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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]

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Marine sediments have been suggested as a reservoir for pathogenic bacteria, including Escherichia coli. The origins, and properties promoting survival of E. coli in marine sediments (including osmotolerance, biofilm formation capacity, and antibiotic resistance), have not been well-characterized. Phenotypes and genotypes of 37 E. coli isolates from coastal marine sediments were characterized. The isolates were diverse: 30 sequence types were identified that have been previously documented in humans, livestock, and other animals. Virulence genes were found in all isolates, with more virulence genes found in isolates sampled from sediment closer to the effluent discharge point of a wastewater treatment plant. Antibiotic resistance was demonstrated phenotypically for one isolate, which also carried tetracycline resistance genes on a plasmid. Biofilm formation capacity varied for the different isolates, with most biofilm formed by phylogroup B1 isolates. All isolates were halotolerant, growing at 3.5% NaCl. This suggests that the properties of some isolates may facilitate survival in marine environments and can explain in part how marine sediments can be a reservoir for pathogenic E. coli. As disturbance of sediment could resuspend bacteria, this should be considered as a potential contributor to compromised bathing water quality at nearby beaches. [ABSTRACT FROM AUTHOR]

The presence and level of faecal indicator bacteria are important factors in estimating the microbiological quality of surface water and the risk of human infection upon exposure to this water. Until 2014, ISO 9308-1:2000 was available and used to enumerate faecal indicator Escherichia coli in bathing water. In 2014, this ISO was technically revised and replaced by ISO 9308-1:2014. This ISO introduced a less selective method for enumeration of E. coli that allows non-specific growth from waters containing high levels of bacteria, such as surface waters. This implies that currently there is no suitable reference membrane filtration method for the compliance monitoring of official bathing sites for E. coli according to the European Bathing Water Directive. Here, the performance characteristics of three chromogenic culture media, namely Tryptone Bile X-glucuronide (TBX) agar, Chromogenic Coliform Agar (CCA), and CHROMagar E. coli/Coliform (ECC) were investigated at 44 °C for water with varying levels of bacteria according to ISO 13843:2017. Based on performance characteristics, colony counts, and practical usage, TBX appeared the most suitable culture medium for the enumeration of E. coli in bathing water and other waters with high levels of background bacteria, such as surface water in agricultural areas and wastewater discharge points. HIGHLIGHTS Performance characteristics at 44 °C, after resuscitation at 36 °C, were comparable for the tested chromogenic culture media TBX, CCA, and ECC.; Based on performance characteristics, colony counts, and practical usage, TBX was selected as the preferential culture medium.;

The presence and level of faecal indicator bacteria are important factors in estimating the microbiological quality of surface water and the risk of human infection upon exposure to this water. Until 2014, ISO 9308-1:2000 was available and used to enumerate faecal indicator Escherichia coli in bathing water. In 2014, this ISO was technically revised and replaced by ISO 9308-1:2014. This ISO introduced a less selective method for enumeration of E. coli that allows non-specific growth from waters containing high levels of bacteria, such as surface waters. This implies that currently there is no suitable reference membrane filtration method for the compliance monitoring of official bathing sites for E. coli according to the European Bathing Water Directive. Here, the performance characteristics of three chromogenic culture media, namely Tryptone Bile X-glucuronide (TBX) agar, Chromogenic Coliform Agar (CCA), and CHROMagar E. coli/Coliform (ECC) were investigated at 44 °C for water with varying levels of bacteria according to ISO 13843:2017. Based on performance characteristics, colony counts, and practical usage, TBX appeared the most suitable culture medium for the enumeration of E. coli in bathing water and other waters with high levels of background bacteria, such as surface water in agricultural areas and wastewater discharge points. [ABSTRACT FROM AUTHOR]

This paper analyses the results of microbiological analyses of bathing water at the Kravica Waterfall during 2018 and 2019 and the impact of bathers on bathing water quality. The microbiological analysis of the samples was performed by the Federal Institute of Public Health in Mostar in accordance with the regulations of Directive 2006/7 EC for management of quality of bathing water. Faecal streptococci were determined using the membrane filtration method BAS EN ISO 7899-2:2003. Escherichia coli was determined using the membrane filtration method for waters with low bacterial background flora BAS EN ISO 9308-1:2015. The quality of bathing water is assessed on the basis of parameters determined by the current Directive 2006/7/EC. The number of visitors does not have a significant impact on the quality of bathing water; the reason is that of the total number of visitors there is a small percentage of bathers. During the bathing seasons in 2018 and 2019, the bathing water at the Kravica Waterfall was of excellent quality.

Escherichia coli is a Gram-negative, facultative anaerobic, rod-shaped coliform bacterium which is widely used as an indicator of biological safety of water. Currently, 'gold' standard for the detection of E. coli (and other pathogens) are microbiological culture-based tests. Microbiological tests are very robust for the detection of live pathogens however it can take several days to get the results. A prospective option for the detection of E. coli in recreational waters in addition to the genetic PCR analyses can be an immunobiosensor, allowing to detect E. coli in 20 min and to issue timely warnings of the safety of water. To compare different methods – microbiological culturing, quantitative PCR analysis and antibody-based immunobiosensor for the analysis of bathing water samples from a popular urban beach Anne Canal in Tartu, Estonia were used. The median value of biosensor results for E. coliwas considerably higher than the results of microbiological cultivation and qPCR: for 40 times, and 4 times, respectively. In addition, the biosensor results were in significant correlation with the number of total coliforms. Considering the current requirements for the biological safety of bathing water, we propose that the indicative safety threshold for bathing water usingimmunosensor analyses is in the range 4 × 103–4 x 104E. coli cells/100 mL. [ABSTRACT FROM AUTHOR]

Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of Escherichia coli and other coliform bacteria on CCA plates. Aeromonas hydrophila and Pseudomonas aeruginosa growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples. [ABSTRACT FROM AUTHOR]

Water quality impairment is a substantial environmental hazard which impacts a wide variety of stakeholders and interests, particularly those who participate in outdoor water-based recreational activities. Recreational bathing water qualities are highly vulnerable to microbial pollution from municipal sewage, industrial effluents, agriculture run-off and river discharges. Fecal contamination impairs water quality and potentiates human health risks. The aim of this study was to see the 5-year trend of microbiological quality of recreational bathing waters in Albania. Every year we collected 1,071 samples taken 30 centimeters below the water's surface at least one meter deep. Assessment of bacterial load of the coastal waters was done nine times for every point, for the Escherichia coli and Intestinal enterococci, according to the methods ISO 7899-1 and ISO 9308-3. Bathing water assessment is to be classified according the categories indicated in the Directive 2006/7/EC and recommendations of WHO/UNEP-2010. Microbial Water Quality Assessment Category (cfu/100 ml water) done in 119 monitoring points were: During 2016, Excellent 53%, Sufficient 23%, Good 9% and Poor 15%. In 2017, Excellent 68%, Sufficient 15%, Good 6% and Poor 10%. During 2018, Excellent 82.4%, Sufficient 13%, Good 0.9% and Poor 3.7%. During 2019, Excellent 89%, Sufficient 2.5%, Good 6% and Poor 2.5%. During 2020 Excellent 89.9%, Sufficient 5%, Good 0.9%, and Poor 4.2%. Based on the above assessment, it is noticed a significant increase of microbial quality of recreational bathing waters in Albania due to investments in the sewerage system and better waste water treatment. [ABSTRACT FROM AUTHOR]

Background microorganism growth on Chromogenic Coliform Agar (CCA) can be challenging. For this reason, a new alternative method with a Cefsulodin/Vancomycin (CV)-supplemented CCA should be developed in this study. CCA supplemented with CV was validated according to ÖNORM EN ISO 16140-4:2021 using water from natural sources in Styria, Austria. Results show that the alternative method using the supplemented CCA has similar values in relation to sensitivity (82.2%), specificity (98.6%) and higher selectivity (59%) compared to the reference method. Repeatability and reproducibility were acceptable for the alternative method and showed similar results with the reference method. The alternative method shows a very low false positive rate and a low false negative rate paired with good performance regarding the inclusion study. The exclusion study shows the advantage of our method by suppressing background microorganisms and facilitating the process of enumeration of Escherichia coli and other coliform bacteria on CCA plates. Aeromonas hydrophila and Pseudomonas aeruginosa growth was inhibited using the supplement. To conclude, the coliform CV selective supplement combined with CCA is an appropriate tool for coliform bacteria detection in water samples.

Despite numerous studies, uncertainty remains about how water quality indicators can best be used in the regulation of recreational water. We conducted a systematic review of this topic with the goal of quantifying the association between microbial indicators of recreational water quality and gastrointestinal (GI) illness. A secondary goal was to evaluate the potential for GI illness below current guidelines. We screened 976 potentially relevant studies and from these identified 27 studies. From the latter, we determined summary relative risks for GI illness in relation to water quality indicator density. Our results support the use of enterococci in marine water at U.S. Environmental Protection Agency guideline levels. In fresh water, (Italic)Escherichia(/Italic) coli was a more consistent predictor of GI illness than are enterococci and other bacterial indicators. A log (base 10) unit increase in enterococci was associated with a 1.34 [95% confidence intervals (CI), 1.00-1.75] increase in relative risk in marine waters, and a log (base 10) unit increase in E. coli was associated with a 2.12 (95% CI, 0.925-4.85) increase in relative risk in fresh water. Indicators of viral contamination were strong predictors of GI illness in both fresh and marine environments. Significant heterogeneity was noted among the studies. In our analysis of heterogeneity, studies that used a nonswimming control group, studies that focused on children, and studies of athletic or other recreational events found elevated relative risks. Future studies should focus on the ability of new, more rapid and specific microbial methods to predict health effects, and estimating the risks of recreational water exposure among susceptible persons.

Vibrio cholerae belonging to serogroups other than O1 and O139 are opportunistic pathogens which cause infections with a variety of clinical symptoms. Due to the increasing number of V. cholerae non-O1/non-O139 infections in association with recreational waters in the past two decades, they have received increasing attention in recent literature and by public health authorities. Since the treatment of choice is the administration of antibiotics, we investigated the distribution of antimicrobial resistance properties in a V. cholerae non-O1/non-O139 population in a large Austrian lake intensively used for recreation and in epidemiologically linked clinical isolates. In total, 82 environmental isolates - selected on the basis of comprehensive phylogenetic information - and nine clinical isolates were analyzed for their phenotypic antimicrobial susceptibility. The genomes of 46 environmental and eight clinical strains were screened for known genetic antimicrobial resistance traits in CARD and ResFinder databases. In general, antimicrobial susceptibility of the investigated V. cholerae population was high. The environmental strains were susceptible against most of the 16 tested antibiotics, except sulfonamides (97.5% resistant strains), streptomycin (39% resistant) and ampicillin (20.7% resistant). Clinical isolates partly showed additional resistance to amoxicillin-clavulanic acid. Genome analysis showed that crp, a regulator of multidrug efflux genes, and the bicyclomycin/multidrug efflux system of V. cholerae were present in all isolates. Nine isolates additionally carried variants of blaCARB–7 and blaCARB–9, determinants of beta-lactam resistance and six isolates carried catB9, a determinant of phenicol resistance. Three isolates had both blaCARB–7 and catB9. In 27 isolates, five out of six subfamilies of the MATE-family were present. For all isolates no genes conferring resistance to aminoglycosides, macrolides and sulfonamides were detected. The apparent lack of either known antimicrobial resistance traits or mobile genetic elements indicates that in cholera non-epidemic regions of the world, V. cholerae non-O1/non-O139 play a minor role as a reservoir of resistance in the environment. The discrepancies between the phenotypic and genome-based antimicrobial resistance assessment show that for V. cholerae non-O1/non-O139, resistance databases are currently inappropriate for an assessment of antimicrobial resistance. Continuous collection of both data over time may solve such discrepancies between genotype and phenotype in the future.

Vibrio cholerae belonging to serogroups other than O1 and O139 are opportunistic pathogens which cause infections with a variety of clinical symptoms. Due to the increasing number of V. cholerae non-O1/non-O139 infections in association with recreational waters in the past two decades, they have received increasing attention in recent literature and by public health authorities. Since the treatment of choice is the administration of antibiotics, we investigated the distribution of antimicrobial resistance properties in a V. cholerae non-O1/non-O139 population in a large Austrian lake intensively used for recreation and in epidemiologically linked clinical isolates. In total, 82 environmental isolates - selected on the basis of comprehensive phylogenetic information - and nine clinical isolates were analyzed for their phenotypic antimicrobial susceptibility. The genomes of 46 environmental and eight clinical strains were screened for known genetic antimicrobial resistance traits in CARD and ResFinder databases. In general, antimicrobial susceptibility of the investigated V. cholerae population was high. The environmental strains were susceptible against most of the 16 tested antibiotics, except sulfonamides (97.5% resistant strains), streptomycin (39% resistant) and ampicillin (20.7% resistant). Clinical isolates partly showed additional resistance to amoxicillin-clavulanic acid. Genome analysis showed that crp , a regulator of multidrug efflux genes, and the bicyclomycin/multidrug efflux system of V. cholerae were present in all isolates. Nine isolates additionally carried variants of bla CARB–7 and bla CARB–9, determinants of beta-lactam resistance and six isolates carried catB9 , a determinant of phenicol resistance. Three isolates had both bla CARB–7 and catB9. In 27 isolates, five out of six subfamilies of the MATE-family were present. For all isolates no genes conferring resistance to aminoglycosides, macrolides and sulfonamides were detected. The apparent lack of either known antimicrobial resistance traits or mobile genetic elements indicates that in cholera non-epidemic regions of the world, V. cholerae non-O1/non-O139 play a minor role as a reservoir of resistance in the environment. The discrepancies between the phenotypic and genome-based antimicrobial resistance assessment show that for V. cholerae non-O1/non-O139, resistance databases are currently inappropriate for an assessment of antimicrobial resistance. Continuous collection of both data over time may solve such discrepancies between genotype and phenotype in the future. [ABSTRACT FROM AUTHOR]

Contaminated marine bathing water has been reported to adversely affect human health. Our data demonstrated a correlation between total endotoxin (lipopolysaccharide; LPS) levels and degree of contamination of marine bathing waters. To assess the potential health implications of LPS present in marine bathing waters, the inflammation-inducing potency of water samples collected at different time points at multiple sampling sites were assessed using a cell culture-based assay. The numbers of fecal indicator bacteria (FIB) were also examined in the same samples. Water samples were used to stimulate two cell culture models: (1) a novel non-transformed continuously growing murine cell line Max Plank Institute (MPI) characteristic of alveolar macrophages and (2) human MonoMac 6 monocyte cell line. The inflammatory potential of the samples was assessed by measuring the release of inflammatory cytokines. The presence of high levels of LPS in contaminated bathing water led to induction of inflammatory response from our in vitro cell-based bioassays suggesting its potential health impact. This finding introduces an in vitro culture assay that reflects the level of LPS in water samples. These observations further promote previous finding that LPS is a reliable surrogate biomarker for fecal contamination of bathing water. [ABSTRACT FROM AUTHOR]

The Systems Approach Framework with an integrated Ecological-Social-Economic assessment was applied to address the issue of zebra mussel (Dreissena polymorpha) farming in the large Oder (Szczecin) Lagoon, southern Baltic Sea. Heavy eutrophication hampers the use of the lagoon and zebra mussel farming is considered as new use and potential measure to improve water quality. Three alternative scenarios were developed in interaction with local stakeholders: 1) the production of mussels as fresh feed and meal on a commercial basis seemed not profitable, because of a limited market for fresh mussels (zoos, aquaculture) and low prices for organic feed. 2) Mussel cultivation to improve transparency and attractiveness of bathing waters near beaches had only a limited potential (0.2 m improvement of Secchi depth). A higher mussel biomass would increase the risk of temporary hypoxia. 3) Mussels farms for improving the environmental status (according to EU Water Framework Directive) by supporting macrophyte restoration were considered as the most promising scenario. Our model simulations suggested that as soon as a compensation for nutrient removal is considered, all mussel farm scenarios could cover the costs. Experiments and literature confirm that the conditions for an environmental friendly farming approach in the lagoon are suitable. Steps towards and problems associated with an implementation, e.g. invasion of Dreissena bugensis (quagga mussel), are discussed. Each step of the Ecological-Social-Economic assessment and major lessons learnt are documented in detail. Altogether, the approach turned out to be very suitable for this issue. [ABSTRACT FROM AUTHOR]

This review examines the aims of and approaches to the Quantitative Microbial Risk Assessment (QMRA) of untreated recreational waters. The literature search was conducted on four databases and yielded 54 papers, which were analyzed on a quantitative (time-trend, geographical distribution, water type) and qualitative (aims, source of microbial data, pathogens and their measurement or estimation, ways to address variability and uncertainty, sensitivity analysis) basis. In addition, the parameters, implications, and limitations were discussed for each QMRA step. Since 2003, the number of papers has greatly increased, highlighting the importance of QMRA for the risk management of recreational waters. Nevertheless, QMRA still exhibits critical issues, above all regarding contamination data and dose-response relationships. To our knowledge, this is the first review to give a wide panoramic view on QMRA in relation to recreational exposure to untreated waters. This could be useful in identifying the current knowledge gaps and research needs. Display Omitted • The application of QMRA to untreated recreational waters is rapidly increasing. • QMRA has been used with multiple purposes. • The input values of pathogen concentrations are drawn from different data sources. • Recovery efficiency and infectivity are not always addressed. • Further research is needed about pathogens quantification and dose-response curves. [ABSTRACT FROM AUTHOR]

To quantify the impact of fecal pollution on the microbiological bathing water quality, predictive modeling is being increasingly used in which the decay rate of the fecal indicators plays an important role. The decay of sewage-sourced enterococci and Escherichia coli culturable cells and their associated molecular markers (16SrRNA) quantified by Quantitative Reverse transcription PCR were measured in controlled microcosms as well in in situ conditions using different water types, from marine waters to fresh waters with intermediate salinity. All bacterial decays were fitted to a first order decay model. In the laboratory study, the light radiation was the most influent factor affecting E. coli and enterococci survival by culture methods although environmental conditions weakly impacted the decay of molecular markers. The results also indicated differential persistence of genetic markers and culturable organisms of fecal indicator bacteria in different water systems. For each bacteria indicator and analytical method, four equations were obtained to predict the time required to have a 90% reduction (T90) according irradiance, salinity and temperature parameters. The weighted model RMSE (Root Mean Square Error) calculated for all field experiments showed that quantification obtained with the equations defined by laboratory-based study compared reasonably well with in-situ observed quantification (0.4 and 0.2 log by standard culture methods for E. coli and Enterococcus spp. and 0.6 and 0.3 log by RT-qPCR for E. coli and Enterococcus spp. respectively). The modeling tool can be used to predict the presence of fecal pollution in marine and fresh waters in combination with either culture based- or rapid molecular methods. [ABSTRACT FROM AUTHOR]

Abstract This study defines performance characteristics of the temperature-modified ISO 9308-1 method for E. coli enumeration in bathing water. After a 4-hour resuscitation period at 36 ± 2 °C, the incubation temperature was changed to 44 ± 0.5 °C. Elevated incubation temperature significantly suppressed the growth of thermo-intolerant bacteria, and enhanced the selectivity of Chromogenic Coliform Agar (CCA) up to 49.5% for inland and up to 66.0% for coastal water. Consequently, most of the selectivity-related performance characteristics are improved. Relative recovery was determined by comparing an alternative method against the reference, ISO 9308-1:2014 method, following the criteria set out in ISO 17994:2014. Temperature modification did not significantly alter the results and the methods were evaluated as "not different" for both, coastal and inland waters. Chromogenic Coliform Agar was assessed as a suitable medium for reliable E. coli enumeration in bathing water when incubated for 17–19 h at 44 ± 0.5 °C after the 4–5 h resuscitation period at 36 ± 2 °C. Graphical abstract Unlabelled Image Highlights • A resuscitation period was crucial for E. coli recovery by the modified method. • Relative recovery was high for both inland and coastal bathing water samples. • Temperature modification significantly enhanced the selectivity of the method. • All performance characteristics meet the requirements of ISO 13843:2017. • The method was assessed as suitable for E. coli enumeration in bathing water. [ABSTRACT FROM AUTHOR]

This study developed, cross-validated and applied a regression-based model to predict concentrations of faecal indicator organisms (FIOs) under different environmental conditions in the North and South bays of Santa Catarina, South of Brazil. The model was developed using a database of FIO concentrations in seawater sampled at 50 sites and the validation was performed using a different database by comparing 288 pairs of measured and modelled results for 15 sites. The index of agreement between the model outputs and the FIO concentrations measured during the validation period was 66%; the mean average error was 0.43 log 10 and the root mean square error was 0.58 log 10 MPN.100 mL −1 . These validation results indicate that the model provides a fair representation of the FIO contamination in the bays for the meteorological conditions under which the model was trained. The simulation of different scenarios showed that under typical levels of resident human population in the catchments and median rainfall and solar radiation conditions, the median FIO concentration in the bays is 0.4 MPN.100 mL −1 . Under extreme meteorological conditions, the combined effect of high rainfall and low solar radiation increased FIO concentrations up to 5 log 10 MPN.100 mL −1 . The simulated scenarios also show that increases in resident population during the summer tourist season and average rainfall concentrations do not increase median FIO concentrations in the bays relative to periods of time with average population, possibly because of higher bacterial die-off in the waters. The models can be an effective tool for management of human health risks in bathing and shellfish waters impacted by sewage pollution. [ABSTRACT FROM AUTHOR]

In recent years, global warming has led to a growing number of Vibrio cholerae infections in bathing water users in regions formerly unaffected by this pathogen. It is therefore of high importance to monitor V. cholerae in aquatic environments and to elucidate the main factors governing its prevalence and abundance. For this purpose, rapid and standardizable methods that can be performed by routine water laboratories are prerequisite. In this study, we applied a recently developed multiplex quantitative PCR (qPCR) strategy (i) to monitor the spatiotemporal variability of V. cholerae abundance in two small soda pools and a large lake that is intensively used for recreation and (ii) to elucidate the main factors driving V. cholerae dynamics in these environments. V. cholerae was detected with qPCR at high concentrations of up to 970,000 genomic units 100 ml-1 during the warm season, up to 2 orders of magnitude higher than values obtained by cultivation. An independent cytometric approach led to results comparable to qPCR data but with significantly more positive samples due to problems with DNA recovery for qPCR. Not a single sample was positive for toxigenic V. cholerae, indicating that only nontoxigenic V. cholerae (NTVC) was present. Temperature was the main predictor of NTVC abundance, but the quality and quantity of dissolved organic matter were also important environmental correlates. Based on this study, we recommend using the developed qPCR strategy for quantification of toxigenic and nontoxigenic V. cholerae in bathing waters with the need for improvements in DNA recovery. [ABSTRACT FROM AUTHOR]

In recent years, a global increase in the number of reports of human vibriosis involving V. cholerae non-O1/O139 (NOVC) and other Vibrio spp. has been observed. In this context, the Belgian National Reference Center for Vibrio conducted an assessment of the presence of Vibrio spp. in recreational waters. Water sampling was performed monthly in different lakes in Wallonia and Flanders, including the North Sea. The collected water was then filtrated and cultured, and Vibrio spp. was quantified according to the Most Probable Number (MPN). Presumptive colonies were confirmed via MALDI-TOF, and PCR for virulence genes was applied if justified. No Vibrio spp. was found in the analyzed water bodies in Wallonia. However, NOVC was isolated from three different lakes in Flanders and from coastal water. In addition, V. alginolyticus and V. parahaemolyticus were also detected in coastal water. No clear impact of the pH and temperature was observed on Vibrio spp. occurrence. Our study demonstrates the presence of Vibrio spp. in different bathing water bodies, mostly in the north of Belgium, and supports the recommendation to include Vibrio spp. as a water quality indicator for bathing water quality assessment to ensure the safety of water recreational users in Belgium.

In early autumn 2011, three dogs died after they had been exposed to a Microcystis aeruginosa bloom on Lake Amstelmeer, The Netherlands. The cyanobacterial scum from the lake contained up to 5.27 × 103 μg g−1 dry-weight microcystin, the vomit of one of the dogs contained on average 94 µg microcystin g−1 dry-weight. In both cases, microcystin-LR was the most abundant variant. This is the first report of dog deaths associated with a Microcystis bloom and microcystin poisoning in The Netherlands.

Introduction: The twinning project entitled "Alignment in Bathing Water Monitoring" was implemented within the framework of EU Pre-Accession Financial Assistance IPA I-2010 Programming by the Ministry of Health, Public Health Institution of Turkey together with France-Italy consortium between the I. quarter of 2013 and II. quarter of 2015. The major aims of the project was to transpose the new bathing water Directive 2006/7/EC into the Turkish National Legislation and strengthening the bathing water quality monitoring system of Ministry of Health - Public Health Institution of Turkey within the framework of the new directive. Methods: The project was designed such as to ensure the alignment of the new bathing water Directive 2006/7/EC and preparation of the draft bylaw on bathing water quality management, transition from 76/160/EEC to 2006/7/EC Directive regarding the classification and quality assessment of bathing water starting gradually with the pilot applications and then disseminating to the whole bathing areas, the practice of establishing experimental bathing water profiles in the selected areas of the pilot provinces, compiling of sets of bathing water quality data, improvement of the bathing water quality monitoring system of the Ministry of Health in the direction of 2006/7/EC Directive, improvement of the technical capacity of the Public Health Laboratories to perform analysis according to the new bathing water directive. Results: The draft "By-law on bathing water quality management" has been prepared with the transposition of 2006/7/EC EU Directive by the Ministry of Health, Public Health Institution of Turkey with the contribution of the relevant institutions. Trainings and workshops were organized. Six guidance documents were prepared, published and distributed. Data quality assessment and classification practice were done at pilot provinces Antalya, Çanakkale and İstanbul. Conclusion: The all activities given in the project contract have been successfully completed and all project mandatory results were reached. The technical and institutional capacity for the full implementation of the 2006/7/EC Directive by the Ministry of Health was impoved successfully with the project. [ABSTRACT FROM AUTHOR]

Fungal infections are commonly reported among outdoor bathers. Recreational water reservoirs are an important element of the mycosis epidemiological chain in the biosphere because they can be a source of fungi from municipal wastes, of asymptomatic carriers or bathers carrying mycoses. Yeast-like fungi and moulds were isolated from samples of four surface water baths and five swimming pools in 2011-2012. Membrane filters and standard laboratory-based protocols were used to identify the isolated fungi. In total, 51 saprotrophic and potentially pathogenic species classified in the biosafety level-2 group were found. In one of the eutrophic lakes, a positive correlation was observed between the frequency of trading and the presence of coliform yeasts, while in the second, a correlation was found between the number of species of fungi and the presence of faecal streptococci. In swimming pool waters, the key factors that determined higher numbers of fungi were increased temperature, followed by low concentrations of chlorine ions. Together with the bacteriological and physicochemical analysis, constant mycological monitoring of recreational water (lake pools and swimming pools) should be a standard inspection element to reduce sanitary and epidemiologic risks to people using these water reservoirs for recreational purposes. [ABSTRACT FROM AUTHOR]

This study investigated the public health risk from exposure to infectious microorganisms at Sandvika recreational beaches, Norway and dose–response relationships by combining hydrodynamic modelling with Quantitative Microbial Risk Assessment (QMRA). Meteorological and hydrological data were collected to produce a calibrated hydrodynamic model using Escherichia coli as an indicator of faecal contamination. Based on average concentrations of reference pathogens (norovirus, Campylobacter , Salmonella , Giardia and Cryptosporidium ) relative to E. coli in Norwegian sewage from previous studies, the hydrodynamic model was used for simulating the concentrations of pathogens at the local beaches during and after a heavy rainfall event, using three different decay rates. The simulated concentrations were used as input for QMRA and the public health risk was estimated as probability of infection from a single exposure of bathers during the three consecutive days after the rainfall event. The level of risk on the first day after the rainfall event was acceptable for the bacterial and parasitic reference pathogens, but high for the viral reference pathogen at all beaches, and severe at Kalvøya-small and Kalvøya-big beaches, supporting the advice of avoiding swimming in the day(s) after heavy rainfall. The study demonstrates the potential of combining discharge-based hydrodynamic modelling with QMRA in the context of bathing water as a tool to evaluate public health risk and support beach management decisions. [ABSTRACT FROM AUTHOR]

The purpose of this equivalence study was to compare an alternative method, Colilert-18 Quanti-Tray (ISO 9308-2) with the European bathing water directive (2006/7/EC) reference method, the miniaturised most probable number (MMPN) method (ISO 9308-3), for the analysis of Escherichia coli. Six laboratories analysed a total of 263 bathing water samples in Finland. The comparison was carried out according to ISO 17994:2004. The recovery of E. coli using the Colilert-18 method was 7.0% and 8.6% lower than that of the MMPN method after 48 hours and 72 hours of incubation, respectively. The confirmation rate of presumptive E. coli-positive wells in the Colilert-18 and MMPN methods was high (97.8% and 98.0%, respectively). However, the testing of presumptive E. colinegative but coliform bacteria-positive (yellow but not fluorescent) Colilert-18 wells revealed 7.3% false negative results. There were more false negatives in the naturally contaminated waters than in the samples spiked with waste water. The difference between the recovery of Colilert-18 and the MMPN method was considered not significant, and subsequently the methods are considered as equivalent for bathing water quality monitoring in Finland. Future bathing water method equivalence verification studies may use the data reported herein. The laboratories should make sure that any wells showing even minor fluorescence will be determined as positive for E. coli. [ABSTRACT FROM AUTHOR]

An electrolysed solution of sodium chloride was examined for its disinfection potential in drinking and bathing water. The electrolysis of NaCl ((=1%) in tap water was performed at room temperature using a 10 A electric current in an electrolysis apparatus. Some laboratory tests were made, initially to determine the stability and efficiency of the disinfectant. Chemical and microbiological measurements of the treated water (according to DIN 19643 for bathing water) were then carried out before and after addition of the disinfectant agent.

Most studies characterize microbial source tracking (MST) target performance using sensitivity and specificity metrics. However, it is important to also consider the temporal stability of MST targets in relation to regulated microbial pollutants. Differences among bacterial target stabilities may lead to erroneous conclusions about sources of contamination. The present study evaluates the relative stability of MST targets and fecal indicator organisms using the gull/pigeon-associated Catellicoccus marimammalium (CAT) marker and enterococci (ENT). The decay rates of CAT and ENT measured by culture (cENT) and QPCR (tENT) were compared in sand and seawater laboratory microcosms under environmentally relevant conditions (subject to tidal wetting versus no wetting in sand, and sunlit versus dark conditions in seawater). Bacterial targets were more persistent in beach sand than in seawater with decay rates on the order of 0.01–0.1 per day and 1 to 10 per day, respectively. Targets were more persistent in unwetted compared to wetted sand, and dark compared to sunlit seawater. During the first 8 days of the sand experiment, the decay rate k of CAT was greater than that of cENT. The decay rates of CAT, tENT, and cENT were similar in sand after day 8 and in dark seawater. In sunlit seawater, the decay rates were different between targets with k cENT > k CAT > k tENT . The decay rates presented here are useful for fate and transport models and also inform the use of MST marker concentrations to infer ENT sources in the environment. [ABSTRACT FROM AUTHOR]

Due to the increasing economic and cultural value of bathing waters and the shellfish industry in the UK and worldwide, water quality in estuarine and coastal waters has attracted considerable public attention in recent years. To obtain accurate predictions of the concentration distributions of faecal indicator organisms (FIOs) in coastal waters for better management of bathing water compliance, it is necessary to build an integrated modelling system to predict the complete diffuse and point source inputs from river and catchment basins. In the present paper, details are given of the development of such an integrated modelling system for simulating the transport and decay processes of FIOs, from catchment areas upstream from the coastal region, in which a distributed catchment module, a 1D river network module and a 2D estuarine and coastal module are linked dynamically by boundary inputs and outputs. Extensive measured data from the catchments, river networks and estuaries have been collated to determine the model parameters. Verification results of the distribution of water levels, flows and velocities, and suspended sediment and Escherichia coli concentrations, at controlled monitoring sites are presented, which show that the integrated model predictions generally agree well with the measurements, although locally appreciable errors can occur. The model results also highlight the importance of including the flux of FIOs via sediments being an important factor in terms of assessing the quality of bathing waters. The main factors influencing the relatively high concentration values in the bathing region are analysed, based on the model predictions and measured data, with four categories of FIO concentration levels being reviewed. [ABSTRACT FROM AUTHOR]

Pollution of surface waters with pathogens from combined sewer overflows limits recreational use of surface waters. Large retention basins are a satisfactory solution but they are rarely sufficient for economic or space reasons. Fast disinfection during the overflow is an alternative, but few methods are known and each has problems. This work evaluated for the first time the full-scale disinfection using performic acid by the removal of the two currently regulated indicator bacteria for bathing water quality, Escherichia coli and Enterococcus . Experiments were performed at a sewage bypass through a sea-outfall pipe with a minimum hydraulic retention time of 24 min. The disinfection efficiency in the field was measured by analyzing samples taken before and after the treatment. Samples were also treated with performic acid in the laboratory to measure the disinfection effectiveness and kinetic of degradation of performic acid. Doses of 1–8 ppm of performic acid achieved 1.0–3.5 log removal of E. coli and 1.0–2.44 log removal of Enterococcus in the field, but were somewhat higher in laboratory conditions at 1.69–4.38 and 1.0–4.27 log units, respectively. Studies of the degradation of performic acid in collected real samples showed more than 50% was degraded in 20 min, and mostly degraded by 120 min. Comparison of field and laboratory dosed samples detected that performic acid synthesis did not start in one event and clogging of the sampler in another event. Overall the tests showed that the treatment was successful but it is indicated that online control could benefit treatments efficiency. [ABSTRACT FROM AUTHOR]