 DOI: 10.1128/aem.00028-17] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 01/25/2017] [Indexed: 11/20/2022] Open
Abstract
Detection of human wastewater contamination in recreational waters is of critical importance to regulators due to the risks posed to public health. To identify such risks, human wastewater-associated microbial source tracking (MST) markers have been developed. At present, however, a greater understanding of the suitability of these markers for the detection of diluted human wastewater in environmental waters is necessary to predict risk. Here, we compared the process limit of detection (PLOD) and process limit of quantification (PLOQ) of six human wastewater-associated MST markers (Bacteroides HF183 [HF183], Escherichia coli H8 [EC H8], Methanobrevibacter smithiinifH, human adenovirus [HAdV], human polyomavirus [HPyV], and pepper mild mottle virus [PMMoV]) in relation to a fecal indicator bacterium (FIB), Enterococcus sp. 23S rRNA (ENT 23S), and three enteric viruses (human adenovirus serotypes 40/41 [HAdV 40/41], human norovirus [HNoV], and human enterovirus [EV]) in beach water samples seeded with raw and secondary-treated wastewater. Among the six MST markers tested, HF183 was the most sensitive measure of human fecal pollution and was quantifiable up to dilutions of 10-6 and 10-4 for beach water samples seeded with raw and secondary-treated wastewater, respectively. Other markers and enteric viruses were detected at various dilutions (10-1 to 10-5). These MST markers, FIB, and enteric viruses were then quantified in beach water (n = 12) and sand samples (n = 12) from South East Queensland (SEQ), Australia, to estimate the levels of human fecal pollution. Of the 12 sites examined, beach water and sand samples from several sites had quantifiable concentrations of HF183 and PMMoV markers. Overall, our results indicate that while HF183 is the most sensitive measure of human fecal pollution, it should be used in conjunction with a conferring viral marker to avoid overestimating the risk of gastrointestinal illness.IMPORTANCE MST is an effective tool to help utilities and regulators improve recreational water quality around the globe. Human fecal pollution poses significant public health risks compared to animal fecal pollution. Several human wastewater-associated markers have been developed and used for MST field studies. However, a head-to-head comparison in terms of their performance to detect diluted human fecal pollution in recreational water is lacking. In this study, we cross-compared the performance of six human wastewater-associated markers in relation to FIB and enteric viruses in beach water samples seeded with raw and secondary-treated wastewater. The results of this study will provide guidance to regulators and utilities on the appropriate application of MST markers for tracking the sources of human fecal pollution in environmental waters and confer human health risks.
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