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Escherichia coli and total coliforms are important tools for identifying potential faecal contamination in drinking water. However, metagenomics offers a powerful approach for delving deeper into a bacterial community when E. coli or total coliforms are detected. Metagenomics can identify microbes native to water systems, track community changes and potential pathogens introduced by contamination events, and evaluate the effectiveness of treatment processes. Here, we demonstrate how the dual application of traditional monitoring practices and metagenomics can improve monitoring and surveillance for water resource management. The robustness of long-read metagenomics across replicates is demonstrated by the effect and interaction between manganese filters and bacterial communities, as well as the impact of chlorination after coliform detection. These examples reveal how metagenomics can identify the complex bacterial communities in the distribution system and the source waters used to supply drinking water treatment plants (DWTPs). The knowledge gained increases confidence in identified causes and mitigations of potential contamination events. By exploring bacterial communities, we can gain additional insights into the impact of faecal contamination events and treatment processes. This insight enables more precise remediation actions and enhances confidence in communicating health risks to drinking water operators and the public. [ABSTRACT FROM AUTHOR]

This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine the potability of water from these waterwork stations. Eighteen sampling points were established across the two reservoir networks for this study. Samples were collected bi-monthly for two annual cycles. Serial dilution and pour plate methods were employed for the enumeration of bacterial load. Total heterotrophic bacteria count (THBC) and total coliform bacteria count (TCBC) were enumerated on nutrient and MacConkey agar at 37 °C, respectively. Bacterial isolates were characterized using biochemical identification methods with reference to Bergey's Manual of Determinative Bacteriology. Bacterial isolates and biofilm formation were further identified molecularly through the PCR method using specific universal primers. Mean values of THBC and TCBC in distributed water from Ede-Erinle (9.61 × 104 ± 1.50 × 104 CFU/mL; 69.56 ± 26.81 CFU/mL) and Opa waterworks (9.58 × 104 ± 2.55 × 104 CFU/mL; 142.94 ± 44.41 CFU/mL) exceeded permissible limits for drinking water. Paenibacillus lautus, Bacillus pseudomycoides, Pseudomonas aeruginosa, and Pseudomonas stutzeri showed biofilm-forming capacity. The study concluded that the presence of coliforms and biofilm-forming bacteria in distributed water implies that the water is unfit for consumption without further treatment. HIGHLIGHTS Molecular identification of coliforms from the two reservoirs and their channels.; Molecular detection of biofilm bacteria in water from the two waterwork systems.; Comparison of molecular loads of water from the two waterwork systems.; Health implications of the identified bacteria from the two waterwork systems.; Potablilty of water from the two reservoirs and their stations.;

There is a need for access to clean potable water worldwide. However, almost every source of surface water in Guatemala is contaminated. This study assesses the potential exposure to water contaminants in proximity to Medecins Sans Frontieres's (MSF) chronic kidney disease clinic population in La Gomera, Guatemala during wet and dry seasons. Five municipal wells and four artisanal wells (servicing approximately 18.9% of La Gomera) were selected for their proximity to MSF La Gomera clinic to determine the presence of coliforms, physicochemical parameters, heavy metals, and pesticide residues. Water samples were collected over 3 consecutive days during La Gomera's wet season and again during the dry season. Wet season 2022: Total coliforms and Escherichia coli exceeded the acceptable limits for several artisanal wells but were not detected in municipal wells. Mercury and arsenic were detected in all wells during at least one sampling period. Dry season 2023: Total coliforms exceeded the acceptable limits for all wells and E. coli was detected in all four artisanal wells. Lead and arsenic were detected in all wells. Our results suggest that water from artisanal wells does not meet COGUANOR or WHO microbiological criteria for human consumption. HIGHLIGHTS No information on water quality in La Gomera, Guatemala.; Comprehensive assessment of water quality in region.; Assess public and private water sources.; Relationship between water quality and health.; Timeseries of water quality.;

This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine the potability of water from these waterwork stations. Eighteen sampling points were established across the two reservoir networks for this study. Samples were collected bi-monthly for two annual cycles. Serial dilution and pour plate methods were employed for the enumeration of bacterial load. Total heterotrophic bacteria count (THBC) and total coliform bacteria count (TCBC) were enumerated on nutrient and MacConkey agar at 37 °C, respectively. Bacterial isolates were characterized using biochemical identification methods with reference to Bergey’s Manual of Determinative Bacteriology. Bacterial isolates and biofilm formation were further identified molecularly through the PCR method using specific universal primers. Mean values of THBC and TCBC in distributed water from Ede-Erinle (9.61 × 104 ± 1.50 × 104 CFU/mL; 69.56 ± 26.81 CFU/mL) and Opa waterworks (9.58 × 104 ± 2.55 × 104 CFU/mL; 142.94 ± 44.41 CFU/mL) exceeded permissible limits for drinking water. Paenibacillus lautus, Bacillus pseudomycoides, Pseudomonas aeruginosa, and Pseudomonas stutzeri showed biofilm-forming capacity. The study concluded that the presence of coliforms and biofilm-forming bacteria in distributed water implies that the water is unfit for consumption without further treatment. [ABSTRACT FROM AUTHOR]

Ensuring the microbiological safety of drinking water is of paramount importance to protect public health. Coliform bacteria, including Escherichia coli, serve as key indicators of water contamination and the potential presence of harmful pathogens. Accurate and reliable detection and enumeration of coliforms in drinking water are essential for monitoring water quality and implementing appropriate interventions. This review article provides an overview of various traditional culture-based methods and rapid molecular methods employed for the analysis of coliforms in drinking water, highlighting their strengths, limitations, and advancements. Culture-based methods such as multiple-tube fermentation (most probable number) and membrane filtration techniques have long been used as standard methods for coliform detection. The emerging molecular-based approaches, including polymerase chain reaction (PCR), quantitative PCR, and nucleic acid sequencing offer improved sensitivity, specificity, and turnaround time. This comprehensive review provides a valuable resource for researchers, water quality professionals, and policymakers engaged in the detection and enumeration of coliform bacteria in drinking water. It offers an up-to-date understanding of different methods, their advancements, and the potential integration of novel technologies. By critically evaluating these approaches, this review aims to contribute to the ongoing efforts toward ensuring safe drinking water for all. HIGHLIGHTS The need for microbiological water quality assessment has been highlighted.; Concept of indicator microorganisms for estimating the water quality.; Classical and modern methods for the detection of coliforms in drinking water.; Advantages and limitations of molecular methods for enumeration of coliforms.; Evaluation of the need for alternative methods for the detection of indicator microorganisms.;

In low-income countries like Ethiopia, waterborne illnesses have posed serious public health problems. This study aimed to evaluate drinking water quality (DWQ) and associated factors in Bahir Dar City and the surrounding rural areas in northwest Ethiopia. A cross-sectional study was conducted from January to June 2022 to determine coliform counts and basic physicochemical parameters from the drinking water samples (DWS) collected from urban, peri-urban, and rural sites. A total of 180 DWS were collected from water collection points and households' containers. Potentially pathogenic bacteria were also isolated from fecal coliform (FC)-positive samples and their antibiotic susceptibility profiles were determined. Moreover, the risk factors associated with water quality were assessed. The water quality test results were evaluated against the WHO guidelines for DWQ. Based on the results of this study, only 16.7 and 73.88% of samples met the standards for total coliform and FC, respectively. Moreover, 95.4 and 43% of the isolated bacteria were resistant at least to one of the commonly used antibiotics and multidrug-resistant, respectively. Educating the public on proper drinking water handling, appropriate treatment, and waterline maintenance are needed to safeguard the community from waterborne diseases. HIGHLIGHTS Most of the drinking water in Bahir Dar City does not comply with the WHO standards.; There were poor drinking water disinfection practices in Bahir Dar City.; Drinking water quality in rural areas of Bahir Dar City was at a high sanitary standard.; There were poor drinking water handling practices in Bahir Dar City at the household levels.; Access to low-drinking water was prevalent in Bahir Dar City.;

The potability of water, including underground sources, is constantly affected by human activities. To assess water quality and water security in rural and urban areas of southern Brazil, a quantitative, retrospective analysis of water samples collected monthly by the Brazilian health authorities (19,687 samples from 2013 to 2021) was performed. In rural areas, 5,979 water samples (77.54%) were found to be contaminated by coliform bacteria and 3,431 (44.50%) by Escherichia coli. In addition, 1,616 (20.95%) of the contaminated samples were significantly correlated with rainfall amount. In urban areas, 1,268 (10.95%) of the samples contained coliform bacteria and 293 (2.53%) of these samples contained E. coli, with the factor of rainfall associated with 1,081 samples (9.33%) with bacterial contamination. In terms of physicochemical parameters, turbidity exceeded the national standard (5 uT) in 448 (2.32%) samples and fluoride fell below the required level (0.8 mg/L) in 106 samples (0.54%). The presence of free residual chlorine (0.2–2.0 mg/L) was verified in 846 samples (14.38%) in rural areas and in 10,825 samples (56.13%) in urban areas. These results suggest a strong association between rainfall factors and physicochemical alterations, as well as the risk of greater microbial contamination of water for human consumption. [ABSTRACT FROM AUTHOR]

Ultraviolet light-emitting diodes (UV-LED) can be a good option for disinfecting water in small and decentralized facilities. A flow-through UV-LED disinfection module was evaluated at three remote locations in Japan. The disinfection efficiency of the module was monitored for over one year, targeting indigenous Escherichia coli, total coliforms, standard plate count, and heterotrophic plate count (HPC) bacteria. The physicochemical parameters of the source water, including UV transmittance (UVT), were also monitored to understand their natural fluctuation and impacts on UV disinfection. Overall, the UV-LED module showed efficient disinfection at all locations, achieving 2.7 log inactivation of E. coli at 30 L/min in a community-based water supply. HPC inactivation did not significantly differ among the three test sites (p . 0.01). One test site experienced a decrease in HPC inactivation after 10 months, whereas the other two sites did not show performance deterioration after one year. HPC inactivation was not correlated with the UVT of source water at any location, implying the difficulty to use UVT as a single parameter to predict disinfection efficiency in practical applications. This study demonstrates the effectiveness of UV-LED technology for water disinfection in small and decentralized water supply systems. [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. [ABSTRACT FROM AUTHOR]

The presence of coliforms, Mastadenovirus (AdV), and Canine protoparvovirus (CPV) in an Environmental Education Center, which contains city kennel, was investigated. Surface water and wastewater, dogs’ stool, and lettuce samples were collected from the irrigation system in both periods October 2017 and February 2018. Water samples were analyzed for the presence of human AdV (HAdV) and canine AdV (CAV), CPV, total coliforms (TC), and Escherichia coli; lettuce for AdV; and dog stool for CAV and CPV. Sixty-seven samples were analyzed: dog stool (n = 33); water (n = 10), and root, stem, and leaf (n = 24) originated from eight lettuce samples. Coliforms and E. coli were tested by Colilert and viruses by PCR assays, respectively; and the amplicon was sequenced. E. coli, TC, and viruses were detected in both collections. Viruses were detected in 34.3% of samples, of which HAdV-C was present in 13% of water samples; HAdV-E in 8.7% (water and lettuce); CAV-1 in 13% (dog stool and water); CPV-2a in 56.5% (dog stool). Raccoon CPV-like and AdV not characterized were detected in one wastewater samples and one dog stool, respectively. To our knowledge, this is the first description of the presence of Raccoon CPV-like in water and HAdV-E in lettuce in Southern Brazil. HIGHLIGHTS Protoparvovirus in wastewater in Brazil is detected.; Raccon CPV-like can represent a potential transmission interspecies.; HAdV-E in lettuce from an irrigation system – Southern Brazil – is presented.; Lettuce diseases are likely waterborne viral diseases.;

Groundwater from boreholes is the major source of bottled water in Algeria. The aim of this study is to determine the bacteriological quality of groundwater that serves bottled water production. A total of 73 groundwater boreholes were sampled and analyzed for the required bacteriological parameters. The analysis was performed in accordance to ISO standards methods. There should be no bacteria growth for each bacteriological parameter to qualify the groundwater of good bacteriological quality. The bacteriological analysis highlighted that 37 of the 73 groundwater samples (51%) were of poor bacteriological quality while 36 of them (49%) were of good bacteriological quality. Total coliforms and E. coli were the major sources of contamination with respectively 35 and 24 contaminated samples, followed in order by Pseudomonas aeruginosa, enterococci and sulfite reducing anaerobic bacteria spores with respectively 8, 7 and 2 contaminated samples. Bacteriological quality was strongly and negatively correlated with urbanization and/or agricultural activity parameter (r = −0.454). The performed logistic regression model showed that the presence of urbanization or agricultural activity multiplies significantly (P < 0.001) the risk by 7 of being a poor bacteriological quality groundwater. These findings are useful to avoid drill costs and to take the best strategy to protect groundwaters. HIGHLIGHTS Half of groundwaters do not satisfy the bacteriological quality criteria.; Total coliforms and E. coli are the major sources of contamination in the studied groundwaters.; The presence of urbanization or agricultural activity has a negative impact on groundwater bacteriological quality.; Evidence was shown that drilling costs could be avoided by adopting the groundwater quality prediction tools.;

The effects of depth and climate seasonality on zooplankton, algal biomass, coliforms and Escherichia coli in a small full-scale shallow maturation pond receiving pre-treated domestic wastewater were evaluated during a tropical climatic seasonal cycle. The experiment revealed that the zooplankton community was dominated by rotifers and protozoans, and concentrations were influenced by seasonality. A negative correlation between zooplankton, and pH, dissolved oxygen, temperature and ultraviolet radiation, and chlorophyll-a and Escherichia coli were observed at all depths. The major driving forces influencing Escherichia coli were pH, dissolved oxygen, ultraviolet radiation and the zooplankton. A significant difference between Escherichia coli removal throughout the three different depths were observed. Both bacterial and zooplankton concentrations were greater closer to the bottom of the pond, therefore reinforcing the integral role of solar radiation on bacterial removal. These results give an insight on the dynamics of these groups in pond systems treating domestic wastewater, by correlating the variation of zooplankton with biotic and abiotic variables and seasonal changes in a tropical climate, where few studies have been performed on this topic. HIGHLIGHTS The variables pH, DO, zooplankton community and solar radiation are shown to be determining factors in reducing E. coli in a maturation pond.; Zooplankton concentrations were greater closer to the bottom of the pond.; E. coli removal varied between the three different depths reinforcing the role of solar radiation on bacterial removal rate.;

Feco-orally transmitted infectious diseases are common in Nigeria where the potable water access is poor. In the south-western Nigerian Ibadan metropolis, supply of municipal water is meagre as residents depend on household wells and boreholes. The likelihood of fecal contamination of household water sources in Ibadan was examined longitudinally to quantify and understand its impact. Well and borehole water samples aseptically collected from 96 households in Ibadan were assessed for total heterotrophic counts (THCs), total coliform counts (TCCs) and total Escherichia coli counts (TECs) using a pour plate technique. E. coli were identified by uidA and whole-genome sequencing using Illumina technology, whereas virulence factors were predicted using VirulenceFinder. There was season-independent abundance of THC and TCC in the well and borehole with a significant recovery of E. coli in the wells during the wet season compared to the dry season (P ¼ 0.0001). Virulence genes associated with pathogenic E. coli were identified in 13 (52%) strains with one E. coli each classified as extra-intestinal E. coli, avian pathogenic E. coli and enteroaggregative E. coli. High heterotrophic and coliform counts, with rainfall-driven E. coli contamination revealed that the water sources evaluated in this study are unfit for consumption. [ABSTRACT FROM AUTHOR]

Direct application of raw municipal wastewater for irrigation purposes may create many undesirable harmful consequences. Therefore, treated effluent through different technologies is generally preferred for reuse especially in water-scarce regions. In the present study, the performances of some treatment technologies like constructed wetland (CW), waste stabilisation pond (WSP), membrane bioreactor (MBR), vermi-biofiltration (VBF) and land treatment methods for removal of chemical and biological impurities from municipal wastewater were reviewed. The study revealed that the treated water quality varied depending on the hydraulic retention time under different treatment methods. The reservoir should be considered an integral part of the wastewater treatment system and not merely an operative ponding volume for irrigation. The comparatively advanced MBR technique showed better performance for removal of BOD, COD, fecal coliforms, Escherichia coli and other biological impurities than the traditional approach. Some techniques like land treatment methods and VBF were found to be equally attractive in developed as well as developing nations. The future projections of global green and blue water scarcities indicate treated water to be a valuable alternative water resource to fulfil required crop water footprints as well as irrigation demands. HIGHLIGHTS The treated water quality varied depending on the hydraulic retention time under different treatment methods.; The reservoir should be considered an integral part of the wastewater treatment system.; Land treatment methods and VBF were found to be equally attractive in developed as well as developing nations.; The treated water is a valuable alternative water resource to fulfil crop water footprints and irrigation demands.;

Drinking water quality from sources other than tap water is increasingly becoming a source of concern in many communities. Communities in the Eastern Coachella Valley (ECV), Riverside County, California, USA have raised concerns regarding bulk drinking water from water vending machines (WVMs) found in public vendors. To address concerns, we conducted microbiological contamination assessments of drinking water from WVMs in the ECV using heterotrophic plate counts (HPC), the presence of total coliforms using IDEXX technology, and real-time PCR (qPCR). We also measured temperature, pH, electrical conductivity, and free chlorine concentration. Twenty-five WVMs were sampled by using positively charged NanoCeram® filters in the field. Results indicated 32% of WVMs had total coliforms, and 21% had HPC above Environmental Protection Agency (EPA) requirements. Through qPCR, we found 81% of WVMs had Salmonella spp., Listeria monocytogenes, and Campylobacter jejuni, 76% had Enterococcus faecalis, and 90% had Pseudomonas aeruginosa. Results indicated most WVM samples we collected contained genetic material of pathogenic microorganisms and therefore, did not meet EPA drinking water standards. There is an urgency to enforce WVM maintenance through drain flushing, spigot cleaning, rust removal, filter replacement, and limits to physico-chemical parameters. HIGHLIGHTS Drinking water quality from vending machines was assessed in a disadvantaged rural community in Southern California.; Real-time qPCR was used to determine water quality via a select panel of indicator bacteria.; Drinking water vending machines were found to be contaminated by using cultivatable IDEXX and qPCR methods.; We emphasize following current regulations for maintaining water vending machines.;

Access to safe drinking water is one of the basic human rights and is essential to human health. The present study investigated the concentration of pathogenic microbial flora and health risk in drinking water samples in households of Bangalore city, Karnataka, India. The samples were analysed for microbiological and physico-chemical parameters. In this study, most probable number and heterotrophic plate count were used to assess the microbial load. The results of the study show that most of the household water samples were contaminated with the presence of coliform bacteria. The dominant bacterial species are Escherichia coli, Salmonella, Shigella, Klebsiella and Enterobacter. The bacteria belonging to the family Enterobacteriaceae showed maximum occurrence in water samples. The overall results of the study showed that the consumption of such contaminated drinking water at the end-user point may cause potential health hazards to the inhabitants. HIGHLIGHTS Study investigated the concentration of pathogenic microbial flora and health risk in drinking water samples in households of Bangalore city, Karnataka, India.; The result of the study shows that most of the household water samples were contaminated with coliform bacteria.; This study indicates that continuous consumption of such contaminated water could pose health risks to water consumers.;

Despite drinking water supply in Kobo town is from a borehole through pipes, a high incidence of waterborne diseases are frequently reported. Hence, this study aimed to assess the bacteriological and physicochemical drinking water quality in Kobo town. One hundred and twenty water samples were collected from four sampling sites (the source, reservoir, taps, and households' containers) from February to April 2020. Total and fecal coliforms were counted from the water samples using membrane filtration while selected physicochemical parameters were determined using standard methods. The mean counts of total and fecal coliforms ranged from 3.9 to 22.9 and 1 to 13.6 CFU/100 mL, respectively. Hence, all water samples did not satisfy the WHO guidelines and national standards. There were statistically significant differences in the coliform counts between the different sampling sites, and the counts were significantly higher in the taps and households' containers compared to the counts in the source and reservoir (p < 0.05). All physicochemical parameters, except for temperature, were within the recommended acceptable limits. High coliform count in the water system demands proper maintenance of the distribution line and good hygiene practices at household level to improve the microbiological quality of drinking water in Kobo town. HIGHLIGHTS Drinking water in Kobo town had high risk score.; Coliform counts in drinking water of Kobo town fail to comply with WHO standards.; Physicochemical water quality parameters in Kobo town comply with WHO standards.; Poor sanitation and water handling practices were observed in the community of Kobo town.; Preventing human activities around the water source and reservoir are highly recommended.;

This study describes the quality of drinking water sampled over 2 years (2018 and 2019) from 20 ASADAS (Spanish acronym for Administrative Associations for Water and Sewer Systems) in Costa Rica. The analysis included Rotavirus (RV), somatic coliphages, fecal coliforms, and Escherichia coli. The ASADAS were categorized into three regions as temperate rainy (region 1), tropical rainy (region 2), and tropical rainy and dry (region 3) according to biogeographic classification. The concentrations of fecal coliforms and E. coli were higher in samples from surface water sources from the ASADAS in region 3 compared to regions 1 and 2. RV-positive samples (24/296) were detected in drinking-water samples from regions 2 and 3 during dry and transition seasons, with higher concentrations more frequently in the dry season. In addition, somatic coliphages were detected in samples from the three regions, with higher concentrations in region 2. Furthermore, a statistically significant relationship was found between somatic coliphages and diarrheal cases, classified as outbreaks or alerts in the region. Thus, the results confirmed that somatic coliphages are a good indicator of the presence of diarrhea cases in a specific region. [ABSTRACT FROM AUTHOR]

The present work evaluated the surveillance of the drinking water quality information system database and correlated the findings of the microbiological analysis with the distribution of intestinal protozoa from the metropolitan region of Rio de Janeiro. From the database, we obtained 1,654 georeferenced monitoring stations that were used in the analysis. The results indicate that the minimum number of samples collected per parameter (free residual chlorine, turbidity, counts of total and fecal coliforms (Escherichia coli)) was not fulfilled, the collection of samples throughout the year was irregular and the representability of sampling points considered strategic was low (48% of municipalities). Besides, municipalities with a high prevalence for intestinal parasite protozoa were also the ones that had the highest counts for coliforms and the reverse can also be observed, indicating a transmission through contaminated drinking water. Despite the increased participation of municipalities in water surveillance actions during the studied period, it is necessary to implement managerial measures to improve the system, aiming to correct flaws and inconsistencies in the application of the water quality monitoring protocol. [ABSTRACT FROM AUTHOR]

This research paper tries to identify and address issues related to efficiency of sewage treatment plants (STPs) and their implications on the Dal Lake ecosystem in Srinagar city, Kashmir, India. Fluidized aerobic bioreactor (FAB) and sequential batch reactor (SBR) technologies having been recently installed along the periphery of Dal Lake were evaluated for efficiency for a continuous period of 24 months from December 2016 to November 2018. Apart from chemical quality, total coliform(TC), fecal coliform (FC), and fecal streptococci (FS) analyses were also carried out. Major highlights of our work using oneway ANOVA (analysis of variance) revealed significant variations (p<0.05) in total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonia (NH3-N), total phosphorus (TP), TC, FC, and FS. Our findings indicate that both technologies are struggling for removal efficiency, which is very low, especially in FAB during three to four months of winter season where a very high drop in the working efficiency of the STP was observed. The treatment facilities did not meet the prescribed standards in respect of TSS, BOD, NH3-N, TP, TC, FC, and FS thereby having the potential to compromise public health and trophic status of Dal Lake. [ABSTRACT FROM AUTHOR]

Effective resin disinfection is mandatory to ensure the microbiological quality of water treated by domestic softeners. The wet and sometimes warm environment inside the softener is ideal for bacteria growth. Our research was focused on the evaluation of the microbial quality of water from softeners sanitized by chlorine solutions or by electrolytic systems. We employed the heterotrophic plate count and specific tests to monitor the presence of opportunistic and pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli, enterococci, and coliforms). Completely new devices were equipped with a commercially available electrolytic system or with a newly patented one or sanitized by automatic or manual addition of chlorine solutions. In all cases, the contamination was reduced, not completely avoided. In particular, the patented electrolytic system significantly reduced bacterial proliferation in strongly contaminated devices. Our data confirm the difficulties encountered to solve the problem of microbiological quality of softened water and offer encouraging information on new possible solutions. [ABSTRACT FROM AUTHOR]

Sanitation planners make complex decisions in the delivery of sanitation services to achieve health outcomes. We present findings from a stakeholder engagement workshop held in Kampala, Uganda, to educate, interact with, and solicit feedback from participants on how the relevant scientific literature on pathogens can be made more accessible to practitioners to support decision-making. We targeted Water, Sanitation and Hygiene (WASH) practitioners involved in different levels of service delivery. Practitioners revealed that different sanitation planning tools are used to inform decisionmaking; however, most of these tools are not user-friendly or adapted to meet their needs. Most stakeholders (68%) expressed familiarity with pathogens, yet less than half (46%) understood that fecal coliforms were bacteria and used as indicators for fecal pollution. A number of stakeholders were unaware that fecal indicator bacteria do not behave and persist the same as helminths, protozoa, or viruses, making fecal indicator bacteria inadequate for assessing pathogen reductions for all pathogen groups. This suggests a need for awareness and capacity development around pathogens found in excreta. The findings underscore the importance to engage stakeholders in the development of support tools for sanitation planning and highlighted broader opportunities to bridge science with practice in the WASH sector. [ABSTRACT FROM AUTHOR]

Three novel and two commercially available low-cost point-of-use (PoU) water treatment technologies were comparatively evaluated using a specialized comparison framework targeted at them. The comparison results and specialized framework have been discussed. The PoU systems were evaluated principally in terms of performance, flow rate and cost per volume of water treated (quantitatively), ease of use, potential acceptability and material availability (qualitatively) with main focus on rural and suburban settings. The three novel systems assessed were developed in an ongoing research project aimed at developing a multibarrier low-cost PoU water treatment system. The comparative evaluation and analysis revealed that the commercially available systems may often produce water free of pathogens (with an apparent 100% removal for Escherichia coli and fecal coliforms) but may not be affordable for application to the poorest groups in much of the developing world. The novel systems, which were principally constructed from local materials, were more affordable, can supply relatively safe water and can be constructed by users with minimal training. Overall, bacterial removal effectiveness, ease of use, flow rate, material availability, cost and acceptability aspects of water were identified as key to potential adoption and sustainability of the evaluated low-cost PoU systems. [ABSTRACT FROM AUTHOR]

In the present study, three low-cost filter aggregate materials were tested and compared for organic matter and fecal coliform (FC) removal at the laboratory scale. Setups were subjected to synthetic wastewater at two hydraulic loading rates (HLR), i.e. 4 cm/day and 40 cm/day. The hydraulic retention time (HRT) at the two HLRs varied from 4 days to 12 h, respectively. The result obtained shows that the biochemical oxygen demand (BOD5) removal efficiency of aggregate materials decreased with the increase in HLR. Both at high and low HLR, the terracotta aggregate material exhibited maximum BOD5 loading removal and without significant difference for the case of FC removal efficiency for all the three aggregate materials. At higher HLR, cell debris and biofilm loss from the aggregate material contributed to the chemical oxygen demand (COD) levels in the treated water. The terracotta aggregate material provided best organic matter removal at both HLRs. The study demonstrates the potential of incorporating inexpensive and readily available local materials into decentralized, frugal green infrastructure interventions capable of lowering the quantum of harmful biological contaminants in open storm water channels in rapidly urbanizing cities of developing countries, and that the terracotta aggregate material provided best organic removal at both HLRs. [ABSTRACT FROM AUTHOR]

Coastal water quality is deteriorating worldwide. Water quality monitoring is therefore essential for public health risk evaluation and the management of water bodies. This study investigated the feasibility of using bacteriophages of Enterococcus faecalis as sewage-specific faecal indicators, together with physicochemical (dissolved oxygen, pH, temperature and total suspended solids) and biological parameters, to assess coastal water quality using multivariate analysis incorporating non-detects. The principal component and cluster analyses demonstrated that coastal water quality was mostly influenced by biological parameters, including Escherichia coli and total coliforms, which were found in all 31 sampling sites, and enterococci, which was found in all but two sampling sites. The enterococcal bacteriophages AIM06 and SR14 were detected in 17 and 18 samples at concentrations up to 1,815 and 2,790 PFU/100 mL, respectively. Both bacteriophages co-presented in approximately 80% of phage-positive samples, and the concentrations at each site were not significantly different. Overall, either bacteriophage could be used to differentiate high- and low-level coastal water pollution, as grouped by cluster analysis. This study is the first to investigate the suitability of sewage-specific bacteriophages of E. faecalis for monitoring coastal water quality and emphasises the importance of a multivariate analysis with non-detects to facilitate coastal water quality monitoring and management. [ABSTRACT FROM AUTHOR]

Ultraviolet disinfection (UVD) units enhance onsite sewage systems (OSSs) in areas where conventional treatment is limited by site characteristics. Although UVD units are efficacious under testing conditions, few studies have considered their effectiveness when installed. This study used a mixedmethods approach to examine UVD unit effluent quality and determine the association between UV bulb status and fecal coliform levels. Samples from UVD units and pump chambers were tested for bacterial and physiochemical parameters. Field data were supplemented with data from retrospective compliance samples. A multivariate Tobit regression model predicted that the geometric mean (GM) fecal coliform concentration was 122% higher when the UV bulb was deficient than when it was not deficient, adjusted for other OSS deficiencies (95% CI: 36-428, p-value<0.001). The predictedGMfecal coliform concentration in malfunctioning UVD unit effluent (745 CFU/100 mL) exceeded field compliance standards (400 CFU/100 mL), and the odds of exceedance were 7.48 times higher when the UV bulb was deficient, adjusted for other OSS deficiencies (95% CI: 4.03-13.9, p-value <0.001). Despite limitations in the characterization of UV dose, the results validate the importance of UVD units to reduce bacterial loads and the need for further research into their field effectiveness. [ABSTRACT FROM AUTHOR]

The Navajo Nation includes approximately 250,000 American Indians living in a remote high desert environment with limited access to public water systems. We conducted a pilot case-control study to assess associations between acute gastroenteritis (AGE) and water availability, use patterns, and quality. Case patients with AGE and non-AGE controls who presented for care to two Indian Health Service hospitals were recruited. Data on demographics and water use practices were collected using a standard questionnaire. Household drinking water was tested for presence of pathogens, coliforms, and residual chlorine. Sixty-one subjects (32 cases and 29 controls) participated in the study. Cases and controls were not significantly different with respect to water sources, quality, or patterns of use. Twenty-one percent (n ¼ 12) of study participants resided in dwellings not connected to a community water system. Eleven percent (n ¼ 7) of subjects reported drinking hauled water from unregulated sources. Coliform bacteria were present in 44% (n ¼ 27) of household water samples, and 68% (n ¼ 40) of samples contained residual chlorine concentrations of <0.2 mg/L. This study highlights issues with water availability, quality, and use patterns within the Navajo Nation, including sub-optimal access to community water systems, and use of water hauled from unregulated sources. [ABSTRACT FROM AUTHOR]

The aim of the present study was to assess performance of waste stabilization ponds (WSPs) on the removal of Listeria spp. in Isfahan, Iran. A total of 104 samples were taken from eight sampling locations from influent and effluent of a wastewater treatment plant (WWTP). Sewage samples were analyzed for the presence of Listeria spp. using selective enrichment protocol. Listeria isolates were also identified by biochemical and polymerase chain reaction (PCR) amplification. Listeria spp. was enumerated by a three tube most probable number (MPN) for total coliform counts (TC), fecal coliform counts (FC), total suspended solids (TSS), and total dissolved solids (TDS). In total, 54/104 (51.92%), 49/104 (47.11%), 36/104 (34.61%), and 27/104 (25.95%) samples were positive for Listeria spp., L. monocytogenes, L. innocua, and L. seeligeri, respectively. The mean MPN/100 mL enumeration of L. monocytogenes for influent, anaerobic, facultative ponds 1, 2, 3, 4 and maturation ponds 1 and 2 were 21.54, 10.61, 8, 5.77, 4, 2.54, 1.38, and 0.46, respectively. The removal percentage of Listeria spp. in the anaerobic, facultative, and maturation ponds were 44.71, 76.5, and 81.4%, respectively. Results showed that the WSPs were able to decrease the Listeria spp. levels significantly, although unable to remove them completely. [ABSTRACT FROM AUTHOR]

We evaluate the behavior of a device designed to automatically divert and store the first flush of harvested rainwater in cisterns. The first phase (PI) was conducted with artificial precipitation in an experimental installation seeking to identify how many millimeters of rainwater should be diverted to preserve the rainwater quality. In the second phase (PII), we designed a PVC-pipe device to store the first millimeter of rainwater, and tested it in field (a rural area in Brazil) during two real rainfall events. In the third phase (PIII), the device and a hand pump were assayed for two years using eight cisterns in a rural area where people drink the rainwater. PI results indicated that the most significant pollution of the rainwater is flushed with the first millimeter of rain, and diversion promoted the removal of 98% and 100% of the total coliforms and Escherichia coli, respectively. The bacteriological behavior was maintained in the subsequent phases. The device was able to preserve the quality of the rainwater most of the time, satisfying drinking requirements for the parameters of turbidity and color. The satisfactory performance of the device was confirmed in the field, behaving as a sanitary barrier for rainwater quality protection. [ABSTRACT FROM AUTHOR]

With increasing stress on our water resources and recent waterborne disease outbreaks, understanding the epidemiology of waterborne pathogens is crucial to build surveillance systems. The purpose of this study was to explore techniques for describing microbial water quality in rural drinking water wells, based on spatiotemporal analysis, time series analysis and relative risk mapping. Tests results for Escherichia coli and coliforms from private and small public well water samples, collected between 2004 and 2012 in Alberta, Canada, were used for the analysis. Overall, 14.6 and 1.5% of the wells were total coliform and E. coli-positive, respectively. Private well samples were more often total coliform or E. coli-positive compared with untreated public well samples. Using relative risk mapping we were able to identify areas of higher risk for bacterial contamination of groundwater in the province not previously identified. Incorporation of time series analysis demonstrated peak contamination occurring for E. coli in July and a later peak for total coliforms in September, suggesting a temporal dissociation between these indicators in terms of groundwater quality, and highlighting the potential need to increase monitoring during certain periods of the year. [ABSTRACT FROM AUTHOR]

The MI, Chromocult® coliform, and Compass CC chromogenic culture-based methods used to assess water quality by the detection of Escherichia coli and total coliforms were compared in terms of their specificity and sensitivity, using 16S rRNA sequencing for colony identification. A sewage water sample was divided in 2-ìL subsamples for testing by all three culture-based methods. All growing colonies were harvested and subjected to 16S rRNA sequencing. Test results showed that all E. coli colonies were correctly identified by all three methods, for a specificity and a sensitivity of 100%. However, for the total coliform detection, the MI agar, Chromocult® coliform agar, and Compass CC agar were specific for only 69.2% (9/13), 47.2% (25/53), and 40.5% (17/42), whereas sensitive for 97.8% (45/46), 97.5% (39/40), and 85.7% (24/28), respectively. Thus, given the low level of specificity of these methods for the detection of total coliforms, confirming the identity of total coliform colonies could help to take public health decisions, in particular for cities connected to a public drinking water distribution system since the growth of few putative total coliform colonies on chromogenic agar is problematic and can lead to unnecessary and costly boiling notices from public health authorities. [ABSTRACT FROM AUTHOR]

Escherichia coli (E. coli) is one of the most commonly adopted indicators for the determination of the microbiological quality in water and treated wastewater. Two main types of methods are used for the enumeration of this faecal indicator: membrane filtration (MF) and enzyme substrate tests. For both types, several substrates based on the β-D-glucuronidase activity have been commercialized. The specificity of this enzyme for E. coli bacteria has generated considerable use of methods that identify the β-D-glucuronidase activity as a definite indication of the presence of E. coli, without any further confirmation. This approach has been recently questioned for the application to wastewater. The present study compares two methods belonging to the above-mentioned types for the enumeration of E. coli in wastewater: MF with Tryptone Bile X-glucuronide agar and the Colilert®-18 test. Confirmation tests showed low average percentages of false positives and false negatives for both enumeration methods (between 4 and 11%). Moreover, the counting capabilities of these two methods were compared for a set of 70 samples of wastewater having different origins and degrees of treatment. Statistical analysis showed that the Colilert®-18 test allowed on average for a significantly higher recovery of E. coli. [ABSTRACT FROM AUTHOR]