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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.
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Affiliation(s)
- Rose Ragot
- INRS Centre Armand-Frappier Santé Biotechnologie, Canada.
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A Shahin S, H Alarcon J, Brosky HN, Lamori JG, Dada AC, Xue J, Gyawali P, P Sherchan S. Occurrence of Naegleria fowleri and faecal indicators in sediments from Lake Pontchartrain, Louisiana. JOURNAL OF WATER AND HEALTH 2022; 20:657-669. [PMID: 35482382 DOI: 10.2166/wh.2022.285] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The occurrence of amoeba, Naegleria fowleri, in sediment samples from Lake Pontchartrain in Louisiana was investigated. This amoeba is pathogenic and can cause primary amoebic meningoencephalitis. In this study, quantitative polymerase chain reaction methods were used to test for the prevalence of Naegleria fowleri, HF183, and E. coli. N. fowleri was detected in 51.25% of our sediment samples. Illumina sequencing of sediment samples revealed ten different phyla, with Cyanobacteria being the most predominant at sites that generally presented with the highest median N. fowleri concentrations. N. fowleri was however strongly negatively correlated with HF183 (r = -0.859, p < 0.001). Whenever sediment E. coli concentrations were below 1.54 Log GC/g, there was only a 37.5% chance that N. fowleri would be detected in the same sample. When sediment E. coli concentrations exceeded 2.77 Log GC/g, the chances of detecting N. fowleri in the same sample increased to 90%, potentially suggesting predatory activity by the amoeba. The effect of temperature was observed to be different in relation to observed N. fowleri concentrations and detection rates. Although sediment samples collected during periods of higher temperatures had significantly lower mean N. fowleri concentrations (2.7 Log GC/g) compared to those collected at lower temperatures (3.7 Log GC/g, t(39) = 4.167, p < 0.001), higher N. fowleri detection rates in the overall samples were observed at higher temperatures (>19.1 °C) than at lower temperatures (<19.1 °C).
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Affiliation(s)
- Shalina A Shahin
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail:
| | - Joshua H Alarcon
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail:
| | - Hanna N Brosky
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail:
| | - Jennifer G Lamori
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail:
| | | | - Jia Xue
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail:
| | - Pradip Gyawali
- Institute of Environmental Science and Research Ltd, Porirua 5240, New Zealand
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112, USA E-mail: ; Department of Biology, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD 21251, USA
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Bouchali R, Mandon C, Marti R, Michalon J, Aigle A, Marjolet L, Vareilles S, Kouyi GL, Polomé P, Toussaint JY, Cournoyer B. Bacterial assemblages of urban microbiomes mobilized by runoff waters match land use typologies and harbor core species involved in pollutant degradation and opportunistic human infections. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152662. [PMID: 34963611 DOI: 10.1016/j.scitotenv.2021.152662] [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: 09/02/2021] [Revised: 11/23/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Cities are patchworks of urban catchments divided into functional units according to their commercial, residential and industrial activities, and socio-urbanistic patterns. The hypothesis of city surface microbiomes being structured by socio-urbanistic variables leading to an emergence of synurbic taxa was tested. According to the r/K microbial ecology theory, a gradient of well-adapted synurbic K-strategists and of opportunistic -r-strategists should occur over city surfaces. K-strategists would be core components while r-ones would be transiently detected. To resolve these patterns, sub-catchments (n = 21) of an area of high commercial and industrial activities were investigated over three time periods covering one year. The sub-catchments' land use patterns and associated human behaviors were converted into socio-urbanistic variables and groupings. Bacterial cells mobilized by runoffs per sub-catchment were recovered, and analyzed by classical approaches, microbial source tracking DNA assays and DNA meta-barcoding approaches. Relationships between these datasets, the runoff physico-chemical properties, and descriptors of the socio-urbanistic groupings were investigated. 16S rRNA meta-barcoding analyses showed evidence of the occurrence of K- and r-like strategists. Twenty-eight core genera were identified, and correlation networks revealed large bacterial modules organized around actinobacterial taxa involved in hydrocarbon degradation processes. Other bacterial networks were related to the occurrences of hygienic wastes, and involved bacteria originating from fecal contaminations. Several r-strategists like Sulfurospirillum were recorded and found associated to point source pollutions. The tpm-metabarcoding approach deciphered these r / K strategists at the species level among more than ten genera. Nine core K-like Pseudomomas species were identified. The P. aeruginosa human opportunistic pathogen and P. syringae phytopathogens were part of these K-strategists. Other tpm-harboring bacterial pathogens showed r-like opportunistic distribution patterns. Correlation network analyses indicated a strong incidence of hygienic wastes and hydrocarbon-pollutions on tpm-harboring bacteria. These analyses demonstrated the occurrence of core synurbic bacterial K-strategists over city surfaces.
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Affiliation(s)
- Rayan Bouchali
- Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRAE 1418, 69280 Marcy L'Etoile, France
| | - Claire Mandon
- Université de Lyon, INSA Lyon, UMR Environnement, Ville, Société, CNRS 5600, 18 rue Chevreul, 69362 Lyon, France
| | - Romain Marti
- Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRAE 1418, 69280 Marcy L'Etoile, France
| | - Jérôme Michalon
- Université de Lyon, UMR Triangle, CNRS 5206 Université Jean Monnet Saint Etienne, 6 rue Basse des Rives, 42023 Saint-Etienne, France
| | - Axel Aigle
- Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRAE 1418, 69280 Marcy L'Etoile, France
| | - Laurence Marjolet
- Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRAE 1418, 69280 Marcy L'Etoile, France
| | - Sophie Vareilles
- Université de Lyon, INSA Lyon, UMR Environnement, Ville, Société, CNRS 5600, 18 rue Chevreul, 69362 Lyon, France
| | - Gislain Lipeme Kouyi
- Université de Lyon, INSA Lyon, DEEP, EA7429, 11 rue de la physique, 69621 Villeurbanne, France
| | - Philippe Polomé
- Université de Lyon, UMR GATE, CNRS 5824, Université Lumière Lyon 2, 93 chemin des Mouilles, 69131 Ecully, France
| | - Jean-Yves Toussaint
- Université de Lyon, INSA Lyon, UMR Environnement, Ville, Société, CNRS 5600, 18 rue Chevreul, 69362 Lyon, France
| | - Benoit Cournoyer
- Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRAE 1418, 69280 Marcy L'Etoile, France.
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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.
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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
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Conrad JW, Harwood VJ. Sewage Promotes Vibrio vulnificus Growth and Alters Gene Transcription in Vibrio vulnificus CMCP6. Microbiol Spectr 2022; 10:e0191321. [PMID: 35171011 PMCID: PMC8849060 DOI: 10.1128/spectrum.01913-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/14/2022] [Indexed: 11/20/2022] Open
Abstract
Vibrio vulnificus is a naturally occurring, potentially lethal pathogen found in coastal waters, fish, and shellfish. Sewage spills in coastal waters occur when infrastructure fails due to severe storms or age, and may affect bacterial populations by altering nutrient levels. This study investigated effects of sewage on clonal and natural V. vulnificus populations in microcosms. Addition of 1% sewage to estuarine water caused the density of a pure culture of V. vulnificus CMCP6 and a natural V. vulnificus population to increase significantly, by two to three orders of magnitude, whether measured by quantitative PCR (qPCR) or culture and in batch and continuous cultures. Changes in the transcription of six virulence- and survival-associated genes in response to sewage were assessed using continuous culture. Exposure to sewage affected transcription of genes that may be associated with virulence, i.e., it modulated the oxidative stress response by altering superoxide dismutase transcription, significantly increasing sodB transcription while repressing sodA. Sewage also repressed transcription of nptA, which encodes a sodium-phosphate cotransporter. Sewage had no effect on sodC transcription or the putative virulence-associated genes hupA or wza. The effects of environmentally relevant levels of sewage on V. vulnificus populations and gene transcription suggest that sewage spills that impact warm coastal waters could lead to an increased risk of V. vulnificus infections. IMPORTANCE Vibrio vulnificus infections have profound impacts such as limb amputation and death for individuals with predisposing conditions. The warming climate is contributing to rising V. vulnificus prevalence in waters that were previously too cold to support high levels of the pathogen. Climate change is also expected to increase precipitation in many regions, which puts more pressure on wastewater infrastructure and will result in more frequent sewage spills. The finding that 1% wastewater in estuarine water leads to 100 to over 1,000-fold greater V. vulnificus concentrations suggests that human exposure to oysters and estuarine water could have greater health impacts in the future. Further, wastewater had a significant effect on gene transcription and has the potential to affect virulence during the initial environment-to-host transition.
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Affiliation(s)
- James W. Conrad
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Valerie J. Harwood
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
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Shahin SA, Keevy H, Dada AC, Gyawali P, Sherchan SP. Incidence of human associated HF183 Bacteroides marker and E. coli levels in New Orleans Canals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150356. [PMID: 34563901 DOI: 10.1016/j.scitotenv.2021.150356] [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: 06/14/2021] [Revised: 08/19/2021] [Accepted: 09/11/2021] [Indexed: 06/13/2023]
Abstract
With a focus on five sites in an impaired, densely populated area in the New Orleans area, we investigated the temporal and spatial variability of standard FIB and a marker of human-associated pollution (Bacteroides HF183). With all sites combined, only a weak positive correlation (r = 0.345; p = 0.001) was observed between E. coli and HF183. Also, specific conductivity (r = - 0.374; p < 0.0001) and dissolved oxygen (r = - 0.390; p < 0.0001) were observed to show a weak moderate correlation with E. coli. These correlations increased to moderately negative when HF183 was correlated with specific conductivity (r = - 0.448; p < 0.0001) and dissolved oxygen (r = - 0.455; p < 0.0001). E. coli contamination was generally highest at the sites in the canal that are situated in the most densely populated part of the watershed while HF183 was frequently detected across all sites. E. coli concentrations were significantly higher (p < 0.05) when HF183 was present. HF183 was detected at significantly higher concentrations in samples that exceeded the EPA water quality standard (WQS) than those that did not (p < 0.05). Dissolved oxygen and specific conductivity were significantly lower when E. coli WQS was exceeded or when HF183 was present (p < 0.05). Rainfall impacted E. coli concentrations and HF183 differently at the study sites. While HF183 and E. coli concentrations levels were significantly higher (p < 0.05) if the days prior to sampling had been wet, the frequency of detection of HF183 was unimpacted, as comparable detection rates were recorded during wet and dry weather conditions. Without testing for HF183, it would have been assumed, based on testing for E. coli alone, that human fecal pollution was only associated with densely populated areas and rainfall events. E. coli alone may not be an effective indicator of sewage pollution at the study sites across all weather conditions and may need to be complemented with HF183 enumeration to optimize human fecal pollution identification and management at the watershed level.
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Affiliation(s)
- Shalina A Shahin
- Department of Environmental Health Sciences, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA 70112, USA
| | - Helen Keevy
- Department of Environmental Health Sciences, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA 70112, USA
| | | | - Pradip Gyawali
- Institute of Environmental Science and Research Ltd, Porirua, 5240, New Zealand
| | - Samendra P Sherchan
- Department of Environmental Health Sciences, Tulane University, 1440 Canal Street, Suite 2100, New Orleans, LA 70112, USA.
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Goh SG, Liang L, Gin KYH. Assessment of Human Health Risks in Tropical Environmental Waters with Microbial Source Tracking Markers. WATER RESEARCH 2021; 207:117748. [PMID: 34837748 DOI: 10.1016/j.watres.2021.117748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Human specific microbial source tracking (MST) markers which are highly specific to human waste contamination offer the advantage of better association with human pathogens than traditional microbial indicators. However, the performance of these MST markers may vary across different geographical regions. The magnitude of MST markers also plays an important role in interpreting the health risks. This study aims to (i) validate the specificity and sensitivity of human markers for tropical urban catchments; (ii) identify the threshold concentrations of MST markers, i.e. human polyomaviruses (HPyVs), Bacteroides thetaiotaomicron (B. theta) and Methanobrevibacter smithii (M. smithii), that correspond to the acceptable gastrointestinal (GI) illness risks associated with swimming using the QMRA approach; and (iii) validate the threshold concentrations of MST markers using the surveillance data obtained from the tropical urban environment. Among the three MST markers, HPyVs showed the highest specificity (100%) to sewage samples, followed by M. smithii (97%) and B. theta (90%). All MST markers showed 100% sensitivity towards sewage contamination, with B. theta present in highest abundance in sewage, followed by HPyVs and M. smithii. This study demonstrates a risk-based framework to identify the threshold concentrations of MST markers associated with GI illness risks in environmental waters by considering two main influencing factors (i.e. decay and dilution factors). This study successfully validated the B. theta threshold concentration range (581 to 8073 GC/100 mL) with field data (370 to 6500 GC/100 mL) in estimating GI illness risks with an Enterococcus model. Field data showed that the MST markers at threshold concentrations were able to classify the safe level in more than 83% of the samples, according to GI illness risks from Enterococcus and adenovirus. The study also highlighted the lack of associations between MST markers and GI illness risks from norovirus. With comprehensive information on specificity, sensitivity and threshold concentrations of MST markers, increasing confidence can be placed on identifying human source contamination and evaluating the health risks posed in environmental waters in Singapore.
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Affiliation(s)
- S G Goh
- NUS Environmental Research Institute, National University of Singapore, T-Lab Building, #02-01, 5A Engineering Drive 1 117411, Singapore
| | - L Liang
- Department of Civil & Environmental Engineering, Faculty of Engineering, National University of Singapore, Block E1A, #07-03,1 Engineering Drive 2 117576, Singapore
| | - K Y H Gin
- NUS Environmental Research Institute, National University of Singapore, T-Lab Building, #02-01, 5A Engineering Drive 1 117411, Singapore; Department of Civil & Environmental Engineering, Faculty of Engineering, National University of Singapore, Block E1A, #07-03,1 Engineering Drive 2 117576, Singapore.
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Yasar SA, Mills TJT, Uluturk ZI, Ruszczyk JMS, LeBard RJ, Neilan BA. Quantitative detection of human- and canine-associated Bacteroides genetic markers from an urban coastal lagoon. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:1732-1744. [PMID: 34662309 DOI: 10.2166/wst.2021.341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The contamination of water catchments by nonpoint source faecal pollution is a major issue affecting the microbial quality of receiving waters and is associated with the occurrence of a range of enteric illnesses in humans. The potential sources of faecal pollution in surface waters are diverse, including urban sewage leaks, surface runoff and wildlife contamination originating from a range of hosts. The major contributing hosts require identification to allow targeted management of this public health concern. In this study, two high-performing Microbial Source Tracking (MST) assays, HF183/Bac242 and BacCan-UCDmodif, were used for their ability to detect host-specific Bacteroides 16Sr RNA markers for faecal pollution in a 12-month study on an urban coastal lagoon in Sydney, Australia. The lagoon was found to contain year-round high numbers of human and canine faecal markers, as well as faecal indicator bacteria counts, suggesting considerable human and animal faecal pollution. The high sensitivity and specificity of the HF183/Bac242 and BacCan-UCDmodif assays, together with the manageable levels of PCR inhibition and high level DNA extraction efficiency obtained from lagoon water samples make these markers candidates for inclusion in an MST 'toolbox' for investigating host origins of faecal pollution in urban surface waters.
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Affiliation(s)
- Serhat A Yasar
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Toby J T Mills
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia E-mail:
| | - Zehra I Uluturk
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | | | - Rebecca J LeBard
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Brett A Neilan
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia E-mail:
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Zhang Y, Wu R, Li W, Chen Z, Li K. Occurrence and distributions of human-associated markers in an impacted urban watershed. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 275:116654. [PMID: 33582625 DOI: 10.1016/j.envpol.2021.116654] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/26/2021] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
Numerous genetic markers for microbial source tracking (MST) have been evaluated by testing a panel of target and nontarget faecal samples. However, the performance of MST markers may vary between faecal and water samples, thereby resulting in inaccurate water quality assessment. In this study, a 30-day sampling study was conducted in an urban river impacted by human- and sewage-associated pollution to evaluate the performance of different human-associated markers in environmental water. Additionally, marker decay was assessed via a microcosms approach. Overall, Bacteroidales 16sRNA and crAssphage markers exhibited higher prevalence in the study area, and their detection frequencies exceeded 90%. In contrast, Bacteroidales protein markers exhibited poor detection frequencies compared to other markers, with the prevalence of Hum2 and Hum163 reaching only 63% and 84%, respectively. Regarding marker abundance, there was no significant difference in the detection concentrations between Bacteroidales 16sRNA and crAssphage markers (p > 0.05); however, the concentrations of Bacteroidales protein markers were nearly 1 order of magnitude lower than those of other MST markers. The microcosm experiments indicated that the decay rate of crAssphage markers was significantly lower than that of other bacterial target markers, which may improve their detectability when the pollution source is located far from the sampling site. Due to the observed differences in performance and decay patterns among Bacteroidales 16sRNA, crAssphage, and Bacteroidales protein markers, we recommend the simultaneous use of multiple markers from different target microorganisms to obtain a more comprehensive understanding of the pollution sources. This approach would also provide an accurate assessment of pollution levels and health risks.
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Affiliation(s)
- Yang Zhang
- 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
| | - 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.
| | - Wenjing Li
- 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
| | - Zhongying Chen
- 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
| | - Kaiming Li
- 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
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Schiaffino F, Rengifo Trigoso D, Colston JM, Paredes Olortegui M, Shapiama Lopez WV, Garcia Bardales PF, Pisanic N, Davis MF, Penataro Yori P, Kosek MN. Associations among Household Animal Ownership, Infrastructure, and Hygiene Characteristics with Source Attribution of Household Fecal Contamination in Peri-Urban Communities of Iquitos, Peru. Am J Trop Med Hyg 2021; 104:372-381. [PMID: 33146117 PMCID: PMC7790101 DOI: 10.4269/ajtmh.20-0810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Using previously validated microbial source tracking markers, we detected and quantified fecal contamination from avian species and avian exposure, dogs, and humans on household cooking tables and floors. The association among contamination, infrastructure, and socioeconomic covariates was assessed using simple and multiple ordinal logistic regressions. The presence of Campylobacter spp. in surface samples was linked to avian markers. Using molecular methods, animal feces were detected in 75.0% and human feces in 20.2% of 104 households. Floors were more contaminated than tables as detected by the avian marker Av4143, dog marker Bactcan, and human marker Bachum. Wood tables were consistently more contaminated than non-wood surfaces, specifically with the mitochondrial avian markers ND5 and CytB, fecal marker Av4143, and canine marker Bactcan. Final multivariable models with socioeconomic and infrastructure characteristics included as covariates indicate that detection of avian feces and avian exposure was associated with the presence of chickens, maternal age, and length of tenancy, whereas detection of human markers was associated with unimproved water source. Detection of Campylobacter in surface samples was associated with the avian fecal marker Av4143. We highlight the critical need to detect and measure the burden of animal fecal waste when evaluating household water, hygiene, and sanitation interventions, and the possibility of decreasing risk of exposure through the modification of surfaces to permit more effective household disinfection practices. Animals may be a more important source of household fecal contamination than humans in many low-resource settings, although interventions have historically focused almost exclusively on managing human waste.
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Affiliation(s)
- Francesca Schiaffino
- 1Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,2Faculty of Veterinary Medicine, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Josh M Colston
- 4Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia
| | | | | | | | - Nora Pisanic
- 5Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Meghan F Davis
- 5Department of Environmental Health and Engineering, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.,6Department of Molecular and Comparative Pathobiology, Johns Hopkins Bloomberg School of Medicine, Baltimore Maryland
| | - Pablo Penataro Yori
- 3Asociacion Benefica Prisma, Iquitos, Peru.,4Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Margaret N Kosek
- 3Asociacion Benefica Prisma, Iquitos, Peru.,4Division of Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, Virginia
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11
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Islam MMM, Islam MA. Quantifying public health risks from exposure to waterborne pathogens during river bathing as a basis for reduction of disease burden. JOURNAL OF WATER AND HEALTH 2020; 18:292-305. [PMID: 32589616 DOI: 10.2166/wh.2020.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A Quantitative Microbial Risk Assessment (QMRA) technique was applied to assess the public health risk from exposure to infectious microorganisms at bathing areas of three rivers in Bangladesh. The QMRA assessed the probability of illness due to the accidental ingestion of river water impacted by untreated sewage. The simplified QMRA was based on average concentrations of four reference pathogens Escherichia coli (E. coli) O157:H7, Cryptosporidium spp, norovirus and rotavirus relative to indicator bacterium E. coli. Public health risk was estimated as the probability of infection and illness from a single exposure of bathers. The risks of illness were ranged from 7 to 10% for E. coli O157:H7, 13 to 19% for Cryptosporidium, 7 to 10% for norovirus and 12 to 17% for rotavirus. The overall risk of illness at the rivers was slightly higher in children (9-19%) compared to adults (7-16%). The risks of illness in individuals exposed to the river bathing were unacceptably high, exceeding the USEPA acceptable risk of 3-6 illnesses per hundred bathing events. This study gives a basis for reducing the burden of disease in the population by applying appropriate risk management. Findings and methods of this study will be helpful for other countries with similar socio-economic and geographic settings.
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Affiliation(s)
- M M Majedul Islam
- Planning Division, Ministry of Planning, Government of Bangladesh, Dhaka, Bangladesh E-mail:
| | - Md Atikul Islam
- Environmental Science Discipline, Khulna University, Khulna, Bangladesh
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12
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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.
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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
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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.
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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
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Hamzah L, Boehm AB, Davis J, Pickering AJ, Wolfe M, Mureithi M, Harris A. Ruminant Fecal Contamination of Drinking Water Introduced Post-Collection in Rural Kenyan Households. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E608. [PMID: 31963600 PMCID: PMC7027003 DOI: 10.3390/ijerph17020608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/07/2020] [Accepted: 01/14/2020] [Indexed: 12/25/2022]
Abstract
In sub-Saharan Africa, many families travel to collect water and store it in their homes for daily use, presenting an opportunity for the introduction of fecal contamination. One stored and one source water sample were each collected from 45 households in rural Kenya. All 90 samples were analyzed for fecal indicator bacteria (E. coli and enterococci) and species-specific contamination using molecular microbial source tracking assays. Human (HF183), avian (GFD), and ruminant (BacR) contamination were detected in 52, two, and four samples, respectively. Stored water samples had elevated enterococci concentrations (p < 0.01, Wilcoxon matched pairs test) and more frequent BacR detection (89% versus 27%, p < 0.01, McNemar's exact test) relative to source water samples. fsQCA (fuzzy set qualitative comparative analysis) was conducted on the subset of households with no source water BacR contamination to highlight combinations of factors associated with the introduction of BacR contamination to stored water supplies. Three combinations were identified: (i) ruminants in the compound, safe water extraction methods, and long storage time, (ii) ruminants, unsafe water extraction methods, and no soap at the household handwashing station, and (iii) long storage time and no soap. This suggests that multiple pathways contribute to the transmission of ruminant fecal contamination in this context, which would have been missed if data were analyzed using standard regression techniques.
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Affiliation(s)
- Latifah Hamzah
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA; (L.H.); (A.B.B.); (J.D.); (M.W.)
| | - Alexandria B. Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA; (L.H.); (A.B.B.); (J.D.); (M.W.)
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
| | - Jennifer Davis
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA; (L.H.); (A.B.B.); (J.D.); (M.W.)
- Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA
| | - Amy J. Pickering
- Department of Civil and Environmental Engineering, Tufts University, Medford, MA 01255, USA;
| | - Marlene Wolfe
- Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305, USA; (L.H.); (A.B.B.); (J.D.); (M.W.)
- Innovations for Poverty Action, Nairobi, Kenya;
| | | | - Angela Harris
- Department of Civil, Construction, and Environmental Engineering, NC State University, Raleigh, NC 27695, USA
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15
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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.
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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
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16
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Highly Specific Sewage-Derived Bacteroides Quantitative PCR Assays Target Sewage-Polluted Waters. Appl Environ Microbiol 2019; 85:AEM.02696-18. [PMID: 30635376 DOI: 10.1128/aem.02696-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 01/02/2019] [Indexed: 12/17/2022] Open
Abstract
The identification of sewage contamination in water has primarily relied on the detection of human-associated Bacteroides using markers within the V2 region of the 16S rRNA gene. Despite the establishment of multiple assays that target the HF183 cluster (i.e., Bacteroides dorei) and other Bacteroides organisms (e.g., Bacteroides thetaiota omicron), the potential for more human-associated markers in this genus has not been explored in depth. We examined the Bacteroides population structure in sewage and animal hosts across the V4V5 and V6 hypervariable regions. Using near-full-length cloned sequences, we identified the sequences in the V4V5 and V6 hypervariable regions that are linked to the HF183 marker in the V2 region and found these sequences were present in multiple animals. In addition, the V4V5 and V6 regions contained human fecal marker sequences for organisms that were independent of the HF183 cluster. The most abundant Bacteroides in untreated sewage was not human associated but pipe derived. Two TaqMan quantitative PCR (qPCR) assays targeting the V4V5 and V6 regions of this organism were developed. Validation studies using fecal samples from seven animal hosts (n = 76) and uncontaminated water samples (n = 30) demonstrated the high specificity of the assays for sewage. Freshwater Bacteroides were also identified in uncontaminated water samples, demonstrating that measures of total Bacteroides do not reflect fecal pollution. A comparison of two previously described human Bacteroides assays (HB and HF183/BacR287) in municipal wastewater influent and sewage-contaminated urban water samples revealed identical results, illustrating the assays target the same organism. The detection of sewage-derived Bacteroides provided an independent measure of sewage-impacted waters.IMPORTANCE Bacteroides are major members of the gut microbiota, and host-specific organisms within this genus have been used extensively to gain information on pollution sources. This study provides a broad view of the population structure of Bacteroides within sewage to contextualize the well-studied HF183 marker for a human-associated Bacteroides The study also delineates host-specific sequence patterns across multiple hypervariable regions of the 16S rRNA gene to improve our ability to use sequence data to assess water quality. Here, we demonstrate that regions downstream of the HF183 marker are nonspecific but other potential human-associated markers are present. Furthermore, we show the most abundant Bacteroides in sewage is free living, rather than host associated, and specifically found in sewage. Quantitative PCR assays that target organisms specific to sewer pipes offer measures that are independent of the human microbiome for identifying sewage pollution in water.
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17
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Human-Associated Lachnospiraceae Genetic Markers Improve Detection of Fecal Pollution Sources in Urban Waters. Appl Environ Microbiol 2018; 84:AEM.00309-18. [PMID: 29728386 DOI: 10.1128/aem.00309-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/24/2018] [Indexed: 11/20/2022] Open
Abstract
The human microbiome contains many organisms that could potentially be used as indicators of human fecal pollution. Here we report the development of two novel human-associated genetic marker assays that target organisms within the family Lachnospiraceae Next-generation sequencing of the V6 region of the 16S rRNA gene from sewage and animal stool samples identified 40 human-associated marker candidates with a robust signal in sewage and low or no occurrence in samples from nonhuman hosts. Two were chosen for quantitative PCR (qPCR) assay development using longer sequences (the V2 to V9 regions) generated from clone libraries. Validation of these assays with these markers, designated Lachno3 and Lachno12, was performed using fecal samples (n = 55) from cat, dog, pig, cow, deer, and gull sources, and the results were compared with those of established host-associated assays (the Lachno2 marker and two human Bacteroides markers, the HB and HF183/BacR287). Each of the established assays cross-reacted with samples from at least one other animal species, including animals common in urban areas. The Lachno3 and Lachno12 markers were primarily human associated; however, the Lachno12 marker demonstrated low levels of cross-reactivity with samples from select cows and nonspecific amplification with samples from pigs. This limitation may not be problematic when testing urban waters. These novel markers resolved ambiguous results from previous investigations of stormwater-impacted waters, demonstrating their utility. The complexity of the microbiome in humans and animals suggests that no single organism is strictly specific to humans, and the use of multiple complementary markers in combination will provide the highest resolution and specificity for assessing fecal pollution sources.IMPORTANCE Traditional fecal indicator bacteria do not distinguish animal from human fecal pollution, which is necessary to evaluate health risks and mitigate pollution sources. Assessing water in urban areas is challenging, since the water can be impacted by sewage, which has a high likelihood of carrying human pathogens, as well as pet and urban wildlife waste. We demonstrate that the Lachno3 and Lachno12 markers are human associated and highly specific for the detection of human fecal pollution from urban sources, offering reliable identification of fecal pollution sources in urban waters.
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Malla B, Ghaju Shrestha R, Tandukar S, Bhandari D, Inoue D, Sei K, Tanaka Y, Sherchand JB, Haramoto E. Validation of host-specific Bacteroidales quantitative PCR assays and their application to microbial source tracking of drinking water sources in the Kathmandu Valley, Nepal. J Appl Microbiol 2018; 125:609-619. [PMID: 29679435 DOI: 10.1111/jam.13884] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Revised: 03/15/2018] [Accepted: 04/03/2018] [Indexed: 11/28/2022]
Abstract
AIMS To validate host-specific Bacteroidales assays to identify faecal-source contamination of drinking water sources in the Kathmandu Valley, Nepal. METHODS AND RESULTS A total of 54 composite faecal-source samples were collected from human sewage, ruminants, pigs, dogs, chickens and ducks, which were analysed by quantitative polymerase chain reaction using human-specific (BacHum, HF183 SYBR, gyrB and HF183 TaqMan), ruminant-specific (BacCow and BacR), pig-specific (Pig2Bac and PF163) and dog-specific assays (BacCan SYBR). The BacHum, BacR and Pig2Bac assays were judged the best performing human-specific, ruminant-specific and pig-specific assays respectively. The BacCan SYBR assay highly cross-reacted with other species, resulting in poor performance. Furthermore, these validated assays were applied to microbial source tracking (MST) of 74 drinking water samples. Out of these, 20, 12 and 4% samples were judged contaminated by human, ruminant and pig faeces respectively. Detection ratios of human and ruminant faecal markers were relatively higher in built-up and agricultural areas respectively. CONCLUSION BacHum, BacR and Pig2Bac assays were found suitable for MST and both, human and animal faecal contaminations of drinking water sources were common in the valley. SIGNIFICANCE AND IMPACT OF THE STUDY MST could be an effective tool for preparing the faecal pollution strategies as these are site specific.
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Affiliation(s)
- B Malla
- Department of Natural, Biotic and Social Environment Engineering, University of Yamanashi, Kofu, Yamanashi, Japan
| | - R Ghaju Shrestha
- Department of Natural, Biotic and Social Environment Engineering, University of Yamanashi, Kofu, Yamanashi, Japan
| | - S Tandukar
- Department of Natural, Biotic and Social Environment Engineering, University of Yamanashi, Kofu, Yamanashi, Japan
| | - D Bhandari
- Institute of Medicine, Tribhuvan University, Maharajgunj, Kathmandu, Nepal
| | - D Inoue
- Division of Sustainable Energy and Environmental Engineering, Osaka University, Suita, Osaka, Japan
| | - K Sei
- Department of Health Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Y Tanaka
- Department of Environmental Sciences, University of Yamanashi, Kofu, Yamanashi, Japan
| | - J B Sherchand
- Institute of Medicine, Tribhuvan University, Maharajgunj, Kathmandu, Nepal
| | - E Haramoto
- Interdisciplinary Center for River Basin Environment, University of Yamanashi, Kofu, Yamanashi, Japan
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Prado T, Bruni ADC, Barbosa MRF, Bonanno VMS, Garcia SC, Sato MIZ. Distribution of human fecal marker GB-124 bacteriophages in urban sewage and reclaimed water of São Paulo city, Brazil. JOURNAL OF WATER AND HEALTH 2018; 16:289-299. [PMID: 29676764 DOI: 10.2166/wh.2017.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Bacteriophages infecting Bacteroides fragilis GB-124 have been described as potential markers of human fecal contamination in water sources. The aim of this study was to evaluate the occurrence of GB-124 phages in raw sewage, secondary effluents and reclaimed water of the São Paulo city using a low-cost microbial source tracking method. Samples were collected monthly from April 2015 to March 2016 in four municipal wastewater treatment plants that operate with activated sludge processes followed by different tertiary treatments (sand-anthracite filtration, membrane bioreactor/reverse osmosis) and final chlorination. GB-124 phages were detected in 100% of the raw sewage samples, with viral loads varying from 7.5 × 103 to 1.32 × 106 PFU/L. Virus removal efficiency in activated sludge processes ranged from 1.89 to 2.31 log10. Frequencies of phage detection were lower in reclaimed water samples (0-22.2%). The results indicated that GB-124 phage could be a complementary low-cost viral marker for the detection of human fecal pollution in waters impacted with urban sewage in this region. However, the datasets of tertiary effluents resulted in several samples with concentrations below the detection limit (DL ≤1 PFU/mL) suggesting the need to obtain analytical methods with lower DL for greater accuracy of negative results.
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Affiliation(s)
- Tatiana Prado
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
| | - Antônio de Castro Bruni
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
| | - Mikaela Renata Funada Barbosa
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
| | - Vilma Marques Santos Bonanno
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
| | - Suzi Cristina Garcia
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
| | - Maria Inês Zanoli Sato
- Environmental Company of the São Paulo State (CETESB-SP), Av. Prof. Frederico Hermann Jr., 345, São Paulo, SP 05459-900, Brazil E-mail:
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Waso M, Khan S, Khan W. Microbial source tracking markers associated with domestic rainwater harvesting systems: Correlation to indicator organisms. ENVIRONMENTAL RESEARCH 2018; 161:446-455. [PMID: 29216491 DOI: 10.1016/j.envres.2017.11.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/03/2017] [Accepted: 11/26/2017] [Indexed: 05/24/2023]
Abstract
Domestic rainwater harvesting (tank water) systems were screened for the presence of a panel of microbial source tracking (MST) markers and traditional indicator organisms. The indicator organisms were enumerated utilizing traditional culture-based methods, while the MST markers were quantified by quantitative PCR (qPCR). The indicators Escherichia coli (E. coli) and enterococci were also quantified using qPCR. Correlations and concurrence between these parameters were then investigated to determine which markers could be utilized to supplement traditional indicator analysis. Quantitative PCR analysis indicated that Bacteroides HF183, adenovirus, Lachnospiraceae and E. coli were detected and quantifiable in 100% of the tank water samples collected throughout the sampling period, while human mitochondrial DNA (mtDNA) was quantifiable in 90% of the tank water samples and Bifidobacterium adolescentis (B. adolescentis) and enterococci were quantifiable in 67% of the tank water samples, respectively. Significant positive correlations were recorded for Lachnospiraceae versus heterotrophic bacteria (p = 0.000), adenovirus versus E. coli (culturing) (p = 0.000) and heterotrophic bacteria (p = 0.024), the HF183 marker versus E. coli (qPCR) (p = 0.024) and B. adolescentis versus fecal coliforms (p = 0.037). In addition, 100% concurrence was observed for the HF183 marker, adenovirus and Lachnospiraceae versus E. coli (qPCR), enterococci (qPCR) and heterotrophic bacteria, amongst others. Based on the correlations and the concurrence analysis, the HF183 marker, Lachnospiraceae and adenovirus may be utilized to supplement indicator organism analysis for the monitoring of harvested rainwater quality.
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Affiliation(s)
- M Waso
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag ×1, Stellenbosch, 7602, South Africa
| | - S Khan
- Faculty of Health and Applied Sciences, Namibia University of Science and Technology, 13 Storch Street, Private Bag 13388, Windhoek, Namibia
| | - W Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag ×1, Stellenbosch, 7602, South Africa.
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Elahi E, Abid M, Zhang L, Alugongo GM. The use of wastewater in livestock production and its socioeconomic and welfare implications. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:17255-17266. [PMID: 28555394 DOI: 10.1007/s11356-017-9263-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
Although epidemiological studies have found a significant amount of toxins in surface water, a complex link between animals' access to wastewater and associated animal and human welfare losses needs to be explored. The scarcity of safe water has put stress on the utilization of wastewater for crops and livestock production. The access of animals to wastewater is related to the emergence of dangerous animal's diseases, hampering productivity, increasing economic losses, and risking human health along the food chain. This review explores use of wastewater for agriculture, epidemiological evidence of microbial contamination in wastewater, and animal and human welfare disruption due to the use of wastewater for crop and livestock production. More specifically, the review delves into animals exposure to wastewater for bathing, drinking, or grazing on a pasture irrigated with contaminated water and related animal and human welfare losses. We included some scientific articles and reviews published from 1970 to 2017 to support our rational discussions. The selected articles dealt exclusively with animals direct access to wastewater via bathing and indirect access via grazing on pasture irrigated with contaminated wastewater and their implication for animal and human welfare losses. The study also identified that some policy options such as wastewater treatments, constructing wastewater stabilization ponds, controlling animal access to wastewater, and dissemination of necessary information to ultimate consumers related to the source of agricultural produce and wastewater use in animal and crop production are required to protect the human and animal health and welfare.
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Affiliation(s)
- Ehsan Elahi
- Department of Agricultural Economics, College of Economics and Management, China Agricultural University, Beijing, 100083, China.
| | - Muhammad Abid
- Centre for Climate Research and Development (CCRD), COMSATS Institute of Information Technology, Park Road, Chak Shahzad, Islamabad, Pakistan
| | - Liqin Zhang
- Department of Agricultural Economics, College of Economics and Management, China Agricultural University, Beijing, 100083, China
| | - Gibson Maswayi Alugongo
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100083, China
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22
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Nshimyimana JP, Cruz MC, Thompson RJ, Wuertz S. Bacteroidales markers for microbial source tracking in Southeast Asia. WATER RESEARCH 2017; 118:239-248. [PMID: 28433694 DOI: 10.1016/j.watres.2017.04.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 04/05/2017] [Accepted: 04/08/2017] [Indexed: 06/07/2023]
Abstract
The island city country of Singapore served as a model to validate the use of host-associated Bacteroidales 16S rRNA gene marker assays for identifying sources of fecal pollution in the urban tropical environment of Southeast Asia. A total of 295 samples were collected from sewage, humans, domesticated animals (cats, dogs, rabbits and chicken), and wild animals (birds, monkeys and wild boars). Samples were analyzed by real time PCR using five human-associated assays (HF183-SYBR Green, HF183, BacHum, BacH and B. thetaiotaomicron α-1-6, mannanase (B. theta), one canine-associated assay (BacCan), and a total Bacteroidales assay (BacUni). The best performing human-associated assay was B. theta with a diagnostic sensitivity of 69% and 100% in human stool and sewage, respectively, and a specificity of 98%. BacHum achieved the second highest sensitivity and specificity for human stool at 65% and 91%, respectively. The canine-associated Bacteroidales assay (BacCan) had a sensitivity and specificity above 80% and was validated for tracking fecal pollution from dogs. BacUni demonstrated a sensitivity and specificity of 100% for mammals, thus BacUni was confirmed for total Bacteroidales detection in the region. We showed for the first time that rabbit fecal samples cross-react with human-associated assays (HF183-SYBR Green, HF183, BacHum and BacH) and with BacCan. Our findings regarding the best performing human-associated assays differ from those reported in Bangladesh and India, which are geographically close to Southeast Asia, and where HF183 and BacHum were the preferred assays, respectively.
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Affiliation(s)
- Jean Pierre Nshimyimana
- School of Civil and Environmental Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore, 639798, Singapore; Singapore Centre for Environmental Life Sciences Engineering, NTU, 60 Nanyang Dr., Singapore, 637551, Singapore; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Centre for Environmental Sensing and Modeling, Singapore-MIT Alliance for Research and Technology, 1 Create Way, Singapore, 138602, Singapore
| | - Mercedes C Cruz
- Singapore Centre for Environmental Life Sciences Engineering, NTU, 60 Nanyang Dr., Singapore, 637551, Singapore
| | - R Janelle Thompson
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology (MIT), 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Centre for Environmental Sensing and Modeling, Singapore-MIT Alliance for Research and Technology, 1 Create Way, Singapore, 138602, Singapore
| | - Stefan Wuertz
- School of Civil and Environmental Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore, 639798, Singapore; Singapore Centre for Environmental Life Sciences Engineering, NTU, 60 Nanyang Dr., Singapore, 637551, Singapore.
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23
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Using Thermal Shock to Inhibit Biofilm Formation in the Treated Sewage Source Heat Pump Systems. APPLIED SCIENCES-BASEL 2017. [DOI: 10.3390/app7040343] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Elahi E, Zhang L, Abid M, Javed MT, Xinru H. Direct and indirect effects of wastewater use and herd environment on the occurrence of animal diseases and animal health in Pakistan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:6819-6832. [PMID: 28092000 DOI: 10.1007/s11356-017-8423-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 01/06/2017] [Indexed: 06/06/2023]
Abstract
The use of wastewater for rearing domestic animals is a common phenomenon in most of the developing countries like Pakistan that face a serious shortage of freshwater resources. However, most of the literature has only focused on the indirect effects of wastewater use on animal health or productivity, and literature on the direct effects of wastewater use is rare. Therefore, this study aims to investigate the direct and indirect effects of wastewater usage on the prevalence of animal diseases and animal health in Pakistan. The study is based on a household-level survey of 360 domestic water buffalo herds collected from 12 districts of Punjab Province, Pakistan. We tested the prevalence of the animal's diseases, animal's health, and wastewater-use preference with various econometric tools, such as the Poisson, negative binomial, and logistic regressions. The findings of the study show that the majority of the farmers use wastewater for buffalo bathing due to the shortage of freshwater resources. Results explore the prevalence of diseases such as clinical mastitis, tick infestation, and foot and mouth disease at the farm level significantly associated with buffalo bathing in the wastewater. Moreover, bathing in wastewater pre- and post-milking also plays a role in the occurrence of diseases. Particularly, if the buffalo's access to wastewater for bathing is within 60 min after milking, the probability of the animals being exposed to mastitis is higher. Furthermore, on investigation, a number of factors are found, such as the distance to the water source, power shortage, groundwater availability, and the education of farmers that influence farmers' behavior of letting their animals take a bath in wastewater. Moreover, the use of different preventive measures improves the animal's health.
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Affiliation(s)
- Ehsan Elahi
- College of Economics and Management, Department of Agricultural Economics, China Agricultural University, Beijing, 100083, China
| | - Liqin Zhang
- College of Economics and Management, Department of Agricultural Economics, China Agricultural University, Beijing, 100083, China.
| | - Muhammad Abid
- Research Group Climate Change and Security (CLISEC), Institute of Geography, University of Hamburg, Grindelberg 7, 20144, Hamburg, Germany
- School of Integrated Climate System Sciences (SICSS), University of Hamburg, Grindelberg 5, 20144, Hamburg, Germany
| | - Muhammad Tariq Javed
- Department of Pathology, Faculty of Veterinary Science, University of Agriculture, Faisalabad, 38040, Pakistan
| | - Han Xinru
- Institute of Agricultural Economics and Development, Chinese Academy of Agricultural Science, Beijing, 100081, China
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Boehm AB, Wang D, Ercumen A, Shea M, Harris AR, Shanks OC, Kelty C, Ahmed A, Mahmud ZH, Arnold BF, Chase C, Kullmann C, Colford JM, Luby SP, Pickering AJ. Occurrence of Host-Associated Fecal Markers on Child Hands, Household Soil, and Drinking Water in Rural Bangladeshi Households. ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS 2016; 3:393-398. [PMID: 32607385 DOI: 10.1021/acs.estlett.6b00382] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We evaluated whether provision and promotion of improved sanitation hardware (toilets and child feces management tools) reduced rotavirus and human fecal contamination of drinking water, child hands, and soil among rural Bangladeshi compounds enrolled in a cluster-randomized trial. We also measured host-associated genetic markers of ruminant and avian feces. We found evidence of widespread ruminant and avian fecal contamination in the compound environment; non-human fecal marker occurrence scaled with animal ownership. Strategies for controlling non- human fecal waste should be considered when designing interventions to reduce exposure to fecal contamination in low-income settings. Detection of a human- associated fecal marker and rotavirus was rare and unchanged by provision and promotion of improved sanitation to intervention compounds. The sanitation intervention reduced ruminant fecal contamination in drinking water and general (non-host specific) fecal contamination in soil but overall had limited effects on reducing fecal contamination in the household environment.
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Affiliation(s)
- Alexandria B Boehm
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Dan Wang
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Ayse Ercumen
- Division of Epidemiology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Meghan Shea
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Angela R Harris
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Orin C Shanks
- Office of Research & Development, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
| | - Catherine Kelty
- Office of Research & Development, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, United States
| | - Alvee Ahmed
- International Center for Diarrheal Diseases Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Zahid Hayat Mahmud
- International Center for Diarrheal Diseases Research, Bangladesh, Dhaka 1000, Bangladesh
| | - Benjamin F Arnold
- Division of Epidemiology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Claire Chase
- The World Bank, Washington, D.C. 20433, United States
| | | | - John M Colford
- Division of Epidemiology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Stephen P Luby
- Woods Institute for the Environment, Stanford University, Stanford, California 94305, United States
| | - Amy J Pickering
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
- Woods Institute for the Environment, Stanford University, Stanford, California 94305, United States
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26
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Templar HA, Dila DK, Bootsma MJ, Corsi SR, McLellan SL. Quantification of human-associated fecal indicators reveal sewage from urban watersheds as a source of pollution to Lake Michigan. WATER RESEARCH 2016; 100:556-567. [PMID: 27236594 DOI: 10.1016/j.watres.2016.05.056] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/06/2016] [Accepted: 05/17/2016] [Indexed: 05/20/2023]
Abstract
Sewage contamination of urban waterways from sewer overflows and failing infrastructure is a major environmental and public health concern. Fecal coliforms (FC) are commonly employed as fecal indicator bacteria, but do not distinguish between human and non-human sources of fecal contamination. Human Bacteroides and human Lachnospiraceae, two genetic markers for human-associated indicator bacteria, were used to identify sewage signals in two urban rivers and the estuary that drains to Lake Michigan. Grab samples were collected from the rivers throughout 2012 and 2013 and hourly samples were collected in the estuary across the hydrograph during summer 2013. Human Bacteroides and human Lachnospiraceae were highly correlated with each other in river samples (Pearson's r = 0.86), with average concentrations at most sites elevated during wet weather. These human indicators were found during baseflow, indicating that sewage contamination is chronic in these waterways. FC are used for determining total maximum daily loads (TMDLs) in management plans; however, FC concentrations alone failed to prioritize river reaches with potential health risks. While 84% of samples with >1000 CFU/100 ml FC had sewage contamination, 52% of samples with moderate (200-1000 CFU/100 ml) and 46% of samples with low (<200 CFU/100 ml) FC levels also had evidence of human sewage. Load calculations in the in the Milwaukee estuary revealed storm-driven sewage contamination varied greatly among events and was highest during an event with a short duration of intense rain. This work demonstrates urban areas have unrecognized sewage inputs that may not be adequately prioritized for remediation by the TMDL process. Further analysis using these approaches could determine relationships between land use, storm characteristics, and other factors that drive sewage contamination in urban waterways.
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Affiliation(s)
- Hayley A Templar
- School of Freshwater Sciences, UW-Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - Deborah K Dila
- School of Freshwater Sciences, UW-Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - Melinda J Bootsma
- School of Freshwater Sciences, UW-Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - Steven R Corsi
- U.S. Geological Survey, 8505 Research Way, Middleton, WI 53562, USA
| | - Sandra L McLellan
- School of Freshwater Sciences, UW-Milwaukee, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA.
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27
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Current Status of Marker Genes of Bacteroides and Related Taxa for Identifying Sewage Pollution in Environmental Waters. WATER 2016. [DOI: 10.3390/w8060231] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Harris AR, Pickering AJ, Harris M, Doza S, Islam MS, Unicomb L, Luby S, Davis J, Boehm AB. Ruminants Contribute Fecal Contamination to the Urban Household Environment in Dhaka, Bangladesh. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:4642-9. [PMID: 27045990 DOI: 10.1021/acs.est.5b06282] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In Dhaka, Bangladesh, the sensitivity and specificity of three human, three ruminant, and one avian source-associated QPCR microbial source tracking assays were evaluated using fecal samples collected on site. Ruminant-associated assays performed well, whereas the avian and human assays exhibited unacceptable cross-reactions with feces from other hosts. Subsequently, child hand rinses (n = 44) and floor sponge samples (n = 44) from low-income-households in Dhaka were assayed for fecal indicator bacteria (enterococci, Bacteroidales, and Escherichia coli) and a ruminant-associated bacterial target (BacR). Mean enterococci concentrations were of 100 most probable number (MPN)/2 hands and 1000 MPN/225 cm(2) floor. Mean concentrations of Bacteroidales were 10(6) copies/2 hands and 10(5) copies/225 cm(2) floor. E. coli were detected in a quarter of hand rinse and floor samples. BacR was detected in 18% of hand rinse and 27% of floor samples. Results suggest that effective household fecal management should account not only for human sources of contamination but also for animal sources. The poor performance of the human-associated assays in the study area calls into the question the feasibility of developing a human-associated marker in urban slum environments, where domestic animals are exposed to human feces that have been disposed in pits and open drains.
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Affiliation(s)
- Angela R Harris
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
| | - Amy J Pickering
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Michael Harris
- Emmett Interdisciplinary Program in Environment and Resources, Stanford University , Stanford, California 94305, United States
| | | | | | | | - Stephen Luby
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Jennifer Davis
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
- Woods Institute for the Environment, Stanford University , Stanford, California 94305, United States
| | - Alexandria B Boehm
- Environmental and Water Studies, Department of Civil and Environmental Engineering, Stanford University , Stanford, California 94305, United States
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29
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Wangkahad B, Bosup S, Mongkolsuk S, Sirikanchana K. Occurrence of bacteriophages infecting Aeromonas, Enterobacter, and Klebsiella in water and association with contamination sources in Thailand. JOURNAL OF WATER AND HEALTH 2015; 13:613-624. [PMID: 26042992 DOI: 10.2166/wh.2014.204] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The co-residence of bacteriophages and their bacterial hosts in humans, animals, and environmental sources directed the use of bacteriophages to track the origins of the pathogenic bacteria that can be found in contaminated water. The objective of this study was to enumerate bacteriophages of Aeromonas caviae (AecaKS148), Enterobacter sp. (EnspKS513), and Klebsiella pneumoniae (KlpnKS648) in water and evaluate their association with contamination sources (human vs. animals). Bacterial host strains were isolated from untreated wastewater in Bangkok, Thailand. A double-layer agar technique was used to detect bacteriophages. All three bacteriophages were detected in polluted canal samples, with likely contamination from human wastewater, whereas none was found in non-polluted river samples. AecaKS148 was found to be associated with human fecal sources, while EnspKS513 and KlpnKS648 seemed to be equally prevalent in both human and animal fecal sources. Both bacteriophages were also present in polluted canals that could receive contamination from other fecal sources or the environment. In conclusion, all three bacteriophages were successfully monitored in Bangkok, Thailand. This study provided an example of bacteriophages for potential use as source identifiers of pathogen contamination. The results from this study will assist in controlling sources of pathogen contamination, especially in developing countries.
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Affiliation(s)
| | - Suchada Bosup
- Inter-University Program on Environmental Toxicology, Technology and Management, Asian Institute of Technology, Chulabhorn Research Institute, Mahidol University, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Department of Biotechnology and Center for Emerging Bacterial Infections, Faculty of Science, Mahidol University, Bangkok 10400, Thailand and Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand E-mail:
| | - Kwanrawee Sirikanchana
- Center of Excellence on Environmental Health and Toxicology, Ministry of Education, Bangkok 10400, Thailand E-mail: ; Translational Research Unit, Chulabhorn Research Institute, Bangkok 10210, Thailand
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30
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LA35 Poultry Fecal Marker Persistence Is Correlated with That of Indicators and Pathogens in Environmental Waters. Appl Environ Microbiol 2015; 81:4616-25. [PMID: 25934617 DOI: 10.1128/aem.00444-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/23/2015] [Indexed: 02/07/2023] Open
Abstract
Disposal of fecally contaminated poultry litter by land application can deliver pathogens and fecal indicator bacteria (FIB) into receiving waters via runoff. While water quality is regulated by FIB enumeration, FIB testing provides inadequate information about contamination source and health risk. This microbial source tracking (MST) study compared the persistence of the Brevibacterium sp. strain LA35 16S rRNA gene (marker) for poultry litter with that of pathogens and FIB under outdoor, environmentally relevant conditions in freshwater, marine water, and sediments over 7 days. Salmonella enterica, Campylobacter jejuni, Campylobacter coli, Bacteroidales, and LA35 were enumerated by quantitative PCR (qPCR), and Enterococcus spp. and E. coli were quantified by culture and qPCR. Unlike the other bacteria, C. jejuni was not detectable after 48 h. Bacterial levels in the water column consistently declined over time and were highly correlated among species. Survival in sediments ranged from a slow decrease over time to growth, particularly in marine microcosms and for Bacteroidales. S. enterica also grew in marine sediments. Linear decay rates in water (k) ranged from -0.17 day(-1) for LA35 to -3.12 day(-1) for C. coli. LA35 levels correlated well with those of other bacteria in the water column but not in sediments. These observations suggest that, particularly in the water column, the fate of LA35 in aquatic environments is similar to that of FIB, C. coli, and Salmonella, supporting the hypothesis that the LA35 marker gene can be a useful tool for evaluating the impact of poultry litter on water quality and human health risk.
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31
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Odagiri M, Schriewer A, Hanley K, Wuertz S, Misra PR, Panigrahi P, Jenkins MW. Validation of Bacteroidales quantitative PCR assays targeting human and animal fecal contamination in the public and domestic domains in India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 502:462-470. [PMID: 25285421 DOI: 10.1016/j.scitotenv.2014.09.040] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 09/13/2014] [Accepted: 09/13/2014] [Indexed: 06/03/2023]
Abstract
We compared host-associated Bacteroidales qPCR assays developed in the continental United States and Europe for the purpose of measuring the effect of improved sanitation on human fecal exposure in rural Indian communities where both human and animal fecal loading are high. Ten candidate Bacteroidales qPCR assays were tested against fecal samples (human, sewage, cow, buffalo, goat, sheep, dog and chicken) from a test set of 30 individual human, 5 sewage, and 60 pooled animal samples collected in coastal Odisha, India. The two universal/general Bacteroidales assays tested (BacUni, GenBac3) performed equally well, achieving 100% sensitivity on the test set. Across the five human-associated assays tested (HF183 Taqman, BacHum, HumM2, BacH, HF183 SYBR), we found low sensitivity (17 to 49%) except for HF183 SYBR (89%), and moderate to high cross-reactivity with dog (20 to 80%) and chicken fecal samples (60 to 100%). BacHum had the highest accuracy (67%), amplified all sewage samples within the range of quantification (ROQ), and did not cross-react with any fecal samples from cows, the most populous livestock animal in India. Of the ruminant- and cattle-associated assays tested (BacCow, CowM2), BacCow was more sensitive in detecting the full range of common Indian livestock animal fecal sources, while CowM2 only detected cow sources with 50% sensitivity. Neither assay cross-reacted with human sources. BacCan, the dog-associated assay tested, showed no cross-reactivity with human sources, and high sensitivity (90%) for dog fecal samples. Overall, our results indicate BacUni, BacHum, HumM2, BacCan and BacCow would be the most suitable MST assays to distinguish and quantify relative amounts of human-associated and livestock/domestic animal-associated contributions to fecal contamination in Odisha, India.
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Affiliation(s)
- Mitsunori Odagiri
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Alexander Schriewer
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Kaitlyn Hanley
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Stefan Wuertz
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Singapore Centre on Environmental Life Sciences Engineering (SCELSE), School of Biological Sciences, and School of Civil and Environmental Engineering, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore.
| | - Pravas R Misra
- Asian Institute of Public Health, Bhubaneswar, Odisha, India
| | - Pinaki Panigrahi
- Departments of Epidemiology and Pediatrics, Center for Global Health and Development, College of Public Health, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Marion W Jenkins
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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32
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Koskey AM, Fisher JC, Eren AM, Terashima RP, Reis MG, Blanton RE, McLellan SL. Blautia and Prevotella sequences distinguish human and animal fecal pollution in Brazil surface waters. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:696-704. [PMID: 25360571 PMCID: PMC4247797 DOI: 10.1111/1758-2229.12189] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 06/09/2014] [Indexed: 05/17/2023]
Abstract
Untreated sewage discharges and limited agricultural manure management practices contribute to fecal pollution in rural Brazilian waterways. Most microbial source tracking studies have focused on Bacteroidales, and few have tested host-specific indicators in underdeveloped regions. Sequencing of sewage and human and animal feces with Illumina HiSeq revealed Prevotellaceae as the most abundant family in humans, with Lachnospiraceae and Ruminococcaceae also comprising a large proportion of the microbiome. These same families were also dominant in animals. Bacteroides, the genus containing the most commonly utilized human-specific marker in the United States was present in very low abundance. We used oligotyping to identify Prevotella and Blautia sequences that can distinguish human fecal contamination. Thirty-five of 61 Blautia oligotypes and 13 of 108 Prevotella oligotypes in humans were host-specific or highly abundant (i.e. host-preferred) compared to pig, dog, horse and cow sources. Certain human Prevotella and Blautia oligotypes increased more than an order of magnitude along a polluted river transect in rural Brazil, but traditional fecal indicator levels followed a steady or even decreasing trend. While both Prevotella and Blautia oligotypes distinguished human and animal fecal pollution in Brazil surface waters, Blautia appears to contain more discriminatory and globally applicable markers for tracking sources of fecal pollution.
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Affiliation(s)
- Amber M. Koskey
- University of Wisconsin - Milwaukee, School of Freshwater Sciences, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - Jenny C. Fisher
- University of Wisconsin - Milwaukee, School of Freshwater Sciences, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
| | - A. Murat Eren
- The Josephine Bay Paul Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
| | | | - Mitermayer G. Reis
- Laboratory of Pathology and Molecular Biology, Gonçalo Moniz Research Center, Oswaldo Cruz Foundation, Salvador, Bahia, Brazil
| | - Ronald E. Blanton
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, Ohio
| | - Sandra L. McLellan
- University of Wisconsin - Milwaukee, School of Freshwater Sciences, 600 E. Greenfield Ave, Milwaukee, WI 53204, USA
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Ahmed W, Gyawali P, Sidhu J, Toze S. Relative inactivation of faecal indicator bacteria and sewage markers in freshwater and seawater microcosms. Lett Appl Microbiol 2014; 59:348-54. [DOI: 10.1111/lam.12285] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 11/28/2022]
Affiliation(s)
- W. Ahmed
- CSIRO Land and Water; Ecosciences Precinct; Brisbane Qld Australia
- Faculty of Science, Health and Education; University of the Sunshine Coast; Maroochydore DC Qld Australia
| | - P. Gyawali
- CSIRO Land and Water; Ecosciences Precinct; Brisbane Qld Australia
- School of Population Health; University of Queensland; Brisbane Qld Australia
| | - J.P.S. Sidhu
- CSIRO Land and Water; Ecosciences Precinct; Brisbane Qld Australia
- Faculty of Science, Health and Education; University of the Sunshine Coast; Maroochydore DC Qld Australia
| | - S. Toze
- CSIRO Land and Water; Ecosciences Precinct; Brisbane Qld Australia
- School of Population Health; University of Queensland; Brisbane Qld Australia
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Nshimyimana JP, Ekklesia E, Shanahan P, Chua LHC, Thompson JR. Distribution and abundance of human-specific Bacteroides and relation to traditional indicators in an urban tropical catchment. J Appl Microbiol 2014; 116:1369-83. [PMID: 24460587 PMCID: PMC4271309 DOI: 10.1111/jam.12455] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 11/29/2022]
Abstract
AIMS The study goals were to determine the relationship between faecal indicator bacteria (FIB), the HF183 marker and land use, and the phylogenetic diversity of HF183 marker sequences in a tropical urban watershed. METHODS AND RESULTS Total coliforms, Escherichia coli, and HF183 were quantified in 81 samples categorized as undeveloped, residential and horticultural from the Kranji Reservoir and Catchment in Singapore. Quantitative-PCR for HF183 followed by analysis of variance indicated that horticultural areas had significantly higher geometric means for marker levels (4·3 × 10(4) HF183-GE 100 ml(-1)) than nonhorticultural areas (3·07 × 10(3) HF183-GE 100 ml(-1)). E. coli and HF183 were moderately correlated in horticultural areas (R = 0·59, P = 0·0077), but not elsewhere in the catchment. Initial upstream surveys of candidate sources revealed elevated HF183 in a wastewater treatment effluent but not in aquaculture ponds. The HF183 marker was cloned, sequenced and determined by phylogenetic analysis to match the original marker description. CONCLUSION We show that quantification of the HF183 marker is a useful tool for mapping the spatial distribution and potential sources of human sewage contamination in tropical environments such as Singapore. SIGNIFICANCE AND IMPACT A major challenge for assessment of water quality in tropical environments is the natural occurrence and nonconservative behaviour of FIB. The HF183 marker has been employed in temperate environments as an alternative indicator for human sewage contamination. Our study supports the use of the HF183 marker as an indicator for human sewage in Singapore and motivates further work to determine HF183 marker levels that correspond to public health risk in tropical environments.
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Affiliation(s)
- J P Nshimyimana
- Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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Improved HF183 quantitative real-time PCR assay for characterization of human fecal pollution in ambient surface water samples. Appl Environ Microbiol 2014; 80:3086-94. [PMID: 24610857 DOI: 10.1128/aem.04137-13] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Quantitative real-time PCR (qPCR) assays that target the human-associated HF183 bacterial cluster within members of the genus Bacteroides are among the most widely used methods for the characterization of human fecal pollution in ambient surface waters. In this study, we show that a current TaqMan HF183 qPCR assay (HF183/BFDrev) routinely forms nonspecific amplification products and introduce a modified TaqMan assay (HF183/BacR287) that alleviates this problem. The performance of each qPCR assay was compared in head-to-head experiments investigating limits of detection, analytical precision, predicted hybridization to 16S rRNA gene sequences from a reference database, and relative marker concentrations in fecal and sewage samples. The performance of the modified HF183/BacR287 assay is equal to or improves upon that of the original HF183/BFDrev assay. In addition, a qPCR chemistry designed to combat amplification inhibition and a multiplexed internal amplification control are included. In light of the expanding use of PCR-based methods that rely on the detection of extremely low concentrations of DNA template, such as qPCR and digital PCR, the new TaqMan HF183/BacR287 assay should provide more accurate estimations of human-derived fecal contaminants in ambient surface waters.
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Harwood VJ, Staley C, Badgley BD, Borges K, Korajkic A. Microbial source tracking markers for detection of fecal contamination in environmental waters: relationships between pathogens and human health outcomes. FEMS Microbiol Rev 2013; 38:1-40. [PMID: 23815638 DOI: 10.1111/1574-6976.12031] [Citation(s) in RCA: 382] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2012] [Revised: 05/08/2013] [Accepted: 06/25/2013] [Indexed: 01/22/2023] Open
Abstract
Microbial source tracking (MST) describes a suite of methods and an investigative strategy for determination of fecal pollution sources in environmental waters that rely on the association of certain fecal microorganisms with a particular host. MST is used to assess recreational water quality and associated human health risk, and total maximum daily load allocations. Many methods rely on signature molecules (markers) such as DNA sequences of host-associated microorganisms. Human sewage pollution is among the greatest concerns for human health due to (1) the known risk of exposure to human waste and (2) the public and regulatory will to reduce sewage pollution; however, methods to identify animal sources are receiving increasing attention as our understanding of zoonotic disease potential improves. Here, we review the performance of MST methods in initial reports and field studies, with particular emphasis on quantitative PCR (qPCR). Relationships among human-associated MST markers, fecal indicator bacteria, pathogens, and human health outcomes are presented along with recommendations for future research. An integrated understanding of the advantages and drawbacks of the many MST methods targeting human sources advanced over the past several decades will benefit managers, regulators, researchers, and other users of this rapidly growing area of environmental microbiology.
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Affiliation(s)
- Valerie J Harwood
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
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Ahmed W, Masters N, Toze S. Consistency in the host specificity and host sensitivity of the Bacteroides HF183 marker for sewage pollution tracking. Lett Appl Microbiol 2012; 55:283-9. [DOI: 10.1111/j.1472-765x.2012.03291.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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