The effect of pesticides on non-target soil microbial functions have been widely reported, yet little is known about how soil physicochemical properties mediate these effects. Most studies have examined one or two pesticides in one or few soil types and assessed limited microbial parameters. Here, we evaluated the effects of three herbicides (2,4-D amine, imazamox, propyzamide) and three fungicides (azoxystrobin, flutriafol, tebuconazole) on 16 microbial parameters, including microbial functional assays (enzymatic activities and potential nitrification rate (PNR) and the abundance of bacterial and fungal communities and key functional microbial genes (nifH amoA, cbhI, chiA, and LMCO) across ten agricultural soils during a 28-day laboratory incubation. Microbial responses were pesticide-specific, including between the two triazole fungicides (flutriafol and tebuconazole). Fungicides, particularly tebuconazole, significantly stimulated (3-glucosidase, cellobiohydrolase, N-acetyl-(3-glu-cosaminidase, and (3-xylosidase activities, yet consistently decreased the absolute abundance of ammonia oxidizing bacteria (AOB) amoA genes across most soils. In contrast, herbicides exhibited more selective, soil dependent significant effects; notably, propyzamide inhibited (3-glucosidase, cellobiohydrolase, and (3-xylosi-dase activities in alkaline soil but stimulated these activities in acidic soil. Multivariate analyses of pesticide-soil interactions further identified soil pH as a key driver, with fungicide-induced stimulation and herbicide-induced inhibition generally more pronounced in alkaline soils. The response differed among microbial parameters, with the absolute abundance of AOB amoA, cbhI, and LMCO genes showing significant sensitivity to pesticide-soil interactions. Overall, these findings highlight the value of assessing a broad suite of microbial functional indicators and demonstrate that soil pH is a major determinant of pesticide effects on soil microbial functions.

Microbial source tracking (MST) using Bacteroidales markers provides information on faecal contamination in environmental waters. The marker BacUni targets a range of sources, while HF183 is primarily associated with human faeces. Duplex quantitative PCR (qPCR) assays allow simultaneous detection of both markers, though competition between primer-probe sets can affect accuracy. Digital PCR (dPCR) offers absolute quantification and higher sensitivity, but multiplexing can be challenging when marker concentrations differ. This study compared HF183 and BacUni quantification across singleplex and duplex qPCR formats and duplex dPCR. Synthetic standards revealed variability due to gBlock design and probe orientation, whereas environmental samples showed minimal format-dependent effects. Duplex qPCR provided comparable results to singleplex, with minor underestimation relative to dPCR. These small differences likely reflect the use of dPCR-quantified standards for qPCR calibration, rather than using DNA concentration-based calibration methods. Low-copy HF183 samples highlighted dPCR's superior sensitivity near detection limits. GoTaq qPCR was the most economical option, especially in duplex format, whereas dPCR offered competitive costs for duplexed samples with the advantage of absolute quantification. These findings demonstrate that duplex qPCR assays reliably quantify HF183 and BacUni in environmental waters, with dPCR serving as a robust complementary method for low-abundance or confirmatory analyses.

Recent evidence highlights the importance of low-abundant subordinate plant species in regulating ecosystem functions in grasslands experiencing drought via plant-microbe interactions. We hypothesized that subordinate and dominant species have distinct carbon (C) allocation and nitrogen (N) uptake patterns affecting soil microbes and their functions during a drought event. We collected soil cores with individuals of Paspalum dilatatum (dominant) or Cynodon dactylon (subordinate) from two independent field drought experiments in mesic Australian grasslands. Cores were subjected to a dual-pulse labelling with 13CO2 and 15NH415NO3. Stable isotopes were traced in plant biomass and the microbial community (PLFA-SIP, DNA/RNA-SIP and NanoSIM), and soil nutrient cycling was measured via enzymatic activities. The subordinate species invested more C below-ground and had higher N uptake in response to drought compared to the dominant, and the active soil microbial community displayed small but consistent differences. The subordinate species showed higher arbuscular mycorrhizae colonization rates but with similar C exchange to the dominant species in response to drought. Synthesis. Our results suggest that the subordinate species achieves higher drought resistance in biomass and soil functions via increased below-ground functioning. The data presented here provide a basis to explain the underlying mechanisms behind the response of grassland communities and their C cycling to drought.

The World Health Organization identified Stenotrophomonas maltophilia as an underestimated, multi-drug-resistant and opportunistic nosocomial pathogen. It poses a threat to patients who are immunocompromised, suffering chronic disease, requiring indwelling catheters and undergoing mechanical ventilation, as well as victims of trauma and burns. Here, whole-genome sequences of 266 Stenotrophomonas spp. from diverse environmental sources in Fiji and Australia were generated and used to improve understanding of the phylogeny of the genus. Isolates were sourced from freshwater, soil, waste biosolids, wastewater and animal agriculture using selective differential growth media. Phylogenomic analysis identified eight species, plus a singular novel Australian isolate most closely related to Stenotrophomonas indicatrix and Stenotrophomonas lactitubi. The Fijian isolates were primarily S. maltophilia (Sm), with isolates belonging to 13 of the previously recognized 19 Sm subgroups, while most Australian isolates were notably non-maltophilia. A genotypic characterization of the collections was performed, with a focus on well-characterized antimicrobial resistance and virulence genes identified in S. maltophilia, highlighting the presence of these key genes within other Stenotrophomonas species, particularly S. indicatrix, S. lactitubi and Stenotrophomonas rhizophila. Allelic analysis of chromosomal β-lactamase bla L2 revealed its presence across the entire Stenotrophomonas genus, while carbapenemase gene bla L1 was restricted to S. maltophilia and its closest relatives. These data represent a significant contribution of non-maltophilia genome sequences to the public domain, and the first dataset representing Stenotrophomonas from Fiji.

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Learn More CiteCitationCitation and abstractCitation and referencesMore citation options ShareShare onFacebookX (Twitter)WeChatLinkedInRedditEmailJump toExpandCollapse ViewpointJanuary 28, 2025Strengthening Policy Relevance of Wastewater-Based Surveillance for Antimicrobial ResistanceClick to copy article linkArticle link copied!Sheena Conforti*Sheena ConfortiEawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, Switzerland*[email protected]More by Sheena ConfortiView Biographyhttps://orcid.org/0000-0002-0173-6170Amy PrudenAmy PrudenCivil and Environmental Engineering, Virginia Polytechnic Institute and State University, 418 Durham Hall, Blacksburg, Virginia 24061, United StatesMore by Amy Prudenhttps://orcid.org/0000-0002-3191-6244Nicole AcostaNicole AcostaUniversity of Calgary, Cumming School of Medicine, Calgary, AB T2N 1N4, CanadaMore by Nicole AcostaChristopher AndersonChristopher AndersonWest Virginia University, Morgantown, West Virginia 26506-6201, United StatesMore by Christopher AndersonHelmut BuergmannHelmut BuergmannEawag, Swiss Federal Institute of Aquatic Science and Technology, Kastenienbaum 6047, SwitzerlandMore by Helmut Buergmannhttps://orcid.org/0000-0002-5651-5906Juliana Calabria De AraujoJuliana Calabria De AraujoFederal University of Minas Gerais, Belo Horizonte, MG 31270-901, BrazilMore by Juliana Calabria De AraujoJudith R. CristobalJudith R. CristobalDepartment of Chemistry, University at Buffalo - The State University of New York, 633 Natural Science Complex, Buffalo, New York 14260, United StatesMore by Judith R. CristobalBarbara DrigoBarbara DrigoUniversity of South Australia, Adelaide, SA 5001, AustraliaMore by Barbara DrigoClaire EllisonClaire EllisonQueen's University, Beaty Water Research Center, Kingston, ON K7L 3N6, CanadaMore by Claire EllisonZanah FrancisZanah FrancisU.S. Department of Health and Human Services, Washington, D.C. 20201-0004, United StatesMore by Zanah FrancisDominic FrigonDominic FrigonMcGill University, Civil Engineering and Applied Mechanics, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, CanadaMore by Dominic Frigonhttps://orcid.org/0000-0003-1587-8943Markus GaenzleMarkus GaenzleUniversity of Alberta, Edmonton, AB T6G 2R3, CanadaMore by Markus GaenzleJulia VierheiligJulia VierheiligTU Wien, Institute of Water Quality and Resource Management, ICC Water & Health, 1040 Wien, AustriaMore by Julia VierheiligTimothy R. JulianTimothy R. JulianEawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, SwitzerlandMore by Timothy R. Julianhttps://orcid.org/0000-0003-1000-0306Uli KlümperUli KlümperInstitute for Hydrobiology, TU Dresden, Dresden 01062, GermanyMore by Uli Klümperhttps://orcid.org/0000-0002-4169-6548Liping MaLiping MaEast China Normal University, Dongchuan Road 500, Shanghai 200241, ChinaMore by Liping Mahttps://orcid.org/0000-0002-1646-6767Chand MangatChand MangatPublic Health Agency of Canada, Wastewater Surveillance Unit, National Microbiology Laboratory, Winnipeg, MB R3E 3R2, CanadaMore by Chand MangatMaya NadimpalliMaya NadimpalliGangarosa Department of Environmental Health, Emory University, Atlanta, Georgia 30322, United StatesMore by Maya Nadimpallihttps://orcid.org/0000-0002-6526-116XManami NakashitaManami NakashitaNational Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, JapanMore by Manami NakashitaGilbert OsenaGilbert OsenaUniversity of Gothenburg, Goteborg, Västra Götaland 405 30, SwedenMore by Gilbert OsenaSasikaladevi RathinaveluSasikaladevi RathinaveluEawag, Swiss Federal Institute of Aquatic Science and Technology, Kastenienbaum 6047, SwitzerlandMore by Sasikaladevi RathinaveluRichard Reid-SmithRichard Reid-SmithPublic Health Agency of Canada Foodborne, Waterborne and Zoonotic Infections Division, Guelph, ON N1G 5B2, CanadaMore by Richard Reid-SmithMichael SaldanaMichael SaldanaSonny Astani Civil and Environmental Engineering, University of Southern California, 920 Downey Way, BHE 201, Los Angeles, California 90089-0001, United StatesMore by Michael SaldanaHeike SchmittHeike SchmittNational Institute for Public Health and the Environment, Bilthoven 3720 BA, The NetherlandsDelft University of Technology, Delft, Zuid-Holland 2600 AA, NetherlandsMore by Heike SchmittShuxian LiShuxian LiDepartment of Civil Engineering, The University of Hong Kong, Hong Kong 999077, ChinaMore by Shuxian LiAndrew C. SingerAndrew C. SingerCentre for Ecology & Hydrology, Mansfield Road, Oxford OX1 3SR, United KingdomMore by Andrew C. Singerhttps://orcid.org/0000-0003-4705-6063Tam T. TranTam T. TranNORCE Norwegian Research Centre AS, Tromso, Troms og Finnmark 9019, NorwayMore by Tam T. TranKadir YanacKadir YanacUniversity of Manitoba, Department of Civil Engineering, Winnipeg, MB CR3T 5V6, CanadaMore by Kadir YanacGustavo YbazetaGustavo YbazetaHealth Sciences North Research Institute, Sudbury, ON P3E 2H2, CanadaMore by Gustavo YbazetaMonika HarniszMonika HarniszUniversity of Warmia and Mazury in Olsztyn, Department of Water Protection Engineering and Environmental Microbiology, Prawochenskiego 1, Olsztyn 10-790, PolandMore by Monika HarniszOpen PDFEnvironmental Science & TechnologyCite this: Environ. Sci. Technol. 2025, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://pubs.acs.org/doi/10.1021/acs.est.4c09663https://doi.org/10.1021/acs.est.4c09663Published January 28, 2025 Publication History Received 11 September 2024Published online 28 January 2025article-commentary© 2025 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 . License Summary*You are free to share (copy and redistribute) this article in any medium or format and to adapt (remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:Creative Commons (CC): This is a Creative Commons license.Attribution (BY): Credit must be given to the creator.View full license*DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. This publication is licensed underCC-BY 4.0 . License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator.View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. ACS Publications© 2025 The Authors. Published by American Chemical SocietySubjectswhat are subjectsArticle subjects are automatically applied from the ACS Subject Taxonomy and describe the scientific concepts and themes of the article.Antibiotic resistanceAntimicrobial agentsImmunologyPeptides and proteinsWastewaterAntimicrobial resistance (AMR) is among the top 10 public health threats, with nearly 5 million deaths in 2019 linked to AMR-related bacterial infections. (1) A One Health approach is needed to combat AMR.Healthcare-based surveillance (HBS) of AMR provides incomplete information about the scope of the AMR threat. HBS screens only patients seeking medical attention, lacking community-level representativeness, and suffers from underreporting. (2) Consequently, researchers are turning to wastewater-based surveillance (WBS) to complement HBS. (3) WBS can provide information about AMR circulating within communities and hospitals, offering a comprehensive understanding of AMR prevalence. However, the surveillance targets and data obtained from WBS are distinct from those derived from HBS, creating uncertainty regarding their utility to the public health sector and ability to yield policy relevant information. In May 2024, participants in a workshop during the 7th Environmental Dimension of Antimicrobial Resistance (EDAR7) conference (Montréal, Canada) sought to answer four questions aimed at advancing the policy relevance of AMR data generated by WBS.What Public Health Relevant Indicators Are Currently Used to Drive Antimicrobial Stewardship Policy?Click to copy section linkSection link copied!There is a pressing need to integrate available information across One Health sectors (human health, agriculture, and environment) to inform policy and practice aimed at mitigating AMR (Figure 1). HBS aims to guide antibiotic prescriptions by generating antibiograms and provides data on AMR prevalence and trends by prescreening inpatients for carriage, assessing resistance of pathogens responsible for infections, and tracking in- and out-patient antibiotic prescription patterns. Tracking trends of multidrug-resistant (MDR) organisms in healthcare facilities helps to identify units experiencing high rates of nosocomial infections and informs the selection of appropriate treatment options. Well-established surveillance programs can result in public health reports used to define strategies to regulate antibiotic stewardship and to monitor and evaluate interventions.Figure 1Figure 1. Integration of data across One Health sectors to inform AMR policy and the potential role of WBS. Clinical settings, environmental studies, and agricultural surveillance can provide indicators used for antimicrobial stewardship and antimicrobial resistance (AMR) management. Indicators include prevalence of AMR and prescription patterns in clinical settings, geographic distribution and emerging threats in the environment to identify horizontal gene transfer (HGT) hot spots, and antibiotic/biocide residues and zoonotic pathways in agriculture. Wastewater-based surveillance (WBS) programs can be designed to integrate within and across all sectors.High Resolution ImageDownload MS PowerPoint SlideSurveillance in agriculture tends to be more focused on antibiotic use than tracking resistant infections, although some monitoring programs track resistant isolates in meat, produce, and other food products. Measuring antibiotic consumption in animals and crops can help identify hot spots for selective pressure and potential for AMR to spread. Monitoring residues in food of animal origin and biocides in vegetables can also contribute. Surveillance of AMR in livestock, wild animals, and the food chain can inform transmission pathways between animals and humans, providing insights into interventions to curb foodborne and zoonotic spread. Agricultural surveillance supports the establishment and enforcement of antibiotic stewardship in animals and plants, including antibiotic use regulations.There is increasing recognition of the environmental dimension of One Health approaches to inform AMR policy, but environmental surveillance programs, including WBS, are still limited. Environmental indicators of AMR, such as the presence and concentration of antibiotic resistance genes (ARGs) and resistant organisms in wastewater effluents, rivers, lakes, air, and soils, are primarily derived from spatial and longitudinal studies. These studies identify hot spots of resistance, guide environmental regulations like wastewater management policies, and inform agricultural practices to reduce antibiotic runoff. Environmental surveillance is also uniquely positioned for identifying emerging threats, including new ARGs, mobile genetic elements (MGEs), biocidal resistance genes, and resistant organisms. Monitoring targeted sources, including human, industrial, and agricultural wastewaters, has identified hot spots of resistance and selective pressure. The study of MGEs, in particular, offers insights into the mobility of ARGs and the potential acquisition of new resistance mechanisms in pathogens.What Public Health Relevant Targets and Data Can Be Derived from Wastewater through Monitoring Programs?Click to copy section linkSection link copied!WBS can include monitoring of antimicrobials, resistant organisms, ARGs, and MGEs in human, industrial, or agricultural/food production wastewaters, with monitoring locations selected to integrate across specific sources of interest. However, there is a need to better strategize and coordinate WBS of AMR in a manner that focuses on targets and data that are very likely to provide actionable information. One strategy could be prioritizing low-prevalence resistant bacteria of high clinical relevance, such as carbapenemase-producing Enterobacterales, vancomycin-resistant Enterococcus spp., or other bacteria of the World Health Organization Bacterial Priority Pathogen List. (4) An increase in the level of resistant organisms in wastewater can indicate rising community-level carriage, potential outbreak risks, or intervention failures. WBS may also help determine if outbreaks have ended or if asymptomatic cases persist in the community. However, it is important to be aware of population-scale detection limits and to determine the necessary temporal resolution (e.g., weekly monitoring) to achieve the monitoring goal. In contrast, monitoring pathogens that are already widespread does not necessarily add significant value to inform public health actions.Metagenomic approaches, i.e., sequencing of DNA across microbial populations encountered in wastewater, can offer a comprehensive view of ARGs and MGEs circulating within the corresponding population. Because metagenomics is a nontargeted approach, this perspective could identify emerging ARGs or provide an early warning regarding acquisition of ARGs by pathogens of concern in a community. For example, early detection of the mcr-1 gene conferring resistance to colistin through metagenomics led to the implementation of stricter colistin stewardship and monitoring in high-risk areas, such as units with high rates of MDR. (5)WBS can also target antimicrobials, thus filling knowledge gaps regarding the patterns and prevalence of the use of antimicrobials and other pharmaceuticals. Efforts are needed to improve reporting of antimicrobial use data. Where data are available, they tend to be highly aggregated and costly and with low spatial and temporal resolution. However, antibiotic testing does require sophisticated instrumentation and expertise and works best for antibiotics, such as macrolides and fluoroquinolones, that persist longer in wastewater environments. Fast-degrading antibiotics such as β-lactams might still be detected in the outflow from hospitals with short retention times.A general advantage of WBS is the ability to capture longitudinal and spatial trends across populations and sources of interest. Notably, different sanitation infrastructures and spatial scales of WBS provide distinct opportunities for measurement and interpretation. For example, in hospital wastewater, the indicators reflect carriage of resistant organisms or antibiotic usage within a specific facility. In municipal wastewater, the indicators reflect trends of resistance or antibiotic consumption within the community. Importantly, most of the world is served by nonsewered sanitation, particularly in low- and middle-income countries; surveillance in these settings might focus on tracking emergence and estimating prevalence in specific community settings (e.g., schools, universities, and hospitals). WBS can help to fill critical knowledge gaps in HBS, particularly in countries lacking comprehensive diagnostic capabilities.What Information, Resources, and Contextualization Are Needed to Align Public Health Indicators Derived from Wastewater with Other Public Health Indicators to Better Inform Our Epidemiological Understanding of AMR?Click to copy section linkSection link copied!A key consensus of the workshop was the need to integrate WBS data with HBS to better inform public health strategies.Information needed includes data on AMR prevalence from clinics, meaning the pathogens encountered in the population and corresponding rates of resistance to specific antibiotics obtained through HBS. Such monitoring can reveal clinically relevant targets for WBS and allow the establishment of standard methodologies for consistent data collection and interpretation. Whole genome sequencing of human and animal clinical strains can provide information needed to calibrate WBS data and track persistent pathogens and ARGs of concern in wastewater, potentially indicating ongoing transmission. Information about antibiotic usage in humans, animals, and plants, prescription practices, rates of antibiotic degradation in wastewater, flow data, and transport in sewage systems will help better align WBS and healthcare sector AMR indicators.Resources necessary for advancing WBS of AMR include institutional, financial, and human capital investments. These can support the design, implementation, and continuity of a monitoring plan to yield comprehensive and longitudinal data collection needed to infer AMR dynamics within the community. Initial costs for setting up laboratories, building infrastructure, and establishing workflows among stakeholders such as those who operate wastewater facilities and other monitoring locations are necessary to centralize analyses and build capacity. The investments made in infrastructure and organization for COVID-19 surveillance, and increasingly other pathogens, provide an opportunity to leverage existing resources for AMR monitoring. Establishing publicly accessible databases to collect, visualize, and analyze data from both wastewater and clinical surveillance will enhance collaboration among clinicians, policy makers, researchers, and other stakeholders.WBS indicators for AMR should be contextualized with respect to clinical and agricultural/food sector surveillance through strong collaborations among researchers, clinicians, and communities. While WBS alone may not always generate information about specific targets of interest, it can identify broader trends and emerging hot spots and inform public health strategies like early warnings and antimicrobial stewardship efforts. Notably, transitioning from WBS to wastewater-based epidemiology for AMR poses significant challenges, for example, in predicting the prevalence of AMR within the population. Complications include the dynamics and complexity of pathogen shedding rates and antibiotic resistance mechanisms, and the growth, fate, and transport processes in sewer networks. One key issue is the potential proliferation of resistant organisms within the sewer network, both in the wastewater and in biofilm, which can decouple wastewater-based quantitative estimates from inferences about AMR epidemiology. Indicators from WBS could be developed to help inform progress toward the Sustainable Development Goals or otherwise provide insight into key socioeconomic factors driving overall trends. Geographical and mobility patterns within sewersheds, and connections between industries and hospitals, should be considered to calibrate wastewater indicators and discern community-sourced data from other origins. Research on the fate of resistant bacteria in wastewater systems, along with cohort studies on resistant bacteria in human carriers, may help improve our understanding and interpretation of WBS-derived data.How Can the Information Derived from WBS of AMR Contribute to the Formulation of Effective Public Health Policies or Interventions?Click to copy section linkSection link copied!WBS offers population-integrated data at comparatively low cost and effort relative to monitoring individuals within a population. It provides broader views on population prevalence, independent of screening effort, participation rates, and the likelihood of reporting to health services. Additionally, it enables a comprehensive overview of the microbial genomes circulating in the environment and provides space- and time-resolved data that can be scaled to various needs. As critiqued in the recent 2024 NASEM report, we acknowledge the limitations of WBS for ARG-focused monitoring at the community level, which can be complicated by ARGs from non-human sources and the amplification of ARGs between the human source and the wastewater treatment plant. (6) However, it is important to recognize that WBS of AMR could provide much broader value beyond serving as an early warning system, especially in terms of evaluating long-term trends and effects of policy interventions on shaping these trends. We highlight alternative use cases that are of particular value for aligning WBS data with actionable public health objectives and HBS, such as detection of the emergence of novel resistance genes, or use of culture- and molecular-based methods to track long-term changes in community prevalence rates. (7)Integrating WBS data with existing surveillance methods (Figure 1) is a promising approach to enhance AMR understanding by correlating wastewater findings with clinical data, making policies actionable. WBS data can expand and provide greater resolution to traditional clinical antibiograms while also filling diagnostic gaps and better optimizing the selection of antibiotic treatments in regions with limited spatial and longitudinal AMR data.Public access and education, e.g., via media outlets, can increase AMR awareness, thereby enhancing public support and compliance with AMR policies. To inform effective public health interventions from WBS, it is necessary to have clear objectives and collaborate closely with stakeholders across One Health sectors, which can facilitate the implementation of targeted and efficient measures aimed at limiting the evolution and transmission of antibiotic-resistant pathogens.Author InformationClick to copy section linkSection link copied!Corresponding AuthorSheena Conforti - Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, Switzerland; https://orcid.org/0000-0002-0173-6170; Email: [email protected]AuthorsAmy Pruden - Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, 418 Durham Hall, Blacksburg, Virginia 24061, United States; https://orcid.org/0000-0002-3191-6244Nicole Acosta - University of Calgary, Cumming School of Medicine, Calgary, AB T2N 1N4, CanadaChristopher Anderson - West Virginia University, Morgantown, West Virginia 26506-6201, United StatesHelmut Buergmann - Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastenienbaum 6047, Switzerland; https://orcid.org/0000-0002-5651-5906Juliana Calabria De Araujo - Federal University of Minas Gerais, Belo Horizonte, MG 31270-901, BrazilJudith R. Cristobal - Department of Chemistry, University at Buffalo - The State University of New York, 633 Natural Science Complex, Buffalo, New York 14260, United StatesBarbara Drigo - University of South Australia, Adelaide, SA 5001, AustraliaClaire Ellison - Queen's University, Beaty Water Research Center, Kingston, ON K7L 3N6, CanadaZanah Francis - U.S. Department of Health and Human Services, Washington, D.C. 20201-0004, United StatesDominic Frigon - McGill University, Civil Engineering and Applied Mechanics, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, Canada; https://orcid.org/0000-0003-1587-8943Markus Gaenzle - University of Alberta, Edmonton, AB T6G 2R3, CanadaJulia Vierheilig - TU Wien, Institute of Water Quality and Resource Management, ICC Water & Health, 1040 Wien, AustriaTimothy R. Julian - Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf 8600, Switzerland; https://orcid.org/0000-0003-1000-0306Uli Klümper - Institute for Hydrobiology, TU Dresden, Dresden 01062, Germany; https://orcid.org/0000-0002-4169-6548Liping Ma - East China Normal University, Dongchuan Road 500, Shanghai 200241, China; https://orcid.org/0000-0002-1646-6767Chand Mangat - Public Health Agency of Canada, Wastewater Surveillance Unit, National Microbiology Laboratory, Winnipeg, MB R3E 3R2, CanadaMaya Nadimpalli - Gangarosa Department of Environmental Health, Emory University, Atlanta, Georgia 30322, United States; https://orcid.org/0000-0002-6526-116XManami Nakashita - National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, JapanGilbert Osena - University of Gothenburg, Goteborg, Västra Götaland 405 30, SwedenSasikaladevi Rathinavelu - Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastenienbaum 6047, SwitzerlandRichard Reid-Smith - Public Health Agency of Canada Foodborne, Waterborne and Zoonotic Infections Division, Guelph, ON N1G 5B2, CanadaMichael Saldana - Sonny Astani Civil and Environmental Engineering, University of Southern California, 920 Downey Way, BHE 201, Los Angeles, California 90089-0001, United StatesHeike Schmitt - National Institute for Public Health and the Environment, Bilthoven 3720 BA, The Netherlands; Delft University of Technology, Delft, Zuid-Holland 2600 AA, NetherlandsShuxian Li - Department of Civil Engineering, The University of Hong Kong, Hong Kong 999077, ChinaAndrew C. Singer - Centre for Ecology & Hydrology, Mansfield Road, Oxford OX1 3SR, United Kingdom; https://orcid.org/0000-0003-4705-6063Tam T. Tran - NORCE Norwegian Research Centre AS, Tromso, Troms og Finnmark 9019, NorwayKadir Yanac - University of Manitoba, Department of Civil Engineering, Winnipeg, MB CR3T 5V6, CanadaGustavo Ybazeta - Health Sciences North Research Institute, Sudbury, ON P3E 2H2, CanadaMonika Harnisz - University of Warmia and Mazury in Olsztyn, Department of Water Protection Engineering and Environmental Microbiology, Prawochenskiego 1, Olsztyn 10-790, PolandAuthor ContributionsS.C. and A.P. contributed equally to this work.NotesThe authors declare no competing financial interest.BiographyClick to copy section linkSection link copied!Sheena ConfortiHigh Resolution ImageDownload MS PowerPoint SlideSheena Conforti is a postdoctoral fellow in the Pathogens and Human Health group at the Department of Environmental Microbiology, Eawag, Switzerland. She earned her Ph.D. in 2024 from the Department of Biosystems Science and Engineering, at ETH Zurich. Her research focuses on antimicrobial resistance surveillance through wastewater and environmental monitoring, combining culture-based methods and whole-genome sequencing to study resistant bacteria and transmission dynamics. Her work supports the One Health framework and aims to inform public health strategies by integrating data from human, animal, and environmental sources.AcknowledgmentsClick to copy section linkSection link copied!The authors thank the 7th Conference on Environmental Dimension of Antimicrobial Resistance for the financial support of this publication. The authors acknowledge the Environmental Dimension of Antimicrobial Resistance (EDAR7) conference, held in May 2024 in Montréal, Canada, for hosting the workshop that contributed to the development of the manuscript. The authors thank all of the workshop participants and Molly Cantrell for their valuable input during the workshop. The authors also thank the Swiss National Science Foundation (Grant 192763) for funding S.C.ReferencesClick to copy section linkSection link copied! This article references 7 other publications. 1Antimicrobial Resistance Collaborators Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 2022, 399 (10325), 629– 655, DOI: 10.1016/S0140-6736(21)02724-0 Google ScholarThere is no corresponding record for this reference.2 Global Antimicrobial Resistance and Use Surveillance System (GLASS) Report 2022. World Health Organization, 2022. https://www.who.int/publications/i/item/9789240062702.Google ScholarThere is no corresponding record for this reference.3Chau, K. K.; Barker, L.; Budgell, E. P.; Vihta, K. D.; Sims, N.; Kasprzyk-Hordern, B.; Harriss, E.; Crook, D. W.; Read, D. S.; Walker, A. S.; Stoesser, N. Systematic review of wastewater surveillance of antimicrobial resistance in human populations. Environ. Int. 2022, 162, 107171, DOI: 10.1016/j.envint.2022.107171 Google ScholarThere is no corresponding record for this reference.4 WHO Bacterial Priority Pathogens List 2024: bacterial pathogens of public health importance to guide research, development and strategies to prevent and control antimicrobial resistance. World Health Organization, 2024. https://www.who.int/publications/i/item/9789240093461.Google ScholarThere is no corresponding record for this reference.5von Wintersdorff, C. J. H.; Wolffs, P. F. G.; van Niekerk, J. M.; Beuken, E.; van Alphen, L. B.; Stobberingh, E. E.; Oude Lashof, A. M. L.; Hoebe, C. J. P. A.; Savelkoul, P. H. M.; Penders, J. Detection of the plasmid-mediated colistin-resistance gene mcr-1 in faecal metagenomes of Dutch travellers. J. Antimicrob. Chemother. 2016, 71 (12), 3416– 3419, DOI: 10.1093/jac/dkw328 Google ScholarThere is no corresponding record for this reference.6National Academies of Sciences, Engineering, and Medicine. Increasing the Utility of Wastewater-based Disease Surveillance for Public Health Action: A Phase 2 Report. The National Academies Press: Washington, DC, 2024. DOI: 10.17226/27516 Google ScholarThere is no corresponding record for this reference.7Conforti, S.; Holschneider, A.; Sylvestre, É; Julian, T. R. Monitoring ESBL-Escherichia coli in Swiss wastewater between November 2021 and November 2022: insights into population carriage. mSphere. 2024, 9 (5), e0076023 DOI: 10.1128/msphere.00760-23 Google ScholarThere is no corresponding record for this reference.Cited By Click to copy section linkSection link copied!This article has not yet been cited by other publications.Download PDFFiguresReferences Get e-AlertsGet e-AlertsEnvironmental Science & TechnologyCite this: Environ. Sci. Technol. 2025, XXXX, XXX, XXX-XXXClick to copy citationCitation copied!https://doi.org/10.1021/acs.est.4c09663Published January 28, 2025 Publication History Received 11 September 2024Published online 28 January 2025© 2025 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 . License Summary*You are free to share (copy and redistribute) this article in any medium or format and to adapt (remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:Creative Commons (CC): This is a Creative Commons license.Attribution (BY): Credit must be given to the creator.View full license*DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. Article Views-Altmetric-Citations-Learn about these metrics closeArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated.Recommended Articles FiguresReferencesAbstractHigh Resolution ImageDownload MS PowerPoint SlideFigure 1Figure 1. Integration of data across One Health sectors to inform AMR policy and the potential role of WBS. Clinical settings, environmental studies, and agricultural surveillance can provide indicators used for antimicrobial stewardship and antimicrobial resistance (AMR) management. Indicators include prevalence of AMR and prescription patterns in clinical settings, geographic distribution and emerging threats in the environment to identify horizontal gene transfer (HGT) hot spots, and antibiotic/biocide residues and zoonotic pathways in agriculture. Wastewater-based surveillance (WBS) programs can be designed to integrate within and across all sectors.High Resolution ImageDownload MS PowerPoint SlideSheena ConfortiHigh Resolution ImageDownload MS PowerPoint SlideSheena Conforti is a postdoctoral fellow in the Pathogens and Human Health group at the Department of Environmental Microbiology, Eawag, Switzerland. She earned her Ph.D. in 2024 from the Department of Biosystems Science and Engineering, at ETH Zurich. Her research focuses on antimicrobial resistance surveillance through wastewater and environmental monitoring, combining culture-based methods and whole-genome sequencing to study resistant bacteria and transmission dynamics. Her work supports the One Health framework and aims to inform public health strategies by integrating data from human, animal, and environmental sources.References This article references 7 other publications. 1Antimicrobial Resistance Collaborators Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis. Lancet 2022, 399 (10325), 629– 655, DOI: 10.1016/S0140-6736(21)02724-0 There is no corresponding record for this reference.2 Global Antimicrobial Resistance and Use Surveillance System (GLASS) Report 2022. World Health Organization, 2022. https://www.who.int/publications/i/item/9789240062702.There is no corresponding record for this reference.3Chau, K. K.; Barker, L.; Budgell, E. P.; Vihta, K. D.; Sims, N.; Kasprzyk-Hordern, B.; Harriss, E.; Crook, D. W.; Read, D. S.; Walker, A. S.; Stoesser, N. Systematic review of wastewater surveillance of antimicrobial resistance in human populations. Environ. Int. 2022, 162, 107171, DOI: 10.1016/j.envint.2022.107171 There is no corresponding record for this reference.4 WHO Bacterial Priority Pathogens List 2024: bacterial pathogens of public health importance to guide research, development and strategies to prevent and control antimicrobial resistance. World Health Organization, 2024. https://www.who.int/publications/i/item/9789240093461.There is no corresponding record for this reference.5von Wintersdorff, C. J. H.; Wolffs, P. F. G.; van Niekerk, J. M.; Beuken, E.; van Alphen, L. B.; Stobberingh, E. E.; Oude Lashof, A. M. L.; Hoebe, C. J. P. A.; Savelkoul, P. H. M.; Penders, J. Detection of the plasmid-mediated colistin-resistance gene mcr-1 in faecal metagenomes of Dutch travellers. J. Antimicrob. Chemother. 2016, 71 (12), 3416– 3419, DOI: 10.1093/jac/dkw328 There is no corresponding record for this reference.6National Academies of Sciences, Engineering, and Medicine. Increasing the Utility of Wastewater-based Disease Surveillance for Public Health Action: A Phase 2 Report. The National Academies Press: Washington, DC, 2024. DOI: 10.17226/27516 There is no corresponding record for this reference.7Conforti, S.; Holschneider, A.; Sylvestre, É; Julian, T. R. Monitoring ESBL-Escherichia coli in Swiss wastewater between November 2021 and November 2022: insights into population carriage. mSphere. 2024, 9 (5), e0076023 DOI: 10.1128/msphere.00760-23 There is no corresponding record for this reference.

Legionella spp. are Gram-negative bacteria present in natural and engineered water systems that can cause legionellosis (Legionnaires' disease and Pontiac fever). When present in biofilms of healthcare facilities, they are a likely source of legionellosis for immunocompromised patients. The objective of this study was to evaluate an electrochemical water disinfection system to produce and dose hypochlorous acid (HOCl) to reduce this risk in a hospital with systemic Legionella spp. contamination. Furthermore, Legionella spp. colony counts were compared to quantitative polymerase chain reaction (qPCR) results. Before and after implementing the disinfection system, tap water and pipe biofilms were analysed for microbial contamination. Post-implementation monitoring continued for over six months, assessing microbial quality using heterotrophic colony counts, Legionella serotyping, and qPCR targeting total bacteria (16S rRNA) and Legionella spp. By the third sampling event (22 days post-commissioning), water quality consistently improved, with no culture-positive Legionella counts observed thereafter. qPCR analysis confirmed these results, proving more sensitive and reliable than traditional methods. The qPCR assays for Legionella spp. and bacterial 16S rRNA were also cost-effective for system optimisation and diagnostics.

Safe, clean water is vital to maintain healthy societies and socioeconomic development, yet providing it remains an evolving challenge for water managers. Among the numerous contaminants that need to be managed, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) are recognized globally as a growing priority, and the development of new and improved disinfection methods to remove them and their drivers (e.g., antibiotics) from treated wastewater effluents for recycling or discharge to water bodies is a matter of increasing interest. This study investigated the disinfection efficacy of hydrogen peroxide (H2O2), chlorination (Cl-2), ultraviolet light at 254 nm (UV-254), UV-254/H2O2, ultraviolet light at 369 nm (UV-369) and UV-369/H2O2 treatments against several bacterial strains (i.e., Escherichia coli, Salmonella enteritidis 11RX, Listeria innocua, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus). Disinfection efficacy was assessed in multiple sample matrices, including ultrapure water, wastewater influent, and effluent waters. Irrespective of the bacterial strain, the removal efficacy followed the order: UV-254/H2O2 > UV-254 > Cl-2 > UV-369/H2O2 > UV-369 > H2O2. 4-log reduction (99.99 % removal) of E. coli was achieved at 0.5, 1, 2, 20 and 30 min by UV-254/H2O2, UV-254, Cl-2, UV-369/H2O2 and UV-369 treatments, respectively, whereas H2O2 alone only achieved 97.6 % removal of E. coli after 30 min of treatment. UV-254 and UV-254/H2O2 were also able to remove antibiotic resistance genes with an observed rate constant ranging from 0.3445 to 0.6122 min(-1). The findings of this study suggest that coupling H2O2 with solar light is a promising alternative approach for reducing the quantity of opportunistic human pathogens in reclaimed water.

Antibiotic resistance genes (ARGs) are considered a contaminant of emerging concern in the environment. ARGs are widely distributed in the environment (e.g., soil, biosolids, plants, wastewater), companion and food-producing animals, wildlife, and insects. Soils are important reservoirs of ARGs and constitute a major pathway for the exchange of ARGs among microorganisms, including clinically relevant pathogens. Naturally available clays and clay minerals show high affinity to ARGs and antibiotics, which can be exploited to develop methods for mitigating ARGs contamination in soil, biosolids, and water. The mechanism of ARGs retention, degradation, and transformation on natural and modified clay surfaces is complex and requires further understanding to develop scalable remediation methods. Here, we discuss the source, availability, and distribution of antibiotics and ARGs in wastewater and soil, and their interactions with natural and modified clays and clay minerals to seek effective strategies for mitigating the overlooked pandemic of antimicrobial resistance (AMR). We shed light on future research requirements to extend the use of inexpensive clay adsorbents and develop nature-based solutions using these materials for mitigating AMR in the environment.

ABSTRACT Acinetobacter baumannii, an important pathogen known for its widespread antibiotic resistance, has been the focus of extensive research within its genus, primarily involving clinical isolates. Consequently, data on environmental A. baumannii and other Acinetobacter species remain limited. Here, we utilized Illumina and Nanopore sequencing to analyze the genomes of 10 Acinetobacter isolates representing 6 different species sourced from aquatic environments in South Australia. All 10 isolates were phylogenetically distinct compared to clinical and other non-clinical Acinetobacter strains, often tens of thousands of single-nucleotide polymorphisms from their nearest neighbors. Despite the genetic divergence, we identified p dif modules (sections of mobilized DNA) carrying clinically important antimicrobial resistance genes in species other than A. baumannii , including carbapenemase oxa58, tetracycline resistance gene tet(39 ), and macrolide resistance genes msr(E)-mph(E ). These p dif modules were located on plasmids with high sequence identity to those circulating in globally distributed A. baumannii ST1 and ST2 clones. The environmental A. baumannii isolate characterized here (SAAb472; ST350) did not possess any native plasmids; however, it could capture two clinically important plasmids (pRAY and pACICU2) with high transfer frequencies. Furthermore, A. baumannii SAAb472 possessed virulence genes and a capsular polysaccharide type analogous to clinical strains. Our findings highlight the potential for environmental Acinetobacter species to acquire and disseminate clinically important antimicrobial resistance genes, underscoring the need for further research into the ecology and evolution of this important genus. IMPORTANCE Antimicrobial resistance (AMR) is a global threat to human, animal, and environmental health. Studying AMR in environmental bacteria is crucial to understand the emergence and dissemination of resistance genes and pathogens, and to identify potential reservoirs and transmission routes. This study provides novel insights into the genomic diversity and AMR potential of environmental Acinetobacter species. By comparing the genomes of aquatic Acinetobacter isolates with clinical and non-clinical strains, we revealed that they are highly divergent yet carry p dif modules that encode resistance to antibiotics commonly used in clinical settings. We also demonstrated that an environmental A. baumannii isolate can acquire clinically relevant plasmids and carries virulence factors similar to those of hospital-associated strains. These findings suggest that environmental Acinetobacter species may serve as reservoirs and vectors of clinically important genes. Consequently, further research is warranted to comprehensively understand the ecology and evolution of this genus.

Antimicrobial resistance (AMR) - the ability of microorganisms to adapt and survive under diverse chemical selection pressures - is influenced by complex interactions between humans, companion and food-producing animals, wildlife, insects and the environment. To understand and manage the threat posed to health (human, animal, plant and environmental) and security (food and water security and biosecurity), a multifaceted 'One Health' approach to AMR surveillance is required. Genomic technologies have enabled monitoring of the mobilization, persistence and abundance of AMR genes and mutations within and between microbial populations. Their adoption has also allowed source-tracing of AMR pathogens and modelling of AMR evolution and transmission. Here, we highlight recent advances in genomic AMR surveillance and the relative strengths of different technologies for AMR surveillance and research. We showcase recent insights derived from One Health genomic surveillance and consider the challenges to broader adoption both in developed and in lower- and middle-income countries. Antimicrobial resistance (AMR) is an important public health issue that affects human, animal and environmental sectors worldwide. The authors review the role of genomics in AMR surveillance using a One Health approach, and how genomic approaches can help mitigate the spread of AMR to improve global health.

Antimicrobial resistance (AMR) is a major public health concern, and environmental bacteria have been recognized as important reservoirs of antimicrobial resistance genes (ARGs). Citrobacter, a common environmental bacterium and opportunistic pathogen in humans and other animals, has been largely understudied interms of its diversity and AMR potential. Whole-genome (short-read) sequencing on a total of 77 Citrobacter isolates obtained from Australian silver gull (Chroicocephalus novaehollandiae) (n = 17) and influent wastewater samples (n = 60) was performed, revealing a diverse Citrobacter population, with seven different species and 33 sequence types, 17 of which were novel. From silver gull using non-selective media we isolated a broader range of species with little to no mobilised ARG carriage. Wastewater isolates (selected using Carbapenem-Resistant Enterobacterales (CRE) selective media) carried a heavy burden of ARGs (up to 21 ARGs, conferring resistance to nine classes of antibiotics), with several novel multidrug-resistant (MDR) lineages identified, including C. braakii ST1110, which carried ARGs conferring resistance to eight to nine classes of antibiotics, and C. freundii ST1105, which carried two carbapenemase genes, blaIMP-4 in class 1 integron structure, and blaKPC-2. Additionally, we identified an MDR C. portucalensis isolate carrying blaNDM-1, blaSHV-12, and mcr-9. We identified IncC, IncM2, and IncP6 plasmids as the likely vectors for many of the critically important mobilised ARGs. Phylogenetic analyses were performed to assess any epidemiological linkages between isolation sources, demonstrating low relatedness across sources beyond the ST level. However, these analyses did reveal some closer relationships between strains from disparate wastewater sources despite their collection some 13,000 km apart. These findings support the need for future surveillance of Citrobacter populations in wastewater and wildlife populations to monitor for potential opportunistic human pathogens.

Antimicrobial resistance (AMR) is a complex challenge that poses a critical threat to food and water safety and security as well as to human, animal and environmental health. It is projected to cost the global economy US$100 trillion by 2050. Australia’s new Cooperative Research Centre (CRC) for Solving Antimicrobial Resistance in Agribusiness, Food and Environments (SAAFE) is part of Australia’s One Health approach to mitigating AMR. SAAFE’s 10-year, A$150-million industry-led program will help protect Australia’s food and agribusiness industries, and the environments in which they operate, from the growing threat of AMR. Through its research programs, CRC SAAFE uses a partner-based approach to assist industries to monitor, analyse and mitigate AMR, with projects spanning horticulture, viticulture, aquaculture, animal industries, water and waste.

Flocs produced during drinking water treatment play a key role in particle separation and removal. Floc characteristics affect both sedimentation and filtration efficiency, however, the methods used to optimise the coagulant dose during treatment do not usually take these into account. This study investigated the feasibility of using the Flocculation Index (FI), obtained from a photometric dispersion analyser (PDA) during flocculation, as a control parameter to optimise turbidity removal. Five waters, natural and synthetic, with different turbidity levels (from 6 to -120 NTU) and low DOC (i.e., <5 mg/L) were used to study the effects of various alum doses on floc characteristics [i.e., initial floc aggregation (IFA), plateau (P) and variance (VAR)]. No correlation was found between the IFA and VAR values and the alum dose achieving the greatest turbidity removal and relative settling factor (RSF). However, P followed a similar pattern to the RSF, and was negatively correlated with the residual turbidity. An optimisation model was developed using response surface methodology and the effects of two independent variables (i.e., raw turbidity and alum dose) on P values were investigated. The model achieved a high correlation (R2 of -98 %, p-value <0.05) and was validated using waters with different turbidity levels. It predicted the alum dose within 8 % error. The results indicate that the FI can be used as an alternative parameter for optimising the coagulation process.

Effective extraction and detection of viral nucleic acids from sewage are fundamental components of a successful SARS-CoV-2 sewage surveillance programme. As there is no standard method employed in sewage surveillance, understanding the performance of different extraction kits in the recovery of SARS-CoV-2 and the impact that PCR inhibitors have on quantification is essential to minimize data discrepancies caused by sample extraction. Three commercial nucleic acid extraction kits: the RNeasy PowerSoil Total RNA Kit (PS), the RNeasy PowerMicrobiome Kit (PMB), and the MagMAX™ Microbiome Ultra Nucleic Acid Isolation Kit (MM), with minor modifications, were evaluated. Their efficacy in recovering viral ribonucleic acid and removal of PCR inhibitors was assessed using two South Australian wastewater matrices-one from a major metropolitan site and one from a regional centre. Both had SARS-CoV-2 present due to active COVID-19 cases in these communities. Overall, the MM kit had a higher recovery of SARS-CoV-2 from the samples tested, followed by PMB and PS. The PMB kit performance was strongly influenced by the sample matrix when compared to the MM kit. It is recommended to assess the performance of extraction kits using different local wastewater matrices to ensure the accuracy and reliability of monitoring results to avoid false reporting.

Pesticides play an important role in conventional agriculture by controlling pests, weeds, and plant diseases. However, repeated applications of pesticides may have long lasting effects on non-target microorganisms. Most studies have investigated the short-term effects of pesticides on soil microbial communities at the laboratory scale. Here, we assessed the ecotoxicological impact of fipronil (insecticide), propyzamide (herbicide) and flutriafol (fungicide) on (i) soil microbial enzymatic activities, (ii) potential nitrification, (iii) abundance of the fungal and bacterial community and key functional genes (nifH, amoA, chiA, cbhl and phosphatase) and (iii) diversity of bacteria, fungi, ammonia oxidizing bacteria (AOB) and archaea (AOA) after repeated pesticide applications in laboratory and field experiments. Our results showed that repeated applications of propyzamide and flutriafol affected the soil microbial community structure in the field and had significant inhibitory effects on enzymatic activities. The abundances of soil microbiota affected by pesticides recovered to levels similar to the control following a second application, suggesting that they might be able to recover from the pesticide effects. However, the persistent pesticide inhibitory effects on soil enzymatic activities suggests that the ability of the microbial community to cope with the repeated application was not accompanied by functional recovery. Overall, our results suggest that repeated pesticide applications may influence soil health and microbial functionalities and that more information should be collected to inform risk-based policy development.

Avian gut microbial communities are complex and play a fundamental role in regulating biological functions within an individual. Although it is well established that diet can influence the structure and composition of the gut microbiota, foraging behaviour may also play a critical, yet unexplored role in shaping the composition, dynamics, and adaptive potential of avian gut microbiota. In this review, we examine the potential influence of coprophagic foraging behaviour on the establishment and adaptability of wild avian gut microbiomes. Coprophagy involves the ingestion of faeces, sourced from either self (autocoprophagy), conspecific animals (allocoprophagy), or heterospecific animals. Much like faecal transplant therapy, coprophagy may (i) support the establishment of the gut microbiota of young precocial species, (ii) directly and indirectly provide nutritional and energetic requirements, and (iii) represent a mechanism by which birds can rapidly adapt the microbiota to changing environments and diets. However, in certain contexts, coprophagy may also pose risks to wild birds, and their microbiomes, through increased exposure to chemical pollutants, pathogenic microbes, and antibiotic-resistant microbes, with deleterious effects on host health and performance. Given the potentially far-reaching consequences of coprophagy for avian microbiomes, and the dearth of literature directly investigating these links, we have developed a predictive framework for directing future research to understand better when and why wild birds engage in distinct types of coprophagy, and the consequences of this foraging behaviour. There is a need for comprehensive investigation into the influence of coprophagy on avian gut microbiotas and its effects on host health and performance throughout ontogeny and across a range of environmental perturbations. Future behavioural studies combined with metagenomic approaches are needed to provide insights into the function of this poorly understood behaviour.

Insufficient dissolved organic matter removal results in higher residual organics (measured as dissolved organic carbon, DOC) in the treated water which can act as precursors for disinfection by-products (DBPs) and consequently increases the potential for health risk. This study aims to use drinking water treatment sludge (DWTS) as a coagulant-aid to improve the DOC removal efficiency. The effect of various DWTS doses (between 0.5 and 3 g/L) on the coagulation performance (by alum) to treat natural surface water that has relatively low turbidity and high DOC at optimum pH (similar to 6) was examined using standard jar tests procedure. Although addition of DWTS at doses lower than 1.5 g/L improved the DOC removal efficiency (by 4% and 12% at DWTS dose of 0.5 and 1.0 g/L, respectively), the turbidity levels increased. In comparison to optimum dose of alum without DWTS, the addition of DWTS at 3 g/L led to reduce the alum dose to similar to 50% to achieve similar removal efficiency of organics (70% DOC removal). Further, addition of DWTS improved the floc's characteristics (achieve larger flocs and rapid growth rate; measured by photometric dispersion analyser, PDA) and settling rate significantly, and the produced sludge volume decreased by similar to 50% compared to the figure with no DWTS addition. Trihalomethane formation potential (THMFP) was also reduced (up to similar to 30%) when DWTS used. The results indicate that DWTS reuse as a coagulant-aid has the potential to reduce DOC and control DBPs formation when the organic loads require high coagulant dose exceeding the WTP design limits.

Ultrafiltration (UF) was assessed at chemical, microbiological, genetical and toxicological level and in terms of removing specific antibiotic-related microcontaminants from urban wastewater. The UF capacity to remove various antibiotics (clarithromycin, erythromycin, ampicillin, ofloxacin, sulfamethoxazole, trimethoprim, and tetracycline; [A0] = 100 μg L-1) was optimised with respect to the feed recirculation rate (25-50%) and feed/transmembrane pressure (1.5-3/1.5-2.4 bar, respectively). Here, we tested the UF capacity to reduce the cultivable bacteria (faecal coliforms, total heterotrophs, Enterococci, Pseudomonas aeruginosa), enteric opportunistic pathogens, including antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) load. Moreover, the toxicity towards Daphnia magna and three plant species was investigated. Upon optimisation of UF, the removal of antibiotics ranged from 19% for trimethoprim to 95% for clarithromycin. The concentration of cultivable faecal coliforms in the permeate was significantly reduced compared to the feed (P < 0.001), whereas all the bacterial species decreased by more than 3 logs. A similar pattern of reduction was observed for the ARGs (P < 0.001) and enteric opportunistic pathogens (~3-4 logs reduction). A nearly complete removal of the antibiotics was obtained by UF followed by granular activated carbon adsorption (contact time: 90 min), demonstrating the positive contribution of such combination to the abatement of chemical microcontaminants.

Strategies for remediation of per- and polyfluoroalkyl substances (PFAS) generally prioritise highly contaminated source areas. However, the mobility of PFAS in the environment often results in extensive low-level contamination of surface waters across broad areas. Constructed Floating Wetlands (CFWs) promote the growth of plants in buoyant structures where pollutants are assimilated into plant biomass. This study examined the hydroponic growth of Juncus krausii, Baumea articulate and Phragmites australis over a 28-day period for remediation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) contaminated (0.2 mu g/L to 30 mu g/L) urban stormwater. With increasing PFOA and PFOS concentrations, accumulation in plant species increased although root and shoot distribution varied depending on PFAS functional group. Less PFOA than PFOS accumulated in plant roots (0.006-0.16 versus 0.008-0.68 mu g/g), while more PFOA accumulated in the plant shoots (0.02-0.55 versus 0.01-0.16 mu g/g) indicating translocation to upper plant portions. Phragmites australis accumulated the highest overall plant tissue concentrations of PFOA and PFOS. The NanoSIMS data demonstrated that PFAS associated with roots and shoots was absorbed and not just surface bound. These results illustrate that CFWs have the potential to be used to reduce PFAS contaminants in surface waters.

Antimicrobial resistance (AMR) poses a global public health threat, and the increase in resistance to “last-resort drugs,” such as carbapenems, is alarming. Wastewater has been flagged as a hot spot for AMR evolution. Comamonas spp. are among the most common bacteria in wastewater and play a role in its bioaugmentation.