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Vibrio parahaemolyticus is a leading cause of human gastroenteritis associated with seafood consumption. The present study aimed to investigate the occurrence and risk assessment of V. parahaemolyticus isolated from live Indian black clams, sediment, and water samples collected from shellfish harvesting areas located along the south-west coast of India. Out of the total 72 samples collected, 55.6% revealed the presence of V. parahaemolyticus; the highest occurrence was observed in shellfish samples. The presence of tdh and trh virulence genes was screened by multiplex PCR. Virulence genes could be detected in 25.8% of the strains; 19.35% of them were trh positive and 3.2% were tdh positive, while 3.2% of strains exhibited the coexistence of both virulence genes. Antimicrobial resistance (AMR) determined by the disk diffusion method revealed that 87% of the strains were multiple drug resistant and exhibited 21 diverse resistance patterns. The overall multiple antibiotic resistance (MAR) index values ranged from 0 to 0.8. To the best of our knowledge, this is the first report to document the presence of pathogenic and multidrug-resistant V. parahaemolyticus in shellfish harvesting areas of the Indian sub-continent. The study reveals possible health hazards associated with consuming shellfish harvested from the study area. [ABSTRACT FROM AUTHOR]

Acanthamoebae spp. are considered the most commonly occurring free-living amoebae (FLA) in the environment. Their high resilience enables them to thrive in different types of environments. Using purposive sampling, 80 surface water samples were collected from identified coastal sites in Mariveles, Bataan, and Lingayen Gulf (40 water samples for each). Nineteen (23.75%) of the 80 water samples yielded positive amoebic growth during the 14-day culture and microscopic examination. The polymerase chain reaction confirmed Acanthamoeba spp. DNA in isolates MB1, A3, A4, A7, C5, and D3 using JDP1 and JDP2 primer sets. Further sequencing revealed that the isolates belonged to Acantha- moeba sp., Acanthamoeba culbertsoni, Acanthamoeba castellani, and Acanthamoeba genotype T4. The sequences were deposited in GenBank and registered under accession numbers PP741651, PP767364, PP741728, PP741729, PP767365, and PP767366, respectively. Potential risk factors such as waste disposal, expansion of human settlements to coastal locations, and soil runoffs in these environments should be controlled to mitigate the proliferation of potentially pathogenic strains of FLAs. [ABSTRACT FROM AUTHOR]

Natural hot springs are ideal places and environmental matrices that offer relaxation to people and microorganisms of different types. A total of 40 surface water samples were collected from the five identified collection sites, eight water samples for each site. Collection sites are designated 200 m apart to cover the entire study site. Surface water samples were collected approximately 10–20 cm from the surface. Water samples were filtered, cultured, and microscopically observed for 14 days. After 14 days of cultivation, eight (20%) water samples revealed cystic and trophozoite stages. Polymerase chain reaction using JDP1 and JDP2 specific primers confirmed the presence of Acanthamoeba spp. from two of our isolates in the hot spring, isolates 1.1 and 5.1. Further sequencing revealed that the isolates are Acanthamoeba T20 and Acanthamoeba genotype T7. Sequences were deposited to GenBank and were assigned accession numbers PP741726 and PP741727, respectively. The isolation of Acanthamoeba spp. in hot springs has significant health implications, especially for those who use it for recreational activity. Private resort owners are highly encouraged to regularly monitor and maintain hot spring resorts to avoid future infections. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the levels of fluoride in drinking water and its health impact in Semema, Tigray, Ethiopia. Water samples were collected in February, March and April from three potential spring water sources, namely May Atkaru, May Sensela and May Liham. Each sample was analyzed for a variety of physicochemical parameters including fluoride using standard APHA procedures through double beam UV–Visible spectrophotometer, atomic absorption spectrophotometer and titrimetric methods. All the measured physicochemical parameters except hardness (345.78–368.35 mg/L) and alkalinity (231.3–354.6 mg/L) were recorded below the WHO permissible limit set for drinking water. The amount of fluoride in May Atkaru (4.00 mg/L) and May Sensela (3.89 mg/L) was significantly greater than the WHO permissible limit set for drinking water, 1.5 mg/L. Moreover, HQ . 1 from May Atkaru and May Sensela revealed the possibility of dental and skeletal fluorosis over extended exposure to fluoride irrespective of age and sex variations. This confirmed people in the area with mottled teeth are vulnerable to the excessive consumption of fluoride, which poses health risks. Therefore, it needs immediate interventions to minimize the debilitating effect of fluoride in drinking water by creating awareness among the community and policymakers to introduce low-cost defluoridation methods. [ABSTRACT FROM AUTHOR]

The study area covers the Banaz (Usak) basin located in the Aegean Region in the western part of Turkey. Metamorphic, sedimentary, ultramafic, and volcanic rocks are dominant in the basin. The groundwaters in the study area are used for domestic, irrigational, and industrial purposes. Hence, the groundwater chemistry and major geochemical processes in the region were determined. The dominance of major elements was of the order of Ca2+. Mg2+ Na+. K+ and HCO3-. CO3-. Cl-. SO42-. Piper, Durov, Chadha, and Radial plots identified generally Ca2+Mg2+-HCO-3 type waters as the dominant types of water in this area. In terms of physical parameters in the basin, the waters are suitable for drinking. However, arsenic content in Yesilyurt and Corum settlements exceeds the limit values of drinking water standards. In addition, the ammonium value is high in the water sample in the Corum region. Isotope contents in water samples from 2008 to 2023 were evaluated in the study area. The waters in the basin are of meteoric origin according to their stable isotope content. Tritium content in the plain waters indicates recent recharge. Additionally, for children, As and U elements were identified as risky with oral intake and As with dermal contact. [ABSTRACT FROM AUTHOR]

The study objective was to evaluate human faecal contamination impacts in the Yal-ku lagoon in the Mexican Caribbean and to estimate adenovirus infection and illness risks associated with recreational exposure during water activities. A total of 20 water samples (10 from each site × two sites) (50 L) were collected monthly over a period of 12 months from two selected sampling sites in the swimming area of the Yal-ku lagoon. The occurrence of faecal-associated viruses was explored, and human adenovirus (HAdV) and pepper mild mottle virus (PMMoV) concentrations were quantified. A quantitative microbial risk assessment (QMRA) model was used to estimate exposure and subsequent adenovirus infection and illness risk for 1 h of swimming or snorkelling. Somatic and Fþ -specific coliphages occurred in 100% of the samples. Both HAdV and PMMoV were detected at a 60% frequency thereby indicating persistent faecal inputs. PMMoV concentrations (44-370 GC/L) were relatively lower than the concentrations of HAdV (64-1,000 GC/L). Estimated mean adenovirus risks were greater for snorkelling than for swimming by roughly one to two orders of magnitude and estimated mean illness risks for snorkelling were .32/1,000. Human faecal contamination is frequent in the Yal-ku lagoon, which is associated with human gastrointestinal illness. [ABSTRACT FROM AUTHOR]

This study aims to determine the background levels of tritium radioisotope in drinking and seawater samples of Sinop province before the nuclear power plant was established in Sinop. In this context, a total of 174 water samples were collected, these are as follows: nine drinking water samples from the Sinop center and districts and 165 seawater samples from the seacoast from Samsun to Kastamonu. Tritium concentrations in the collected water samples were measured by the liquid scintillation counter. The minimum detectable activity for the method used was found to be 1.48 Bq/L. The tritium concentrations of the seawater and drinking water samples were found in the range of, MDA (minimum detectable activity)-6.29 Bq/L and 2.45-3.17 Bq/L, respectively. In addition, the annual effective dose rates of the people consuming these drinking waters due to the tritium radioisotope were calculated separately for infants, children and adults and found to be 12.12, 16.96 and 35.38 nSv, respectively. [ABSTRACT FROM AUTHOR]

In Nigeria, artisanal mining has become a serious issue. In the Nigerian mining region of Arufu Pb–Zn–F, this study assessed the level of pollution, ecological hazards, and health risks related to the presence of metals in the water. In the dry and rainy seasons, 36 water samples (20 from the ground, 10 from the surface, and six from the mine) were gathered. Samples were examined for the presence of heavy metals such as Cr, Co, Ni, Cu, Zn, As, Cd, and Pb. Other than Cu, Zn, As, Cd, Sb, and Cd (surface water, dry season), which were below the acceptable norm, all water samples had metals over the suggested limits. Heavy metals from nearby mining activities polluted the water, according to contamination evaluations utilizing the contamination factor (CF). Metals in the water may pose very significant ecological dangers, according to ecological risk assessments. The evaluation of human health risks revealed that both adults and children in the region are susceptible to carcinogenic and non-carcinogenic health hazards since the hazard index (HI) values for both indices were above 1* ( 10-5 and above 1, respectively. This report emphasizes the need for monitoring mining operations in the nation to safeguard public health [ABSTRACT FROM AUTHOR]

The European Union currently has no specific regulations on fungi in water. The only country where fungi are listed as the parameter is Sweden, with the maximal number of 100 CFU per 100 mL. The present study thus compared culturable mycobiota from Swedish drinking water with Slovenian, which has no specific requirements for fungi. Fungi were isolated with up to 38 CFU/L from 75% of Swedish samples. The most common were the genera Varicosporellopsis (27.3%), Paracremonium (14.5%), and black yeasts Cadophora, Cyphellophora, and Exophiala (18.2%). Using the same sampling and isolation methods, 90% of tap water samples in Slovenia were positive for fungi, with Aspergillus spp. (46%), Aureobasidium melanogenum (36%), and Exophiala spp. (24%) being the most common. The observed differences between countries are likely the consequence of geographical location, the use of different raw water sources, and water treatment methods. However, the core species and emerging fungi Aspergillus fumigatus, Candida parapsilosis sensu stricto, Exophiala phaeomuriformis, Bisifusarium dimerum, and Rhodotorula mucilaginosa were isolated in both studies. These findings point out the relevance of tracking the presence of emerging fungi with known effects on health in drinking water and encourage further studies on their transmission from raw water sources to the end-users. [ABSTRACT FROM AUTHOR]

Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems (DWPS). The respective action levels differ at the international level. In Germany, the Federal Environment Agency (UBA) specifies the application of ISO 11731 for the detection of legionella in drinking water and gives a binding recommendation for the methods to be used for culturing and evaluation. Effective from 01 March 2019, the UBA recommendation was revised. The utilized culture media in the culture approach were altered, consequently affecting the spectrum of legionella colonies detected in drinking water. Using data from a routine legionella monitoring of a large laboratory, over a period of 6 years and 17,270 individual drinking water samples, allowed us to assess the impact of the alteration on the assessment of DWPS. By comparing the amount of action level exceedances before and after the method change, it could be demonstrated that exceedances are reported significantly more often under the new method. Consequently, the corresponding action level for evaluation of legionella contamination and the resulting risk to human health needs to be revised to avoid the misleading impression of increased health risk. [ABSTRACT FROM AUTHOR]

Microplastic (MP) debris is now a global concern. The Chao Phraya is the largest river in Thailand and transports MPs from terrestrial areas to the ocean. MP debris in its water and sediment were measured in March 2021, September 2021, and March 2022 in five provinces along the watercourse. Hydrological data were also collected to estimate the MP riverine flux between provinces. Size, shape, color, and types of MP polymers were observed, with sedimentation data collected for MP content. Results showed that MPs were found at all sample stations, with average abundance in all province water samples ranging from 0.54 ± 0.05 to 1.07 ± 0.28 pieces/L, while in sediment sample, numbers ranged from 183.84 ± 38.76 to 546.18 ± 86.84 pieces/kg dry weight throughout all seasons. Overall contamination and accumulation were similar between provinces but significantly different between seasons. Sizes of MPs in water varied between seasons with MPs in sediment mostly 330-5,000 μm (Kruskal-Wallis, P < 0.05). Sedimentation of MPs was different between seasons (Kruskal-Wallis, P < 0.05). The highest MP flux values discharged from Samut Prakan Province to the inner Gulf of Thailand were 1.83 x 105 and 1.60 x 105 million items/day in September 2021 and March 2022, respectively. [ABSTRACT FROM AUTHOR]

Cooling towers have been linked to Legionnaires’ disease cases and outbreaks. Legionella pneumophila results (from a culture-based method) are presented for 557 cooling towers across the City of Vancouver, Canada for 2021. Results of 10 CFU/mL or greater (defined as exceedances) were reported for 30 cooling towers (5.4%), including six .1,000 CFU/mL, and L. pneumophila serogroup 1 (sg1) was identified in 17 of these cooling towers (out of 28 with serogroup-level analysis). The data indicate highly localised Legionella issues, with exceedances concentrated within 16 facilities, including two hospitals. In the 3 months preceding each cooling tower exceedance, the nearest municipal water sampling station had a free chlorine residual of at least 0.46 mg/L and a temperature of,20 °C. There was not a statistically significant correlation between the L. pneumophila concentration of a cooling tower in exceedance and the municipal water free chlorine residual, temperature, pH, turbidity or conductivity. There was a statistically significant negative correlation between the concentrations of L. pneumophila sg1 and other L. pneumophila serogroups in cooling towers. This unique dataset underscores the pivotal role of building owners and managers in preventing the growth of Legionella bacteria and the value of regulations to verify operations and maintenance practices. [ABSTRACT FROM AUTHOR]

Wastewater released into the environment without proper treatment contributes to the high prevalence of parasitic infections. We aimed to investigate the occurrence of parasites in sewage waters in both rainy and dry seasons in the city of Santana do Ipanema, Brazil. This is a descriptive cross-sectional study carried out between the months of June, July (rainy season) and October (dry season) of 2021. A total of 50 streets were selected by a sample calculation in the Epi Info™ program. From each street, two wastewater samples were collected in both climatic periods. In the laboratory, the water samples were submitted to the Bailenger method with some adaptations and analyzed under an optic microscope. In the rainy season, we detected Strongyloides stercoralis (87.6%; 134), Strongylus spp. (4.6%; 7), hookworms (2.0%; 3) and Iodamoeba butschlii (62.5%; 5), and in the dry season, it was detected S. stercoralis (55.0%; 71), Metastrongylids (19.4%; 25), hookworms (12.4%; 16) and I. butschlii (76.5%; 13). The spatial analysis has shown that most hotspots were associated with S. stercoralis, mainly during periods of intense rainfall and close to river areas. Thus, the city population is subject to infections, especially by helminths regardless of seasonality. [ABSTRACT FROM AUTHOR]

Acanthamoeba, a free-living and opportunistic protozoan parasite, is a causative agent of severe human infections of the cornea and brain. The present study evaluated the distribution and genotyping of Acanthamoeba spp. in water and soil of recreational places in various areas in Guilan province in northern Iran. Eighty water and 20 soil samples were collected from the study area. Water samples were vacuum filtered through a 0.45 μm pore-size membrane filter. Soil samples were washed with sterile distilled water, and washings were similarly filtered, as mentioned for water samples. The filtered material was cultured on non-nutrient agar plates seeded with heat-killed Escherichia coli. Molecular analysis was performed by PCR and sequencing using specific primers for Acanthamoeba. Finally, 26 isolates were successfully sequenced. According to culture and PCR methods, 54% of water and 100% of soil samples were contaminated with Acanthamoeba. Based on the sequencing data, genotypes T4 (47%), T5 (35.29%), T3 (11.76%), and T11 (5.88%) were identified in water samples. Genotypes T4 (66.6%), T5 (22.2%) and T15 (11.1%) were identified in water samples. Most isolates might present a potential health hazard for humans in this region. To the best of our knowledge, this is the first comprehensive survey of water and soil of recreational areas in northern Iran and the first report on identifying genotype T15 from soil sources. [ABSTRACT FROM AUTHOR]

Concerns over fecal contamination in stormwater canals have promoted the need for pollution control strategies, including the use of microbial source tracking, to identify fecal contamination in the Greater New Orleans Area. Surface water samples were collected over a 12-month period at five canal locations within Jefferson Parish, Louisiana. Quantitative polymerase chain reaction and the IDEXX method were used to assess the concentrations of coliforms, Escherichia coli (E. coli) and human fecal 183 bacteroides (HF183) in stormwater samples. A 100% positive detection rate of total coliforms and E. coli was observed across all tested sites. Despite the closeness of the five sites, when averaged across all sampling time points, Kruskal–Wallis tests indicated that E. coli was present at significantly different concentrations in these locations (χ2 (5) ¼ 19.8, p ¼ 0.0005). HF183 was detected in 62% of the water samples collected during the stormwater sampling. Without further testing for HF183 markers, the conclusion from this study would have been that fecal contamination from an unknown source was always present at varying levels during the study period. Analysis of HF183 markers therefore adds another layer of conclusions to the results deductible from E. coli concentrations. A 100% E. coli detection rate, high E. coli concentrations coupled with low rates of HF183 detection particularly at the Esplanade, Poplar Street, and Bonnabel Boat Launch sites, the sites closest to the lake outlet, throughout the study period, indicate that fecal contamination at these stormwater canal sites comes primarily from non-human sources. However, the Metairie Road and Napoleon Avenue sites, which have the highest HF183 detection rates, on top of chronic pollution by other non-human sources, are also influenced by human fecal pollution, possibly because of human development and faulty infrastructure. This study highlights the advantages of the use of microbial source-tracking methods to complement traditional indicator bacteria. [ABSTRACT FROM AUTHOR]

Although the presence of free-living amoebae (FLAs) in various water sources has been reported, few studies have been surveyed on their abundance in medical-unit and dental-unit water samples. The current study aimed to identify morphological and molecular characteristics of FLA isolates in the water samples of the dental unit in Iran. A total of 232 water samples were collected from 17 dental units. Then, filtration and cultivation were conducted on a non-nutrient agar (NNA) medium. Also, polymerase chain reaction (PCR) assay and sequencing were performed by using the genus/species-specific primers plus a common primer set on positive samples. One hundred and sixty-six samples were positive for FLA by the microscopic method, whereas 114 samples were positive by the molecular method with a common primer set. Considering the PCR assay with genus/species-specific primers, 23.27% (54/232) samples were identified as Acanthamoeba spp. (belonging to T4 genotype), 36.63% (85/232) as Vermamoeba vermiformis, and 1.72% (4/232) as Vahlkampfiidae family (Naegleria lovaniensis). These results highlight a need to improve filtration systems in dental units and periodic screenings for FLA in dental-unit water. [ABSTRACT FROM AUTHOR]

The aim of the present study was to detect free-living amoeba (FLA) in the water resources of Arak, Iran using molecular tools. A total of 154 samples were collected from different water supplies. Molecular analyses, sequencing, and phylogenetic study were conducted to confirm the species and genotypes of FLA. Fisher exact test was used to determine the significance. Of 154 water samples, 19 (12.3%) samples were tested positive for FLA. Three genotypes of Acanthamoeba including T4, subtype D, and T5 were identified among the isolates. The pathogenicity assay showed that the isolate of Acanthamoeba in drinking water was highly pathogenic. Three species of Naegleria, including N. australiensis, N. pagei, and N. gruberi were found among the samples. Six isolates of Vermamoeba were identified as V. vermiformis. Meanwhile, three other species including Vannella sp., Vahlkampfia avara, and Stenamoeba polymorpha were also recovered from the water samples. Statistical analysis showed a significant difference between the various water resources contaminated with FLA. This is the first study to reveal the presence of S. polymorpha in water sources in Iran. According to the findings of the present study, health officials should be beware of potential public health impacts of FLA in water resources. [ABSTRACT FROM AUTHOR]

This paper evaluates the performance of a low-cost technology in rural Benin (West Africa) that locally produces chlorine (sodium hypochlorite) and then injects it into the community water tanks. Thirty-one water tanks were selected in cooperation with local authorities to receive electro-chlorinator devices (WATA™). Water samples were tested at two points: before chlorination and at the most distant terminal after chlorination. Residual chlorine control tests and microbiology control tests were performed. Water samples that tested positive for the presence of microorganisms were analyzed at a laboratory when possible. The water provided to the community was not always chlorinated, and over half of the tanks lacked access to chlorine powder. Among the sites using the technology, 30% (9/31) of them had structural problems that prevented the existing system from performing adequately. Furthermore, 60% of the water samples collected before chlorination were positive for microbiological contamination. All samples collected from systems where proper chlorination was taking place tested negative for microbiological contamination. However, the water from six tanks presenting structural problems continued to be distributed to the population despite contamination. The average residual chlorine level analyzed at the most distant terminal fountain was 0.29±0.2 mg/L, which is within the country's reference level 0.1-0.8 mg/L. The installation of water-chlorinator devices (WATA™) produces water without microbiological contamination and with chlorine levels within the WHO's recommended values. However, the success of the technology depends on the pre-existing structure of the water tank. [ABSTRACT FROM AUTHOR]

Free-living amoebas (FLAs) can cause neurological and ocular complications in humans. Water supplies play a critical role in transmitting FLAs to humans. The aim of the present study was to investigate the presence of FLAs in various aquatic sources including drinking water, stagnant water, and surface water in Alborz province, northern Iran, using morphological and molecular techniques. A total of 70 water samples were collected from 34 drinking waters, 23 surface waters, and 13 stagnant waters. Filtration and cultivation were employed to isolate FLAs. PCR assay was applied by using the genus-specific primers on positive samples. Pathogenicity tests (osmo-and thermo-tolerance properties) were performed for Acanthamoeba spp., positive sample. Considering the morphological criteria, four positive samples of Acanthamoeba sp., three Vermamoeba sp., two mixed Vermamoeba sp. with Vahlkamfiids, and one mixed Acanthamoeba sp. with Vahlkamfiids were isolated. Five Acanthamoeba sp. isolates were amplified using the JDP primer pairs. Among them, two genotypes, T4 (three isolates) and T5 (two isolates) corresponding to A. lenticulata, were identified. Four V. vermiformis samples were confirmed using the sequencing. This study highlighted the occurrence of potentially pathogenic waterborne FLAs in water habitats associated with high human activity. The results of such research on the prevalence of FLAs, as a human hazard, should be communicated to health policymakers. [ABSTRACT FROM AUTHOR]

The objective of this study was to understand the drinking water quality state in the Inner Mongolia Autonomous Region from 2014 to 2018 and to derive information that will provide a basis for improving the drinking water quality in the region. Monitoring data for drinking water from the Inner Mongolia Autonomous Region for 2014 to 2018 were analyzed and the results were compared with GB 5749-2006, the Standard Test Method for Drinking Water, and GB 5749-2006, the Drinking Water Quality Standards. Data for a total of 30,613 water samples were assessed. Of the data for the microbiological index, sensory trait and general chemical index, and toxicological index, 89, 80, and 69% were qualified, respectively. For the toxicological index, the fluoride and nitrate nitrogen data were the least compliant. The water quality in all the cities was generally very suitable for drinking. However, there were marked differences in the qualified rates of drinking water in different areas and the qualified rates of the data for the three indexes were lower in rural areas than in urban areas. Given the varied issues with the drinking water quality, the relevant departments of League cities should implement appropriate and effective treatment measures to improve the drinking water quality and ensure it is safe for residents. [ABSTRACT FROM AUTHOR]

Radon in the household water collected from hand pumps is measured using a continuous radon monitor. Water samples are collected from 25 villages from the surrounding regions of the National Capital Power Cooperation (NTPC), Dadri. The radon concentration ranges from 17+1 to 68+3 Bql-1 with a mean value of 33+13 Bql-1. The measured radon concentration in all collected samples lies well within the limit of 100 Bql-1as set by the World Health Organization (WHO). The mean values of the annual effective dose due to ingestion of radon and due to the inhalation of radon released from water are 84+33 and 167+65 μSvy-1, respectively. In addition, the mean values of estimated total annual effective doses are found to be 167+65 μSvy-1. The mean value of total annual effective doses is found to be higher than the reference dose level of 100 μSvy-1recommended by the WHO and the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The mean values of effective doses per annum to the lungs and stomach are 9.9+3.9 and 10.1+3.9 μSv, respectively. [ABSTRACT FROM AUTHOR]

Free-living amoebae (FLA) are protozoa ubiquitously found in nature. In addition to their natural distribution, some species have been documented as pathogenic to humans. The main aim of the current study was the molecular identification, sequencing and phylogenetic analysis of morphologically detected FLA in water sources in El-Qalyubia, Egypt. A total of 96 water samples were collected from different water sources. Each water sample was filtrated and cultured on non-nutrient agar (NNA). Morphologically positive FLA were subjected to PCR, PCR products were sequenced and the obtained sequences were phylogenetically analysed. FLA were found in 41 water samples examined (42.7%). Nile water and groundwater were the sources with the highest prevalence rates (83.3 and 62.5%, respectively). Naegleria italica was first identified in Egypt from the waters of the Nile. In addition, Vahlkampfia spp. and Hartmannella spp. were also detected. However, other FLA species, including Acanthamoeba spp. and the pathogenic Naegleria fowleri, previously reported in Egypt, were not included in this study. The recent identification of these FLA in the Egyptian waters related to human populations indicates the need for more phylogenetic studies using larger sample sizes to investigate their potential threat to human health. [ABSTRACT FROM AUTHOR]

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]

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

Cholera localized outbreaks/epidemics accounting for high morbidity and mortality have been reported in different years both from the coastal and tribal districts of Odisha. In the present study, the emergence and spread of two sequential cholera outbreaks reported in July to October 2012 from Rayagada and Kalahandi districts of Odisha was investigated. Environmental water samples from different sources and rectal swabs from diarrhoea patients were analysed for identification, antibiogram profiles and molecular studies using DMAMA-PCR assays. The pulsed field gel electrophoresis (PFGE) was done on some selected Vibrio cholerae O1 strains isolated from these cholera outbreak areas. Results showed 42% of rectal swabs and 2.3% of water samples collected from both the districts were positive for Vibrio cholerae O1 Ogawa biotype El Tor carrying both ctxB1 and ctxB7 genotypes. The common resistance profile of V. cholerae O1 strains was ampicillin, nalidixic acid, furazolidone and co-trimoxazole. The PFGE analysis on selected V. cholerae O1 strains of ctxB1 and ctxB7 genotypes showed three pulsotypes with 96% similarity matrix exhibiting the relationship with their respective water sources. Hence, continuous surveillance is highly essential to monitor the antibiogram profile and changing pattern of ctxB genotypes of V. cholerae O1 in this region. [ABSTRACT FROM AUTHOR]

Tap water that is safe to consume may cause respiratory illness (e.g., Legionnaires' disease) when water conditions allow for proliferation and aerosolization of biofilm-associated pathogens. This study assessed household tap water consumption, exposure to aerosolized tap water, and associated demographics. A nationally representative FallStyles survey administered by Porter Novelli Public Services was sent to 4,677 US adult panelists in October 2019. There were 3,624 adults who completed the survey (77.5% response rate). Respondents were asked about self-reported use of household tap water for consumption (i.e., drinking, rinsing produce, or making ice) and use through water-aerosolizing devices (e.g., showerheads, humidifiers). Demographics included gender, age, race/ethnicity, education, income, region, and health status. Weighted analyses using complex sample survey procedures were used to assess tap water exposure by route and demographics. Most US adults are exposed to aerosolized tap water through showering (80.6%), and one in five are exposed through other water-aerosolizing devices (20.3%). Consumption and showering were greatest among older, White, higher educated, and higher-income adults. Aerosolized tap water can transmit waterborne pathogens and cause respiratory illness, especially among older age groups and people with weakened immune systems. These results will help target health messages for using water-aerosolizing devices safely. [ABSTRACT FROM AUTHOR]

Nowadays, cyanobacteria blooms and microcystins (MCs) pollution are threatening water safety and public health. In this study, a rapid detection method was established for detecting MCs producing cyanobacteria. The MC synthesis gene mcyG was measured through recombinase polymerase amplification combined with lateral flow strips (LF-RPA) technology. The target gene mcyG was amplified at a temperature range of 37-45 °C, and the amplification time to detect mcyG was only 15 min at 37 °C. The optimal reaction conditions were confirmed using single dependent variable experiments, suggesting that the best probe dosage for 50 µL of the reaction mixture was 0.2 µL, the best dilution ratio of products was 1/100, and the best loading volume was 10 µL. The specificity test proved that the LF-RPA assay could distinguish MCs producing cyanobacteria from nontoxic algae well. Within 35 min of amplification time, the detection limit of the LF-RPA assay was 103 copies/mL mcyG and 104 cells/mL Microcystis aeruginosa FACHB-905. Overall, the LF-RPA assay could detect MCs producing cyanobacteria in water samples quickly and accurately, and it has a great promise to be applied for monitoring the MCs producing cyanobacteria blooms in natural waters. [ABSTRACT FROM AUTHOR]

Objective: Environmental monitoring of Legionella in hot water systems of hotels in Morocco was performed during the period from January 2016 to April 2018. A total of 149 water samples from 118 different hotels were analyzed. Methods: A total of 149 water samples from 118 different hotels were analyzed. Possible risk factors were prospectively recorded, and data were analyzed in connection with building and plumbing systems characteristics. Data about building and risk factors were collected through a questionnaire survey. Results: Out of the 149 samples, 77(51.7%) were positive for L. pneumophila. Serological typing of the isolates revealed that 54 (70.1%) are L. pneumophila serogroup 2-15 and 23 (29.9%) are L. pneumophila serogroup 1. 56.8% of all buildings were colonized by L. pneumophila. Counts were over 1,000 CFU/L in 44%. Contamination was strongly correlated with temperature in the circulation, the age of the premise plumbing and the size of the building. Conclusions: The results showed a relevant exposure to L. pneumophila in the community and the identified risk factors can serve as indicators for risk assessment and relevant actions. [ABSTRACT FROM AUTHOR]

Acanthamoeba spp. is a free-living amoeba that can cause major infections in humans, including keratitis and granulomatous encephalitis. Thus, water resources play an important role in transmitting Acanthamoeba spp. infection to humans. The purpose of this study was to investigate the presence of Acanthamoeba spp. in public swimming pools from three cities of Kerman Province, southeastern Iran. Eighty water samples of 20 public indoor swimming pools were taken from Kerman, Jiroft, and Kahnauj cities. Water temperature (°C), pH, and free chlorine concentration (ppm) were measured. Filtration and cultivation were applied on non-nutrient agar medium. The polymerase chain reaction was applied by using the genus-specific primers (JDP1 and JDP2) on positive samples; these primers can amplify the 423-551 bp fragment. Eighteen of the 20 swimming pools (including 32/80; 40% samples) were contaminated with Acanthamoeba spp. All swimming pools of Jiroft and Kahnauj and 88.2% of swimming pools in Kerman were contaminated. As such, all 32 Acanthamoeba isolates were amplified using the JDP primer pairs. Two genotypes, T3 and T4, were also identified. The present research is the first to report Acanthamoeba spp. in public swimming pools from Kerman Province. Due to high occurrence of this protozoan, it is recommended to use warning signs around swimming pools to create awareness of this infection. [ABSTRACT FROM AUTHOR]

Sulfate radical (•SO4-)-based advanced oxidation processes are widely used for wastewater treatment. This study explored the potential use of UV/persulfate (UV/PS) system for the degradation of 17β-estradiol (E2). The pH of the reaction system can affect the degradation rate of E2 by UV/PS and the optimum pH was 7.0; Br- and Cl- in water can promote the degradation rate, HCO3- has an inhibitory effect on the reaction, SO4²- and cations (Na+, Mg2+, K+) have no effect on the degradation rate. The degradation of E2 by UV/PS was a mineralization process, with the mineralization rate reaching 90.97% at 8 h. E2 in the UV/PS system was mainly degraded by hydroxylation, deoxygenation, and hydrogenation. E2 reaction sites were mainly located on benzene rings, mainly carbonylation on quinary rings, and bond breakage between C10 and C5 resulted in the removal of benzene rings and carboxyl at C2 and C3 sites. In the presence of halogen ions, halogenated disinfection by-products were not formed in the degradation process of E2 by UV/PS. E2 in the UV/PS system could inhibit the formation of bromate. The results of this study suggest that UV/PS is a safe and reliable method to degrade E2. [ABSTRACT FROM AUTHOR]

We investigated 22 water samples (17 well water and five pipe water - both chlorinated) and six soil samples from the surroundings of wells of the households of suspected patients from Palakkad district, Kerala (India), from where a cholera outbreak was reported during June-July 2016. A total of 25 Vibrio cholerae isolates were collected from three well water samples during a recent cholera outbreak. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. PCR assays confirmed the occurrence of ctxB, ctxA, hlyA, tcpA El Tor,VPI, ace, zot, ompW, rfbO1 and toxR genes in all isolates. The presence of the ctxB gene of the classical biotype in all of the El Tor isolates suggests that it is a new variant of El Tor biotype. Antibiogram profile of all V. cholerae O1 isolates revealed resistance towards five classes of antibiotics island and indicates that they were multidrug resistant. ERIC-PCR and PFGE finger prints showed the clonal relationship among the V. cholerae O1 isolates. The results of this study revealed the emergence of a new variant of El Tor biotype in the water samples from Palakkad district, from where a cholera outbreak was reported. [ABSTRACT FROM AUTHOR]

Water quality deterioration in source waters poses increased health, environmental, and economic risks. Here, we genotyped Cryptosporidium spp. obtained from water samples of Laguna Lake, Philippines, and its tributaries for the purpose of source-tracking fecal contamination. A total of 104 surface water samples were collected over a 1-year period (March 2018 to April 2019). Detection of Cryptosporidium was carried out using genus-specific primers targeting a fragment of the small subunit (SSU) rRNA gene. The study revealed 8 (14%) tributary samples and 1 (2.77%) lake sample positive for contamination. The species were determined to be C. parvum (n = 4), C. muris (n = 2), C. hominis (n = 1), C. galli (n = 1), C. baileyi (n = 1), C. suis (n = 1), as well as rat genotype IV (n = 1). Two species were detected in duck (C. baileyi) and cattle (C. parvum) fecal samples. The data presented suggest that Cryptosporidium contamination is likely to come from sewage or human feces as well as various agricultural sources (i.e. cattle, swine, and poultry). This information reveals the importance of mitigating fecal pollution in the lake system and minimizing health risks due to exposure to zoonotic Cryptosporidium species. [ABSTRACT FROM AUTHOR]

Legionella infections have steadily increased in the United States over the last 20 years, and most of these infections have been attributed to contaminated water. The gold standard for confirmation of Legionella presence in water is culturing with Buffered Charcoal Yeast Extract (BCYE) agar. Following many modifications, this method is still time-consuming, expensive, and can take longer than 10 days for full confirmation. The Legiolert is a newer and simpler culture product that is claimed to be able to quantify Legionella pneumophila in 7 days with high sensitivity and specificity and does not need further confirmation for the presence of L. pneumophila. This study compared the culturability of L. pneumophila occurring in a simulated home plumbing system using both Legiolert and BCYE agar methods. Out of 185 water samples, Legiolert and BCYE method detected L. pneumophila in 83 and 85% of the samples, respectively. The two methods were determined to be statistically equivalent for culturability of L. pneumophila, though the detected levels by Legiolert were slightly higher than the BCYE method. The molecular confirmation of positive (n=254) and negative wells (n=82) with Legiolert also showed a high specificity of 96.5% (i.e., 3.5% false positives (9/254) and 0% false negatives (0/82)). [ABSTRACT FROM AUTHOR]