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Lobos AE, Brandt AM, Gallard-Góngora JF, Korde R, Brodrick E, Harwood VJ. Persistence of sewage-associated genetic markers in advanced and conventional treated recycled water: implications for microbial source tracking in surface waters. mBio 2024:e0065524. [PMID: 38864636 DOI: 10.1128/mbio.00655-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Accepted: 05/14/2024] [Indexed: 06/13/2024] Open
Abstract
Sewage contamination of environmental waters is increasingly assessed by measuring DNA from sewage-associated microorganisms in microbial source tracking (MST) approaches. However, DNA can persist through wastewater treatment and reach surface waters when treated sewage/recycled water is discharged, which may falsely indicate pollution from untreated sewage. Recycled water discharged from an advanced wastewater treatment (AWT) facility into a Florida stream elevated the sewage-associated HF183 marker 1,000-fold, with a minimal increase in cultured Escherichia coli. The persistence of sewage-associated microorganisms was compared by qPCR in untreated sewage and recycled water from conventional wastewater treatment (CWT) and AWT facilities. E. coli (EC23S857) and sewage-associated markers HF183, H8, and viral crAssphage CPQ_056 were always detected in untreated sewage (6.5-8.7 log10 GC/100 mL). Multivariate analysis found a significantly greater reduction of microbial variables via AWT vs CWT. Bacterial markers decayed ~4-5 log10 through CWT, but CPQ_056 was ~100-fold more persistent. In AWT facilities, the log10 reduction of all variables was ~5. In recycled water, bacterial marker concentrations were significantly correlated (P ≤ 0.0136; tau ≥ 0.44); however, CPQ_056 was not correlated with any marker, suggesting varying drivers of decay. Concentrations of cultured E. coli carrying the H8 marker (EcH8) in untreated sewage were 5.24-6.02 log10 CFU/100 mL, while no E. coli was isolated from recycled water. HF183 and culturable EcH8 were also correlated in contaminated surface waters (odds ratio β1 = 1.701). Culturable EcH8 has a strong potential to differentiate positive MST marker signals arising from treated (e.g., recycled water) and untreated sewage discharged into environmental waters. IMPORTANCE Genes in sewage-associated microorganisms are widely accepted indicators of sewage pollution in environmental waters. However, DNA persists through wastewater treatment and can reach surface waters when recycled water is discharged, potentially causing false-positive indications of sewage contamination. Previous studies have found that bacterial and viral sewage-associated genes persist through wastewater treatment; however, these studies did not compare different facilities or identify a solution to distinguish sewage from recycled water. In this study, we demonstrated the persistence of bacterial marker genes and the greater persistence of a viral marker gene (CPQ_056 of crAssphage) through varying wastewater treatment facilities. We also aim to provide a tool to confirm sewage contamination in surface waters with recycled water inputs. This work showed that the level of wastewater treatment affects the removal of microorganisms, particularly viruses, and expands our ability to identify sewage in surface waters.
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Affiliation(s)
- Aldo E Lobos
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Amanda M Brandt
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Javier F Gallard-Góngora
- Department of Earth, Marine, and Environmental Sciences, Institute of Marine Science, University of North Carolina at Chapel Hill, Morehead City, North Carolina, USA
| | - Ruchi Korde
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Eleanor Brodrick
- 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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2
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Adhikary RK, Starrs D, Wright D, Croke B, Glass K, Lal A. Spatio-Temporal Variation in the Exceedance of Enterococci in Lake Burley Griffin: An Analysis of 16 Years' Recreational Water Quality Monitoring Data. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2024; 21:579. [PMID: 38791793 PMCID: PMC11121496 DOI: 10.3390/ijerph21050579] [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: 02/20/2024] [Revised: 04/22/2024] [Accepted: 04/24/2024] [Indexed: 05/26/2024]
Abstract
Recreational waterbodies with high levels of faecal indicator bacteria (FIB) pose health risks and are an ongoing challenge for urban-lake managers. Lake Burley Griffin (LBG) in the Australian Capital city of Canberra is a popular site for water-based recreation, but analyses of seasonal and long-term patterns in enterococci that exceed alert levels (>200 CFU per 100 mL, leading to site closures) are lacking. This study analysed enterococci concentrations from seven recreational sites from 2001-2021 to examine spatial and temporal patterns in exceedances during the swimming season (October-April), when exposure is highest. The enterococci concentrations varied significantly across sites and in the summer months. The frequency of the exceedances was higher in the 2009-2015 period than in the 2001-2005 and 2015-2021 periods. The odds of alert-level concentrations were greater in November, December, and February compared to October. The odds of exceedance were higher at the Weston Park East site (swimming beach) and lower at the Ferry Terminal and Weston Park West site compared to the East Basin site. This preliminary examination highlights the need for site-specific assessments of environmental and management-related factors that may impact the public health risks of using the lake, such as inflows, turbidity, and climatic conditions. The insights from this study confirm the need for targeted monitoring efforts during high-risk months and at specific sites. The study also advocates for implementing measures to minimise faecal pollution at its sources.
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Affiliation(s)
- Ripon Kumar Adhikary
- National Centre for Epidemiology and Population Health, Australian National University, Canberra 2601, Australia; (K.G.); (A.L.)
- Department of Fisheries and Marine Bioscience, Jashore University of Science and Technology, Jashore 7408, Bangladesh
| | - Danswell Starrs
- Environment, Planning and Sustainable Development Directorate, ACT Government, Canberra 2601, Australia;
- Research School of Biology, Australian National University, Canberra 2601, Australia
| | - David Wright
- Lake and Dam, National Capital Authority, Canberra 2601, Australia;
| | - Barry Croke
- Institute for Water Futures, Mathematical Sciences Institute and Fenner School of Environment and Society, Australian National University, Canberra 2601, Australia;
| | - Kathryn Glass
- National Centre for Epidemiology and Population Health, Australian National University, Canberra 2601, Australia; (K.G.); (A.L.)
| | - Aparna Lal
- National Centre for Epidemiology and Population Health, Australian National University, Canberra 2601, Australia; (K.G.); (A.L.)
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3
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Kalvaitienė G, Bučas M, Vaičiūtė D, Balčiūnas A, Gyraitė G, Kataržytė M. Impact of beach wrack on microorganisms associated with faecal pollution at the Baltic Sea Sandy beaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170442. [PMID: 38278231 DOI: 10.1016/j.scitotenv.2024.170442] [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: 10/12/2023] [Revised: 12/21/2023] [Accepted: 01/23/2024] [Indexed: 01/28/2024]
Abstract
We investigated whether higher quantities of faecal indicator bacteria (FIB) are in the areas with red algae-dominated wrack compared to areas without it and if the birds are the primary source of faecal pollution on sandy beaches of the Baltic Sea. Water, sand and wrack samples were collected during the recreational season, and abundances of FIB, HF183 (human faecal pollution) and GFD (bird faecal pollution) markers, as well as the presence of Salmonella and Campylobacter, were assessed. Significantly higher levels of Enterococcus spp. were found in the wrack accumulation areas in water and sand than in the areas without wrack when there was a faecal pollution event, which could be explained by entrapment and changed physico-chemical water conditions. Both faecal pollution markers were identified, however, with no apparent pattern. Campylobacter bacteria were identified in the wrack-affected water, sand, and beach wrack. While this research provides valuable insights into beach wrack serving as a reservoir for FIB, further investigations, including multi-day samplings, are necessary to gain a deeper understanding of the long-term dynamics of microbiota within red algae-dominated wrack.
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Affiliation(s)
- Greta Kalvaitienė
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
| | - Martynas Bučas
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
| | - Diana Vaičiūtė
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
| | - Arūnas Balčiūnas
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
| | - Greta Gyraitė
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
| | - Marija Kataržytė
- Klaipėda University, Marine Research Institute, University Avenue 17, 92295 Klaipėda, Lithuania.
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4
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Ben-Haddad M, Charroud I, Mghili B, Abelouah MR, Hajji S, Aragaw TA, Rangel-Buitrago N, Alla AA. Examining the influence of COVID-19 lockdowns on coastal water quality: A study on fecal bacteria levels in Moroccan seawaters. MARINE POLLUTION BULLETIN 2023; 195:115476. [PMID: 37677975 DOI: 10.1016/j.marpolbul.2023.115476] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/24/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
Fecal bacteria in bathing seawater pose a substantial public health risk and require rigorous monitoring. The unexpected beach closures during the COVID-19 lockdowns have afforded unique opportunities to evaluate the impact of human activities on bathing water quality (BWQ). This study examined the temporal changes in fecal coliforms (FC) and streptococci (FS) within bathing seawater across a popular coastal region in Morocco during two lockdown periods (2020 L and 2021 L), comparing these data with observations from pre-lockdown years (2018, 2019) and post-lockdown periods (2020, 2021, 2022). Our findings illuminate the influential role the hiatus periods played in enhancing bathing water quality, attaining an "excellent" status with marked reductions in fecal coliform and streptococci levels. Consequently, the FC/FS analysis exposed a clear preponderance of humans as the primary sources of fecal contamination, a trend that aligns with the burgeoning coastal tourism and the escalating numbers of beach visitors. Additionally, the presence of domestic animals like camels and horses used for tourist rides, coupled with an increase in wild animals such as dogs during the lockdown periods, compounded the potential sources of fecal bacteria in the study area. Furthermore, occasional sewage discharge from tourist accommodations and wastewater treatment plants may also contribute to fecal contamination. To effectively mitigate these concerns and bolster public health, a commitment to relentless surveillance efforts, leveraging novel and innovative tools, is essential. These findings underline the crucial interplay between human activities and the health of our coastal ecosystems, emphasizing the need for sustainable practices for a safer and healthier future.
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Affiliation(s)
- Mohamed Ben-Haddad
- Laboratory of Aquatic Systems: Marine and Continental Environments (AQUAMAR), Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
| | - Imane Charroud
- Laboratory of Biotechnologies and Valorization of Natural Resources, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco; Laboratory of Biology and Ecology of Deep Marine Ecosystems (BEEP), UMR 6197 (UBO, CNRS, Ifremer), Plouzané, France.
| | - Bilal Mghili
- LESCB, URL-CNRST N° 18, Abdelmalek Essaadi University, Faculty of Sciences, Tetouan, Morocco.
| | - Mohamed Rida Abelouah
- Laboratory of Aquatic Systems: Marine and Continental Environments (AQUAMAR), Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
| | - Sara Hajji
- Laboratory of Aquatic Systems: Marine and Continental Environments (AQUAMAR), Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
| | - Tadele Assefa Aragaw
- Faculty of Chemical and Food Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar, Ethiopia.
| | - Nelson Rangel-Buitrago
- Programa de Física, Facultad de Ciencias Basicas, Universidad del Atlantico, Barranquilla, Atlantico, Colombia.
| | - Aicha Ait Alla
- Laboratory of Aquatic Systems: Marine and Continental Environments (AQUAMAR), Faculty of Sciences, Ibn Zohr University, Agadir, Morocco.
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5
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Abdool-Ghany AA, Sahwell PJ, Klaus J, Gidley ML, Sinigalliano CD, Solo-Gabriele HM. Fecal indicator bacteria levels at a marine beach before, during, and after the COVID-19 shutdown period and associations with decomposing seaweed and human presence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158349. [PMID: 36041612 DOI: 10.1016/j.scitotenv.2022.158349] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 08/06/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Studies are limited that evaluate seaweed as a source of bacteria to beach waters. The objective of the current study was to evaluate whether seaweed, along with humans and other animals, could be the cause of beach advisories due to elevated levels of enterococci. The monitoring period occurred a year prior to and through the COVID-19 beach shutdown period, which provided a unique opportunity to evaluate bacteria levels during prolonged periods without recreational activity. Samples of water, sediment, and seaweed were measured for enterococci by culture and qPCR, in addition to microbial source tracking by qPCR of fecal bacteria markers from humans, dogs, and birds. During periods of elevated enterococci levels in water, these analyses were supplemented by chemical source tracking of human-associated excretion markers (caffeine, sucralose, acetaminophen, ibuprofen, and naproxen). Results show that enterococci with elevated levels of human fecal markers persist in the seaweed and sediment and are the likely contributor to elevated levels of bacteria to the nearshore waters. During the shutdown period the elevated levels of enterococci in the sediment were isolated to the seaweed stranding areas. During periods when the beaches were open, enterococci were distributed more uniformly in sediment across the supratidal and intertidal zones. It is hypothesized from this study that human foot traffic may be responsible for the spread of enterococci throughout these areas. Overall, this study found high levels of enterococci in decomposing seaweed supporting the hypothesis that decomposing seaweed provides an additional substrate for enterococci to grow.
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Affiliation(s)
- Afeefa A Abdool-Ghany
- Department of Chemical, Environmental, and Materials Engineering, College of Engineering, University of Miami, Coral Gables, FL, USA
| | - Peter J Sahwell
- Department of Chemical, Environmental, and Materials Engineering, College of Engineering, University of Miami, Coral Gables, FL, USA
| | - James Klaus
- Department of Marine Geosciences, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Key Biscayne, FL, USA
| | - Maribeth L Gidley
- University of Miami, Cooperative Institute for Marine and Atmospheric Studies (CIMAS), Miami, FL, USA; National Oceanic and Atmospheric Administration (NOAA), Atlantic Oceanographic and Meteorological Laboratory (AOML), Miami, FL, USA
| | - Christopher D Sinigalliano
- National Oceanic and Atmospheric Administration (NOAA), Atlantic Oceanographic and Meteorological Laboratory (AOML), Miami, FL, USA
| | - Helena M Solo-Gabriele
- Department of Chemical, Environmental, and Materials Engineering, College of Engineering, University of Miami, Coral Gables, FL, USA.
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6
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Lima A, França A, Muzny CA, Taylor CM, Cerca N. DNA extraction leads to bias in bacterial quantification by qPCR. Appl Microbiol Biotechnol 2022; 106:7993-8006. [PMID: 36374332 PMCID: PMC10493044 DOI: 10.1007/s00253-022-12276-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/28/2022] [Accepted: 11/02/2022] [Indexed: 11/16/2022]
Abstract
Quantitative PCR (qPCR) has become a widely used technique for bacterial quantification. The affordability, ease of experimental design, reproducibility, and robustness of qPCR experiments contribute to its success. The establishment of guidelines for minimum information for publication of qPCR experiments, now more than 10 years ago, aimed to mitigate the publication of contradictory data. Unfortunately, there are still a significant number of recent research articles that do not consider the main pitfalls of qPCR for quantification of biological samples, which undoubtedly leads to biased experimental conclusions. qPCR experiments have two main issues that need to be properly tackled: those related to the extraction and purification of genomic DNA and those related to the thermal amplification process. This mini-review provides an updated literature survey that critically analyzes the following key aspects of bacterial quantification by qPCR: (i) the normalization of qPCR results by using exogenous controls, (ii) the construction of adequate calibration curves, and (iii) the determination of qPCR reaction efficiency. It is primarily focused on original papers published last year, where qPCR was applied to quantify bacterial species in different types of biological samples, including multi-species biofilms, human fluids, and water and soil samples. KEY POINTS: • qPCR is a widely used technique used for absolute bacterial quantification. • Recently published papers lack proper qPCR methodologies. • Not including proper qPCR controls significantly affect experimental conclusions.
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Affiliation(s)
- Angela Lima
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal
- LABBELS -Associate Laboratory, Braga, Guimarães, Portugal
| | - Angela França
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal
- LABBELS -Associate Laboratory, Braga, Guimarães, Portugal
| | - Christina A Muzny
- Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, USA
| | - Christopher M Taylor
- Department of Microbiology, Immunology, and Parasitology & Microbial Genomics Resource Group, Louisiana State University Health Sciences Center, New Orleans, USA
| | - Nuno Cerca
- Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), Centre of Biological Engineering (CEB), University of Minho, Braga, Portugal.
- LABBELS -Associate Laboratory, Braga, Guimarães, Portugal.
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7
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Li D, Van De Werfhorst LC, Steets B, Ervin J, Murray JLS, Smith J, Holden PA. Assessing multiple fecal sources to surf zone waters of two recreational beaches by bacterial community analysis. WATER RESEARCH 2022; 221:118781. [PMID: 35759849 DOI: 10.1016/j.watres.2022.118781] [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: 03/16/2022] [Revised: 06/17/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
Fecal sources to recreational surf zone waters should be identified to protect public health. While watershed origins of human and other fecal sources are often discoverable by quantitative polymerase chain reaction (qPCR) of fecal markers using spatially stratified samples, similarly assessing wastewater treatment plant (WWTP) outfall and other offshore contributions to surf zones is challenged by individual marker fate and transport. Here, bacterial communities were assessed for relatedness between all hypothesized fecal sources and surf zone waters for two urban California recreational beaches, by sequencing genes encoding 16S rRNA and analyzing data using SourceTracker and FEAST. Ambient marine bacterial communities dominated the surf zone, while fecal (human, dog, or gull) or wastewater (sewage or treated WWTP effluent) bacterial communities were present at low proportions and those from recycled water were absent. Based on the relative abundances of bacterial genera specifically associated with human feces, the abundances of HF183 in bacterial community sequences, and FEAST and SourceTracker results when benchmarked to HF183, the major sources of HF183 to surf zone waters were human feces and treated WWTP effluent. While surf zone sequence proportions from human sources (feces, sewage and treated WWTP effluent) appeared uncorrelated to previously obtained qPCR HF183 results, the proportions of human fecal and potential human pathogen sequences in surf zone waters were elevated when there were more swimmers (i.e. during weekday afternoons, holidays and busy weekends, and race events), thus confirming previously-published qPCR-based conclusions that bather shedding contributed low levels of human fecal contamination. Here, bacterial community sequencing also showed evidence that treated WWTP effluent from an offshore outfall was entering the surf zone, thereby resolving a prior uncertainty. Thus, bacterial community sequencing not only confirms qPCR HF183-based human marker detections, but further allows for confirming fecal sources for which individual marker quantification results can be equivocal.
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Affiliation(s)
- Dong Li
- Bren School of Environmental Science & Management, University of California, Santa Barbara, USA
| | | | | | - Jared Ervin
- Geosyntec Consultants, Santa Barbara, CA 93101, USA
| | - Jill L S Murray
- Department of Parks & Recreation, Creeks Division, Santa Barbara, CA 93102, USA
| | - Jen Smith
- California NanoSystems Institute, University of California, Santa Barbara, USA
| | - Patricia A Holden
- Bren School of Environmental Science & Management, University of California, Santa Barbara, USA.
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Williams NLR, Siboni N, Potts J, Campey M, Johnson C, Rao S, Bramucci A, Scanes P, Seymour JR. Molecular microbiological approaches reduce ambiguity about the sources of faecal pollution and identify microbial hazards within an urbanised coastal environment. WATER RESEARCH 2022; 218:118534. [PMID: 35537251 DOI: 10.1016/j.watres.2022.118534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 06/14/2023]
Abstract
Urbanised beaches are regularly impacted by faecal pollution, but management actions to resolve the causes of contamination are often obfuscated by the inability of standard Faecal Indicator Bacteria (FIB) analyses to discriminate sources of faecal material or detect other microbial hazards, including antibiotic resistance genes (ARGs). We aimed to determine the causes, spatial extent, and point sources of faecal contamination within Rose Bay, a highly urbanised beach within Sydney, Australia's largest city, using molecular microbiological approaches. Sampling was performed across a network of transects originating at 9 stormwater drains located on Rose Bay beach over the course of a significant (67.5 mm) rainfall event, whereby samples were taken 6 days prior to any rain, on the day of initial rainfall (3.8 mm), three days later after 43 mm of rain and then four days after any rain. Quantitative PCR (qPCR) was used to target marker genes from bacteria (i.e., Lachnospiraceae and Bacteroides) that have been demonstrated to be specific to human faeces (sewage), along with gene sequences from Heliobacter and Bacteriodes that are specific to bird and dog faeces respectively, and ARGs (sulI, tetA, qnrS, dfrA1 and vanB). 16S rRNA gene amplicon sequencing was also used to discriminate microbial signatures of faecal contamination. Prior to the rain event, low FIB levels (mean: 2.4 CFU/100 ml) were accompanied by generally low levels of the human and animal faecal markers, with the exception of one transect, potentially indicative of a dry weather sewage leak. Following 43 mm of rain, levels of both human faecal markers increased significantly in stormwater drain and seawater samples, with highest levels of these markers pinpointing several stormwater drains as sources of sewage contamination. During this time, sewage contamination was observed up to 1000 m from shore and was significantly and positively correlated with often highly elevated levels of the ARGs dfrA1, qnrS, sulI and vanB. Significantly elevated levels of the dog faecal marker in stormwater drains at this time also indicated that rainfall led to increased input of dog faecal material from the surrounding catchment. Using 16S rRNA gene amplicon sequencing, several indicator taxa for stormwater contamination such as Arcobacter spp. and Comamonadaceae spp. were identified and the Bayesian SourceTracker tool was used to model the relative impact of specific stormwater drains on the surrounding environment, revealing a heterogeneous contribution of discrete stormwater drains during different periods of the rainfall event, with the microbial signature of one particular drain contributing up to 50% of bacterial community in the seawater directly adjacent. By applying a suite of molecular microbiological approaches, we have precisely pinpointed the causes and point-sources of faecal contamination and other associated microbiological hazards (e.g., ARGs) at an urbanised beach, which has helped to identify the most suitable locations for targeted management of water quality at the beach.
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Affiliation(s)
- Nathan L R Williams
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Nachshon Siboni
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Jaimie Potts
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Meredith Campey
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Colin Johnson
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Shivanesh Rao
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Anna Bramucci
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Peter Scanes
- Waters, Wetlands, Coasts Science Branch, NSW Department of Primary Industries and Environment, Lidcombe, NSW, 2141, Australia
| | - Justin R Seymour
- Climate Change Cluster Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
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Li D, Van De Werfhorst LC, Holden PA. Genetic Sequence Data Evidence that Human Fecal‐associated
HF183
sequences Are on Human Skin and in Urine. J Appl Microbiol 2022; 133:232-240. [PMID: 35429105 PMCID: PMC9544380 DOI: 10.1111/jam.15577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 04/26/2022] [Accepted: 04/08/2022] [Indexed: 12/03/2022]
Abstract
Aims The DNA marker HF183 is a partial 16S rRNA gene sequence highly specific to human‐associated Bacteroides including Bacteroides dorei. While HF183 is used to assess human faecal contamination in aquatic environments worldwide, little is known about the existence of HF183 and B. dorei in human microbiomes outside of the human gastrointestinal tract and faeces. Methods and Results Previously published human skin and urine microbiome data sets from five independent human body skin studies, the Human Microbiome Project (HMP) and three independent human urine studies were analysed. The HF183 gene sequence was detected in all skin data sets, with the ratios of positive samples ranging from 0.5% to 36.3%. Popliteal fossa (knee), volar forearm and inguinal (groin) creases were identified as hot spots. HF183 was detected in two of three urine data sets, with ratios of positive samples ranging from 0% to 37.5%. All HF183‐containing sequences from these data sets were classified as associated with B. dorei. Conclusions HF183 is widespread on human skin and present in urine. Significance and Impact of Study Skin and urine microbiomes could be sources of HF183 to environmental waters. Such non‐faecal sources of HF183 might explain low concentrations of HF183 in recreational waters when swimmers are present.
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Affiliation(s)
- Dong Li
- Bren School of Environmental Science & Management University of California Santa Barbara
| | | | - Patricia A. Holden
- Bren School of Environmental Science & Management University of California Santa Barbara
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10
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Li D, Van De Werfhorst LC, Steets B, Ervin J, Murray JLS, Devarajan N, Holden PA. Bather Shedding as a Source of Human Fecal Markers to a Recreational Beach. Front Microbiol 2021; 12:673190. [PMID: 34248883 PMCID: PMC8269448 DOI: 10.3389/fmicb.2021.673190] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/30/2021] [Indexed: 11/24/2022] Open
Abstract
Microbial source tracking (MST) can identify and locate surf zone fecal indicator bacteria (FIB) sources. However, DNA-based fecal marker results may raise new questions, since FIB and DNA marker sources can differ. Here, during 2 years of summertime (dry season) MST for a Goleta, California recreational beach, surf zone FIB were mainly from gulls, yet low level human-associated DNA-based fecal marker (HF183) was detected in 25 and 14% of surf zone water samples, respectively. Watershed sources were hypothesized because dry weather creek waters had elevated FIB, and runoff-generating rain events mobilized human (and dog) fecal markers and Salmonella spp. into creeks, with human marker HF183 detected in 40 and 50% of creek water samples, dog markers detected in 70 and 50% of samples, and Salmonella spp. in 40 and 33.3% of samples, respectively over 2 years. However, the dry weather estuary outlet was bermed in the first study year; simultaneously, creek fecal markers and pathogens were lower or similar to surf zone results. Although the berm breached in the second year, surf zone fecal markers stayed low. Watershed sediments, intertidal beach sands, and nearshore sediments were devoid of HF183 and dog-associated DNA markers. Based on dye tests and groundwater sampling, beach sanitary sewers were not leaking; groundwater was also devoid of HF183. Offshore sources appeared unlikely, since FIB and fecal markers decreased along a spatial gradient from the surf zone toward nearshore and offshore ocean waters. Further, like other regional beaches, surf zone HF183 corresponded significantly to bather counts, especially in the afternoons when there were more swimmers. However, morning detections of surf zone HF183 when there were few swimmers raised the possibility that the wastewater treatment plant (WWTP) offshore outfall discharged HF183 overnight which transported to the surf zone. These findings support that there may be lowest achievable limits of surf zone HF183 owing to several chronic and permanent, perhaps diurnal, low concentration sources.
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Affiliation(s)
- Dong Li
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Laurie C. Van De Werfhorst
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA, United States
| | | | - Jared Ervin
- Geosyntec Consultants, Santa Barbara, CA, United States
| | - Jill L. S. Murray
- Creeks Division, Department of Parks and Recreation, Santa Barbara, CA, United States
| | - Naresh Devarajan
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA, United States
| | - Patricia A. Holden
- Bren School of Environmental Science and Management, University of California, Santa Barbara, Santa Barbara, CA, United States
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