Background/Objectives: Short-term low-fermentable oligo-, di-, and monosaccharide and polyol (FODMAP) diets can reduce exercise-associated gastrointestinal symptoms (Ex-GIS); however, their effects on the gut microbiome, short-chain fatty acids (SCFAs), and gastrointestinal biomarkers remain unclear. This study explored the effects of 48 h dietary FODMAP manipulation within a high-carbohydrate diet on faecal bacterial and SCFA profiles, and their relationships with exercise-induced gastrointestinal syndrome (EIGS) biomarkers, Ex-GIS, and performance. Methods: Twelve endurance athletes experiencing Ex-GIS were randomly allocated to a 48 h high-carbohydrate (mean ± SD: 12.1 ± 1.8 g∙d-1)-high-FODMAP (HC-HFOD) (54.8 ± 10.5 g∙d-1) and a 48 h high-carbohydrate-low-FODMAP (HC-LFOD) (3.0 ± 0.2 g∙d-1) diet before 2 h of running at 60% V˙O2max, followed by a 1 h distance test (22.9 ± 1.2 °C, 46 ± 8% RH). Baseline faecal samples were collected before exercise trials to determine faecal bacterial and SCFA profiles. Blood samples were collected pre- and post-exercise to determine plasma I-FABP, sCD14, and CRP concentrations. Ex-GIS were recorded every 15 min throughout exercise. Results: Faecal bacterial α-diversity and relative abundance (RA%) at the phylum level were unchanged following both diets, while several family- and genus-level taxa RA% values were changed (p < 0.05), with greater shifts after HC-HFOD. HC-HFOD significantly increased faecal total-SCFA (p = 0.004), acetic (p = 0.002), and butyric (p = 0.028) acid concentrations. Strong positive and negative correlations between bacterial RA% and EIGS biomarkers and Ex-GIS were observed. Strong negative correlations with bacterial RA% and performance were observed. Conclusions: The 48 h HC-HFOD resulted in greater increases in bacterial RA% and SCFA concentrations compared with baseline. Bacterial RA% correlated bidirectionally with EIGS biomarkers and Ex-GIS, alongside strong negative associations with performance.
To evaluate the suitability of water environments for water-based recreation, water quality guidelines rely on a risk framework based on the quantification of faecal indicator bacteria (FIB), and sanitary surveys. The purpose of sanitary surveys is to identify the sources of faecal pollution and their likelihood to contaminate the water environment. In general, FIBs such as enterococci are assumed to be primarily human-derived; an assumption that can lead to a disconnect between measured FIB levels and the broader site context, particularly in environments with multiple faecal sources. As a result, the framework often struggles to accurately link microbial contamination to specific sources and risks. This study investigates the application of community-based microbial source tracking (MST) with adjustment of FIB concentrations, via metaMST, to generate source-specific FIB profiles for eight Australian beaches. Results demonstrated that metaMST source proportioning could attribute enterococci levels across multiple faecal sources, better reflecting the reality of mixed catchments inputs. MetaMST analysis also revealed dynamic relationships between enterococci and antecedent rainfall, varying by source and site. However, sanitary surveys, when not conducted concurrently with metaMST sampling, often failed to capture site-specific spatial and temporal variability. In combination it was demonstrated that through integration of metaMST, hazard identification becomes more precise, enabling better-informed risk assessments and mitigation strategies that can better inform long-term management of risks to recreational water quality, in addition to reduced public health alerts associated with faecal contamination in recreational waters.
IntroductionMonitoring of drinking water sources is an essential component of broader public health practise. However, routine water monitoring programmes that follow established methodological standards, such as low-volume grab sampling with standard filtration, have limitations in being representative. Particularly for protected source waters where (wildlife introduced) pathogens are in low concentration and are not evenly distributed. Microbial source tracking (MST) offers a promising approach to close this gap, enabling more precise identification of faecal contamination sources and their associated risk. However, as with other culture- and molecular-based approaches, the sensitivity of MST is constrained by sample capture methodology, limited by sample volume, timing, and randomness of grab sampling.MethodsThis study investigated the application of a high-volume sample concentration method (EasyElute ultrafiltration) to enhance microbial recovery from source water. All evaluation was conducted alongside standard grab sampling and filtration methods. Post-concentration analyses combined traditional culture-based quantification of faecal indicator organisms (FIOs) and reference pathogens, with 16S rRNA amplicon MST to provide an integrated approach to surveillance of animal-derived microbial risks in forested water supply catchments.ResultsThe results demonstrated that high-volume ultrafiltration enhanced bacterial recovery from source water samples, although turbidity was observed to limit overall efficiency, highlighting potential operational challenges. Comparative analysis demonstrated that amplicon-based MST produced consistent faecal source attribution across both standard and ultrafiltration methods, showing greater sensitivity at increasing volumes.DiscussionThis study advances MST methodology by demonstrating the feasibility and added sensitivity achievable through high-volume, concentrated sample collection approaches. This is particularly relevant where water samples are expected to carry low microbial loads, ultimately offering a practical approach for improving faecal source tracking and risk assessment for water sources to protect public health in water supply catchments.
This study evaluates the use of passive samplers containing passive materials and qPCR array cards to understand the microbial quality of stormwater and constructed wetlands. Passive samplers were deployed at the inlet and outlet of a stormwater-constructed wetland alongside paired water sample collection, all of which indicated high fecal contamination and human wastewater inputs. Passive materials demonstrated good performance for frequently detected enteric bacteria (e.g., Campylobacter spp.) and surrogate viruses (e.g., CrAssphage), but showed mixed performance for protozoa (e.g., Cryptosporidium spp.). Logistic regression indicated a significant interactive effect between material and location (p < 0.01), but further analysis indicated that location was likely a proxy for turbidity, significantly different between the inlet and outlet (p < 0.01). Some passive materials performed better at the inlet, which had a median turbidity of 20.6 NTU (e.g., cotton-based materials for Campylobacter spp.), while others were better at the outlet, with a median turbidity of 90.15 NTU (e.g., electronegative membrane for Campylobacter spp. and crAssphage, swab for crAssphage, and gauze for Cryptosporidium spp.). Passive sampling is a promising approach for continuously sampling urban stormwater to monitor and manage pathogen risks. Further research should compare composite samples and passive materials to evaluate target attachments during rainfall events.
Integration of water monitoring and disease reporting systems is crucial for addressing the interconnected challenges of human, animal, and environmental health. Enteric pathogens introduced into water systems via faecal contamination pose persistent public health risks, particularly in recreational and drinking water sources. Using Australia as a case study, this review examines data collection protocols, surveillance efforts, and reporting guidelines across health and water sectors, identifying gaps and opportunities for improving collaboration nationally and internationally. We collated national and jurisdictional notifiable disease guidelines and notification forms to evaluate data collection and reporting. Drinking and recreational water guidelines and public-facing water surveillance programmes were also reviewed to evaluate monitoring practices, data collection, and accessibility. Findings revealed disparities in pathogen reporting between water and health sectors. Most monitoring guidelines relied on outdated data, failing to reflect contemporary risks and analytical advancements. Clinical disease reporting also lacked adequate waterborne pathogen metadata collection, limiting outbreak tracking. We identified opportunities to enhance data integration and cross-sector collaboration, potentially enabling clinicians, decision-makers, and the public to utilise data on recreational water environments and waterborne infections more effectively. This review underscores the need for greater coordination between water and health sectors, with broader implications for global health surveillance.
Rapid urbanization leads to the growth of informal settlements, where inadequate sanitation infrastructure is common, thus promoting environmental contamination and risk of gastrointestinal infection. Soil contamination contributes to the transmission of enteropathogens, but traditional sampling approaches may poorly indicate public health risks due to limited spatial representation. This study compares traditional grab sampling of soil with a boot sock method, a composite technique designed to better reflect human-pathogen interactions. The boot sock method provided more sensitive detection of E. coli and lower inter-replicate variation compared to grab samples. Post hoc power analyses indicated that the boot sock technique required fewer samples to achieve adequate spatial representation across a sampling area than grab samples, potentially improving time and cost efficiency in pathogen exposure risk estimation.
Rapid and efficient bacterial lysis is crucial for point-of-care diagnostics, environmental monitoring, and integrated analytical platforms. However, conventional lysis methods often involve trade-offs between lysis efficiency, biomolecule integrity, and workflow complexity. Here, we present a reagent-free, non-thermal acoustofluidic platform that uses bulk acoustic waves (BAWs) to rapidly lyse both Gram-negative and Gram-positive bacteria via high energy acoustic streaming and localised shear forces. The method achieved lysis efficiencies of ∼82 % for Escherichia coli and ∼50 % for Enterococcus faecalis within milliseconds, evaluated by colony counting, live/dead imaging, and DNA quantification. We integrated Fourier transform infrared (FT-IR) spectroscopy for downstream biomolecular characterisation, revealing enhanced spectral intensities of proteins, nucleic acids, and lipids following lysis. PCR amplification of the 16S rRNA gene and protein quantification further confirmed the integrity and compatibility of lysed samples with standard downstream assays. This streamlined, reagent-free, and scalable approach for bacterial cell disruption minimises sample preparation and contamination risks, making it ideal for miniaturised, integrated platforms. With applications in clinical diagnostics and environmental monitoring, our approach demonstrates the potential to overcome current challenges in bacterial lysis and molecular analysis.
Quantification of faecal indicator organism (FIO) is essential for surveillance monitoring, performance compliance and public health interventions. IDEXX's automated FIO detection technique, TECTATM, and IDEXX Colilert offer greater efficiency than traditional methods but have not been critically compared across diverse levels of faecal contamination or evaluated against key practical requirements and cost factors. This study compared the use of IDEXX Colilert and TECTATM for measuring indicative contamination in 785 samples from drinking water, wells, surface water, greywater and a constructed wetland system, collected from Fijian and Indonesian informal settlements. Both methods ranked sample types in the same order in terms of indicative faecal contamination, and at Escherichia coli (E. coli) concentrations between <1-105 CFU or MPN/100 mL (municipal, shallow and deep well samples), both methods were highly correlated. However, at 102-109 CFU/100 mL (TECTATM) or 102-106 MPN/100 mL (IDEXX Colilert) E. coli (surface water samples), a moderate positive correlation was observed (R = 0.56, p = 2.2-13), and a high proportion of samples exceeded the detection limit of the IDEXX Colilert method. Greywater and septic tank samples exhibited total coliform mean values greater than 106 CFU/ 100 mL, with no correlation between IDEXX Colilert and TECTATM results. TECTATM required only one dilution for returning specific E. coli values, ideal for performance compliance and faecal contamination assessments, while IDEXX Colilert often needed two levels of dilution. For surveillance purposes, IDEXX Colilert may be more cost-effective given the higher initial setup costs of TECTATM; however, TECTATM's faster turnaround times and automated results may offset expenses. This study presents a versatile decision analysis that enables laboratories worldwide to customise method comparisons based on their unique requirements, driving more effective implementation and global standardisation of these methods.
Motivation:Understanding the quality of the source library prior to undertaking library-dependent microbial source-tracking (MST) is an essential, but often overlooked, primary analysis step. Results:We propose an assessment approach to validate the quality of amplicon-derived faecal source libraries. This approach was demonstrated on a faecal source library consisting of 16S rRNA paired-end amplicon sequences, obtained from various animal types in Victoria, Australia. First, a leave-one-out (LOO) analysis was performed to assess the accuracy of source category groupings by identifying the number of samples incorrectly assigned to a different source category (i.e. animal type). Following a quality control procedure to decide retaining/removing/grouping incorrectly assigned samples, we then assessed if the sample sizes for each source type were sufficient to properly characterize the source fingerprints. Results from LOO demonstrated 15.5% of samples were incorrectly assigned, with high error rates in birds and wallabies within our source library. Increasing the sample size improved source identification accuracy. However, accuracy eventually plateaued in a source-specific manner. Importantly, this highlights the importance of conducting thorough assessments to understand the quality and limitations of the source library prior to library-dependent MST applications. Availability and implementation:QIIME2 is available via https://qiime2.org/; SourceTracker v2.0.1 is available via https://github.com/caporaso-lab/sourcetracker2; Pipeline for LOO is available via https://github.com/MonashOWL/Bioinformatics-IlluminaMGI/tree/main/16S/LOO; Pipeline for sample size assessment is available via https://github.com/MonashOWL/Bioinformatics-IlluminaMGI/tree/main/16S/Source%20variability.
Human fecal waste is a global health risk associated with diarrheal diseases, responsible for approximately 1.2 million deaths annually. Microbial Source Tracking (MST) is a molecular method that evaluates environmental sources of fecal contamination, aiding quantification of this contamination and associated health risks. However, reported variations in global human gut microbiomes and geographic performance of human-specific fecal markers suggest that current MST targets may not have broad applicability across populations. This systematic review quantified the performance of human-specific fecal markers to identify those suitable for use across various geographic regions. We evaluated data from primary research articles, published before 18th October 2023, identified through PubMed, Scopus, and Web of Science using PRISMA guidelines. 103 studies published between 1995 and 2023, spanning 34 countries, 6 continents, and 4 climate zones met inclusion criteria, with quantifiable performance metrics (sensitivity, specificity or accuracy) and a geographic testing location. Extracted data was analyzed to establish marker performance across geographic locations, climate zones, and development status. Over 80% were conducted in High-Income Countries (HICs) and >50% in temperate zones, primarily in the USA (43%), Australia (24%), and Spain (19%). Bacteroides HF183 was the most commonly tested (n = 45 studies). However, no target consistently demonstrated sensitivity, specificity, and/or accuracy >80% across different settings. Consequently, a decision tree is presented supporting selection of appropriate human-specific markers for regional-specific baseline studies. This provides critical information to support new MST research, particularly in Low- and Middle-Income Countries (LMICs), assisting with informed decision and method selection for assessing risks of faecal derived pathogens.
Background/Objectives: This exploratory study aimed to evaluate the impact of an 80 km ultra-marathon trail running event on changes in faecal bacterial composition, and to investigate whether any correlations exist between exercise-associated gastrointestinal symptoms (Ex-GIS) with faecal bacterial profiles. Such events represent a unique physiological stressor and may impact the composition of the gut microbiota. Studying this impact may provide insights into acute (i.e., <24 h) gut microbiota changes under extreme conditions. Methods: Thirteen endurance athletes (n = 7 males, n = 6 females) aged 41 ± 8 years completed the 80 km Margaret River (Australia) ultra-marathon race in 2022. Faecal samples were collected pre- and post-race. Faecal bacterial profile, as per relative abundance (RA) of operational taxonomic units and the determination of α-diversity (Shannon Equitability Index (SEI)), was achieved by 16S rRNA amplicon gene sequencing. Changes in RA% and SEI pre- to post-race were assessed by the Wilcoxon signed-rank test. Correlations between Ex-GIS with bacterial profile and changes pre-, during, and post-ultra-marathon race were determined by Spearman’s rank correlation coefficients. Results: Bacterial calculations of phyla (n = 5), family (n = 23), and genus (n = 41) were detected for RA (≥0.5%). A significant decrease pre- to post-race of Actinobacteriota (p = 0.035) phyla, Bifidobacteriaceae (p = 0.007), and Clostridiaceae (p = 0.010) family, and Blautia (p = 0.039) and Subdoligranulum (p = 0.023) genus was determined; meanwhile, Oscillospiraceae (p = 0.016) and Monoglobaceae (p = 0.039) family significantly increased pre- to post-race. No other bacterial group changes were observed. No correlations were observed between pre- to post-ultra-marathon RA change and Ex-GIS. Conclusions: The completion of an 80 km ultra-marathon did not invoke substantial changes in the gut microbiota as determined by faecal bacterial profiling. Very strong and strong correlations were observed between certain bacterial groups and Ex-GIS; however, no significant correlations were observed between pre- to post-ultra-marathon changes in RA ≥ 0.5% and Ex-GIS.
The number, scale and ambition of transdisciplinary research initiatives between the global north and the global south is increasing, yet there is very little theoretical or empirical scholarship on how to lead and manage implementation to promote responsible practice. Within science, technology and innovation (STI) studies and decolonising research frameworks, and utilising collaborative autoethnography, this study codifies experience with implementing the 'Revitalising Informal Settlements and their Environments' (RISE) program (2017-2020). Our specific aim is to explore the leadership and management tensions and challenges of implementing transboundary transdisciplinary research. The findings reaffirm the importance of research leaders and managers carefully operationalising north-south research by critically reflecting on power asymmetries between disciplines, partners and locations, leveraging the potential for transdisciplinary consortia to build research capabilities in the global south, and creating a culture of reflexivity on the historical and social positionality in which research is designed, funded, implemented and evaluated. The findings foreground the role of boundary-spanning 'integrators' and 'pracademics', roles that have received little attention to date but are essential for effective delivery and societal impact beyond scientific advances. A framework for implementing north-south transdisciplinary research is outlined with five domains: (1) collaborative leadership; (2) agile management; (3) flexible consortia; (4) researcher positionality; and (5) co-design and participation. The framework can support efforts for responsibly designing and implementing large, transdisciplinary, cross-country research programs in line with ambitions for decolonising north-south research.
Enumeration of Campylobacter from environmental waters can be difficult due to its low concentrations, which can still pose a significant health risk. Spectrophotometry is an approach commonly used for fast detection of water-borne pollutants in water samples, but it has not been used for pathogen detection, which is commonly done through a laborious and time-consuming culture or qPCR Most Probable Number enumeration methods (i.e., MPN-PCR approaches). In this study, we proposed a new method, MPN-Spectro-ML, that can provide rapid evidence of Campylobacter detection and, hence, water concentrations. After an initial incubation, the samples were analysed using a spectrophotometer, and the spectrum data were used to train three machine learning (ML) models (i.e., supported vector machine - SVM, logistic regression-LR, and random forest-RF). The trained models were used to predict the presence of Campylobacter in the enriched water samples and estimate the most probable number (MPN). Over 100 stormwater, river, and creek samples (including both fresh and brackish water) from rural and urban catchments were collected to test the accuracy of the MPN-Spectro-ML method under various scenarios and compared to a previously standardised MPN-PCR method. Differences in the spectrum were found between positive and negative control samples, with two distinctive absorbance peaks between 540-542nm and 575-576nm for positive samples. Further, the three ML models had similar performance irrespective of the scenario tested with average prediction accuracy (ACC) and false negative rates at 0.763 and 13.8%, respectively. However, the predicted MPN of Campylobacter from the new method varied from the traditional MPN-PCR method, with a maximum Nash-Sutcliffe coefficient of 0.44 for the urban catchment dataset. Nevertheless, the MPN values based on these two methods were still comparable, considering the confidence intervals and large uncertainties associated with MPN estimation. The study reveals the potential of this novel approach for providing interim evidence of the presence and levels of Campylobacter within environmental water bodies. This, in turn, decreases the time from risk detection to management for the benefit of public health.
Objectives: The primary aim was to explore the impact of exertional-heat stress (EHS) promoted exerciseassociated bacteraemia. A secondary aim was to examine if an amino acid beverage (AAB) intervention may mitigate exercise-associated bacteraemia. Design: Counterbalanced randomised control trial. Methods: Twenty endurance trained male participants completed two randomised EHS trials. On one occasion, participants consumed a 237 mL AAB twice daily for 7 days prior, immediately before and every 20 min during EHS (2 h running at 60 % VO2max in 35 degrees C). On the other occasion, a water volume control (CON) equivalent was consumed. Whole blood samples were collected pre- and immediately post-EHS, and were analysed for plasma DNA concentration by fluorometer quantification after microbial extraction, and bacterial relative abundance by next generation 16s rRNA gene sequencing. Results: Increased concentration of microbial DNA in plasma pre- to post-EHS was observed on CON (pre-EHS 0.014 ng/mu L, post-EHS 0.039 ng/mu L) (p < 0.001) and AAB (pre-EHS 0.015 ng/L, post-EHS 0.031 ng/mu L) (p < 0.001). The magnitude of change from pre- to post-exercise on AAB was 40 % lower, but no significant difference was observed versus CON (p = 0.455). Predominant bacterial groups identified included: phyla-Proteobacteria (88.0 %), family-Burkholderiaceae (59.1 %), and genus-Curvibacter (58.6 %). No significant variation in absolute and relative change in alpha-diversity and relative abundance for phyla, family, and genus bacterial groups was observed in AAB versus CON. Conclusions: The increased presence of microbial-bacterial DNA in systemic circulation in response to EHS appears positive in all participants. An amino acid beverage supplementation period prior to and consumption during EHS did not provide significant attenuation of EHS-associated bacteraemia. (c) 2024 The Authors. Published by Elsevier Ltd on behalf of Sports Medicine Australia. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Pathogenic and antimicrobial-resistant (AMR) microorganisms are continually transmitted between human, animal, and environmental reservoirs, contributing to the high burden of infectious disease and driving the growing global AMR crisis. The sheer diversity of pathogens, AMR mechanisms, and transmission pathways connecting these reservoirs create the need for comprehensive cross-sectoral surveillance to effectively monitor risks. Current approaches are often siloed by discipline and sector, focusing independently on parts of the whole. Here we advocate that integrated surveillance approaches, developed through transdisciplinary cross-sector collaboration, are key to addressing the dual crises of infectious diseases and AMR. We first review the areas of need, challenges, and benefits of cross-sectoral surveillance, then summarise and evaluate the major detection methods already available to achieve this (culture, quantitative PCR, and metagenomic sequencing). Finally, we outline how cross-sectoral surveillance initiatives can be fostered at multiple scales of action, and present key considerations for implementation and the development of effective systems to manage and integrate this information for the benefit of multiple sectors. While methods and technologies are increasingly available and affordable for comprehensive pathogen and AMR surveillance across different reservoirs, it is imperative that systems are strengthened to effectively manage and integrate this information.
Stormwater biofilters demonstrate promising treatment of faecal microorganisms, however performance can vary with design and operational conditions. This study investigated whether plants with significant documented antimicrobial activity could improve faecal bacterial treatment within biofilters. Laboratory-scale biofilters (n = 30) were dosed with synthetic stormwater containing faecal bacteria Escherichia coli, Enterococcus faecalis and Campylobacter jejuni under south-eastern Australian climatic conditions. Systems vegetated with Melaleuca species, renowned for their in vitro antimicrobial activity, consistently enhanced removal of all tested culturable bacteria in total outflow and submerged zone water relative to other plant configurations. Within just 1-2 days of stormwater dosing, M. linariifolia submerged zones demonstrated significantly reduced bacterial concentrations compared to C. appressa (p = 0.023 and <0.001 for C. jejuni and E. coli, respectively), removing ∼1.47 log10 MPN/100 mL E. coli, ∼1.14 log10 MPN/100 mL E. faecalis and ∼0.81 log10 MPN/L C. jejuni from inflow. These trends continued even after all but one M. linariifolia replicate perished during an extended drying period (p = 0.002 and 0.003 for C. jejuni and E. coli, respectively). Through a systematic process of elimination, these observations were attributed to enhanced bacterial attenuation with elevated plant inhibitory activity. Cumulative biofilter age reinforced plant-mediated bacterial treatment (p = 0.023 for E. faecalis), ostensibly due to increased plant size/growth and net biological activity. Notably, E. coli and E. faecalis attenuation improved with prolonged antecedent drying length (14 vs. 4 days; p < 0.0001 for both), while the converse was observed for C. jejuni (not significant). This study addresses significant knowledge gaps around plant-mediated faecal microbe treatment within biofilters, providing key direction for real-world system design to optimise stormwater pathogen treatment.
Harnessing prokaryotes’ metabolic capacity and adaptive potential is of interest for environmental bioremediation and biological treatment of domestic and industrial waste. Bioaugmentation is commonly implicated in the cleanup of high-dosed environmental pollution. In this study, Arthrobacter aurescens TC1 was used to augment biofiltration systems for bioremediation of stormwater micropollutant. Bioaugmentation was tested on non-vegetated and vegetated system designs, with or without an adsorbent biocarrier [granulated activated carbon (GAC)]. This study investigated how system design affects microbial function and structure. It focused on long-term metabolic responses of the biofilter’s microbiome to low chronic exposure to the herbicide atrazine and fluctuations in atrazine load. Shotgun metagenomics analyses demonstrated that the major contributor to microbiome structure was the supplementation of GAC. Vegetation affected microbiome structure mainly in sand biofilter-media. GAC showed a significant shift in atrazine-degrading genes over time compared to sand. Diversity and richness increased with time in all system designs, regardless of atrazine load fluctuations. To conclude, incorporating GAC in stormwater-biofiltration systems effectively enhances the micropollutant-biodegradation capacity in stormwater with negligible effects on the biofilter’s microbiome diversity and function.