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

Tracking SARS-CoV-2 genetic diversity is strongly indicated because diversifying selection may lead to the emergence of novel variants resistant to naturally acquired or vaccine-induced immunity. To monitor New York City (NYC) for the presence of novel variants, we amplified regions of the SARS-CoV-2 Spike protein gene from RNA acquired from all 14 NYC wastewater treatment plants (WWTPs) and ascertained the diversity of lineages from these samples using high throughput sequencing. Here we report the detection and increasing frequencies of novel SARS-CoV-2 lineages not recognized in GISAID’s EpiCoV database. These lineages contain mutations rarely observed in clinical samples, including Q493K, Q498Y, H519N and T572N. Many of these mutations were found to expand the tropism of SARS-CoV-2 pseudoviruses by allowing infection of cells expressing the human, mouse, or rat ACE2 receptor. In addition, pseudoviruses containing the Spike amino acid sequence of these lineages were found to be resistant to many different classes of receptor binding domain (RBD) binding neutralizing monoclonal antibodies. We offer several hypotheses for the anomalous presence of these mutations, including the possibility of a non-human animal reservoir. Although wastewater sampling cannot provide direct inference of SARS-CoV-2 clinical sequences, our research revealed several lineages that could be relevant to public health and they would not have been discovered if not for wastewater surveillance.

Legionella pneumophila is the cause of Legionnaires’ disease, a life-threatening pneumonia that occurs after inhalation of aerosolized water containing the bacteria. Legionella growth occurs in stagnant, warm-to-hot water (77°F–113°F) that is inadequately disinfected. Piped hot spring water in Hot Springs National Park, Arkansas, USA, has naturally high temperatures (>135°F) that prevent Legionella growth, and Legionnaires’ disease has not previously been associated with the park or other hot springs in the United States. During 2018–2019, Legionnaires’ disease occurred in 5 persons after they visited the park; 3 of these persons were potentially exposed in spa facilities that used untreated hot spring water. Environmental testing revealed Legionella bacteria in piped spring water, including 134°F stagnant pipe water. These findings underscore the importance of water management programs to reduce Legionella growth in plumbing through control activities such as maintaining hot water temperatures, reducing stored water age, and ensuring adequate water flow.

Introduction: Enteric viruses have been associated with the production of a variety of diseases transmitted by the fecal-oral route and carried through contaminated food and water. Given their structure and composition, they are highly resistant to environmental conditions and most of the chemical agents used in the purification processes. Therefore, the systematic monitoring of raw water is necessary to ensure its quality especially when it is used for producing drinking water for human consumption. Objective: We identifed the presence of rotavirus and hepatitis A virus by means of the fluoro-immuno-magnetic separation technique (FIMS) in raw water taken from four purification plants and their water supplies in the department of Norte de Santander. Materials and methods: The viruses were captured and separated from the water samples using magnetic microparticles functionalized with monoclonal anti-Hepatitis A and antiRotavirus antibodies. Confocal microscopy was used to monitor the viral concentration process and transmission electron microscopy for the morphological visualization of the separated viruses. The reverse transcriptase-coupled polymerase chain reaction (RT-PCR) was applied to confrm the presence of pathogens. Results: The two enteric viruses were identifed in the majority of the analyzed water samples including water supply sources. Conclusion: We determined that the FIMS technique together with RT-PCR is highly effective for the detection of viral pathogens in complex matrices such as raw water. Resumen: Introducción. Los virus entéricos se asocian con una serie de enfermedades transmitidas por vía fecal-oral en alimentos o agua contaminada. Dada su estructura y composición, son muy resistentes a las condiciones ambientales y a la mayoría de los agentes químicos empleados en los procesos de potabilización, por lo cual es necesario un monitoreo sistemático del agua cruda para asegurar su calidad, máxime cuando se emplea como materia prima en la producción de agua potable para consumo humano. Objetivo. Determinar la presencia de rotavirus y del virus de la hepatitis A mediante la técnica de separación fluoro-inmuno-magnética en agua cruda procedente de cuatro plantas de potabilización y sus fuentes hídricas en el departamento de Norte de Santander. Materiales y métodos. Los virus fueron capturados y separados a partir de las muestras de agua, empleando micropartículas magnéticas funcionalizadas con anticuerpos monoclonales anti-hepatitis A y anti-rotavirus. Se empleó microscopía confocal para hacer el seguimiento del proceso de concentración viral y, microscopía electrónica de transmisión, para la visualización morfológica de los virus separados. La reacción en cadena de la polimerasa acoplada a transcriptasa inversa (RT-PCR) se utilizó para confrmar la presencia de los patógenos. Resultados. Los dos virus entéricos se detectaron en la mayoría de las muestras de agua analizadas, incluidas las de sus fuentes hídricas. Conclusión. La técnica de separación fluoro-inmuno-magnética acoplada a RT-PCR fue altamente efectiva en la detección de patógenos virales en matrices complejas como el agua cruda.

All animals carry specialized microbiomes, and their gut microbiota are continuously released into the environment through excretion of waste. Here we propose the meta-gut as a novel conceptual framework that addresses the ability of the gut microbiome released from an animal to function outside the host and alter biogeochemical processes mediated by microbes. We demonstrate this dynamic in the hippopotamus (hippo) and the pools they inhabit. We used natural field gradients and experimental approaches to examine fecal and pool water microbial communities and aquatic biogeochemistry across a range of hippo inputs. Sequencing using 16S RNA methods revealed community coalescence between hippo gut microbiomes and the active microbial communities in hippo pools that received high inputs of hippo feces. The shared microbiome between the hippo gut and the waters into which they excrete constitutes a meta-gut system that could influence the biogeochemistry of recipient ecosystems and provide a reservoir of gut microbiomes that could influence other hosts. We propose that meta-gut dynamics may also occur where other animal species congregate in high densities, particularly in aquatic environments.

Flow cytometry is a promising tool used to identify the phenotypic features of bacterial communities in aquatic ecosystems by measuring the physical and chemical properties of cells based on their light scattering behavior and fluorescence. Compared to molecular or culture-based approaches, flow cytometry is suitable for the online monitoring of microbial water quality because of its relatively simple sample preparation process, rapid analysis time, and high-resolution phenotypic data. Advanced statistical techniques (e.g., denoising and binning) can be utilized to successfully calculate phenotypic diversity by processing the scatter data obtained from flow cytometry. These phenotypic diversities were well correlated with taxonomic-based diversity computed using next-generation 16S RNA gene sequencing. The protocol provided in this paper should be a useful guide for a fast and reliable flow cytometric monitoring of bacterial phenotypic diversity in aquatic ecosystems.

Human activity in wilderness areas has the potential to affect aquatic ecosystems, including through the introduction of microorganisms associated with fecal contamination. We examined fecal microorganism contamination in water sources (lake outlets, snowmelt streams) in the popular Absaroka Beartooth Wilderness in the United States. Although the region is remote, increasing human visitation has the potential to negatively affect water quality, with particular concern about human-derived microorganism fecal contaminants.We used standard fecal indicator bacterial assays that quantified total coliform bacteria and Escherichia coli concentrations, together with more specific polymerase chain reaction-based microbial assays that identified possible human sources of fecal microorganisms in these waters.Total coliforms were detected at all lake outlets (21 of 21 sites), and E coli was detected at 11 of 21 sites. Droplet digital polymerase chain reaction assays revealed the presence of human feces-derived microorganisms, albeit at abundances below the limit of detection (10 gene copies per milliliter of water) at all but 1 of the sampling sites.Our results suggest low prevalence of water-borne pathogens (specifically E coli and human-derived Bacteroides) in this popular wilderness area. However, widespread detection of total coliforms, Bacteroides, and E coli highlight the importance of purifying water sources in wilderness areas before consumption. Specific sources of total coliforms and E coli in these waters remain unknown but could derive from wild or domesticated animals that inhabit or visit the Absaroka Beartooth Wilderness. Hence, although contamination by human fecal microorganisms appears minimal, human visitation could indirectly influence fecal contamination through domesticated animals.

Legionella pneumophila is an opportunistic bacterial respiratory pathogen that is one of the leading causes of drinking water outbreaks in the United States. Dental offices pose a potential risk for inhalation or aspiration of L. pneumophila due to the high surface area to volume ratio of dental unit water lines—a feature that is conducive to biofilm growth. This is coupled with the use of high-pressure water devices (e.g., ultrasonic scalers) that produce fine aerosols within the breathing zone. Prior research confirms that L. pneumophila occurs in dental unit water lines, but the associated human health risks have not been assessed. We aimed to: (1) synthesize the evidence for transmission and management of Legionnaires’ disease in dental offices; (2) create a quantitative modeling framework for predicting associated L. pneumophila infection risk; and (3) highlight influential parameters and research gaps requiring further study. We reviewed outbreaks, management guidance, and exposure studies and used these data to parameterize a quantitative microbial risk assessment (QMRA) model for L. pneumophila in dental applications. Probabilities of infection for dental hygienists and patients were assessed on a per-exposure and annual basis. We also assessed the impact of varying ventilation rates and the use of personal protective equipment (PPE). Following an instrument purge (i.e., flush) and with a ventilation rate of 1.2 air changes per hour, the median per-exposure probability of infection for dental hygienists and patients exceeded a 1-in-10,000 infection risk benchmark. Per-exposure risks for workers during a purge and annual risks for workers wearing N95 masks did not exceed the benchmark. Increasing air change rates in the treatment room from 1.2 to 10 would achieve an ∼85% risk reduction, while utilization of N95 respirators would reduce risks by ∼95%. The concentration of L. pneumophila in dental unit water lines was a dominant parameter in the model and driver of risk. Future risk assessment efforts and refinement of microbiological control protocols would benefit from expanded occurrence datasets for L. pneumophila in dental applications.

Solar disinfection (SODIS) could be a key to providing a clean, hygiene water for birthing uses, but the recommended climate zone is limited, the microbial indicators are related to gastrointestinal illness and not wound infections. SODIS feasibility was investigated to remove Escherichia coli from turbid water at temperatures less than 50 °C in Lexington, KY. Increasing turbidity from 0 to 200 NTU decreased E. coli inactivation from 5 to 1 log. With the same experimental protocol, more than 4-log inactivation of Staphylococcus aureus and Staphylococcus epidermidis (common human-skin microorganisms related to serious post-partum infections of both mother and child) was achieved at different turbidity levels with a maximum, in-bottle temperature of 49.2 °C after 5.5 h. The thermal inactivation of the bacterial indicators was assessed without UV radiation and turbidity in water at 37 and 47 °C. Skin bacteria were inactivated completely after 9.5 h at 47 °C, but only 58% removal happened for thermo-tolerant E. coli. These results suggest that SODIS application may be expanded geographically to treat water for hygiene purposes. However, as E. coli is also capable of causing wound infections, UV with thermal inactivation may be required to produce safe hygiene water by SODIS outside of recommended latitudes. HIGHLIGHTS Solar disinfection (SODIS) was applied for the first time to remove Staphylococcus aureus from water to provide safe hygiene water for birthing.; Human skin bacteria are more susceptible to thermal inactivation than gastrointestinal bacteria.; SODIS protocols need to be updated to evaluate process indicators bacteria for hygiene purposes.; Consideration of solar disinfection for treating contaminated water for hygiene purposes could have a significant positive impact on saving the lives of women in labour and those of their newborns and decreasing the number of postpartum infections.

Background An outbreak of Legionella pneumonia occurred at a university hospital using copper-silver ionization for potable water disinfection. We present the epidemiological and laboratory investigation of the outbreak, and associated case-control study. Methods Cases were defined by syndrome compatible with Legionella pneumonia with laboratory-confirmed Legionella infection. The water circuit and disinfection system were assessed, and water samples collected for Legionella culture. Whole genome multi-locus sequence typing (wgMLST) was used to compare the genetic similarity of patient and environmental isolates. A case-control study was conducted to identify risk factors for Legionella pneumonia. Results We identified 13 cases of hospital-acquired Legionella. wgMLST revealed >99.9% shared allele content among strains isolated from clinical and water samples. Smoking (P= .008), steroid use (P= .007), and documented shower during hospitalization (P= .03) were risk factors for Legionella pneumonia on multivariable analysis. Environmental assessment identified modifications to the hospital water system had occurred in the month preceding the outbreak. Multiple mitigation efforts and application of point of use water filters stopped the outbreak. Conclusions Potable water system Legionella colonization occurs despite existing copper-silver ionization systems, particularly after structural disruptions. Multidisciplinary collaboration and direct monitoring for Legionella are important for outbreak prevention. Showering is a modifiable risk factor for nosocomial Legionella pneumonia. Shower restriction and point-of-use filters merit consideration during an outbreak.

Regular monitoring and measurement of Legionella in tower water and preventive measures against contamination are particularly important in hospitals. This study aimed at risk assessment and disease burden because of legionella presence in cooling towers of Iran’s central hospitals. Then its correlation with temperature, pH, turbidity, residual chlorine, and EC was investigated by the Pearson test. The health risk and burden of diseases caused by Legionella exposure were determined using QMRA and DALY models. Statistical analysis and modeling were performed in MATLAB2018. Of the total samples, 30–43% was infected with Legionella. The mean concentrations in hospital A and B were 5–102.5 ± 10 and 5–89.7 ± 0.7 CFU/L, respectively. Among environmental factors, turbidity and pH were the most effective factors in increasing and decreasing Legionella concentration, respectively. According to the QMRA model, the risks of Legionella infections and annual mortality in both hospitals were 0.2–0.3, 0–0.19, 2–2.9 × 10−5, and 0–0.7 × 10−5, respectively, which was higher than the acceptable risk range for Legionella (10-4–10-7). However, the trend of its change was negatively correlated with time (RB = − 0.77). According to the results, the concentration of Legionella and the exposure risk in both hospitals were higher than the permissible range, which is necessary to decrease to 0.1 current concentrations.

The relatively unknown genus Iodobacter sp. has been repeatedly isolated from skin ulcers and saprolegniosis on freshwater fish in Finland, especially farmed salmonids. Genetic characterization verified that all 23 bacterial isolates studied here belonged to the species Iodobacter limnosediminis, previously undescribed from the fish microbiota. Whole-genome pulsed-field gel electrophoresis revealed variability between the I. limnosediminis strains, suggesting that they were most likely of environmental origin. Two I. limnosediminis strains caused lesions in 27%–53% of brown trout (Salmo trutta) injected intramuscularly (p ≤ .05). The lesions represented moderate to severe tissue damage, but for most fish, the tissues had been repaired by the end of the experiment through the accumulation of fibrocytes and macrophages at the site of the lesion. I. limnosediminis was reisolated from some lesions and/or internal organs. Phenotypically and biochemically, I. limnosediminis resembles several common bacterial species found in the aquatic environment, as it grows well on several media as whitish medium-sized colonies, is Gram negative and rod-shaped. Here, we characterized I. limnosediminis strains with several methods, including MALDI-TOF. This characterization will help in further investigations into the occurrence and possible involvement of I. limnosediminis in skin lesions of freshwater fish. peerReviewed

BackgroundIn recent years, researchers are interested in the discovery of active compounds from traditional remedies and natural sources, as they reveal higher therapeutic efficacies and improved toxicological profiles. Among the various traditional treatments that have been widely studied and explored for their potential therapeutic benefits, kefir, a fermented beverage, demonstrates a broad spectrum of pharmacological properties, including antioxidant, anti-inflammation, and healing activities. These health-promoting properties of kefir vary among the kefir cultures found at the different part of the world as different media and culture conditions are used for kefir maintenance and fermentation.MethodsThis study investigated the microbial composition and readily found bioactive compounds in water kefir fermented in Malaysia using 16S rRNA microbiome and UHPLC sequencing approaches. The toxicity effects of the kefir water administration in BALB/c mice were analysed based on the mice survival, body weight index, biochemistry profile, and histopathological changes. The antioxidant activities were evaluated using SOD, FRAP, and NO assays.ResultsThe 16S rRNA amplicon sequencing revealed the most abundant species found in the water kefir wasLactobacillus hilgardiifollowed byLactobacillus harbinensis,Acetobacter lovaniensis,Lactobacillus satsumensis,Acetobacter tropicalis,Lactobacillus zeae, andOenococcus oeni. The UHPLC screening showed flavonoid and phenolic acid derivatives as the most important bioactive compounds present in kefir water which has been responsible for its antioxidant activities. Subchronic toxicity study showed no toxicological signs, behavioural changes, or adverse effects by administrating 10 mL/kg/day and 2.5 mL/kg/day kefir water to the mice. Antioxidants assays demonstrated enhanced SOD and FRAP activities and reduced NO level, especially in the brain and kidney samples.ConclusionsThis study will help to intensify the knowledge on the water kefir microbial composition, available phytochemicals and its toxicological and antioxidant effects on BALB/c mice since there are very limited studies on the water kefir grain fermented in Malaysia.

Livestock pigs and porcine norovirus could be candidate tools for future studies on the geographic isolation of norovirus. In this study, we provide the first evidence for geographic isolation of the host as a determinant of the distribution of subgenotypes of the porcine norovirus genogroup II (GII) genotype 11. Environmental water samples were collected from peri-urban streams and estuaries in South Korea between 2014 and 2020. In total, 488 GII region C sequences of norovirus open reading frame 2 were isolated. A total of 14 genotypes were detected, two of which (GII.11 and GII.18) corresponded to porcine norovirus. Five human norovirus genotypes (GII.2, GII.3, GII.4, GII.6, and GII.17) and one porcine norovirus genotype (GII.11) comprised the subgenotypes. Integrated analysis of seasonal and geographical factors revealed that the possibility of the co-emergence of different GII.11 subgenotypes in the same province was lower than that of human norovirus subgenotypes in the same province. Additional algorithms designed to eliminate potential biases further supported the estimated restricted geographical spread of the GII.11 subgenotypes. Fecal contamination source tracking revealed low detection rates of porcine norovirus in the absence of upstream pig farms. These results suggest that a one-sided viral transmission route, mainly dependent on indirect contact owing to the limited chance of direct contact between geographically separated livestock pig populations, may be responsible for the restricted geographical spread of the GII.11 subgenotypes.

Introduction: Tularemia has reemerged and spread throughout Turkey, and the number of cases has increased. In this study, we report on a waterborne outbreak of tularemia in the spring of 2013 in a region which was previously disease-free, and we investigated the reasons for the outbreak. Methodology: The index case, a 17-year-old male, was diagnosed with oropharyngeal tularemia. An outbreak investigation was initiated after receiving information from other patients with similar symptoms from the same village along with Balkıca, Tavas, and Denizli. An epidemiological and environmental investigation was conducted. Tonsil swab specimens/lymph node aspirates collected from patients, and water samples collected from unchlorinated drinking water sources, were cultured. Additionally, a real-time polymerase chain reaction (RT-PCR) was performed on these samples. Serum samples from patients were analyzed for antibody response. Results: A total of 7 patients were found in this outbreak investigation. The attack rate was found to be 1% among the people of the village and 25% among patients’ family members. The drinking-water system was contaminated with F. tularensis during this outbreak. Conclusions: Lack of appropriate water infrastructure and sanitation was the primary reason for this tularemia outbreak in Turkey. Improving the water source infrastructure and sanitation should be the primary approach to preventing tularemia outbreaks.

Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In this study, we investigated the occurrence of enteric viruses in the first flush (10 mm) of RHRW from a densely populated and low-income urbanized region of Rio de Janeiro. One hundred samples (5 L) were collected from 10 rainfall events between April 2015 and March 2017. RNA and DNA viruses were concentrated using the skimmed milk flocculation method and analyzed using the TaqMan® quantitative RT-qPCR and qPCR. Human adenoviruses, noroviruses, rotaviruses A, and avian parvoviruses were detected in 54%, 31%, 12%, and 12% of the positive samples. JC polyomavirus, also targeted, was not detected. Virus concentrations ranged from 1.09 × 101 to 2.58 × 103 genome copies/Liter (GC/L). Partial nucleotide sequence confirmed the presence of HAdV type 41, norovirus genotype GII.4, and avian parvovirus 1. The results suggest that the first flush diversion devices may not adequately remove enteric virus from the rainwater. Additional treatment of RHRW is required to mitigate potential health risks from potable use of captured water.

Many Cameroonian cities lack access to potable drinking water where populations rely on alternative water sources of doubtful quality. This study aimed at describing the trends and patterns of waterborne diseases (WBDs) reported in some health facilities in Bamboutos Division between 2013 and 2017 as baseline data towards understanding the profile of WBDs in this area. A retrospective review of clinical data kept on patients who visited the main health facilities in Bamboutos Division from January 2013 to December 2017 was conducted. Overall, 39.1% (n = 8,124) of total patients were positive for at least one WBD. Categories of WBDs were dysenteries (18.6%), gastroenteritis (4.2%), viral hepatitis (0.2%) and typhoid was the most preponderant (24.4%). The most affected age groups were those above 24 years but significant differences were observed only in 2013 and 2017. Distribution of potential WBDs was locality dependent. The highest prevalence of typhoid fever was recorded in Bameboro (35.4%), dysenteries in Bamedjinda (20.4%) and gastroenteritis (17.3%) in Bamekoumbou. The study shows very high overall prevalence of WBDs in some localities which could be considered as ‘hotspots’ of WBDs in Bamboutos. This suggests the urgent need for setting up measures to tackle the challenges of potable drinking water supply. HIGHLIGHTS The study shows an extremely high prevalence of potential waterborne diseases (WBDs). This can be used as baseline data to fight against WBDs.; High prevalence of Helicobacter pylori, an emerging WBDs is an issue of public health concern.; Spacial distribution of WBDS reveals some vulnerable localities that could be considered as ‘foci’ for waterborne diseases and used as a guide during epidemiological interventions.

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

Background Colistin is regarded as a last-resort antimicrobial against multi-drug resistant Gram-negative bacteria (GNB), therefore the dissemination of colistin resistance in the environment is of great concern. Horizontal transfer of mobile colistin resistance (mcr) genes to potential pathogens poses a serious problem. This study aimed to describe the presence of colistin resistant GNB and mcr genes in river and storm water in regions of the Western Cape. Methods Water samples were collected from three rivers during May 2019 and January 2020 and two storm water samples were collected in November 2019. Colistin resistant GNB were cultured on MacConkey agar containing colistin and identified by MALDI-TOF. Colistin resistance was confirmed using broth microdilution (BMD). mcr-1-5 genes were detected by PCR performed directly on the water samples and on the colistin resistant isolates. mcr functionality was assessed by BMD after cloning the mcr genes into pET-48b(+) and expression in SHuffle T7 E. coli. Results mcr-5.1 and various mcr-3 gene variants were detected in the Plankenburg-, Eerste- and Berg rivers and in storm water from Muizenberg, and only mcr-5.1 was detected in storm water from Fish Hoek. Colistin resistant GNB were isolated from all of the water sources. Aeromonas spp. were the most common colistin resistant organisms detected in the water sources; 25% (6/24) of colistin resistant Aeromonas spp. isolated from the Berg river contained novel mcr-3 variants; mcr-3.33 (n = 1), mcr-3.34 (n = 1) mcr-3.35 (n = 1) mcr-3.36 (n = 2) and mcr-3.37 (n = 1), which were confirmed to confer colistin resistance. Conclusions The mcr-5.1 and mcr-3 colistin resistance gene variants were present in widely dispersed water sources in regions of the Western Cape. The mcr genes were only detected in water sampled downstream of and alongside communities, suggesting that their presence is driven by human influence/contamination. This is the first documentation of mcr-3 and mcr-5 gene variants in any setting in South Africa. Spill-over of these genes to communities could result in horizontal gene transfer to pathogenic bacteria, exacerbating the challenge of controlling multidrug resistant GNB infections.

The frequencies of Escherichia coli, Staphylococcus aureus and Methicillin-resistant S. aureus (MRSA) and 'aerobic mesophilic bacteria' (AMB) counts in different seasons and marine sources were compared to understand the microbiological dynamics at beaches in N. Cyprus. Also, antibiotic resistance patterns were evaluated. The characterization and AMB enumeration studies were performed by conventional microbiological methods. AMB counts increased from winter to summer significantly (45.5*104 CFU/mL to 2.5*106 CFU/mL). Similarly, percentage detection frequencies of the bacteria were higher in summer compared to winter and were significant particularly for E. coli in both sand and seawater samples in 2019 and 2020 (p = 0.0181, p = 0.0142, p = 0.1257, p = 0.0446, respectively). However, a significant difference was not detected in percentage detection frequencies in terms of different sources or recreational status of beaches. The highest resistance percentages were detected against beta-lactam and lincosamides group of antibiotics. Results of the study signified that regular microbiological monitoring for beaches is essential.

Outbreaks associated with treated recreational water can be caused by pathogens or chemicals in aquatic venues such as pools, hot tubs, water playgrounds, or other artificially constructed structures that are intended for recreational or therapeutic purposes. For the pseriod 2015-2019, public health officials from 36 states and the District of Columbia (DC) voluntarily reported 208 outbreaks associated with treated recreational water. Almost all (199; 96%) of the outbreaks were associated with public (nonbackyard) pools, hot tubs, or water playgrounds. These outbreaks resulted in at least 3,646 cases of illness, 286 hospitalizations, and 13 deaths. Among the 155 (75%) outbreaks with a confirmed infectious etiology, 76 (49%) were caused by Cryptosporidium (which causes cryptosporidiosis, a gastrointestinal illness) and 65 (42%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms). Cryptosporidium accounted for 2,492 (84%) of 2,953 cases resulting from the 155 outbreaks with a confirmed etiology. All 13 deaths occurred in persons affected by a Legionnaires' disease outbreak. Among the 208 outbreaks, 71 (34%) were associated with a hotel (i.e., hotel, motel, lodge, or inn) or a resort, and 107 (51%) started during June-August. Implementing recommendations in CDC's Model Aquatic Health Code (MAHC) (1) can help prevent outbreaks associated with treated recreational water in public aquatic venues.

Summary Background Pseudomonas aeruginosa is a common opportunistic pathogen and molecular typing in outbreaks has linked patient acquisition to contaminated hospital water systems. Aim To elucidate the role of P. aeruginosa transmission rates in non-outbreak augmented care settings in the UK. Methods Over a 16-week period, all water outlets in augmented care units of four hospitals were sampled for P. aeruginosa and clinical isolates were collected. Outlet and clinical P. aeruginosa isolates underwent whole-genome sequencing (WGS), which with epidemiological data identified acquisition from water as definite (level 1), probable (level 2), possible (level 3), and no evidence (level 4). Findings Outlets were positive in each hospital on all three occasions: W (16%), X (2.5%), Y (0.9%) and Z (2%); and there were 51 persistently positive outlets in total. WGS identified likely transmission (at levels 1, 2 and 3) from outlets to patients in three hospitals for P. aeruginosa positive patients: W (63%), X (54.5%) and Z (26%). According to the criteria (intimate epidemiological link and no phylogenetic distance), approximately 5% of patients in the study ‘definitely’ acquired their P. aeruginosa from their water outlets in the intensive care unit. This study found extensive evidence of transmission from the outlet to the patients particularly in the newest hospital (W), which had the highest rate of positive outlets. Conclusions The overall findings suggest that water outlets are the most likely source of P. aeruginosa nosocomial infections in some settings, and that widespread introduction of control measures would have a substantial impact on infections.

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. HIGHLIGHTS Analysis of the water surveillance protocol of Rio de Janeiro metropolitan area.; First report to evaluate the surveillance of the drinking water quality information system database of RJ (Brazil).; Possible transmission route of intestinal parasitic infections through drinking water contamination.; Noncompliance with drinking water legislation.; Need for urgent improvement in the drinking water surveillance program.

Research on the quality of surface waters has been erformed in Italy during the development of large urban areas, and in Rome this has been the duty of the Istituto di Igiene of the Sapienza University since 1890. Using MedLine - along with traditional consultation of papers printed before 1968 - we identified 100 articles published in the period from 1890-2010. Thirty of them met the inclusion criteria (to have been written by researchers of Roman universities and to contain microbiological information about the surface waters of Rome). The majority of papers identified (46.6%) were published during the Sixties and Seventies, and 30% in the twenty years that followed (1980-1999). The most frequent microbiological descriptors were “Total coliforms” and “Streptococci”. The body of waters most frequently investigated were the river Tiber and the coastal waters around Fiumicino, where the Tiber flows into the Tyrrhenian sea. The quality of surface waters has always been of central interest to the researchers of the Roman School of Hygiene. The excellent quality of past research, and the renovated interest of International Organizations and of the European Union, should encourage public health researchers to persist in this strategic field of investigation which has strong interconnections with the protection of individual well-being and community health, as well as with environmental preservation.

Legionella species are the causative agent of Legionnaires' disease, a potentially fatal bacterial pneumonia. New regulations and standards have prioritized the development of water safety plans to minimize the growth and spread of Legionella species in buildings. To determine the presence and type of Legionella in a water system, microbiological culturing is the gold standard method. However, recently new methodologies have been developed that claim to be sensitive and specific for Legionella at the genus or L. pneumophila at the species level. Published and anecdotal reports suggest that one of these newer culture-based, enzyme-substrate methods, the IDEXX Legiolert test, may exhibit false positivity with other microbes common to water sources. We experimentally evaluated the IDEXX Legiolert method using these other waterborne bacteria including Elizabethkingia meningoseptica, Pseudomonas aeruginosa, Proteus mirabilis and Serratia marcescens at real-world environmental concentrations. We saw false-positive results for the Legiolert test with several of these organisms, at sample concentrations as low as 60 CFU per ml. False-positive Legionella results can trigger costly remediation and water-use restrictions, that may be implemented while waiting for additional, confirmatory microbiological testing that could, in this case, yield no L. pneumophila.

Monitoring of Escherichia coli concentrations in river water (RW) is essential to identify fecal pollution of the river. The objective of this study was to assess the suitability of a novel, simple and high throughput method developed in our laboratory to enumerate E. coli concentrations in RW samples. The method is based on the use of the synthetic substrate specific for the β-d-glucuronidase (GUS) produced by E. coli. GUS activities and E. coli concentrations were monitored at eight selected sites in rivers running through Sapporo, Japan. Because the fluorescence intensities of the synthetic substrate in the RW samples increased linearly over a 4-h incubation period, we could estimate the GUS activities of the RW samples. The GUS activities were highly correlated with E. coli concentrations at >100 most probable numbers 100 mL−1 with a correlation coefficient of 0.87. The GUS activities of the RW samples collected from all sampling sites fitted well to a single correlation equation, which indicates that it was applicable to the estimation of E. coli concentrations regardless of the sampling sites. This method is simple, rapid, reliable, inexpensive, and high throughput, and is therefore useful for monitoring E. coli in RW. HIGHLIGHTS A novel method was applied for enumeration of Escherichia coli in urban rivers.; Response time was

The present study reports the monitoring of viruses indicating fecal contamination in two distinct regions affected by poor management of wastewater located above the Guarani Aquifer, which is one of the biggest freshwater reservoirs in the world. In the city of Três Lagoas (located in the Midwest region, in the state of Mato Grosso do Sul), water samples were collected from Lagoa Maior, a lake used for recreation, and in Concórdia (located in the South region, in the state of Santa Catarina), from the Queimados River, which crosses the urban area. Four sampling sites were monitored from March to July 2018 in Lagoa Maior, and four sampling sites were monitored along the urban part of the Queimados River area over two periods (rainy and dry). Water samples were analyzed by concentration of Human adenovirus (HAdV), Norovirus (NoV), Rotavirus A (RAV), and Hepatitis A virus (HAV) for the Lagoa Maior samples and RVA, HAV, and Porcine circovirus 2 (PCV2) for the Queimados River samples. All sampling sites presented enteric viruses, demonstrating fecal input and potential contamination of groundwater. Results highlight the need for wastewater management to improve environmental health quality.

An important group of viruses are Coronaviruses that affect the health of people worldwide, in particular the acute respiratory syndrome. The present work has addressed the updated literature on the topic of coronaviruses transmission through water and wastewater as well as identified gaps in research to inform future studies. In total, 198 articles were selected, then after screening, 48 eligible studies were fully reviewed. Accordingly, the studies showed that the coronavirus has been isolated and identified from water as well as wastewater. The results of researches show that the presence of SARS-Co-2 virus in municipal wastewater is possible due to the excretion of the virus in human feces. In addition, the SARS-Co-2 virus was isolated from contaminated water and rivers, but there is insufficient evidence for virus transmission by water and wastewater. Water and wastewater treatment methods are able to reduce the pollution load caused by this virus in water sources. Water disinfection has an effective role in removing it from water and wastewater sources. Due to the short period of time in the global pandemic and the small number of studies in this field, further studies are needed to make a definite statement about the transferability of virus in water and wastewater.

Aims The aims of this study were to: (i) estimate the effectiveness of ultraviolet radiation (UV) and sulphuric acid‐based fertilizer (SA), at reducing levels of generic Escherichia coli in surface irrigation water and on produce and surface soil in open produce fields; and (ii) describe the population dynamics of generic E. coli in produce fields. Methods and Results Spinach and cantaloupe plots were randomly assigned to control, UV or SA treatment groups. Irrigation water was inoculated with Rifampicin‐resistant E. coli prior to treatment. More than 75% of UV‐ and SA‐treated tank water samples had counts below the detection limit, compared to a mean count of 3·3 Log10 CFU per ml before treatment. Levels of Rifampicin‐resistant E. coli in soil and produce both increased and decreased over 10–15 days after irrigation, depending on the plot and time‐period. Conclusions UV and SA treatments effectively reduce the levels of E. coli in surface irrigation water. Their effectiveness at reducing contamination on produce was dependent on environmental conditions. Applying wait‐times after irrigation and prior to harvest is not a reliable means of mitigating against contaminated produce. Significance and Impact of the Study The results are of timely importance for the agricultural industry as new FSMA guidelines require producers to demonstrate a low microbial load in irrigation water or allow producers to apply a wait‐time to mitigate the risk of contaminated produce.

Waterborne diseases continue to challenge communities in low-income countries like Ethiopia. Clinical information in Wegeda town showed that the prevalence of waterborne diseases was 58%. This study aimed to evaluate bacteriological and physicochemical drinking water quality in Wegeda town. This study will add valuable scientific data for future intervention. Water samples from protected and unprotected springs, hand-dug well, taps, and households’ containers were collected from November 2018 to June 2019 for bacteriological and physicochemical analyses. Besides, information about the potential risk factors was collected using a structured questionnaire. A total of 120 water samples were collected and analyzed for total and fecal coliform counts using the multiple tube fermentation method (MPN). The presence of Escherichia coli was also checked from fecal coliform positive samples collected from households’ containers. Selected physicochemical parameters were also determined using the standard methods. In all cases, the median values of total and fecal coliform counts ranged from 5 to 27 and 2 to 13 MPN/100 ml, respectively. Accordingly, all of the drinking water samples did not comply with the standards. Coliforms were significantly higher in the households’ containers than in the sources ( p < 0.05 ) and also significantly varied by water sources. The highest and lowest coliform counts were recorded in unprotected spring and taps, respectively. Besides, 18.33% of water samples collected from households’ containers were tested positive for E. coli. Regarding physicochemical parameters, most values were within the acceptable limit values recommended by the WHO. However, water samples from unprotected spring and hand-dug well did not satisfy the turbidity limit value set by the WHO. Drinking water systems in Wegeda town were likely contaminated with pathogenic bacteria likely due to poor protection and sanitation practices. Providing the community with potable water, toilets, domestic and animal waste disposal systems, and intensive health education and sanitation practices for the community are highly recommended.

High biomasses of the marine dinoflagellate Lepidodinium chlorophorum cause green seawater discolorations along Southern Brittany (NE Atlantic, France). The viscosity associated to these phenomena has been related to problems in oyster cultivation. The harmful effect of L. chlorophorum might originate from the secretion of Extracellular Polymeric Substances (EPS). To understand whether the EPS are produced by L. chlorophorum or its associated bacteria, or if they are a product of their interaction, batch cultures were performed under non-axenic and pseudo-axenic conditions for three strains. Maximum dinoflagellate cell abundances were observed in pseudo-axenic cultures. The non-sinking fraction of polymers (Soluble Extracellular Polymers, SEP), mainly composed of proteins and the exopolysaccharide sulphated galactan, slightly increased in pseudo-axenic cultures. The amount of Transparent Exopolymer Particles (TEP) per cell increased under non-axenic conditions. Despite the high concentrations of Particulate Organic Carbon (POC) measured, viscosity did not vary. These results suggest that the L. chlorophorum-bacteria interaction could have a detrimental consequence on the dinoflagellate, translating in a negative effect on L. chlorophorum growth, as well as EPS overproduction by the dinoflagellate, at concentrations that should not affect seawater viscosity.

Synthetic estrogens such as ethinylestradiol (EE2) are persistent micropollutants that are not effectively removed from wastewater by conventional treatments. These contaminants are released into waterbodies, where they disrupt endocrine systems of organisms and cause harmful effects such as feminization, infertility, reproduction problems and genital malformations. The consequences of this pollution for key marine ecosystems such as coral reefs and their associated microbiomes are underexplored. We evaluated the effects of EE2 concentrations of 100 ng L−1 and 100 µg L−1 on the coral metaorganism Mussismilia harttii. The results indicated no effects on visible bleaching or Fv/Fm ratios in the corals during a 17-day microcosm experiment. However, next-generation sequencing of 16S rDNA revealed a statistically significant effect of high EE2 concentrations on OTU richness, and shifts in specific microbial groups after treatments with or without EE2. These groups might be bioindicators of early shifts in the metaorganism composition caused by EE2 contamination.

Water contamination by pathogenic bacteria is a major public health concern globally. Monitoring bacterial contamination in water is critically important to protect human health, but this remains a critical challenge. Engineered whole-cell biosensors created through synthetic biology hold great promise for rapid and cost-effective detection of waterborne pathogens. In this study, we created a novel whole-cell biosensor to detect water contamination by

Legionnaires’ disease has been recognized since 1976 and Legionella pneumophila still accounts for more than 95% of cases. Approaches in countries, including France, suggest that focusing risk reduction specifically on L. pneumophila is an effective strategy, as detecting L. pneumophila has advantages over targeting multiple species of Legionella. In terms of assays, the historically accepted plate culture method takes 10 days for confirmed Legionella spp. results, has variabilities which affect trending and comparisons, requires highly trained personnel to identify colonies on a plate in specialist laboratories, and does not recover viable-but-non-culturable bacteria. PCR is sensitive, specific, provides results in less than 24 h, and determines the presence/absence of Legionella spp. and/or L. pneumophila DNA. Whilst specialist personnel and laboratories are generally required, there are now on-site PCR options, but there is no agreement on comparing genome units to colony forming units and action limits. Immunomagnetic separation assays are culture-independent, detect multiple Legionella species, and results are available in 24 h, with automated processing options. Field-use lateral flow devices provide presence/absence determination of L. pneumophila serogroup 1 where sufficient cells are present, but testing potable waters is problematic. Liquid culture most probable number (MPN) assays provide confirmed L. pneumophila results in 7 days that are equivalent to or exceed plate culture, are robust and reproducible, and can be performed in a variety of laboratory settings. MPN isolates can be obtained for epidemiological investigations. This accessible, non-technical review will be of particular interest to building owners, operators, risk managers, and water safety groups and will enable them to make informed decisions to reduce the risk of L. pneumophila.

In both Brazilian and European regulations, the impact assessment of sewage discharges into coastal waters is based on microbiological analyses of fecal indicators such as Escherichia coli, frequently used in prevision hydrodynamic models. However, the decay rates of E. coli vary depending on environmental conditions, and analysis may lead to inaccurate conclusions. This study aimed to analyze the decay of culturable and viable (but not culturable) E. coli in outdoor conditions, by creating microcosms inoculated with pre-treated sewage. The microcosms were filled with 9.88 L of filtered water (0.22 μm membrane), 3.5% salt, 0.1-0.2% BHI, and 1% bacterial suspension obtained by reverse filtration. PMA-qPCR of E. coli uidA gene and Colilert measurements were applied to evaluate population counts after 2 h, 4 h, and 26 h. After nine hours of exposure to solar radiation, the viable cells decreased to 2.76% (interpolated value) of the initial population, and the cultivable fraction of the viable population accounted for 0.50%. In the dark period, the bacteria grew again, and viable cells reached 8.54%, while cultivable cells grew to 48.14% of initial population. This behavior is possibly due to the use of nutrients recycled from dead cells. Likewise, populations of E. coli in sewage outfalls remain viable in the sediments, where resuspension can renew blooming.

Waterborne ailments pose a serious threat to public health and are a huge economic burden. Lack of hygiene in drinking and recreational water is the chief source of microbial pathogens in developing countries. Poor water quality and sanitation account for more than 3.4 million deaths a year worldwide. This has urged authorities and researchers to explore different avenues of pathogen detection. There is a growing demand for rapid and reliable sensor technologies, in particular those that can detect in situ and perform in harsh conditions. Some of the major waterborne pathogens include Vibrio cholerae, Leptospira interrogans, Campylobacter jejuni, Shigella spp., enterotoxigenic Escherichia coli, Clostridium difficile, Cryptosporidium parvum, Entamoeba histolytica, and Hepatitis A virus. While conventional methods of pathogen detection like serodiagnosis and microbiological methods have been superseded by nucleic acid amplification methods, there is still potential for improvement. This review provides an insight into aptamers and their utility in the form of aptasensors. It discusses how aptamer-based approaches have emerged as a novel strategy and its advantages over more resource-intensive and complex biochemical approaches.

Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million-12.0 million), results in 601,000 ED visits (95% CrI 364,000-866,000), 118,000 hospitalizations (95% CrI 86,800-150,000), and 6,630 deaths (95% CrI 4,520-8,870) and incurring US $3.33 billion (95% CrI 1.37 billion-8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, Pseudomonas, Legionella), costing US $2.39 billion annually.

Healthcare-related Legionnaires’ disease has a devastating impact on high risk patients, with a case fatality rate of 30-50%. Legionella prevention and control in hospitals is therefore crucial. To control Legionella water colonisation in a hospital setting we evaluated the effect of pipeline improvements and temperature increase, analysing 237 samples over a two-year period (first year: 129, second year: 108). In the first year, 25.58% of samples were positive for Legionella and 16.67% for amoeba. Assessing the distance of the points analysed from the hot water tank, the most distal points presented higher proportion of Legionella colonisation and lower temperatures (nearest points: 6.4% colonised, and temperature 61.4°C; most distal points: 50% and temperature 59.1°C). After the first year, the hot water system was repaired and the temperature stabilised. This led to a dramatic reduction in Legionella colonisation, which was negative in all the samples analysed; however, amoeba colonisation remained stable. This study shows the importance of keeping the temperature stable throughout the circuit, at around 60°C. Special attention should be paid to the most distal points of the circuit; a fall in temperature at these weak points would favour the colonisation and spread of Legionella, because amoeba (the main Legionella reservoir) are not affected by temperature.

Naegleria fowleri is a free-living ameba that causes primary amebic meningoencephalitis (PAM), a rare but usually fatal disease. We analyzed trends in recreational water exposures associated with PAM cases reported during 1978–2018 in the United States. Although PAM incidence remained stable, the geographic range of exposure locations expanded northward.

Introduction: Monitoring water quality in mobile dialysis (MD) services, assessing critical points and characterizing the risks inherent in the process, is essential to avoid risks to the patient's health. This study evaluated the microbiological quality of water in the MD of 36 hospitals with intensive treatment in the city of Rio de Janeiro. Methods: 204 water samples were collected from the points of entry to the network (NET), post-osmosis (PO) and dialysis solution (DS). The samples were evaluated for heterotrophic bacteria count, pathogen search, presence of endotoxins and aluminum content. Results: Bacterial contamination at 3 collection points in 36 hospitals was 30% (32/108); 42% from DS, 31% from PO and 17% from NET, with the presence of Pseudomonas aeruginosa, Stenotrophomonas maltophilia , Burkholderia cepacia and Ralstonia pickettii in the 3 points. Endotoxin concentrations above 0.25 EU/mL occurred in 77% of the samples (17/22) analyzed in the PO. In the aluminum content, values above 0.01 mg/L were presented in 47% (7/15) of PO samples and 27% (4/15) of NET samples. There is no specific legislation for water used in the MD; therefore, the limits of the RDC of the National Health Surveillance Agency (Anvisa) 11/2014 were used; which regulates conventional hemodialysis services. Conclusion: The results highlight the importance of evaluating water quality in MD services to ensure patient safety and support the sanitary monitoring of this process as a healthcare promoter. Resumo Introdução: Monitorar a qualidade da água nos serviços de diálise móvel (DM), avaliando os pontos críticos e caracterizando os riscos inerentes ao processo, é fundamental para evitar riscos à saúde do paciente. Este estudo avaliou a qualidade microbiológica da água na DM de 36 hospitais com tratamento intensivo no município do Rio de Janeiro. Métodos: Foram coletadas 204 amostras de água dos pontos de entrada da rede (REDE), pós-osmose (PO) e solução de diálise (SD). As amostras foram avaliadas quanto à contagem de bactérias heterotróficas, pesquisa de patógenos, presença de endotoxinas e teor de alumínio. Resultados: A contaminação bacteriana, em 3 pontos de coleta nos 36 hospitais, foi de 30% (32/108), sendo 42% provenientes da SD, 31% da PO e 17% da REDE, com presença de Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cepacia e Ralstonia pickettii nos 3 pontos. Concentrações de endotoxina acima de 0,25 EU/mL ocorreram em 77% das amostras (17/22) analisadas na PO. No teor de alumínio, os valores acima de 0,01 mg/L foram apresentados em 47% (7/15) das amostras da PO e 27% (4/15) das amostras da REDE. Não existe uma legislação específica para água utilizada na DM; logo, foram utilizados os limites da RDC da Agência Nacional de Vigilância Sanitária (Anvisa) 11/2014, que regulamenta os serviços de hemodiálise convencional. Conclusão: Os resultados ressaltam a importância da avaliação da qualidade da água nos serviços de DM para garantir a segurança do paciente e subsidiar o monitoramento sanitário desse processo como um promotor de saúde.

Human leptospirosis involves the classic epidemiological triad (agent, host and environment); hence the investigations should include the knowledge on Leptospira within the animals and the environment. The objectives of this study are to explore the abundance of Leptospira in different climate zones of Sri Lanka and to describe the presence of Leptospira in the same water source at serial time points. First, water and soil samples were collected from different parts of Sri Lanka (Component-1); second, water sampling continued only in the dry zone (Component-2). Finally, serial water sampling from ten open wells was performed at five different time points (Component-3). Quantitative PCR of water and metagenomic sequencing of soil were performed to detect Leptospira. Three replicates for each sample were used for PCR testing, and positive result of two or more replicates was defined as ‘strongly positive,’ and one positive replicate was defined as positive. In the water and soil sample analysis in the whole country (Component-1), two out of 12 water sites were positive, and both were situated in the wet zone. Very small quantities of the genus Leptospira were detected by 16 amplicon analysis of soil in all 11 sites. In the dry zone water sample analysis (Component-2), only samples from 6 out of 26 sites were positive, of which one site was strongly positive. In the serial sample analysis (Component-3), Six, five, four, five, and six wells were positive in serial measurements. All wells were positive for at least one time point, while only one well was positive for all five time points. Proximity to the tank and greater distances from the main road were associated with strong positive results for Leptospira (PLeptospira was not consistent, indicating the variable abundance of Leptospira in the natural environment. This intermittent nature of positivity could be explained by the repetitive contamination by animal urine.

Escherichia coli normally cannot grow in the environment. One environmental stress that prevents E. coli growth may be the competition for growth substrates with co-existing micro-organisms. In this study, the growth substrates of E. coli were screened by high-resolution mass spectrometry and compared with those of indigenous bacteria in river water. In an incubation experiment, E. coli multiplied in sterilized river water, but did not multiply when indigenous micro-organisms were present in the water. By analysing dissolved organic matter in the river water before and after E. coli growth, 35 compounds were identified as putative growth substrates of E. coli. Among them, 33 compounds were also identified as putative growth substrates of indigenous bacteria. These results indicate that E. coli and indigenous bacteria compete for organic substrates in river water, which could suppress the growth of E. coli.

Jordan is one of the lowest countries in the world in terms of water resources. The reuse of treated wastewater is an important alternative to supply agricultural demands for water. In Jordan, Kherbet Al-Samra wastewater treatment plant (KSWWTP) is the largest and its effluent is mainly used for irrigation purposes. In this study, bacterial contamination and mutagenic potential were evaluated in six sites, beginning with KSWWTP and ending with King Tallal Dam. The results showed high contamination with many pathogenic bacteria and coliforms. The isolated pathogenic bacteria were Salmonella sp., Shigella sp., Bacillus cereus and Staphylococcus aureus. The isolated opportunistic pathogenic bacteria were Acinetobacter lwoffii, Elizabethkingia meningosepticum, Pseudomonas fluorescens and Bacillus licheniformis. These bacteria were found in all sampling sites without a specific prevalence pattern. Differences in temperature between seasons affect total coliform and other bacterial count. All water samples showed positive mutagenic activity and high bacterial pollution. Improving the disinfection efficiency in the wastewater treatment plant is important to minimize potential toxicity and exposure of public health to pathogenic bacteria, reduce water resources' contamination and environmental pollution. Increasing effluent sampling frequency from KSWWTP is required to monitor bacterial contamination and toxicity/mutagenicity level for water safety and public health risk assessments.

High levels of microbial fecal pollution are a major concern in many countries. A human-associated genetic marker for Escherichia coli (H8) has recently been developed for fecal source tracking. The assessment of the H8 marker performance is crucial before it can be applied as a suitable method for fecal source tracking in each country. The performance (specificity and sensitivity) of the H8 marker was evaluated by using non-target host groups (cattle, buffalo, chicken, duck, and pig feces) and target host groups (influent and effluent from a wastewater treatment plant and septages). SYBR based real-time PCR (polymerase chain reaction) was done on 400 E. coli isolates from non-target and target host groups after E. coli isolation. It was found that the specificity from animal feces samples collected in Thailand was 96%. Moreover, influent, effluent, and septage samples showed the values of the sensitivity at 18, 12, and 36%, respectively. All of the non-target host groups were found to be significantly different with positive proportions from the target host group (septage samples) (p ≤ 0.01). Based on the results, this marker is recommended for use as a human-associated E. coli marker for identifying sources of fecal pollution in Thailand.

Fecal indicator organisms (FIOs), such as Escherichia coli and enterococci, are often used as surrogates of contamination in the context of beach management; however, bacteriophages may be more reliable indicators than FIO due to their similarity to viral pathogens in terms of size and persistence in the environment. In the past, mechanistic modeling of environmental contamination has focused on FIOs, with virus and bacteriophage modeling efforts remaining limited. In this paper, we describe the development and application of a fate and transport model of somatic and F-specific coliphages for the Washington Park beach in Lake Michigan, which is affected by riverine outputs from the nearby Trail Creek. A three-dimensional model of coliphage transport and photoinactivation was tested and compared with a previously reported E. coli fate and transport model. The light-based inactivation of the phages was modeled using organism-specific action spectra. Results indicate that the coliphage models outperformed the E. coli model in terms of reliably predicting observed E. coli/coliphage concentrations at the beach. This is possibly due to the presence of additional E. coli sources that were not accounted for in the modeling. The coliphage models can be used to test hypotheses about potential sources and their behavior and for predictive modeling.

BackgroundOn 23 February 2018, the Uganda Ministry of Health (MOH) declared a cholera outbreak affecting more than 60 persons in Kyangwali Refugee Settlement, Hoima District, bordering the Democratic Republic of Congo (DRC). We investigated to determine the outbreak scope and risk factors for transmission, and recommend evidence-based control measures.MethodsWe defined a suspected case as sudden onset of watery diarrhoea in any person aged ≥ 2 years in Hoima District, 1 February–9 May 2018. A confirmed case was a suspected case withVibrio choleraecultured from a stool sample. We found cases by active community search and record reviews at Cholera Treatment Centres. We calculated case-fatality rates (CFR) and attack rates (AR) by sub-county and nationality. In a case-control study, we compared exposure factors among case- and control-households. We estimated the association between the exposures and outcome using Mantel-Haenszel method. We conducted an environmental assessment in the refugee settlement, including testing samples of stream water, tank water, and spring water for presence of fecal coliforms. We tested suspected cholera cases using cholera rapid diagnostic test (RDT) kits followed by culture for confirmation.ResultsWe identified 2122 case-patients and 44 deaths (CFR = 2.1%). Case-patients originating from Demographic Republic of Congo were the most affected (AR = 15/1000). The overall attack rate in Hoima District was 3.2/1000, with Kyangwali sub-county being the most affected (AR = 13/1000). The outbreak lasted 4 months, which was a multiple point-source. Environmental assessment showed that a stream separating two villages in Kyangwali Refugee Settlement was a site of open defecation for refugees. Among three water sources tested, only stream water was feacally-contaminated, yielding > 100 CFU/100 ml. Of 130 stool samples tested, 124 (95%) yieldedV. choleraeby culture.Stream water was most strongly associated with illness (odds ratio [OR] = 14.2, 95%CI: 1.5–133), although tank water also appeared to be independently associated with illness (OR = 11.6, 95%CI: 1.4–94). Persons who drank tank and stream water had a 17-fold higher odds of illness compared with persons who drank from other sources (OR = 17.3, 95%CI: 2.2–137).ConclusionsOur investigation demonstrated that this was a prolonged cholera outbreak that affected four sub-counties and two divisions in Hoima District, and was associated with drinking of contaminated stream water. In addition, tank water also appears to be unsafe. We recommended boiling drinking water, increasing latrine coverage, and provision of safe water by the District and entire High Commission for refugees.

Background and Objectives: According to hazardous infection possibility in patients with a weakened immune system, old adults, and children, microbial contamination in the waterlines of dental units has become a recent concern. The aim of the present study was to evaluate the microbial contamination in dental unit waterlines in the School of Dentistry, Qom University of Medical Sciences, Qom, Iran. Methods: This descriptive-analytical study investigated 94 water samples collected from three parts of each unit, including air/water syringe, turbine headpiece, and cup filler, in the School of Dentistry in 2019. The water samples were taken on Saturday and Wednesday before and 60 sec after flushing on the same unit. The samples were transported in closed sterile containers to the Microbiology Laboratory. All the samples were incubated on nutrient agar plates using the Spread plate technique. Subsequently, bacterial contaminations were counted and reported based on CFU/ml for every plate. The data were analyzed using the Kruskal-Wallis test and Wilcoxon signed-rank test by SPSS software version 25. Results: The total mean of the bacterial counts was reported as 16,457 CFU/ml. The pre-clinic and periodontics were reported with the highest and lowest bacterial counts, respectively. The mean of bacterial counts after flushing was significantly lower than that reported before flushing on the same unit (P