1
|
Malajacan GT, Nacario MAG, Obusan MCM, Rivera WL. Host-Associated Bacteroides 16S rDNA-Based Markers for Source Tracking of Fecal Pollution in Laguna Lake, Philippines. Microorganisms 2023; 11:1142. [PMID: 37317116 DOI: 10.3390/microorganisms11051142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 06/16/2023] Open
Abstract
Sources of fecal contamination in Laguna Lake, Philippines, were identified using a library-independent microbial source tracking method targeting host-associated Bacteroides 16S rDNA-based markers. Water samples from nine lake stations were assessed for the presence of the fecal markers HF183 (human), BoBac (cattle), Pig-2-Bac (swine), and DuckBac (duck) from August 2019 to January 2020. HF183 (average concentration = 1.91 log10 copies/mL) was the most frequently detected, while Pig-2-Bac (average concentration = 2.47 log10 copies/mL) was the most abundant. The detected marker concentrations in different stations corresponded to the land use patterns around the lake. Generally, all marker concentrations were higher during the wet season (August-October), suggesting the effect of rainfall-associated factors on the movement and retention of markers from sources. There was a significant association (ρ = 0.45; p < 0.001) between phosphate and the concentration of HF183, suggesting domestic sewage-derived pollution. The markers had acceptable sensitivity and specificity, i.e., HF183 (S = 0.88; R = 0.99), Pig-2-Bac (S = 1.00; R = 1.00), and DuckBac (S = 0.94; R = 1.00), and therefore may be used for the continuous monitoring of fecal pollution in the lake and in designing interventions to improve the quality of the lake water.
Collapse
Affiliation(s)
- Gicelle T Malajacan
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Mae Ashley G Nacario
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Marie Christine M Obusan
- Microbial Ecology of Terrestrial and Aquatic Systems Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Windell L Rivera
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| |
Collapse
|
2
|
Wang J, Yang H, Chen S, Li W, Yu J, Hu Z, Zhuo Y, Huang Q, Liu Z, Zhou L, Wu J, Wang Z, Guo F, Yun P, Wang X, Liu JF. Genome-wide association study reveals candidate genes for pollution excreta traits in pigs. Anim Genet 2023. [PMID: 37040927 DOI: 10.1111/age.13323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 11/13/2022] [Accepted: 03/18/2023] [Indexed: 04/13/2023]
Abstract
Excreta traits comprise a very important characteristic in breeding that have been neglected for a long time. With the growth of intensive pig farming, plenty of environment problems have been raised, and people have begun to pay attention to pig excreta behaviors from genetics and breeding perspectives. However, the genetic architecture of excreta traits remains unclear. To investigate the genetic architecture of excreta traits in pigs, eight excreta traits and feed conversion ratio (FCR) were analyzed in this study. We performed genome-wide association studies (GWASs) on 213 Yorkshire pigs and estimated genetic parameters for a total number of 290 pigs, comprising 213 Yorkshire, 52 Landrace and 25 Duroc. After analysis, eight and 22 genome-wide significant SNPs were detected for FCR and the eight excreta traits in single-trait GWASs separately, and 18 were detected in a multi-trait meta-analysis for excreta traits, six of which were detected in both the single-trait and the multi-trait GWAS. Eighty, 182 and 133 genes were detected within 1 Mb of the genome-wide significant SNPs for FCR, excreta traits and multi-trait meta-analysis, respectively. Five candidate genes (BCKDC, DBT, ANKRD7, SHPRH and HCRT) with biochemical and physiological effects relevant to feed efficiency and excreta traits might be interesting markers for future breeding. Meanwhile, functional enrichment analysis indicates that most of the significant pathways are associated with the glutathione catabolic process, DNA topological change and replication fork protection complex. This study reveals the architecture of excreta traits in commercial pigs and offers an opportunity for decreasing the pollution from excreta using genomic selection in pigs.
Collapse
Affiliation(s)
- Junjian Wang
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Huawei Yang
- Shenzhen Kingsino Technology Co., Ltd., 518107, Shenzhen, No.18 Guangdian North Rd, High-Tech Industrial Park, Guangming District, China
| | - Shaokang Chen
- Beijing General Station of Animal Husbandry, 100107, Beijing, China
| | - Weining Li
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jian Yu
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhengzheng Hu
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yue Zhuo
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Qianqian Huang
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zhen Liu
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Lei Zhou
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jianliang Wu
- Beijing Zhongyu Pig Breeding Co. Ltd., 100194, Beijing, China
| | - Zhaojun Wang
- Beijing Zhongyu Pig Breeding Co. Ltd., 100194, Beijing, China
| | - Feng Guo
- Beijing General Station of Animal Husbandry, 100107, Beijing, China
| | - Peng Yun
- Beijing General Station of Animal Husbandry, 100107, Beijing, China
| | - Xiaofeng Wang
- Beijing General Station of Animal Husbandry, 100107, Beijing, China
| | - Jian-Feng Liu
- State Key Laboratory of animal Biotech Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| |
Collapse
|
3
|
Ragot R, Villemur R. Influence of temperature and water quality on the persistence of human mitochondrial DNA, human Hf183 Bacteroidales, fecal coliforms and enterococci in surface water in human fecal source tracking context. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156025. [PMID: 35588844 DOI: 10.1016/j.scitotenv.2022.156025] [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: 01/31/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Mitochondrial DNA (mtDNA) is used as a genetic marker to track fecal contamination in surface water. Its potential to effectively discriminate between the nonpoint sources of fecal pollution (e.g. human, livestock) in water environments is relevant for water quality management. However, there is a lack of knowledge about the environmental persistence of mtDNA in relation to those of other microbial parameters, such as fecal indicator bacteria (FIB). In this study, mesocosms composed of water collected from four rivers and tap water were spiked with raw wastewater to mimic human fecal contamination. Mesocosms composed of raw wastewater were also studied. The mesocosms were incubated at 4 °C or at 22 °C for 189 days, from which the levels of human mtDNA (HumtDNA) and human Bacteroidales (Hf183) were measured by qPCR. The levels of FIB (fecal coliforms and enterococci) and heterotrophs were determined by culture methods along with the determination of physicochemical attributes. The decay rates of the genetic markers and FIB were determined with first-order decay rate models. The decay rates of HumtDNA (0.004-0.059 d-1), Hf183 (0.007-0.082 d-1), and the two FIBs (0.005-0.066 d-1) were similar at 4 °C, while the genetic markers both had higher decay rates (0.013-0.919 d-1) at 22 °C. Different HumtDNA decay rates were observed between the river mesocosms (0.043-0.919 d-1) and the wastewater and tap water mesocosms (0.004-0.095 d-1). Covariations of pH and conductivity among the HumtDNA, Hf183 and FIB decay rates were observed. HumtDNA and Hf183 had similar environmental persistence, whereas fecal coliforms and enterococci persisted longer at 22 °C. Finally, HumtDNA had the same trends of persistence in the four river mesocosms, suggesting a relative stability of this marker in different rivers. Our results suggest that HumtDNA could be more suitable for tracking the source of a recent fecal contamination in complement to FIB.
Collapse
Affiliation(s)
- Rose Ragot
- INRS Centre Armand-Frappier Santé Biotechnologie, Canada.
| | | |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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: 0] [Impact Index Per Article: 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.
Collapse
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
| |
Collapse
|
6
|
Zhu K, Suttner B, Knee J, Capone D, Moe CL, Stauber CE, Konstantinidis KT, Wallach TE, Pickering AJ, Brown J. Elevated Fecal Mitochondrial DNA from Symptomatic Norovirus Infections Suggests Potential Health Relevance of Human Mitochondrial DNA in Fecal Source Tracking. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2022; 9:543-550. [PMID: 35719858 PMCID: PMC9202355 DOI: 10.1021/acs.estlett.2c00140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 06/15/2023]
Abstract
An end goal of fecal source tracking (FST) is to provide information on risk of transmission of waterborne illnesses associated with fecal contamination. Ideally, concentrations of FST markers in ambient waters would reflect exposure risk. Human mtDNA is an FST marker that is exclusively human in origin and may be elevated in feces of individuals experiencing gastrointestinal inflammation. In this study, we examined whether human mtDNA is elevated in fecal samples from individuals with symptomatic norovirus infections using samples from the United States (US), Mozambique, and Bangladesh. We quantified hCYTB484 (human mtDNA) and HF183/BacR287 (human-associated Bacteroides) FST markers using droplet digital polymerase chain reaction. We observed the greatest difference in concentrations of hCYTB484 when comparing samples from individuals with symptomatic norovirus infections versus individuals without norovirus infections or diarrhea symptoms: log10 increase of 1.42 in US samples (3,820% increase, p-value = 0.062), 0.49 in Mozambique (308% increase, p-value = 0.061), and 0.86 in Bangladesh (648% increase, p-value = 0.035). We did not observe any trends in concentrations of HF183/BacR287 in the same samples. These results suggest concentrations of fecal mtDNA may increase during symptomatic norovirus infection and that mtDNA in environmental samples may represent an unambiguously human source-tracking marker that correlates with enteric pathogen exposure risk.
Collapse
Affiliation(s)
- Kevin
J. Zhu
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Brittany Suttner
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Jackie Knee
- Department
of Disease Control, London School of Hygiene
and Tropical Medicine, London WC1E 7HT,United Kingdom
| | - Drew Capone
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27599, United States
| | - Christine L. Moe
- Center
for Global Safe Water, Sanitation, and Hygiene, Rollins School of
Public Health, Emory University, Atlanta, Georgia 30322, United States
| | - Christine E. Stauber
- Department
of Population Health Sciences, School of Public Health, Georgia State University, Atlanta, Georgia 30302, United States
| | - Kostas T. Konstantinidis
- School
of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Thomas E. Wallach
- Division
of Pediatric Gastroenterology, SUNY Downstate
Health Sciences University, Brooklyn, New York 11203, United States
| | - Amy J. Pickering
- Department
of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Joe Brown
- Department
of Environmental Sciences and Engineering, Gillings School of Global
Public Health, University of North Carolina
at Chapel Hill, Chapel
Hill, North Carolina 27599, United States
| |
Collapse
|
7
|
Hachad M, Lanoue M, Vo Duy S, Villlemur R, Sauvé S, Prévost M, Dorner S. Locating illicit discharges in storm sewers in urban areas using multi-parameter source tracking: Field validation of a toolbox composite index to prioritize high risk areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:152060. [PMID: 34861306 DOI: 10.1016/j.scitotenv.2021.152060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 06/13/2023]
Abstract
In urban areas served by separate sewerage systems, illicit connections to the storm drain system from residences or commercial establishments are frequent whether these misconnections were made accidentally or deliberately. As a result, untreated and contaminated wastewater enters into storm sewers leading to pollution of receiving waters and non-compliance with water quality standards. Typical procedures for detecting illicit connections to the storm sewer system are time consuming and expensive, especially in a highly urbanised area. In this study, we investigated the use of human wastewater micropollutants WWMPs (caffeine, theophylline, and carbamazepine) and advanced DNA molecular markers (human specific Bacteroides HF183 and mitochondrial DNA) as anthropogenic tracers in order to assist identifying potential cross connections. Water samples from storm outfalls and storm sewer pipes in three urban subcatchments were collected in dry weather from 2013 to 2018. All samples contained various concentrations of these markers especially HF183, caffeine and theophylline, suggesting that the storm pipe system studied is widely contaminated by sanitary sewers. None of the traditional indicators or markers tested is sufficient alone to determine the origin of fecal pollution. In a highly urbanised area, the combination of at least three specific human markers was needed in order to locate the residential section with likely misconnections. The human specific Bacteroides HF183, and theophylline appeared to be the most effective markers (along with E. coli) of crossconnections, whereas carbamazepine can provide an indication of contamination through sanitary sewer exfiltration. A composite sewer cross-connection index was developed, and eight misconnected houses were identified and corrected. The index approach enables the reduction of false positives that could lead to expensive interventions to identify cross-connected households. The results show the multiparameter source tracking toolbox as an effective method to identify sewer cross connections for sustainable storm water management.
Collapse
Affiliation(s)
- Mounia Hachad
- Civil, Geological and Mining Engineering Department, Polytechnique de Montréal, CP 6079, succ. Centre-Ville, Montréal, QC H3C 3A7, Canada.
| | - Martine Lanoue
- City of Laval, soutien technique eau et salubrité, service de l'environnement et de l'écocitoyenneté, 480, Boulevard Armand-Frappier, Laval, QC H7V 3Z4, Canada
| | - Sung Vo Duy
- Department of Chemistry, Université de Montréal, P.O. Box 6128, succ, Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Richard Villlemur
- Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada
| | - Sébastien Sauvé
- Department of Chemistry, Université de Montréal, P.O. Box 6128, succ, Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Michèle Prévost
- Civil, Geological and Mining Engineering Department, Polytechnique de Montréal, CP 6079, succ. Centre-Ville, Montréal, QC H3C 3A7, Canada; NSERC Industrial Chair on Drinking Water, Civil, Geological and Mining Engineering Department, Polytechnique de Montréal, QC, Canada
| | - Sarah Dorner
- Civil, Geological and Mining Engineering Department, Polytechnique de Montréal, CP 6079, succ. Centre-Ville, Montréal, QC H3C 3A7, Canada; Canada Research Chair in Microbial Contaminant Dynamics in Source Waters, Civil, Geological and Mining Engineering Department, Polytechnique de Montréal, QC, Canada
| |
Collapse
|
8
|
Abello JJM, Malajacan GT, Labrador KL, Nacario MAG, Galarion LH, Obusan MCM, Rivera WL. Library-independent source tracking of fecal contamination in selected stations and tributaries of Laguna Lake, Philippines. JOURNAL OF WATER AND HEALTH 2021; 19:846-854. [PMID: 34665776 DOI: 10.2166/wh.2021.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Laguna Lake is the largest inland freshwater body in the Philippines. Although it is classified to be usable for agricultural and recreational purposes by the country's Department of Environment and Natural Resources (DENR), studies looking at lake ecology revealed severe fecal contamination which contributes to the deterioration of water quality. Determining the sources of fecal contamination is necessary for lake protection and management. This study utilized a library-independent method of microbial source tracking (LIM-MST) to identify sources of fecal contamination in selected Laguna Lake stations and tributaries. Genetic markers of the host-associated Escherichia coli, heat-labile toxin (LTIIA) and heat-stable II (STII), were used to identify cattle and swine fecal contaminations, respectively. Meanwhile, human mitochondrial DNA (mtDNA) was used to identify human fecal contamination. Results identified the presence of agricultural and human fecal contamination in Laguna Lake Stations 1 and 5, Mangangate River, and Alabang River. The selected sites are known to be surrounded by residential and industrial complexes, and most of their discharges find their way into the lake. The identification of the specific sources of fecal contamination will guide management practices that aim to regulate the discharges in order to improve the water quality of Laguna Lake.
Collapse
Affiliation(s)
- Joseth Jermaine M Abello
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Gicelle T Malajacan
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Kevin L Labrador
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Mae Ashley G Nacario
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Luiza H Galarion
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Marie Christine M Obusan
- Microbial Ecology of Terrestrial and Aquatic Systems Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| | - Windell L Rivera
- Pathogen-Host-Environment Interactions Research Laboratory, Institute of Biology, College of Science, University of the Philippines Diliman, Quezon City 1101, Philippines
| |
Collapse
|
9
|
Liang H, Yu Z, Wang B, Ndayisenga F, Liu R, Zhang H, Wu G. Synergistic Application of Molecular Markers and Community-Based Microbial Source Tracking Methods for Identification of Fecal Pollution in River Water During Dry and Wet Seasons. Front Microbiol 2021; 12:660368. [PMID: 34194406 PMCID: PMC8236858 DOI: 10.3389/fmicb.2021.660368] [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: 01/29/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
It is important to track fecal sources from humans and animals that negatively influence the water quality of rural rivers and human health. In this study, microbial source tracking (MST) methods using molecular markers and the community-based FEAST (fast expectation–maximization microbial source tracking) program were synergistically applied to distinguish the fecal contributions of multiple sources in a rural river located in Beijing, China. The performance of eight markers were evaluated using 133 fecal samples based on real-time quantitative (qPCR) technique. Among them, six markers, including universal (BacUni), human-associated (HF183-1 and BacH), swine-associated (Pig-2-Bac), ruminant-associated (Rum-2-Bac), and avian-associated (AV4143) markers, performed well in the study. A total of 96 water samples from the river and outfalls showed a coordinated composition of fecal pollution, which revealed that outfall water might be a potential input of the Fsq River. In the FEAST program, bacterial 16S rRNA genes of 58 fecal and 12 water samples were sequenced to build the “source” library and “sink,” respectively. The relative contribution (<4.01% of sequence reads) of each source (i.e., human, swine, bovine, or sheep) was calculated based on simultaneous screening of the operational taxonomic units (OTUs) of sources and sinks, which indicated that community-based MST methods could be promising tools for identifying fecal sources from a more comprehensive perspective. Results of the qPCR assays indicated that fecal contamination from human was dominant during dry weather and that fecal sources from swine and ruminant were more prevalent in samples during the wet season than in those during the dry season, which were consistent with the findings predicted by the FEAST program using a very small sample size. Information from the study could be valuable for the development of improved regulation policies to reduce the levels of fecal contamination in rural rivers.
Collapse
Affiliation(s)
- Hongxia Liang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Zhisheng Yu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China.,RCEES-IMCAS-UCAS Joint-Lab of Microbial Technology for Environmental Science, Beijing, China
| | - Bobo Wang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Fabrice Ndayisenga
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Ruyin Liu
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Hongxun Zhang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
| | - Gang Wu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
10
|
Rytkönen A, Tiwari A, Hokajärvi AM, Uusheimo S, Vepsäläinen A, Tulonen T, Pitkänen T. The Use of Ribosomal RNA as a Microbial Source Tracking Target Highlights the Assay Host-Specificity Requirement in Water Quality Assessments. Front Microbiol 2021; 12:673306. [PMID: 34149662 PMCID: PMC8206488 DOI: 10.3389/fmicb.2021.673306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/19/2021] [Indexed: 12/28/2022] Open
Abstract
For microbial source tracking (MST), the 16S ribosomal RNA genes (rDNA) of host-specific bacteria and mitochondrial DNA (mtDNA) of animal species, known to cause fecal contamination of water, have been commonly used as molecular targets. However, low levels of contamination might remain undetected by using these DNA-based qPCR assays. The high copy numbers of ribosomal RNA (rRNA) could offer a solution for such applications of MST. This study compared the performance of eight MST assays: GenBac3 (general Bacteroidales), HF183 (human), BacCan (dog), Rum-2-Bac (ruminant), Pig-2-Bac (swine), Gull4 (gull), GFD, and Av4143 (birds) between rRNA-based and rDNA-based approaches. Three mtDNA-based approaches were tested: DogND5, SheepCytB, and HorseCytB. A total of 151 animal fecal samples and eight municipal sewage samples from four regions of Finland were collected for the marker evaluation. The usability of these markers was tested by using a total of 95 surface water samples with an unknown pollution load. Overall, the performance (specificity, sensitivity, and accuracy) of mtDNA-based assays was excellent (95–100%), but these markers were very seldom detected from the tested surface water samples. The rRNA template increased the sensitivity of assays in comparison to the rDNA template. All rRNA-based assays (except Av4143) had more than 80% sensitivity. In contrast, only half (HF183, Rum-2-Bac, Pig-2-Bac, and Gull4) of rDNA-based assays reached this value. For markers targeted to bird feces, the use of the rRNA-based assay increased or at least did not change the performance. Regarding specificity, all the assays had >95% specificity with a DNA template, except the BacCan assay (71%). While using the RNA template for the assays, HF183 and BacCan exhibited only a low level of specificity (54 and 55%, respectively). Further, the HF183 assay amplified from multiple non-targeted animal fecal samples with the RNA template and the marker showed cross-amplification with the DNA template as well. This study recommends using the rRNA-based approach for MST assays targeting bird fecal contamination. In the case of mammal-specific MST assays, the use of the rRNA template increases the sensitivity but may reduce the specificity and accuracy of the assay. The finding of increased sensitivity calls for a further need to develop better rRNA-based approaches to reach the required assay performance.
Collapse
Affiliation(s)
- Annastiina Rytkönen
- Expert Microbiology Unit, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Ananda Tiwari
- Expert Microbiology Unit, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Anna-Maria Hokajärvi
- Expert Microbiology Unit, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Sari Uusheimo
- Lammi Biological Station, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Asko Vepsäläinen
- Environmental Health Unit, Finnish Institute for Health and Welfare, Kuopio, Finland
| | - Tiina Tulonen
- Lammi Biological Station, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Tarja Pitkänen
- Expert Microbiology Unit, Finnish Institute for Health and Welfare, Kuopio, Finland.,Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| |
Collapse
|
11
|
Greaves J, Stone D, Wu Z, Bibby K. Persistence of emerging viral fecal indicators in large-scale freshwater mesocosms. WATER RESEARCH X 2020; 9:100067. [PMID: 32995735 PMCID: PMC7516186 DOI: 10.1016/j.wroa.2020.100067] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 08/30/2020] [Accepted: 09/02/2020] [Indexed: 05/18/2023]
Abstract
Fecal indicator bacteria (FIB) are typically used to monitor microbial water quality but are poor representatives of viruses due to different environmental fate. Viral fecal indicators have been proposed as alternatives to FIB; however, data evaluating the persistence of emerging viral fecal indicators under realistic environmental conditions is necessary to evaluate their potential application. In this study, we examined the persistence of five viral fecal indicators, including crAssphage and pepper mild mottle virus (PMMoV), and three bacterial fecal indicators (E. coli, enterococci and HF183/BacR287) in large-scale experimental ponds and freshwater mesocosms. Observed inactivation rate constants were highly variable and ranged from a minimum of -0.09 d-1 for PMMoV to a maximum of -3.5 d-1 for HF183/BacR287 in uncovered mesocosms. Overall, viral fecal indicators had slower inactivation than bacterial fecal indicators and PMMoV was inactivated more slowly than all other targets. These results demonstrate that bacterial fecal indicators inadequately represent viral fate following aging of sewage contaminated water due to differential persistence, and that currently used fecal indicator monitoring targets demonstrate highly variable persistence that should be considered during water quality monitoring and risk assessment.
Collapse
Affiliation(s)
- Justin Greaves
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, IN, 46556, USA
| | - Daniel Stone
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, IN, 46556, USA
| | - Zhenyu Wu
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, IN, 46556, USA
| | - Kyle Bibby
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, IN, 46556, USA
| |
Collapse
|
12
|
Schiaffino F, Pisanic N, Colston JM, Rengifo D, Paredes Olortegui M, Shapiama V, Peñataro Yori P, Heaney CD, Davis MF, Kosek MN. Validation of microbial source tracking markers for the attribution of fecal contamination in indoor-household environments of the Peruvian Amazon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 743:140531. [PMID: 32758812 PMCID: PMC7511695 DOI: 10.1016/j.scitotenv.2020.140531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/23/2020] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
The performance of eight microbial source tracking (MST) markers was evaluated in a low-resource, tropical community located in Iquitos, Peru. Fecal samples from humans, dogs, cats, rats, goats, buffalos, guinea-pigs, chickens, ducks, pigeons, and parrots were collected (n = 117). All samples were tested with human (BacHum, HF183-Taqman), dog (BactCan), pig (Pig-2-Bac), and avian (LA35, Av4143, ND5, cytB) markers using quantitative PCR (qPCR). Internal validity metrics were calculated using all animal fecal samples, as well as animal fecal samples contextually relevant for the Peruvian Amazon. Overall, Pig-2-Bac performed best, with 100% sensitivity and 88.5% specificity to detect the correct fecal source. Human-associated markers showed a sensitivity of 80.0% and 76.7%, and specificity of 66.2% and 67.6%. When limiting the analysis to contextually relevant animal fecal samples for the Peruvian Amazon, Av143 surpassed cytB with 95.7% sensitivity and 81.8% specificity. BactCan demonstrated 100% sensitivity and 47.4% specificity. The gene copy number detected by BacHum and HF183-Taqman were positively correlated (Pearson's correlation coefficient: 0.785), as well as avian markers cytB with Av4143 (Pearson's correlation coefficient: 0.508) and nd5 (Pearson's correlation coefficient: 0.949). These findings suggest that markers such as Av4143, Pig2Bac, cytb and BacHum have acceptable performance to be impactful in source attribution studies for zoonotic enteric disease transmission in this and similar low-resource communities.
Collapse
Affiliation(s)
- Francesca Schiaffino
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Faculty of Veterinary Medicine, Universidad Peruana Cayetano Heredia, San Martin de Porres, Lima, Peru
| | - Nora Pisanic
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Josh M Colston
- Division of Infectious Diseases, University of Virginia, Charlottesville, VA, USA
| | - Dixner Rengifo
- Division of Infectious Diseases, University of Virginia, Charlottesville, VA, USA
| | | | | | - Pablo Peñataro Yori
- Division of Infectious Diseases, University of Virginia, Charlottesville, VA, USA; Asociacion Benefica Prisma, Iquitos, Peru
| | - Christopher D Heaney
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Meghan F Davis
- Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Molecular and Comparative Pathobiology, Johns Hopkins Bloomberg School of Medicine, Baltimore, MD, USA
| | - Margaret N Kosek
- Division of Infectious Diseases, University of Virginia, Charlottesville, VA, USA; Asociacion Benefica Prisma, Iquitos, Peru.
| |
Collapse
|
13
|
Zhu K, Suttner B, Pickering A, Konstantinidis KT, Brown J. A novel droplet digital PCR human mtDNA assay for fecal source tracking. WATER RESEARCH 2020; 183:116085. [PMID: 32750535 PMCID: PMC7495096 DOI: 10.1016/j.watres.2020.116085] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 05/22/2023]
Abstract
Human mitochondrial DNA provides a promising target for fecal source tracking because it is unique and intrinsic to humans. We developed a TaqMan chemistry assay, hCYTB484, targeting the cytochrome b gene of the human mitochondrial genome on a droplet digital PCR (ddPCR) platform and compared the performance of hCYTB484 with the HF183/BacR287 assay, a widely used assay targeting human-associated Bacteroides. For both assays, we defined the analytical limit of detection and analytical lower limit of quantification using frequency of detection and imprecision goals, respectively. We then established these analytical limits using empirical ddPCR data, presenting a novel approach to determining the analytical lower limit of quantification. We evaluated assay sensitivity using individual human feces from US, Bangladesh, and Mozambique and evaluated assay specificity using cow, pig, chicken, and goat samples collected from the US. To compare assay performance across a range of thresholds, we utilized receiver operating characteristic curves. The hCYTB484 marker was detected and quantifiable in 100% of the human feces from the 3 geographical distant regions whereas the HF183/BacR287 marker was detectable and quantifiable in 51% and 31% (respectively) of human feces samples. The hCYTB484 marker also was more specific (97%), having fewer detections in pig, chicken, and goat samples than the HF183/BacR287 marker (80%). The higher performance of the hCYTB484 marker in individual feces from geographically distant regions is desirable in the detection of fecal pollution from sources to which fewer individuals contribute, such as the non-sewered forms of sanitation (e.g. pit latrines and septic tanks) that serve most of Earth's population and carry the highest risk of exposure to fecal-oral pathogens.
Collapse
Affiliation(s)
- Kevin Zhu
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Brittany Suttner
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Amy Pickering
- Civil and Environmental Engineering, Tufts University, Medford, MA, USA
| | | | - Joe Brown
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
| |
Collapse
|
14
|
Zhang Y, Wu R, Lin K, Wang Y, Lu J. Performance of host-associated genetic markers for microbial source tracking in China. WATER RESEARCH 2020; 175:115670. [PMID: 32171096 DOI: 10.1016/j.watres.2020.115670] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Numerous genetic markers have been developed to establish microbial source tracking (MST) assays in the last decade. However, the selection of suitable markers is challenging due to a lack of understanding of fundamental factors such as sensitivity, specificity, and concentration in target/nontarget hosts, especially in East Asia. In this study, a total of 506 faecal samples comprised of human and 12 nonhuman hosts were collected from 28 cities across China and tested for marker performance characteristics. We firstly tested 40 host-associated markers based on a binary (presence/absence) criterion. Here, 15 markers (7 human-associated, 4 pig-associated, 3 ruminant-associated, and 1 poultry-associated) showed potential applicability in our study area. The selected 15 markers were then tested using qualitative and quantitative methods to characterise their performance. Overall, Bacteroidales markers presented higher sensitivity and concentrations in target samples compared to other bacterial or viral markers, but their specificity was low. Among nontarget samples, pets accounted for 43.7% and 35.7% of cross-reactivity with human-associated and poultry-associated markers, respectively. Noncommon animals, including horse and donkey, contributed 61.3% of cross-reactivity with ruminant-associated markers. When considering the quantitative distribution of markers, their concentration in nontarget samples were 1-3 orders of magnitude lower than in target samples. Moreover, a novel classification method was proposed to classify the nontarget hosts into four groups spanning "no cross-reactivity", "weak cross-reactivity", "moderate cross-reactivity", and "strong cross-reactivity" animal hosts. There were 77.9% nontarget samples identified as no cross-reactivity and weak cross-reactivity hosts, suggesting that these nontarget hosts produce little interference for corresponding markers. Our findings elucidate the performance of host-associated markers around China in a qualitative and quantitative manner, and reveal the interference degree of cross-reactivity from nontarget animals to genetic markers, which will facilitate tracking of multiple faecal pollution sources and planning timely remedial strategies in China.
Collapse
Affiliation(s)
- Yang Zhang
- Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Renren Wu
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510000, PR China; State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510530, PR China.
| | - Kairong Lin
- Department of Water Resources and Environment, Sun Yat-sen University, Guangzhou, 510275, PR China.
| | - Yishu Wang
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510000, PR China; State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510530, PR China
| | - Junqing Lu
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510000, PR China; State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou, 510530, PR China
| |
Collapse
|
15
|
Jeong SH, Shin SB, Lee JH, Kwon JY, Lee HC, Kim SJ, Ha KS. Level of contamination in the feces of several species at major inland pollution sources in the drainage basin of Yeoja Bay, Republic of Korea. ENVIRONMENTAL MONITORING AND ASSESSMENT 2020; 192:170. [PMID: 32034525 DOI: 10.1007/s10661-020-8131-7] [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: 09/23/2019] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
We assessed the levels of fecal contamination and the originating species of 12 major inland pollutants in the drainage basin of Yeoja Bay. The presence of the human-specific (HF183), ruminant-specific (BacR and Rum-2-Bac), pig-specific (Pig-Bac-2 and Pig-2-Bac), avian-specific (GFD), and gull-specific (Gull2) markers in water samples (n = 34) from 12 inland pollution sources around Yeoja Bay was analyzed. HF183 was detected in 97% of the water samples, and all major inland pollution sources were contaminated with human feces. BacR and Rum-2-Bac were detected in 94% and 11%, respectively, of the water samples. Pig-2-Bac was not detected in the inland pollution sources, but site L5 might be contaminated with swine feces. Gull2 was not detected, whereas GFD was detected in 26% of the water samples. This study highlights the utility of a MST toolbox approach for characterizing the water quality of inland pollution sources and identifying the feces producing species.
Collapse
Affiliation(s)
- Sang Hyeon Jeong
- Southeast Sea Fisheries Research Institute, National Institute of Fisheries Science, 397-68, Sanyangilju-ro, Sanyang-eup, Tongyeong-si, Gyeongsangnam-do, 53085, Republic of Korea.
| | - Soon Bum Shin
- South Sea Fisheries Research Institute, National Institute of Fisheries Science, 22, Sepodangmeori-gil, Hwayang-myeon, Yeosu-si, Jeollanam-do, 59780, Republic of Korea
| | - Ji Hee Lee
- South Sea Fisheries Research Institute, National Institute of Fisheries Science, 22, Sepodangmeori-gil, Hwayang-myeon, Yeosu-si, Jeollanam-do, 59780, Republic of Korea
| | - Ji Young Kwon
- Southeast Sea Fisheries Research Institute, National Institute of Fisheries Science, 397-68, Sanyangilju-ro, Sanyang-eup, Tongyeong-si, Gyeongsangnam-do, 53085, Republic of Korea
| | - Hee Chung Lee
- Southeast Sea Fisheries Research Institute, National Institute of Fisheries Science, 397-68, Sanyangilju-ro, Sanyang-eup, Tongyeong-si, Gyeongsangnam-do, 53085, Republic of Korea
| | - Seon-Jae Kim
- Department of Marine Bio Food Science, Chonnam National University, 50, Daehak-ro, Yeosu-si, Jeollanam-do, 59626, Republic of Korea
| | - Kwang Soo Ha
- Southeast Sea Fisheries Research Institute, National Institute of Fisheries Science, 397-68, Sanyangilju-ro, Sanyang-eup, Tongyeong-si, Gyeongsangnam-do, 53085, Republic of Korea
| |
Collapse
|
16
|
Motlagh AM, Yang Z. Detection and occurrence of indicator organisms and pathogens. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2019; 91:1402-1408. [PMID: 31505073 PMCID: PMC7169830 DOI: 10.1002/wer.1238] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 06/10/2023]
Abstract
This review paper focuses on detection and quantification techniques of indicator organisms that can be used for water quality assessment. The environmental pathogens that are critical to understand and better evaluate water quality are also discussed in this paper. Several recent studies using culture-independent methods such as microbial source tracking, pulsed field gel electrophoresis, mitochondrial DNA, and next generation sequencing to assess various environmental samples and water bodies have been reviewed. PRACTITIONER POINTS: Various waterborne pathogens and cases of outbreak occurances due to presence of pathogens are studied in this review paper. Recent studies for detecting major indicator organisms to evaluate the presence of pathogens in water bodies are reviewed. Culture-independent techniques as robust tools to detect and quantify waterborne pathogens are discussed in this review paper.
Collapse
Affiliation(s)
- Amir M. Motlagh
- Department of Civil EngineeringCalifornia State UniversitySacramentoCalifornia
| | - Zhengjian Yang
- Department of Civil EngineeringCalifornia State UniversitySacramentoCalifornia
| |
Collapse
|
17
|
Vadde KK, McCarthy AJ, Rong R, Sekar R. Quantification of Microbial Source Tracking and Pathogenic Bacterial Markers in Water and Sediments of Tiaoxi River (Taihu Watershed). Front Microbiol 2019; 10:699. [PMID: 31105648 PMCID: PMC6492492 DOI: 10.3389/fmicb.2019.00699] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/20/2019] [Indexed: 12/13/2022] Open
Abstract
Taihu Lake is one of the largest freshwater lakes in China, serving as an important source of drinking water; >60% of source water to this lake is provided by the Tiaoxi River. This river faces serious fecal contamination issues, and therefore, a comprehensive investigation to identify the sources of fecal contamination was carried out and is presented here. The performance of existing universal (BacUni and GenBac), human (HF183-Taqman, HF183-SYBR, BacHum, and Hum2), swine (Pig-2-Bac), ruminant (BacCow), and avian (AV4143 and GFD) associated microbial source tracking (MST) markers was evaluated prior to their application in this region. The specificity and sensitivity results indicated that BacUni, HF183-TaqMan, Pig-2-Bac, and GFD assays are the most suitable in identifying human and animal fecal contamination. Therefore, these markers along with marker genes specific to selected bacterial pathogens were quantified in water and sediment samples of the Tiaoxi River, collected from 15 locations over three seasons during 2014 and 2015. Total/universal Bacteroidales markers were detected in all water and sediment samples (mean concentration 6.22 log10 gene copies/100 ml and 6.11 log10 gene copies/gram, respectively), however, the detection of host-associated MST markers varied. Human and avian markers were the most frequently detected in water samples (97 and 89%, respectively), whereas in sediment samples, only human-associated markers were detected more often (86%) than swine (64%) and avian (8.8%) markers. The results indicate that several locations in the Tiaoxi River are heavily polluted by fecal contamination and this correlated well with land use patterns. Among the five bacterial pathogens tested, Shigella spp. and Campylobacter jejuni were the most frequently detected pathogens in water (60% and 62%, respectively) and sediment samples (91% and 53%, respectively). Shiga toxin-producing Escherichia coli (STEC) and pathogenic Leptospira spp. were less frequently detected in water samples (55% and 33%, respectively) and sediment samples (51% and 13%, respectively), whereas E. coli O157:H7 was only detected in sediment samples (11%). Overall, the higher prevalence and concentrations of Campylobacter jejuni, Shigella spp., and STEC, along with the MST marker detection at a number of locations in the Tiaoxi River, indicates poor water quality and a significant human health risk associated with this watercourse. GRAPHICAL ABSTRACTTracking fecal contamination and pathogens in watersheds using molecular methods.
Collapse
Affiliation(s)
- Kiran Kumar Vadde
- Department of Biological Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, China
| | - Alan J. McCarthy
- Microbiology Research Group, Institute of Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Rong Rong
- Department of Biological Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, China
| | - Raju Sekar
- Department of Biological Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, China
| |
Collapse
|
18
|
Devane ML, Moriarty EM, Robson B, Lin S, Wood D, Webster-Brown J, Gilpin BJ. Relationships between chemical and microbial faecal source tracking markers in urban river water and sediments during and post-discharge of human sewage. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 651:1588-1604. [PMID: 30360285 DOI: 10.1016/j.scitotenv.2018.09.258] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/19/2018] [Accepted: 09/20/2018] [Indexed: 06/08/2023]
Abstract
This study explores the relationships between faecal source tracking (FST) markers (quantitative Polymerase Chain Reaction (qPCR) markers and steroids), microbial indicators, the faecal ageing ratio of atypical colonies/total coliforms (AC/TC) and potential human pathogens (Giardia, Cryptosporidium and Campylobacter). Faecal source PCR markers tested were GenBac3, HumM3, HumBac (HF183-Bac708R); Bifidobacterium adolescentis, wildfowl and canine-associated markers. Sediment and water samples from the Avon River were collected during and post-discharge of untreated human sewage inputs, following a series of earthquakes, which severely damaged the Christchurch sewerage system. Significant, positive Spearman Ranks (rs) correlations were observed between human-associated qPCR markers and steroid FST markers and Escherichia coli and F-specific RNA bacteriophage (rs 0.57 to 0.84, p < 0.001) in water samples. These human source indicative FST markers demonstrated that they were also effective predictors of potentially pathogenic protozoa in water (rs 0.43-0.74, p ≤ 0.002), but correlated less well with Campylobacter. Human-associated qPCR and steroid markers showed significant, substantial agreement between the two FST methods (Cohen's kappa, 0.78, p = 0.023), suggesting that water managers could be confident in the results using either method under these contamination conditions. Low levels of fluorescent whitening agents (FWA) (mean 0.06 μg/L, range 0.01-0.40 μg/L) were observed in water throughout the study, but steroids and FWA appeared to be retained in river sediments, months after continuous sewage discharges had ceased. No relationship was observed between chemical FST markers in sediments and the overlying water, and few correlations in sediment between chemical FST markers and target microorganisms. The low values observed for the faecal ageing ratio, AC/TC in water, were significantly, negatively correlated with increasing pathogen detection. This study provides support for the use of the AC/TC ratio, and qPCR and steroid FST markers as indicators of health risks associated with the discharge of raw human sewage into a freshwater system.
Collapse
Affiliation(s)
- Megan L Devane
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand.
| | - Elaine M Moriarty
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand
| | - Beth Robson
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand
| | - Susan Lin
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand
| | - David Wood
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand
| | - Jenny Webster-Brown
- Waterways Centre for Freshwater Management, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Brent J Gilpin
- Institute of Environmental Science and Research Limited, Christchurch Science Centre, PO Box 29-181, Christchurch, New Zealand
| |
Collapse
|
19
|
Boehm AB, Graham KE, Jennings WC. Can We Swim Yet? Systematic Review, Meta-Analysis, and Risk Assessment of Aging Sewage in Surface Waters. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9634-9645. [PMID: 30080397 DOI: 10.1021/acs.est.8b01948] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
This study investigated the risk of gastrointestinal illness associated with swimming in surface waters with aged sewage contamination. First, a systematic review compiled 333 first order decay rate constants ( k) for human norovirus and its surrogates feline calicivirus and murine norovirus, Salmonella, Campylobacter, Escherichia coli O157:H7, Giardia, and Cryptosporidium, and human-associated indicators in surface water. A meta-analysis investigated effects of sunlight, temperature, and water matrix on k. There was a relatively large number of k for bacterial pathogens and some human-associated indicators ( n > 40), fewer for protozoans ( n = 14-22), and few for human norovirus and its Caliciviridae surrogates ( n = 2-4). Average k ranked: Campylobacter > human-associated markers > Salmonella> E. coli O157:H7 > norovirus and its surrogates > Giardia > Cryptosporidium. Compiled k values were used in a quantitative microbial risk assessment (QMRA) to simulate gastrointestinal illness risk associated with swimming in water with aged sewage contamination. The QMRA used human-associated fecal indicator HF183 as an index for the amount of sewage present and thereby provided insight into how risk relates to HF183 concentrations in surface water. Because exposure to norovirus contributed the majority of risk, and HF183 k is greater than norovirus k, the risk associated with exposure to a fixed HF183 concentration increases with the age of contamination. Swimmer exposure to sewage after it has aged ∼3 days results in median risks less than 30/1000. A risk-based water quality threshold for HF183 in surface waters that takes into account uncertainty in contamination age is derived to be 4100 copies/100 mL.
Collapse
Affiliation(s)
- Alexandria B Boehm
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| | - Katherine E Graham
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| | - Wiley C Jennings
- Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305 , United States
| |
Collapse
|
20
|
Ballesté E, García-Aljaro C, Blanch AR. Assessment of the decay rates of microbial source tracking molecular markers and faecal indicator bacteria from different sources. J Appl Microbiol 2018; 125:1938-1949. [PMID: 30066371 DOI: 10.1111/jam.14058] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 07/11/2018] [Accepted: 07/28/2018] [Indexed: 01/18/2023]
Abstract
AIMS Evaluate the T90 and compare the decay of different faecal indicator bacteria (FIB) and molecular microbial source tracking (MST) markers of human and animal sources during summer and winter. METHODS AND RESULTS The persistence of Escherichia coli and enterococci and several MST molecular markers targeting host-specific Bifidobacterium and Bacteroidales species (BifHM, BifCW, BifPL, HF183/BFD, Rum2Bac and Pig2Bac) was assessed at the same time using mesocosms. Dialysis bags filled with diluted wastewater from different sources were kept in an outdoor water tank and monitored regularly to assess the inactivation rates. The T90 values of E. coli by culture methods ranged from 1·52 to 5·69 days in summer and 2·06 to 6·19 days in winter, whereas with qPCR 2·29-4·23 days in summer and 4·17-8·09 days in winter. T90 values for enterocci ranged from 1·15 to 3·10 days in summer and from 3·01 to 5·46 days in winter. Significant differences were observed between faecal sources for both markers. For the MST makers similar T90 values were obtained in summer (1·05-1·91 days), whereas higher variability was observed in winter (2·90-6·12 days). CONCLUSIONS Different decay rates were observed for the FIB from the different sources, especially for E. coli in ruminant samples. A higher variability among T90 values of the different MST markers in winter was observed, whereas similar T90 values were detected in summer highlighting the stronger effect of environmental parameters during this season. SIGNIFICANCE AND IMPACT OF THE STUDY The diverse inactivation rates observed in bacteria from different faecal sources have implications when these rates are used to model faecal pollution in water. The use of FIBT90 of different sources is essential to develop reliable predictive models. Since different inactivation of E. coli regarding the source of pollution has been observed, the source of the pollution has to be considered for modelling approaches.
Collapse
Affiliation(s)
- E Ballesté
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
| | - C García-Aljaro
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
| | - A R Blanch
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Barcelona, Catalonia, Spain
| |
Collapse
|
21
|
Mayer R, Reischer GH, Ixenmaier SK, Derx J, Blaschke AP, Ebdon JE, Linke R, Egle L, Ahmed W, Blanch AR, Byamukama D, Savill M, Mushi D, Cristóbal HA, Edge TA, Schade MA, Aslan A, Brooks YM, Sommer R, Masago Y, Sato MI, Taylor HD, Rose JB, Wuertz S, Shanks OC, Piringer H, Mach RL, Savio D, Zessner M, Farnleitner AH. Global Distribution of Human-Associated Fecal Genetic Markers in Reference Samples from Six Continents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5076-5084. [PMID: 29570973 PMCID: PMC5932593 DOI: 10.1021/acs.est.7b04438] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 03/09/2018] [Accepted: 03/23/2018] [Indexed: 05/19/2023]
Abstract
Numerous bacterial genetic markers are available for the molecular detection of human sources of fecal pollution in environmental waters. However, widespread application is hindered by a lack of knowledge regarding geographical stability, limiting implementation to a small number of well-characterized regions. This study investigates the geographic distribution of five human-associated genetic markers (HF183/BFDrev, HF183/BacR287, BacHum-UCD, BacH, and Lachno2) in municipal wastewaters (raw and treated) from 29 urban and rural wastewater treatment plants (750-4 400 000 population equivalents) from 13 countries spanning six continents. In addition, genetic markers were tested against 280 human and nonhuman fecal samples from domesticated, agricultural and wild animal sources. Findings revealed that all genetic markers are present in consistently high concentrations in raw (median log10 7.2-8.0 marker equivalents (ME) 100 mL-1) and biologically treated wastewater samples (median log10 4.6-6.0 ME 100 mL-1) regardless of location and population. The false positive rates of the various markers in nonhuman fecal samples ranged from 5% to 47%. Results suggest that several genetic markers have considerable potential for measuring human-associated contamination in polluted environmental waters. This will be helpful in water quality monitoring, pollution modeling and health risk assessment (as demonstrated by QMRAcatch) to guide target-oriented water safety management across the globe.
Collapse
Affiliation(s)
- René
E. Mayer
- Research
Group Environmental Microbiology and Molecular
Diagnostics 166-5-3, Institute of Chemical, Environmental
and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
| | - Georg H. Reischer
- Research
Group Environmental Microbiology and Molecular
Diagnostics 166-5-3, Institute of Chemical, Environmental
and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
- Molecular
Diagnostics Group, IFA-Tulln, Institute
of Chemical, Environmental and Bioscience Engineering, TU Wien, 3430 Tulln, Austria
| | - Simone K. Ixenmaier
- Research
Group Environmental Microbiology and Molecular
Diagnostics 166-5-3, Institute of Chemical, Environmental
and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
| | - Julia Derx
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
- Institute of Hydraulic
Engineering and Water Resources Management, TU Wien, 1040 Vienna, Austria
| | - Alfred Paul Blaschke
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
- Institute of Hydraulic
Engineering and Water Resources Management, TU Wien, 1040 Vienna, Austria
| | - James E. Ebdon
- Environment
& Public Health Research and Enterprise Group, School of Environment
and Technology, University of Brighton, BN2 4GJ Brighton, U.K.
| | - Rita Linke
- Research
Group Environmental Microbiology and Molecular
Diagnostics 166-5-3, Institute of Chemical, Environmental
and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
| | - Lukas Egle
- Institute for Water Quality
and Resource Management, TU Wien, 1040 Vienna, Austria
| | - Warish Ahmed
- CSIRO
Land and Water, Ecosciences Precinct, 41 Boggo Road, Qld 4102, Australia
| | - Anicet R. Blanch
- Department
of Genetics, Microbiology and Statistics, University of Barcelona, 08028 Barcelona, Spain
| | - Denis Byamukama
- Department
of Biochemistry, Makerere University, P.O. Box 27755 Kampala, Uganda
| | - Marion Savill
- Affordable Water Limited, 1011 Auckland, New Zealand
| | - Douglas Mushi
- Department
of Biosciences, Sokoine University of Agriculture, PO BOX 3038, Morogoro, Tanzania
| | - Héctor A. Cristóbal
- Laboratorio
de Aguas y Suelos, Instituto de Investigaciones para la Industria
Química (INIQUI), Consejo Nacional
de Investigaciones Científicas y Técnicas and Universidad
Nacional de Salta, CP 4400 Salta, Argentina
| | - Thomas A. Edge
- Environment and Climate Change Canada, Canada Centre for Inland Waters, Burlington, L7S 1A1, Ontario, Canada
| | | | - Asli Aslan
- Department
of Epidemiology and Environmental Health Sciences, Georgia Southern University, Statesboro, 30460 Georgia, United States
| | - Yolanda M. Brooks
- Department of Fisheries and Wildlife, Michigan State University East Lansing, 48824 Michigan, United States
| | - Regina Sommer
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
- Institute
for Hygiene and Applied Immunology, Water Hygiene, Medical University of Vienna, 1090 Vienna, Austria
| | - Yoshifumi Masago
- New
Industry Creation Hatchery Center, Tohoku
University, 980-8579 Sendai, Japan
| | - Maria I. Sato
- Departamento
de Análises Ambientais, CETESB -
Cia. Ambiental do Estado de São Paulo, 05459-900 São
Paulo, Brasil
| | - Huw D. Taylor
- Environment
& Public Health Research and Enterprise Group, School of Environment
and Technology, University of Brighton, BN2 4GJ Brighton, U.K.
| | - Joan B. Rose
- Department of Fisheries and Wildlife, Michigan State University East Lansing, 48824 Michigan, United States
| | - Stefan Wuertz
- Singapore Centre
for Environmental Life Sciences Engineering and
School of Civil and Environmental Engineering, Nanyang Technological University, 637551 Singapore
| | - Orin C. Shanks
- U.S. Environmental Protection Agency, Office
of Research and Development, 45268 Cincinnati, Ohio, United States
| | | | - Robert L. Mach
- Research Division Biochemical Technology, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
| | - Domenico Savio
- Division Water Quality and Health, Department Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, 3500 Krems an der Donau, Austria
| | - Matthias Zessner
- Institute for Water Quality
and Resource Management, TU Wien, 1040 Vienna, Austria
| | - Andreas H. Farnleitner
- Research
Group Environmental Microbiology and Molecular
Diagnostics 166-5-3, Institute of Chemical, Environmental
and Bioscience Engineering, TU Wien, 1060 Vienna, Austria
- Interuniversity
Cooperation Centre Water & Health, Vienna, Austria
- Division Water Quality and Health, Department Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, 3500 Krems an der Donau, Austria
- Phone: +43 664 605882244; e-mail:
| |
Collapse
|
22
|
Seidel L, Strathmann M, Nocker A. The feasibility of improved live-dead distinction in qPCR-based microbial source tracking. J Microbiol Methods 2017. [DOI: 10.1016/j.mimet.2017.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
23
|
Bucci JP, Shattuck MD, Aytur SA, Carey R, McDowell WH. A case study characterizing animal fecal sources in surface water using a mitochondrial DNA marker. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:406. [PMID: 28730580 DOI: 10.1007/s10661-017-6107-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
Water quality impairment by fecal waste in coastal watersheds is a public health issue. The present study provided evidence for the use of a mitochondrial (mtDNA) marker to detect animal fecal sources in surface water. The accurate identification of fecal pollution is based on the notion that fecal microorganisms preferentially inhabit a host animal's gut environment. In contrast, mtDNA host-specific markers are inherent to eukaryotic host cells, which offers the advantage by detecting DNA from the host rather than its fecal bacteria. The present study focused on sampling water presumably from non-point sources (NPS), which can increase bacterial and nitrogen concentrations to receiving water bodies. Stream sampling sites located within the Piscataqua River Watershed (PRW), New Hampshire, USA, were sampled from a range of sites that experienced nitrogen inputs such as sewer and septic systems and suburban runoff. Three mitochondrial (mtDNA) gene marker assays (human, bovine, and canine) were tested from surface water. Nineteen sites were sampled during an 18-month period. Analyses of the combined single and multiplex assay results showed that the proportion of occurrence was highest for bovine (15.6%; n = 77) compared to canine (5.6%; n = 70) and human (5.7%; n = 107) mtDNA gene markers. For the human mtDNA marker, there was a statistically significant relationship between presence vs. absence and land use (Fisher's test p = 0.0031). This result was evident particularly for rural suburban septic, which showed the highest proportion of presence (19.2%) compared to the urban sewered (3.3%), suburban sewered (0%), and agricultural (0%) as well as forested septic (0%) sites. Although further testing across varied land use is needed, our study provides evidence for using the mtDNA marker in large watersheds.
Collapse
Affiliation(s)
- John P Bucci
- School of Marine Science and Ocean Engineering, University of New Hampshire, Durham, 03824, New Hampshire, USA.
| | - Michelle D Shattuck
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, 03824, New Hampshire, USA
| | - Semra A Aytur
- Department of Health Management and Policy, University of New Hampshire, Durham, 03824, New Hampshire, USA
| | - Richard Carey
- Department of Natural Resources and the Environment, Earth Systems Research Center, University of New Hampshire, Durham, 03824, New Hampshire, USA
| | - William H McDowell
- Department of Natural Resources and the Environment, University of New Hampshire, Durham, 03824, New Hampshire, USA
| |
Collapse
|