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Aims This study aims to identify and address significant limitations in current culture-based regulatory methods used for monitoring microbiological water quality. Specifically, these methods' inability to distinguish between planktonic forms and aggregates containing higher bacterial loads and associated pathogens may lead to a severe underestimation of exposure risks, with critical public health implications. Methods and results We employed a novel methodology combining size fractionation with ALERT (Automatic Lab-in-a-vial E.coli Remote Tracking), an automated rapid method for comprehensive quantification of culturable fecal indicator bacteria (FIB). Our findings reveal a substantial and widespread presence of aggregate-bound indicator bacteria across various water matrices and geographical locations. Comprehensive bacterial counts consistently exceeded those obtained by traditional methods by significant multiples, such as an average of 3.4× at the Seine River 2024 Olympic venue, and occasionally up to 100× in irrigation canals and wastewater plant effluent. These results, supported by microscopic and molecular analyses, underscore a systematic bias in global water safety regulatory frameworks. Conclusions Our research demonstrates the inadequacy of traditional culture-based techniques in assessing microbiological risks posed by aggregate-bound FIB and associated pathogens, particularly in water matrices affected by FIB-rich fecal particles from recent sewer overflows or sediment, which can carry higher infectious risks. Incorporating comprehensive FIB analysis techniques, including molecular methods and rapid culture-based approaches as shown in this study, offers a promising and effective solution to these risk assessment limitations. [ABSTRACT FROM AUTHOR]

Escherichia coli is commonly found in the gastrointestinal tract of warm-blooded animals and is routinely used as an indicator of fecal contamination in recreational waters. While most E. coli are commensal, some can harbor pathogenic potential, posing a major public health risk. This study investigated the sources of fecal contamination in recreational waters through the characterization of E. coli isolates. Presumptive E. coli detection was performed using selective and differential media, confirmed by PCR, and followed by characterization. E. coli were detected in all studied aquatic environments, with most isolates belonging to phylogenetic groups D1 (24%, non-human mammals) and B1 (20%, birds), suggesting animals as primary contaminants sources. Among E. coli isolates, 35% were identified as diarrheagenic E. coli (DEC), with enterotoxigenic (34%) and enterohemorrhagic (26%) being the most prevalent pathotypes. Furthermore, 85% of all isolates and 86.5% of DEC isolates exhibited multi-drug resistance, with highest rates displayed in phylogenetic subgroups A1 (human and non-human mammals) and B1. This study highlights the importance of the One Health approach encompassing a human, animal, and environmental holistic health perspective to effectively manage public health strategies and ensure the safety of beachgoers. [ABSTRACT FROM AUTHOR]

Contamination of water bodies, associated with urbanization, agricultural, and industrial activities, is a serious environmental challenge, with particular concern about microbial pollution due to its public health implications. This study is aimed at evaluating the spatial and temporal variations in the microbiological and physicochemical quality of a floodplain lake used for recreational purposes, whose watershed has been disturbed by diverse anthropogenic activities. The results showed that, while the spatial variation of water quality principally depends on the basin characteristics, temporal variation of water quality depends on land uses, hydrological conditions, and climatic conditions. Rainfall and rising water level intensified the influence of land use on the water quality by increasing concentrations of Escherichia coli, thermotolerant coliforms, and organic matter and decreasing dissolved oxygen. Thus, the residents and tourists are potentially exposed to microbiological risks given that it exceeds the international standards suggested for recreational waters on some occasions. It would be advisable to improve routine bathing water monitoring and management to preserve the health of the inhabitants and limit the recreational use of the water body in the days following heavy rainfall as well as during the beginning of the increase in the hydrometric level. [ABSTRACT FROM AUTHOR]

Recreational water activities are widely recognized to have a positive impact on our physical and mental well-being. However, recreational water sources and their management are also a risk factor for human health due to different agents, including the overgrowth of cyanobacteria and algae. The presence of cyanobacteria and algae in recreational waters represents a One Health threat because of their potential release and the overuse of biocides. These organisms have the potential to metabolize organic matter and produce thermophilic and thermotolerant toxins. Moreover, different species of algae are involved in biofilm formation processes, thus impacting water quality and safety and also posing risks to the environment and animal and human health. Different species of algae participate in biofilm formation and have an impact on managing water and equipment maintenance. By searching literature databases, e.g., PubMed, we reviewed the state of the art, providing basic definitions, taxonomy, and epidemiological or medical issues related to the recreational uses of water. Methods of treatments and monitoring were summarized, considering both traditional and innovative strategies. Public health and surveillance approaches focus on the detection of toxins, the formation of biofilms, and the understanding of the benthonic and planktonic components as part of the larger microbial biodiversity. The review process allowed us to acknowledge that this is the first comprehensive overview of algae in recreational waters carried out within a wider One Health outlook. [ABSTRACT FROM AUTHOR]

ABSTRACT Sewage contamination of environmental waters is increasingly assessed by measuring DNA from sewage-associated microorganisms in microbial source tracking (MST) approaches. However, DNA can persist through wastewater treatment and reach surface waters when treated sewage/recycled water is discharged, which may falsely indicate pollution from untreated sewage. Recycled water discharged from an advanced wastewater treatment (AWT) facility into a Florida stream elevated the sewage-associated HF183 marker 1,000-fold, with a minimal increase in cultured Escherichia coli. The persistence of sewage-associated microorganisms was compared by qPCR in untreated sewage and recycled water from conventional wastewater treatment (CWT) and AWT facilities. E. coli (EC23S857) and sewage-associated markers HF183, H8, and viral crAssphage CPQ_056 were always detected in untreated sewage (6.5–8.7 log10 GC/100 mL). Multivariate analysis found a significantly greater reduction of microbial variables via AWT vs CWT. Bacterial markers decayed ~4–5 log10 through CWT, but CPQ_056 was ~100-fold more persistent. In AWT facilities, the log10 reduction of all variables was ~5. In recycled water, bacterial marker concentrations were significantly correlated (P ≤ 0.0136; tau ≥ 0.44); however, CPQ_056 was not correlated with any marker, suggesting varying drivers of decay. Concentrations of cultured E. coli carrying the H8 marker (EcH8) in untreated sewage were 5.24–6.02 log10 CFU/100 mL, while no E. coli was isolated from recycled water. HF183 and culturable EcH8 were also correlated in contaminated surface waters (odds ratio β1 = 1.701). Culturable EcH8 has a strong potential to differentiate positive MST marker signals arising from treated (e.g., recycled water) and untreated sewage discharged into environmental waters.IMPORTANCEGenes in sewage-associated microorganisms are widely accepted indicators of sewage pollution in environmental waters. However, DNA persists through wastewater treatment and can reach surface waters when recycled water is discharged, potentially causing false-positive indications of sewage contamination. Previous studies have found that bacterial and viral sewage-associated genes persist through wastewater treatment; however, these studies did not compare different facilities or identify a solution to distinguish sewage from recycled water. In this study, we demonstrated the persistence of bacterial marker genes and the greater persistence of a viral marker gene (CPQ_056 of crAssphage) through varying wastewater treatment facilities. We also aim to provide a tool to confirm sewage contamination in surface waters with recycled water inputs. This work showed that the level of wastewater treatment affects the removal of microorganisms, particularly viruses, and expands our ability to identify sewage in surface waters.

Antibiotic-resistant bacteria represent a major public health concern, especially impacting medical care centers and hospitals, thereby challenging the effectiveness of current infection treatment protocols. The emergence and persistence of antimicrobial resistance in the environment have been thoroughly researched, with a focus on the aquatic environment as a potential reservoir of these bacteria in areas with anthropogenic contamination. Having this in mind, this work aims to investigate the water streams of Riguinha and Brito Capelo Street, both of which ultimately flow into Matosinhos Beach in Portugal, to determine the potential presence of fecal contamination. Six water samples were collected and analyzed within twenty-four hours from these two water streams. A phenotypic characterization was performed in various volumes on MacConkey agar with antibiotics. Randomly selected lactose-fermenting gram-negative bacteria underwent antimicrobial susceptibility tests using the agar diffusion method following EUCAST guidelines, covering β-lactam and non-β-lactam antibiotics. The isolates were analyzed through Polymerase Chain Reaction. The findings of this study confirm that both water streams were contaminated by multidrug-resistant bacteria such as Enterobacteriaceae, including Escherichia coli, the KESC group, and Pseudomonas, exhibiting extended-spectrum β-lactamases (ESBL), AmpC β-lactamases, and carbapenemases. These indicate the presence of fecal contamination with relevant antimicrobial-resistant threats. [ABSTRACT FROM AUTHOR]

These data represent the abundance, diversity and predicted function gene profiles of the microbial communities present on human skin before and after swimming in the ocean. The skin microbiome has been shown to provide protection against infection from pathogenic bacteria. It is well-known that exposure to ocean water can cause skin infection, but little is known about how exposure can alter the bacterial communities on the skin. Skin microbiome samples were collected from human participants before and after swimming in the ocean. These data were used to analyze the changes in abundance and diversity of microbial communities on the skin and the changes in the functional profiles of the bacteria, specifically focusing on genes involved in antibiotic resistance and bacterial virulence.

Abstract Background Swimming pools are places for practicing sports, recreation, relaxation, and socialization. However, swimming pools can expose swimmers to physicochemical and microbiological risks. Accordingly, we studied the environmental health aspects and microbial infections for such recreational water aiming to disclose the possible risks they pose on swimmers. Methods 26 pools in Alexandria, Egypt were checked for water quality; 13 pools were checked in winter then summer, and other 13 pools were checked in summer only. Water was collected from both the top and the bottom of each pool; a total of 78 samples were collected in sterile containers. Each sample was divided into three parts; the first part was used for assessing the bacteriological quality of water. They were tested for total colony count (TCC), total coliform (TC), fecal coliform, and E. coli. The second part was used for chemical analysis. The third part was checked for parasitological study. Results Obtained data showed that only 7.7%, 78.2%, and 100% of the examined water samples have been found to fulfill the Egyptian standards for TCC, TC, and E. coli, respectively. Moreover, parasitic infection (PI) was noticed in 73.1% of the collected water samples; mainly Cyclospra and Isospora (37.2% each), followed by Cryptosporidium spp., Giradia lamblia, Microsporidia spp., and Blastocystis spp. (34.6%, 21.8%, 15.4%, and 14.1%, respectively). Acanthameba spp. was detected but at a lower rate (5.1%). The frequency of cleaning the swimming pools, flow rate, Cl2, and total dissolved solids are significantly affected PI, independently. Conclusion The tested water samples don’t meet Egyptian bacteriological criteria. High parasitic contamination despite high residual chlorine level mainly intestinal coccidia, G. lamblia, microsporidia, and Blastocystis spp. Thus, monitoring pool’s water quality and improving the disinfection system are mandatory. Consequently, Health education regarding hygienic behaviors before and during swimming should be included in governmental programs.

Float tanks are recreational water baths with high concentrations of MgSO4 used for sensory deprivation. Documentation on standard operating practices within float tank facilities is lacking, which is useful for understanding the need for regulation. The goal of this study was to explore typical float tank operating practices by issuing a questionnaire to US float facilities on water treatment, testing, replacement and other maintenance methods. The survey was completed by 45 float tank operators across the US. Results show a spectrum of operating practices across float tank facilities and operational and risk distinctions from swimming pools and spas. To date, only one case of Pseudomonas aeruginosa associated with float tank use, and one outbreak associated with exposure to an art exhibition mimicking a float tank, have been published. Although float tanks pose a lower risk to users than swimming pools, they still pose some risk and health authorities should consider licensing float facilities. Knowledge gaps in float tank water quality best management practices were also observed. Most facilities use micron bag filtration, yet the contaminant removal efficacy of these systems is understudied. Additionally, more research is needed exploring chlorine, pH and alkalinity test kit accuracy in water with MgSO4. HIGHLIGHTS Environmental health authorities should consider licensing and inspecting float tank facilities to minimize risks associated with chemical and biological hazards on-site.; Chlorine is the most common primary disinfectant used to treat swimming pool and hot tub water but is not appropriate for use in float tanks.; More research is needed exploring the contaminant removal efficiency of micron bag filters in float tanks.;

This study aimed to understand the performance and utility of US EPA-approved coliphage methods in comparison to fecal indicator bacteria (FIB) and molecular microbial source tracking (MST) methods in recreational waters. We used US EPA Method 1642 to quantify concentrations of coliphage along with culture- and molecular-based enumeration of E. coli and Enterococcus sp, and human fecal source marker HF183. We also conducted a feasibility assessment to determine the utility of US EPA Method 1642 for application to routine recreational water monitoring. Ten sampling events were conducted at three sampling sites over the duration of a year. Average concentrations of somatic (SC) (log10 1.48 PFU/100 mL) and male-specific (MSC) coliphages (log10 1.00 PFU/100 mL) at all sites were low with SC found across a broader range (0.3–3.1 log10 PFU/100 mL) of concentrations compared to MSC (non-detect-1.7 log10 PFU/100 mL). A feasibility assessment was conducted across US EPA Method 1642 for coliphage enumeration, culture-based FIB, defined substrate technology (DST) approaches Enterolert™ and Colilert®, and quantitative microbial source tracking (qMST) US EPA Method 1696. US EPA Method 1642 had the longest processing times, but also was moderate in cost, compared to the DST and qMST molecular methods. Given the poor correlations between MSC and SC with FIB and qMST markers in this study and the cumbersome nature of US EPA Method 1642, the method may not be the most applicable method for use in systems impacted predominantly by stormwater and other non-point source pollution. Findings from this study, however, provide guidance on the application of fecal indicator virus in ambient coastal surface waters. [ABSTRACT FROM AUTHOR]

Water quality monitoring of a particular river is crucially important to determine if the river water meets the requirement for its designated uses. Therefore, an assessment of the physiochemical water quality at Satow Waterfall, Sarawak, and the prevalence of antibiotic-resistant bacteria (ARB) was conducted to corroborate the safety of the water from the waterfall. A total of 42 water samples were collected at the subsurface water of the upstream, midstream, and downstream on two sampling trips in June 2021 (dry season) and December 2021 (wet season), with six months intervals. The water quality index (WQI) of the sampling stations ranged from 92.60 to 95, classifying the water under Class I. However, the water is microbiologically polluted, with the highest coliform count of 2.59 × 105 CFU/ mL recorded at the middle stream during the wet season, which has surpassed the regulatory standard set by the Malaysian Department of Environment (DOE). A total of 54 bacterial isolates were chosen as representatives and identified by 16S rRNA sequencing, which confirmed the existence of 21 bacterial genera. All identified isolates were tested against 15 antibiotics of various classes employing the Clinical and Laboratory Standards Institute (CLSI) protocols. The antibiotic susceptibility test (AST) demonstrated substantial resistance to sulfamethoxazole (48%) and erythromycin (48%), as well as high susceptibility to chloramphenicol (84%), levofloxacin (60%) and ofloxacin (60%). The Multiple Antibiotic Resistance Index (MARI) evaluations demonstrated the MARI varied from 0-0.60, with 33% of the isolates having a MARI greater than 0.2. In this study, the occurrence of ARB in a water environment where there is an undisclosed source of antibiotic utilization is still inevitable, highlighting the necessity to constantly monitor the water quality and the pervasiveness of ARB in recreational water. [ABSTRACT FROM AUTHOR]

Skin is the body's first line of defense against invading microorganisms. The skin microbiome has been shown to provide immunity against exogenous bacterial colonization. Recreational water exposures may alter the skin microbiome and potentially induce skin infections. This study explored the link between ocean water exposures and the human skin microbiome. Skin microbiome samples were collected, using swabs, from human participants' calves before and after they swam in the ocean, and at 6 hour and 24 hour post-swim. Genomic analysis showed that skin microbiomes were different among individuals before swimming. But after swimming, microbial communities were no longer different, which was demonstrated by a decrease in inter-sample diversity. Taxonomic analysis showed that ocean bacteria, including potential pathogens, replaced the native skin bacteria and remained on the skin for at least 24 hour post-swim. This research provides insight into the relationship between the human skin microbiome and the environment.

The study aimed to examine the characteristics of the beaches of Sinop Province, monitor the faecal pollution trend in the years 2011 - 2022, examine its causes, comparison with studies conducted in Turkey, awareness of people regarding pollution in the seas, and the compatibility of the classification system of the Ministry of Health with the WHO. A total of 2503 samples collected from 29 beaches in Sinop Province during the years 2011 - 2022 were evaluated. Descriptive statistics like Mann-Whitney U and Kruskal-Wallis tests were used to summarize the data and concordance analyses was used to compare the groups. The highest microbial pollution in beach water was observed in 2020. When the source of pollution was examined for the cause, the most evident (40.0 %) was "pollution from wild animals". When the microbial quality assessment of the World Health Organization for recreational waters and the assessment of the Ministry of Health were examined, it was found that there was a low-medium level of agreement. In some beaches of Sinop Province, certain indicators of bacteriological pollution have reached poor levels within twenty four day period from 2011 to 2022. In the follow-up of bathing waters, classification and measurements should be based on differences between provinces, prioritizing public health. [ABSTRACT FROM AUTHOR]

Swimming in public pools can expose bathers to microbiological (e.g., Cryptosporidium) and chemical (e.g., disinfection by-product) hazards, which can lead to recreational water illness. Adequate hygienic behaviours among bathers are important to reduce these risks. However, prior studies have found low compliance with pre-swim showering and avoidance of urinating in pools. We conducted a mixed-methods analysis of online discussion comments to identify key determinants of these two behaviours. We identified relevant discussion threads on Reddit, Quora, and swimming forums. Identified comments were classified as having a positive or negative sentiment towards the behaviour, and they were thematically analyzed according to the Theoretical Domains Framework (TDF). We analyzed 986 comments from 45 threads; 49.8% of comments were classified as expressing a positive sentiment towards the behaviour. Positive sentiments were more commonly expressed towards pre-swim showering compared to avoidance of urinating in pools (60.1 vs. 47.1%). Eleven themes were identified across the following eight TDF domains: beliefs about consequences (n = 362 comments), social influences (n = 298), beliefs about capabilities (n = 240), social/professional role and identity (n = 144), knowledge (n = 138), emotions (n = 137), reinforcement (n = 78), and environmental context and resources (n = 33). Results can help to inform targeted educational and outreach strategies with bathers to encourage increased adoption of hygienic behaviours. HIGHLIGHTS Users in online forums have inconsistent beliefs towards hygienic behaviours in swimming pools.; Positive beliefs were more commonly expressed towards pre-swim showering compared to avoiding urinating in pools.; Behaviours were mostly influenced by expectations of other swimmers, outcome expectancies, and self-efficacy.; Other important factors related to risk perceptions, etiquette, emotions, and misconceptions.;

Swimming and recreating in lakes, oceans, and rivers is common, yet the literature suggests children may be at greater risk of illness following such exposures. These effects might be due to differences in immunity or differing behavioral factors such as poorer hygiene, longer exposures to, and greater ingestion of potentially contaminated water and sand. We pooled data from 12 prospective cohorts (n=68,685) to examine exposures to potentially contaminated media such as beach water and sand among children compared with adults, and conducted a simulation using self-reported time spent in the water and volume of water swallowed per minute by age to estimate the total volume of water swallowed per swimming event by age category. Children aged 4-7 and 8-12 years had the highest exposures to water, sand, and algae compared with other age groups. Based on our simulation, we found that children (6-12 years) swallow a median of 36 ml (90th percentile=150 ml), whereas adults aged ≥35 years swallow 9 ml (90th percentile=64 ml) per swimming event, with male children swallowing a greater amount of water compared with females. These estimates may help to reduce uncertainty surrounding routes and durations of recreational exposures and can support the development of chemical and microbial risk assessments.

Background: Swimming pools are places for practicing sports, recreation, relaxation, and socialization. However, swimming pools can expose swimmers to physicochemical and microbiological risks. Accordingly, we studied the environmental health aspects and microbial infections for such recreational water aiming to disclose the possible risks they pose on swimmers. Methods: 26 pools in Alexandria, Egypt were checked for water quality; 13 pools were checked in winter then summer, and other 13 pools were checked in summer only. Water was collected from both the top and the bottom of each pool; a total of 78 samples were collected in sterile containers. Each sample was divided into three parts; the first part was used for assessing the bacteriological quality of water. They were tested for total colony count (TCC), total coliform (TC), fecal coliform, and E. coli. The second part was used for chemical analysis. The third part was checked for parasitological study. Results: Obtained data showed that only 7.7%, 78.2%, and 100% of the examined water samples have been found to fulfill the Egyptian standards for TCC, TC, and E. coli, respectively. Moreover, parasitic infection (PI) was noticed in 73.1% of the collected water samples; mainly Cyclospra and Isospora (37.2% each), followed by Cryptosporidium spp., Giradia lamblia, Microsporidia spp., and Blastocystis spp. (34.6%, 21.8%, 15.4%, and 14.1%, respectively). Acanthameba spp. was detected but at a lower rate (5.1%). The frequency of cleaning the swimming pools, flow rate, Cl2, and total dissolved solids are significantly affected PI, independently. Conclusion: The tested water samples don't meet Egyptian bacteriological criteria. High parasitic contamination despite high residual chlorine level mainly intestinal coccidia, G. lamblia, microsporidia, and Blastocystis spp. Thus, monitoring pool's water quality and improving the disinfection system are mandatory. Consequently, Health education regarding hygienic behaviors before and during swimming should be included in governmental programs. [ABSTRACT FROM AUTHOR]

Float tanks are recreational water baths with high concentrations of MgSO4 used for sensory deprivation. Documentation on standard operating practices within float tank facilities is lacking, which is useful for understanding the need for regulation. The goal of this study was to explore typical float tank operating practices by issuing a questionnaire to US float facilities on water treatment, testing, replacement and other maintenance methods. The survey was completed by 45 float tank operators across the US. Results show a spectrum of operating practices across float tank facilities and operational and risk distinctions from swimming pools and spas. To date, only one case of Pseudomonas aeruginosa associated with float tank use, and one outbreak associated with exposure to an art exhibition mimicking a float tank, have been published. Although float tanks pose a lower risk to users than swimming pools, they still pose some risk and health authorities should consider licensing float facilities. Knowledge gaps in float tank water quality best management practices were also observed. Most facilities use micron bag filtration, yet the contaminant removal efficacy of these systems is understudied. Additionally, more research is needed exploring chlorine, pH and alkalinity test kit accuracy in water with MgSO4. [ABSTRACT FROM AUTHOR]

The bacterium Legionella pneumophila is a ubiquitous microorganism naturally present in water environments. The actual presence of this opportunistic premise plumbing pathogen in recreational swimming pools and hot tubs in the northwestern part of Croatia has not been investigated. This study aimed to analyze the presence of the opportunistic pathogen L. pneumophila in public swimming pool water in Primorje-Gorski Kotar County (N = 4587) over a four-year period (2018–2021). Additionally, the second aim was to investigate the connection between the presence of L. pneumophila and pool water physicochemical parameters using mathematical predictive models. The presence of L. pneumophila was detected in six pool samples. Five positive samples were found in the water of indoor hot tubs filled with fresh water, and one positive sample in an outdoor recreational saltwater pool. A predictive mathematical model showed the simultaneous influence of chemical parameters dominated by the temperature in saltwater and freshwater pools, as well as the significant influence of free residual chlorine and trihalomethanes. Our results pointed out that keeping all physicochemical parameters in perfect harmony is necessary to reach the best disinfection procedure and to avoid the optimum conditions for L. pneumophila occurrence. [ABSTRACT FROM AUTHOR]

Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible. HIGHLIGHTS Enhanced surveillance of recreational waters can supplement water quality monitoring and inform our understanding of what contributes to the risk of human illness.; Water collected at reservoir beaches was less contaminated than sites along the main river.; Subtyping of pathogens at the beach sites suggested a narrow range of sources.; The nature of the sampling site influenced the prevalence and types of pathogens.;

In recent decades, natural swimming pools (NSPs) have gained popularity in Europe, especially in Germany and Austria. NSPs differ from swimming pools in that they utilize biological treatment processes based on wetland processes with no disinfection residual. However, data are missing on the specific log-reduction performance of NSPs to address enteric virus, bacteria, and parasitic protozoa removal considered necessary to meet the North American risk-based benchmark (

The purpose of this review was to highlight the most frequent biological indicators used to estimate the microbiological quality of drinking and recreational water. It was observed that the incorporation of other microbiological indicators should be considered to strengthen the decision-making process on water quality management and guarantee its safe consumption in recreational activities.

Cities that are densely populated are reservoirs of antibiotic resistant genes (ARGs). The overall presence of all resistance genes in a specific environment is defined as a resistome. Spatial proximity of surfaces and different hygienic conditions leads to the transfer of antibiotic resistant bacteria (ARB) within urban environments. Built environments, public transportation, green spaces, and citizens' behaviors all support persistence and transfer of antimicrobial resistances (AMR). Various unique aspects of urban settings that promote spread and resilience of ARGs/ARB are discussed: (i) the role of hospitals and recreational parks as reservoirs; (ii) private and public transportation as carriers of ARGs/ARB; (iii) the role of built environments as a hub for horizontal gene transfer even though they support lower microbial biodiversity than outdoor environments; (iv) the need to employ ecological and evolutionary concepts, such as modeling the fate of a specific ARG/ARB, to gain enhanced health risk assessments. Our understanding and our ability to control the rise of AMR in an urban setting is linked to our knowledge of the network connecting urban reservoirs and the environment. [ABSTRACT FROM AUTHOR]

The decay and distribution of bacterial pathogens in water is an important information for the health risk assessment to guide water safety management, and suspended algae might affect bacterial pathogens in water. This study established microcosms to investigate the effects of algae-related factors on the representative indicators and opportunistic pathogen species in water. We found that suspended algae increased the persistence of targeted species by 1-2 orders of magnitude of concentrations compared to microcosms without algae; and the effect of algae on microbial survival was affected by water nutrient levels (i.e., carbon, nitrogen and phosphorus), as the increased microbial persistence were correlated to the increased algae concentrations with more nutrient supplies. Moreover, decay and distribution profiles of representative species were determined. The three opportunistic pathogen species (Pseudomonas aeruginosa, Aeromonas hydrophila and Staphylococcus aureus) showed lower decay rates (0.82–0.98/day, 0.76–0.98/day, 0.63–0.87/day) largely affected by algae-related factors, while the enteric species (Escherichia coli and Enterococcus faecalis) had higher decay rates (0.94–1.31/day, 0.89–1.21/day) with little association with algae, indicating the propensity for attachment to algae is an important parameter in microbial fate. Together results suggest suspended algae played an evident role in the decay and distribution of bacterial pathogens, providing important implications regarding microbial safety in recreational water. [Display omitted] [ABSTRACT FROM AUTHOR]

The study focused on the physicochemical and bacteriological quality of public swimming pools in the Tamale Metropolis. Physicochemical properties such as pH, temperature, and conductivity, and bacteria counts—including total coliform, faecal coliform, Escherichia coli (E. coli), Staphylococcus aureus, and total heterotrophic bacteria—were analyzed for their conformity with required health standards. The results obtained were analyzed using Student t test and compared with World Health Organization (WHO) and Environmental Protection Agency (EPA) standards for safe recreational and drinking water. The highest and the lowest temperatures were recorded in April (32.53 °C) and February (28.16 °C), respectively. The lowest and the highest mean pH values were 4.04 and 6.13, which were below acceptable standards. The conductivity level varied from 469.1563 µS cm−1 to 928.1563 µS cm−1. While the pH did not conform to acceptable standards, temperature and conductivity were within the EPA and/or the WHO acceptable limits. The total coliform (TC) expressed in colony-forming units per 100 mL ranged from 0 to 397 (cfu/100 mL), faecal coliform (FC) 0 to196 cfu/100 mL, E. coli 0 to 52 cfu/100 mL, Staphylococcus aureus (S. aureus) 8 to 27 cfu/100 mL, and Total Heterotrophic Bacteria (THB) 44 to 197 (cfu/mL). TC, FC, E. coli, S. aureus, and THB counts in most of the samples complied with the bacteriological standards. However, the bacterial loads increased and exceeded the WHO and/or EPA standards as the number of bathers increased. Besides, there were positive correlations between physicochemical parameters such as temperature, pH, and bacterial loads. Most parameters studied met the acceptable standards of recreational water stipulated by the WHO and EPA. However, the presence of pathogenic organisms in the recreational waters at any point in time should be treated as a public health concern, and hence a call for routine monitoring and inspection of public swimming pools in the Tamale Metropolis.

There is an urgent need for research on the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) causing coronavirus disease 2019 (COVID‐19), as the transmissibility differs between settings and populations. Here we report on a questionnaire‐based retrospective cohort study of the prevalence and transmission of SARS‐CoV‐2 among participants in swimming activities in Denmark in the last 5 months of 2020 during the COVID‐19 pandemic. Eight of 162 swimming activities with a SARS‐CoV‐2 positive participant led to transmission to 23 other participants. Overall, the percentage of episodes leading to transmission was 4.9% (competitive swimming 8.9%; recreational swimming 1.3%). Overall, the incidence rate of transmission was 19.5 participants per 100 000 pool activity hours (corresponding values: 43.5 and 4.7 for competitive and recreational swimming, respectively). Compliance with precautionary restrictions was highest regarding hand hygiene (98.1%) and lowest in distancing personal sports bags (69.9%). As a result of low statistical power, the study showed no significant effect of restrictions. Insight into the risk of transmission of SARS‐CoV‐2 during indoor swimming is needed to estimate the efficiency of restrictive measures on this and other sports and leisure activities. Only when we know how the virus spreads through various settings, optimal strategies to handle the COVID‐19 pandemic can be developed. [ABSTRACT FROM AUTHOR]

Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible. [ABSTRACT FROM AUTHOR]

The bacterium Legionella pneumophila is a ubiquitous microorganism naturally present in water environments. The actual presence of this opportunistic premise plumbing pathogen in recreational swimming pools and hot tubs in the northwestern part of Croatia has not been investigated. This study aimed to analyze the presence of the opportunistic pathogen L. pneumophila in public swimming pool water in Primorje-Gorski Kotar County (N = 4587) over a four-year period (2018–2021). Additionally, the second aim was to investigate the connection between the presence of L. pneumophila and pool water physicochemical parameters using mathematical predictive models. The presence of L. pneumophila was detected in six pool samples. Five positive samples were found in the water of indoor hot tubs filled with fresh water, and one positive sample in an outdoor recreational saltwater pool. A predictive mathematical model showed the simultaneous influence of chemical parameters dominated by the temperature in saltwater and freshwater pools, as well as the significant influence of free residual chlorine and trihalomethanes. Our results pointed out that keeping all physicochemical parameters in perfect harmony is necessary to reach the best disinfection procedure and to avoid the optimum conditions for L. pneumophila occurrence.

Abstract In the last decade, the world population has become more urban than rural, but the human contact with nature is still a necessity for a proper physical and mental development. The urban green areas are a significant part of the urban heritage, providing fundamental ecosystem services. They give us the possibility of having social and cultural interaction surrounded by nature. Water is usually part of the landscape of these areas. The quality of the recreational water in urban green areas impacts on multiple factors like soil, vegetation, aquatic and terrestrial life and public health. A complete evaluation of this quality requires applying different methodologies simultaneously. Samples were collected at eight sites of Buenos Aires City in order to assess the quality of its recreational water. Results were compared with water quality standards in established legislation and were ranked by the National Sanitation Foundation Water Quality Index (NSF-WQI). Euphotic zone transparency was used as a parameter of the impact on aquatic life, measuring the Secchi depth. A test for fecal coliform bacteria was used as a risk indicator for human health. In accordance with the NSF-WQI ranking, the eight sampling sites have medium or bad water quality. Fifty percent of the sites exceeded the allowed count of coliform bacteria. According to established legislation, five of the studied sites were found to be unsuitable for primary, secondary or passive aquatic activities. Of the remaining sites, two were suitable for passive activities and only one qualified to be suitable for all kinds of aquatic activities. Secchi depth measures reveal a bad water quality for aquatic life at four of the analyzed sites.

These data represent the abundance, diversity and predicted function gene profiles of the microbial communities present on human skin before and after swimming in the ocean. The skin microbiome has been shown to provide protection against infection from pathogenic bacteria. It is well-known that exposure to ocean water can cause skin infection, but little is known about how exposure can alter the bacterial communities on the skin. Skin microbiome samples were collected from human participants before and after swimming in the ocean. These data were used to analyze the changes in abundance and diversity of microbial communities on the skin and the changes in the functional profiles of the bacteria, specifically focusing on genes involved in antibiotic resistance and bacterial virulence.

In recent decades, natural swimming pools (NSPs) have gained popularity in Europe, especially in Germany and Austria. NSPs differ from swimming pools in that they utilize biological treatment processes based on wetland processes with no disinfection residual. However, data are missing on the specific log-reduction performance of NSPs to address enteric virus, bacteria, and parasitic protozoa removal considered necessary to meet the North American risk-based benchmark (,35 illnesses per 1,000 swimming events) set by the USEPA for voluntary swimming. In this study, we examined Canada's first NSP at Borden Park, Edmonton, Canada, to address the following three questions: (1) Given normal faecal shedding rates by bathers, what is the total log reduction (TLR) theoretically needed to meet the EPA benchmark? (2) what is the in-situ performance of the NSP based on spiking suitable microbial surrogates (MS2 coliphage, Enterococcus faecalis, and Saccharomyces cerevisiae [Baker's yeast])? and (3) how much time is required to reach acceptable bather risk levels under different representative volume-turnover rates? A reverse-quantitative microbial risk assessment (QMRA) revealed that of the four reference pathogens selected (Norovirus, Campylobacter, Cryptosporidium, and Giardia), only Norovirus was estimated to exceed the risk benchmark at the 50th, 75th, and 95th percentiles, while Campylobacter was the only other reference pathogen to exceed at the 95th percentile. Logreduction values (LRVs) were similar to previous reports for bacterial indicators, and novel LRVs were estimated for the other two surrogates. A key finding was that more than 24 h treatment time would be necessary to provide acceptable bather protection following heavy bather use (378 bathers/day for main pool and 26 bathers/day for children's pool), due to the mixing dynamics of the treated water diluting out possible residual pool faecal contamination. The theoretical maximum number of people in the pool per day to be below USEPA's 35 gastro cases in 1,000 swimming events was 113, 47, and 8, at the 50th, 75th, and 95th percentiles. Further, the use of ultra-violet disinfection to the pool return flow had little effect on reducing the treatment time required. [ABSTRACT FROM AUTHOR]

Introduction: From April 1 to May 31, 2022, Grand Canyon National Park received increased acute gastroenteritis reports. Pooled portable toilet specimens identified norovirus genogroups I and II. We sought to determine outbreak transmission contributors and individual risk factors while rafting or backpacking in the park., Methods: Grand Canyon rafters and backpackers were surveyed online from June 13-July 8, 2022, and a Cox proportional hazards model was used to identify predictors associated with illness and adjusted for potential confounding factors., Results: Among 762 surveys, 119 cases and 505 well persons submitted complete survey data. Illness among rafters was associated with interaction with ill persons during the trip (adjusted hazard ratio [adjHR] = 3.4 [95%CI 2.3-5.0]) and lack of any hand hygiene (1.2 [0.7-1.9]) or use of only sanitizer or water (1.6 [1.04-2.6]) before snacks. Younger rafters had higher illness rates compared to those ≥60 y (1.5 [1.2-1.8] for ages 40-59 and 2.2 [1.4-3.5] for ages <40 y)., Conclusions: Person-to-person transmission likely accounted for the widespread outbreak. Future outbreak mitigation efforts on river trips could focus on symptom screening before the trip starts, prompt separation of ill and well passengers, strict adherence to hand hygiene with soap and water, minimizing social interactions among rafting groups, and widespread outbreak notices and education to all park users., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Cities that are densely populated are reservoirs of antibiotic resistant genes (ARGs). The overall presence of all resistance genes in a specific environment is defined as a resistome. Spatial proximity of surfaces and different hygienic conditions leads to the transfer of antibiotic resistant bacteria (ARB) within urban environments. Built environments, public transportation, green spaces, and citizens’ behaviors all support persistence and transfer of antimicrobial resistances (AMR). Various unique aspects of urban settings that promote spread and resilience of ARGs/ARB are discussed: (i) the role of hospitals and recreational parks as reservoirs; (ii) private and public transportation as carriers of ARGs/ARB; (iii) the role of built environments as a hub for horizontal gene transfer even though they support lower microbial biodiversity than outdoor environments; (iv) the need to employ ecological and evolutionary concepts, such as modeling the fate of a specific ARG/ARB, to gain enhanced health risk assessments. Our understanding and our ability to control the rise of AMR in an urban setting is linked to our knowledge of the network connecting urban reservoirs and the environment.

The purpose of this review was to highlight the most frequent biological indicators used to estimate the microbiological quality of drinking and recreational water. It was observed that the incorporation of other microbiological indicators should be considered to strengthen the decision-making process on water quality management and guarantee its safe consumption in recreational activities. [ABSTRACT FROM AUTHOR]

In recent years, recreational waterbodies are increasingly favoured in urban areas. In spite of the growing concerns for maintaining the required bathing water quality, the impacts of stormwater drainage are still poorly controlled. In this context, this study originally develops an integrated urban catchment-pipes-lake monitoring and modelling approach to simulate the impacts of microbial quality from stormwater drainage on recreational water quality. The modelling system consists of three separated components: the urban catchment component, the 3D lake hydrodynamic component and the 3D lake water quality component. A series of processes are simulated in the model, such as rainfall-discharge, build-up, wash-off of Escherichia coli (E. coli) on urban surfaces, sewer flows, hydrothermal dynamics of lake water and transport and mortality of E. coli in the lake. This integrated model is tested for an urban catchment and its related recreational lake located in the Great Paris region. Continuous monitoring and samplings were performed at the stormwater drainage outlet and three different sites in the lake. Comparing the measured data with simulation results over 20 months, the modelling system can correctly represent the E. coli dynamics in the stormwater sewer systems and in the lake. Although uncertainties related to parameter values, pollution sources and E. coli mortality processes could be further discussed, the good performance of this modelling approach emphasizes a promising potential for urban bathing water quality management. [ABSTRACT FROM AUTHOR]

The microbial quality of recreational coastal waters along the southwestern coast of Grenada was assessed. A total of 120 samples taken from 12 sites were analyzed for enterococcus faecalis, fecal coliform, pH, temperature. Two samples per day from six sites were collected bi-weekly between 8 a.m. and 12 p.m. during the period of November- December 2008. Rainfall data for the sampling period was obtained from the Grenada Meteorological Office. The highest percentage of sampling days exceeding the World Health Organization's (WHO) recommended limits for enterococcus faecalis was recorded at two sites---- Beausejour-Bay [70%] and Carenage-Bay [60%]. The Carenage-Bay sampling site had the highest percentage of sampling days exceeding recommended limits for total fecal coliform [60%]. Overall, 30% of the samples analyzed showed enterococcus faecalis and total coliform levels above the recommended limits. Other measured variables were inconsistent with increased microbial content. No correlation was observed between rainfall and enterococcus faecalis. This study found that the majority of beaches along the Southwestern coast of Grenada exceeded the recommended limits by WHO for fecal coliform and enterococcus faecalis period. [ABSTRACT FROM AUTHOR]

Public health measures to cope with the Covid-19 pandemic, imposed also a shutdown of sports facilities and swimming pools. Safety issues related to recreational waters were emerging during the lockdown, rising concerns on how and when reopening pools and on how improve their management while SARS-CoV-2 is circulating in the population. The GSMS-SItI, Working Group on Movement Sciences for Health of the Italian Society of Hygiene Preventive Medicine and Public Health, discussed and summarized some indications for a suitable preventive approach. Several measures are highlighted, including social distancing, optimized water management, airflow and microclimatic parameters in the pool as well in the annexed rooms, verification of sanitation procedures. The GSMS-SItI underlines that prevention should be based on monitoring of the local epidemiological situation and on the constant collaboration with the local health authority and the national health service. [ABSTRACT FROM AUTHOR]

Exposure to contaminated recreational waters (defined by levels of fecal and other types of indicator bacteria) is associated with adverse health outcomes. The principal health outcome studied previously has been gastrointestinal illness. Although many studies included reports of frequent skin complaints (e.g. rash or itch) following recreational water exposure, no systematic reviews have examined the association between indicator levels and skin-related symptoms. Twenty relevant peer-reviewed studies were identified. The relative risks (swimmers vs. non-swimmers) of skin-related symptoms among those exposed to recreational water with bacterial indicator concentrations above threshold levels were determined using meta-analysis. Similarly, the relative risks (swimmers vs. non-swimmers) of skin-related complaints after exposure to water with bacterial indicator concentrations below threshold levels were determined. The ratio of these odds ratios (ROR) was then computed for each indicator. The risk of skin-related symptoms was significantly elevated in marine water with high levels of total coliforms ROR 1.86, (95% CI 1.21, 2.87); fecal coliforms ROR 1.45 (95% CI 1.02, 2.07); E. coli ROR 1.98, (95% CI 1.43, 2.75); enterococci ROR 2.04 (95% CI 1.34, 3.09) and fecal streptococci ROR 1.70 (95% CI 1.07, 2.71). However, no significant associations with water quality indicators were demonstrated for the freshwater indicators examined (total coliform, fecal coliform, E. coli). Swimmers exposed to marine water at high levels of several indicator bacteria experience a significant increase in skin-related symptoms compared to non-swimmers. This relationship was not demonstrated in freshwater settings.

Bacteriological analysis of a Recreational Park Pond in Port Harcourt was investigated to evaluate the water quality of the pond for recreational purposes. Samples collected from the pond were evaluated for physiochemical and bacteriological study. pH showed a slight alkaline range of 6.66 − 6.94 in sample A and D with a temperature range of 28.6 − 29oC. Samples evaluated for turbidity and salinity showed values of 0.309 − 0.784 NTU and 0.10ppt to 0.32ppt respectively. Similar bacteriological load ranging from 6.9 × 105cfu/ml − 2.1 × 106cfu/ml was observed, with coliform counts ranging from 3.4 × 105 − 1.3×106cfu/ml. Thirteen different bacterial genera were identified in total (Escherichia coli, Salmonella spp., Proteus spp., Citrobacter spp., Klebsiella spp, Bacillus spp., Serratia spp., Pseudomonas spp., Vibrio spp., Enterobacter spp., Staphylococcus aureus, Streptococcus spp., and Staphylococcus spp). Escherichia coli was the most commonly occurring group (14.7%) and Staphylococcus sp the least occurring (2.9%). Varying levels of resistance was noted against the 14 antibiotics tested, with the highest resistance noted against pefloxacin (55.9%) while the lowest resistance was against erythromycin (2.9%). Majority of isolates (67.7%) however had MAR index values less than 0.21, indicative of a source related to low antibiotic use. Despite the association of potentially pathogenic bacteria with this water body, the low level of drug resistance associated with these organisms as well as the MAR index values, could point at these being environmental rather than human strains. Further molecular studies would be advised to confirm this. Keywords: Bacteriological analysis, recreational water, antibiotic resistance, pefloxacin

In the last decade, the world population has become more urban than rural, but the human contact with nature is still a necessity for a proper physical and mental development. The urban green areas are a significant part of the urban heritage, providing fundamental ecosystem services. They give us the possibility of having social and cultural interaction surrounded by nature. Water is usually part of the landscape of these areas. The quality of the recreational water in urban green areas impacts on multiple factors like soil, vegetation, aquatic and terrestrial life and public health. A complete evaluation of this quality requires applying different methodologies simultaneously. Samples were collected at eight sites of Buenos Aires City in order to assess the quality of its recreational water. Results were compared with water quality standards in established legislation and were ranked by the National Sanitation Foundation Water Quality Index (NSF-WQI). Euphotic zone transparency was used as a parameter of the impact on aquatic life, measuring the Secchi depth. A test for fecal coliform bacteria was used as a risk indicator for human health. In accordance with the NSF-WQI ranking, the eight sampling sites have medium or bad water quality. Fifty percent of the sites exceeded the allowed count of coliform bacteria. According to established legislation, five of the studied sites were found to be unsuitable for primary, secondary or passive aquatic activities. Of the remaining sites, two were suitable for passive activities and only one qualified to be suitable for all kinds of aquatic activities. Secchi depth measures reveal a bad water quality for aquatic life at four of the analyzed sites. [ABSTRACT FROM AUTHOR]