Recreational Water Sources Research Articles

Assessing Per- and Polyfluoroalkyl Substances in Fish Fillet Using Non-Targeted Analyses.

Per- and polyfluoroalkyl substances (PFAS) are a class of thousands of man-made chemicals that are persistent and highly stable in the environment. Fish consumption has been identified as a key route of PFAS exposure for humans. However, routine fish monitoring targets only a handful of PFAS, and non-targeted analyses have largely only evaluated fish from heavily PFAS-impacted waters. Here, we evaluated PFAS in fish fillets from recreational and drinking water sources in central North Carolina to assess whether PFAS are present in these fillets that would not be detected by conventional targeted methods. We used liquid chromatography, ion mobility spectrometry, and mass spectrometry (LC-IMS-MS) to collect full scan feature data, performed suspect screening using an in-house library of 100 PFAS for high confidence feature identification, searched for additional PFAS features using non-targeted data analyses, and quantified perfluorooctanesulfonic acid (PFOS) in the fillet samples. A total of 36 PFAS were detected in the fish fillets, including 19 that would not be detected using common targeted methods, with a minimum of 6 and a maximum of 22 in individual fish. Median fillet PFOS levels were concerningly high at 11.6 to 42.3 ppb, and no significant correlation between PFOS levels and number of PFAS per fish was observed. Future PFAS monitoring in this region should target more of these 36 PFAS, and other regions not considered heavily PFAS contaminated should consider incorporating non-targeted analyses into ongoing fish monitoring studies.

Naegleria fowleri 98 Percent Fatal a Comprehensive Survey

Naegleria fowleri, colloquially termed the "brain-eating amoeba," presents a formidable public health concern due to its astonishingly high fatality rate of 98%. This abstract provides a thorough examination of the various aspects surrounding Naegleria fowleri, encompassing its morphology, life cycle, transmission routes, clinical manifestations, diagnostic methods, treatment strategies, and preventive measures. Naegleria fowleri, an amoeboid protist, thrives in warm freshwater environments, predominantly in regions with elevated temperatures. Infections occur when contaminated water enters the nasal passages, leading to primary amebic meningoencephalitis (PAM), an acute and often fatal condition affecting the central nervous system. The clinical course of PAM is rapid, with symptoms escalating from initial flu-like manifestations to severe neurological impairment within days. Diagnosis of PAM remains challenging, relying on specialized laboratory techniques such as polymerase chain reaction (PCR) and immunofluorescence assays. Despite efforts to develop effective treatments, mortality rates remain alarmingly high, emphasizing the critical importance of preventive measures. Avoiding freshwater activities in warm, stagnant water bodies, utilizing nose clips or plugs during water-related activities, and ensuring proper disinfection of recreational water sources are key strategies in mitigating the risk of the risk of Naegleria fowleri infections and reducing its devastating impact on public health.

Algae in Recreational Waters: An Overview within a One Health Perspective

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

Application of Artificial Intelligence in the Management of Drinking Water: A Narrative Review.

Waterborne illnesses are a significant concern worldwide. The management of water resources can be facilitated by artificial intelligence (AI) with the help of data analytics, regression models, and algorithms. Achieving the Sustainable Development Goals (SDGs) of the 2030 Agenda for Sustainable Development of the United Nations depends on understanding, communicating, and measuring the value of water and incorporating it into decision-making. Various barriers are used from the source to the consumer to prevent microbiological contamination of drinking water sources or reduce contamination to levels safe for human health. Infrastructure development and capacity-building policies should be integrated with guidelines on applying AI to problems relating to water to ensure good development outcomes. Communities can live healthily with such technology if they can provide clean, economical, and sustainable water to the ecosystem as a whole. Quick and accurate identification of waterborne pathogens in drinking and recreational water sources is essential for treating and controlling the spread of water-related diseases, especially in resource-constrained situations. To ensure successful development outcomes, policies on infrastructure development and capacity building should be combined with those on applying AI to water-related problems. The primary focus of this study is the use of AI in managing drinking water and preventing waterborne illness.

A spatial analysis of urban gulls contribution to the potential spread of zoonotic and antibiotic-resistant bacteria

Wildlife human interactions within cities are becoming more common with consequences for pathogen transmission and human health. Large gulls are opportunistic feeders, adapted to coexist with humans in urban environments, and are potential vectors for spread and transmission of pathogens, including antimicrobial-resistant bacteria. We investigated the potential role that urban gulls play in the spread and dispersal of these bacteria. We analysed 129 faecal swabs from yellow-legged gulls (Larus michahellis) of different ages (56 adults and 73 immatures) during the breeding period from three years in the highly populated city of Barcelona (northeastern Spain). Thirteen individuals tested positive for the pathogenic bacteria (Escherichia coli, Listeria monocytogenes, Campylobacter jejuni), including antibiotic-resistant strains. We modelled the potential spatial spread of pathogens using the GPS trajectories of 58 yellow-legged gulls (23 adults, 35 immature individuals), which included the thirteen individuals that tested positive for pathogenic bacteria. By overlapping the spatially explicit pathogen dispersal maps with the distribution of urban installations sensitive at risk of possible pathogen spillover (e.g. elder and medical centres, markets, food industries, kindergartens, or public water sources), we identified potential areas at risk of pathogen spillover. Pathogens may be potentially spread to municipalities beyond Barcelona city borders. The results revealed that immature gulls dispersed pathogens over larger areas than adults (maximum dispersal distances of 167 km versus 53.2 km, respectively). Recreational urban water sources were the most sensitive habitats visited by GPS-tagged gulls that tested positive, followed by schools. Combining GPS movement data with pathogen analytics allows spatially explicit maps to be generated using a One Health approach that can help urban and public health management within large cities, such as Barcelona, and identify areas used by humans that are sensitive to pathogen spillover from gulls.

Assessment of antibacterial potentials of violacein extract from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Nigeria

This study was carried out with the aim of assessing the antibacterial potentials of violacein extracted from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Nigeria. Water samples were collected from different locations of the domestic water sources, five different swimming pools, and three borehole stations using sterile amber bottles. The isolation of C. violaceum was done using pour plate method on nutrient agar. The violet colonies of C. violaceum were counted, characterized and identified using standard microbiological and biochemical techniques. The mean viable bacterial counts were high. Water sample from Otamiri station-1 have the highest bacterial count (200 × 101 CFU/ml and 19.50 × 101 CFU/ml) respectively. Swimming pool 1 and 3 bacterial counts were (4.50 × 101 CFU/ml, 11 × 101 CFU/ml and 11.50 × 101 CFU/ml) respectively. For borehole 1, 2 and 3, swimming pool 2, 4 and 5, counts were (0.00 × 101 CFU/ml). Ethanolic extraction of violacein from C. violaceum was performed from a 48-hour culture broth. The sensitivity of the bacteria isolates to violacein was assayed on nutrient agar and nutrient broth by agar diffusion and broth dilution methods respectively. All the bacterial isolates were susceptible to the violacein extract at various concentrations, except MRSA that showed resistance to the violacein at 2.19mg/ml for extract from recreational water isolate and at 17.5mg/ml to 2.19mg/ml for extract from domestic water isolates. Conclusively, violacein has the potential to be used as an antibacterial compound for treatment of multidrug resistant bacterial infections.

Assessment of antifungal potentials of violacein extract from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria

Anti-Microbial Resistance (AMR) in superficial fungal infections are major worldwide public health problem that affects a large part of the human population globally. The antifungal potentials of violacein extracted from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria, was assessed. Three water samples were collected from different locations of the Otamiri River, five from different swimming pools and three from different borehole locations in Owerri Metropolis. The samples were cultured on nutrient agar by pour plate method. The violet colonies of Chromobacterium violaceum were counted, characterized and identified. Water sample from Otamiri River station-1 had the highest bacteria count (20.00 × 101 CFU/Ml and 19.50 × 101 CFU/mL) respectively. Swimming pool 1 and 3 bacterial counts were (14.50 × 101 CFU/mL, 11.00 × 101 CFU/mL and 11.50 × 101 CFU/mL) respectively. For borehole 1, 2 and 3, swimming pool 2, 4 and 5 counts were (0.00 × 101 CFU/mL). The ethanolic extracts from the isolates (violacein) and the control drug (fluconazole 50µg/mL) both had inhibitory effects on the test organisms (Candida albicans and Aspergillus niger) at different concentrations. The MIC of Fluconazole on Candida albicans and A. niger were 25µg/ml and 50µg/Ml, respectively. Violacein from both swimming pools and Otamiri River isolates had MIC of 8.75mg/ml on A. niger and MIC of 4.375mg/ml on Candida albicans. Violacein which proved to have inhibitory effects on Candida albicans and Aspergillus niger can be harnessed for treatment of infections caused by these fungi.

Assessment of antifungal potentials of violacein extract from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria

Assessment of antifungal potentials of violacein extract from Chromobacterium violaceum isolated from domestic and recreational water sources in Owerri, Imo State, Nigeria

Cyanobacterial risk prevention under global warming using an extended Bayesian network

Cyanobacterial blooms under global warming are increasing worldwide, producing emerging contaminants, which threaten the health of human beings and aquatic ecosystems. The health burdens warrant the development of a useful risk-assessment tool and a holistic preventive-control scheme to prevent cyanobacterial blooms. This paper aims to integrate cyanobacterial risk assessment and risk preventive control by investigating the relationships amongst cyanobacterial blooms and multi-dimensional influencing variables. Two challenges hinder such a task. First, the time-series variations in cyanobacteria and influencing variables are uncertain and nonlinear. Second, there rarely exists an explicit modelling framework for integrating cyanobacterial risk assessment and risk preventive control. This study builds an extended Bayesian network model and proposes an integrated framework with functions of assessment, inference, preventive control, and visualisation of the risk of cyanobacterial blooms. Field data from a tropical lake are used to evaluate the model and framework. The proposed model achieves better performance than the seven models in comparison. The cyanobacterial risk is anticipated to increase by 38.5% under global warming. On the contrary, guided by the model and framework, the risk could be reduced by about 60% by taking the identified risk preventive control scheme. The cyanobacterial risk prevention would reduce aquatic emerging contaminants in drinking and recreational water sources.

Evaluation of a satellite-based cyanobacteria bloom detection algorithm using field-measured microcystin data

Widespread occurrence of cyanobacterial harmful algal blooms (CyanoHABs) and the associated health effects from potential cyanotoxin exposure has led to a need for systematic and frequent screening and monitoring of lakes that are used as recreational and drinking water sources. Remote sensing-based methods are often used for synoptic and frequent monitoring of CyanoHABs. In this study, one such algorithm – a sub-component of the Cyanobacteria Index called the CIcyano, was validated for effectiveness in identifying lakes with toxin-producing blooms in 11 states across the contiguous United States over 11 bloom seasons (2005–2011, 2016–2019). A matchup data set was created using satellite data from MEdium Resolution Imaging Spectrometer (MERIS) and Ocean Land Colour Imager (OLCI), and nearshore, field-measured Microcystins (MCs) data as a proxy of CyanoHAB presence. While the satellite sensors cannot detect toxins, MCs are used as the indicator of health risk, and as a confirmation of cyanoHAB presence. MCs are also the most common laboratory measurement made by managers during CyanoHABs. Algorithm performance was evaluated by its ability to detect CyanoHAB ‘Presence’ or ‘Absence’, where the bloom is confirmed by the presence of the MCs. With same-day matchups, the overall accuracy of CyanoHAB detection was found to be 84% with precision and recall of 87 and 90% for bloom detection. Overall accuracy was expected to be between 77% and 87% (95% confidence) based on a bootstrapping simulation. These findings demonstrate that CIcyano has utility for synoptic and routine monitoring of potentially toxic cyanoHABs in lakes across the United States.

Application of Water Quality Index in Assessment of Swimming Pools Water Quality in Hotels in Emerging Africa Littoral Metropolis of Warri, Delta State, Nigeria

Swimming pools in guest houses and hotels in many cities in sub-Saharan Africa have been labelled ‘beautiful irritation’ or hazard zones for public health issues due to the unwholesomeness of water. Pollution in swimming pools is therefore, not uncommon and it is a serious public health issue both at the global, regional, national and local levels. This study focused on application of water quality index in assessment of swimming pools water quality in hotels in emerging Africa littoral metropolis of Warri, Delta State, Nigeria. It used stratified random sampling technique to select five hotels with swimming pool in Warri for assessment. Temperature, pH, turbidity, free (residual) chlorine, total heterotrophic bacteria, total heterotrophic fungi, Escherichia coli and Staphylococcus aureus tested in the laboratory using scientific method of sampling. Water quality index (WQI) was computed using Weighted Arithmetic Water Quality Index (WAWQI) to evaluate in general, the quality of water in each of the five sampled swimming pools. A five-point scale (excellent, good, poor, very poor and unsuitable) was used to rank each swimming pool quality. Result showed that Wellington Hotel had the value of 2.52 and considered excellent in terms of water quality index value. Also, Brook View and Best Western Plus Hotels were classified as good water based on water quality index values of 36.9 and 39.9 respectively while BB swimming pool was ranked poor due to water quality index of 51.4. In contrast, Oasis Place Hotel swimming pool was declared unsuitable for recreational purpose due to a water quality index of 102.1. The study recommended routine and periodic surveillance of swimming pools and other recreational water sources to guarantee optimum health and wellbeing of users.

Growth inhibition of the toxic cyanobacterium Cylindrospermopsis raciborskii by extremely low-frequency electromagnetic fields

This study investigates the effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on the growth and antioxidant defence enzymes of the toxic cyanobacterium Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju. To determine resonance frequency of growth inhibition of C. raciborskii, cells were subjected to ELF square amplitude modulated waves (QAMW) with a range of frequencies (0.1, 0.3, 0.5, 0.7, 0.9 Hz) at single intensity of 100 V m–1 for 30 minutes. The results revealed that the highest growth inhibition of Cylindrospermopsis occurred upon exposure to 0.7 Hz QAMW for 30 min. ELF-EMF-exposed cultures exhibited a marked decrease in cell number, chlorophyll-a content and activity of antioxidant enzymes compared to control cultures, and this effect increased with the prolongation of exposure time. Moreover, ELF-EMF induced morphological changes in Cylindrospermopsis cells upon exposure to 0.7 Hz QAMW for 120 min, including shrinking and disintegration of cytoplasmic contents, and thickening of the cell wall. Changes in dielectric properties, as a measure of interaction of cellular constituents (e.g., plasma membrane, cell wall and cytoplasm), with electromagnetic fields were also observed for treated cells. Our results provide a new possibility for using ELF-EMFs to eliminate toxic cyanobacteria from drinking and recreational water sources.

Measurement of Cyanobacterial Bloom Magnitude using Satellite Remote Sensing

Cyanobacterial harmful algal blooms (cyanoHABs) are a serious environmental, water quality and public health issue worldwide because of their ability to form dense biomass and produce toxins. Models and algorithms have been developed to detect and quantify cyanoHABs biomass using remotely sensed data but not for quantifying bloom magnitude, information that would guide water quality management decisions. We propose a method to quantify seasonal and annual cyanoHAB magnitude in lakes and reservoirs. The magnitude is the spatiotemporal mean of weekly or biweekly maximum cyanobacteria biomass for the season or year. CyanoHAB biomass is quantified using a standard reflectance spectral shape-based algorithm that uses data from Medium Resolution Imaging Spectrometer (MERIS). We demonstrate the method to quantify annual and seasonal cyanoHAB magnitude in Florida and Ohio (USA) respectively during 2003–2011 and rank the lakes based on median magnitude over the study period. The new method can be applied to Sentinel-3 Ocean Land Color Imager (OLCI) data for assessment of cyanoHABs and the change over time, even with issues such as variable data acquisition frequency or sensor calibration uncertainties between satellites. CyanoHAB magnitude can support monitoring and management decision-making for recreational and drinking water sources.

Thermotolerant Acanthamoeba spp. isolated from recreational water in Gorgan City, north of Iran.

Acanthamoeba as free-living parasites are scattered ubiquitously, throughout the world. This study was aimed to evaluate the presence of Acanthamoeba spp. genotypes in the recreational water sources in Gorgan County, the capital of Golestan Province using both morphological and molecular approaches. Thirty water samples were collected from different recreational waters in Gorgan, the capital of Golestan Province, northern Iran during 2015-2016. Samples were filtered and followed by culture in non-nutrient agar. Acanthamoeba were identified both by morphological and molecular analysis. The pathogenical potential of positive cloned samples were also determined using tolerance test. Twenty-six percent of recreational water were identified as Acanthamoeba spp. based on the morphological analysis and from these positive samples, five samples were successfully sequenced after molecular studies. Phylogenetic analysis showed the clustering of four samples in T4 genotype group and only one sample as T15 genotype. Thermotolerance test revealed that all cloned samples were highly positive. Since the attractiveness of recreational places for people is increasing, the potential risk of this water should be monitored routinely in each region. More studies are needed to better evaluate the risk of this ubiquitous parasite for the human.

Legionellosis Associated with Recreational Waters: A Systematic Review of Cases and Outbreaks in Swimming Pools, Spa Pools, and Similar Environments.

Legionella spp. is widespread in many natural and artificial water systems, such as hot water distribution networks, cooling towers, and spas. A particular risk factor has been identified in the use of whirlpools and hot tubs in spa facilities and public baths. However, there has been no systematic synthesis of the published literature reporting legionellosis cases or outbreaks related to swimming/spa pools or similar environments used for recreational purposes (hot springs, hot tubs, whirlpools, natural spas). This study presents the results of a systematic review of the literature on cases and outbreaks associated with these environments. Data were extracted from 47 articles, including 42 events (17 sporadic cases and 25 outbreaks) and 1079 cases, 57.5% of which were diagnosed as Pontiac fever, without any deaths, and 42.5% were of Legionnaires’ disease, with a fatality rate of 6.3%. The results are presented in relation to the distribution of Legionella species involved in the events, clinical manifestations and diagnosis, predisposing conditions in the patients, favourable environmental factors, and quality of the epidemiological investigation, as well as in relation to the different types of recreational water sources involved. Based on the epidemiological and microbiological criteria, the strength of evidence linking a case/outbreak of legionellosis with a recreational water system was classified as strong, probable, and possible; in more than half of the events the resulting association was strong.

Transcriptional Responses of Pseudomonas aeruginosa to Potable Water and Freshwater.

Many Pseudomonas aeruginosa infections are derived from residential, recreational, or surface water sources; thus, these environments represent an important preinfection niche. To better understand P. aeruginosa biology in these environments, we quantified transcriptional changes by microarray after exposure to diluted LB, diluted R2B, potable tap water, and freshwater from a eutrophic pond. Quantitative reverse transcription-PCR (qRT-PCR) confirmed the conservation of these responses in other water sources, and competition experiments were used to test the importance of three implicated metabolic pathways. The global transcriptional responses in potable water and freshwater showed strong induction of genes involved in metabolism of the head groups and acyl tails of phospholipids, as well as nucleotide metabolism, with commensurate decreased transcript expression of genes encoding their synthetic pathways. These data suggest that phospholipids and nucleotides are part of the nutritional milieu of these two environments. A unique response in municipal-delivered potable water was to the metals in the piping system, particularly copper. To identify potential nutrient sources used by P. aeruginosa in these environments, we used competition assays between the wild-type and deletion mutant strains in three pathways induced under these conditions. For phospholipid head-group metabolism, ethanolamine utilization (eutB) was important for competition in potable water, while choline oxidation (betBA) was important for competition in freshwater. Nucleotide utilization, particularly pyrimidine metabolism (dht), showed a trend toward importance in freshwater but was not statistically significant. These findings provide new insights into the P. aeruginosa response to potable water and freshwater and led to the identification of potentially important nutrient sources in these environments.IMPORTANCE Much of our knowledge about Pseudomonas aeruginosa comes from the infection niche, and much less is known about its lifestyle in the environment. P. aeruginosa is an adaptable bacterium capable of growing in many environments but is particularly common in potable water systems and freshwater. We used the transcriptional responses of P. aeruginosa to these environments to identify important nutrient sources specific to either of these two environments. Additionally, these environments could provide experimental situations to understand gene function for the large number of transcripts with unknown functions induced under these conditions.

Isolation, identification of pathogenic Acanthamoeba from drinking and recreational water sources in Saudi Arabia.

Objective:The present study was conducted to isolate and identify the Acanthamoeba species from various water sources such as drinking water, tap water, swimming pool, and other recreational water.Materials and methods:During the study period, 57 water samples were collected from various sources such as tap water, drinking water, swimming pool, and recreational water. All samples were processed and cultured on non-nutrient agar medium (NNA) with Escherichia coli overlay for the isolation of Acanthamoeba species. Organism identified based on the microscopic morphology of cyst and trophozoites forms. The pathogenicity of Acanthamoeba was analyzed by thermotolerance and osmotolerance assays.Results:Acanthamoeba were detected in 10 out of 57 (17.5%) examined water samples. The high percentage of positivity was observed in bore well water stored in tanks (37.5%) and in recreational water samples (26.7%). All processed drinking water samples were free from Acanthamoeba. Based on pathogenicity test assays, four (40%) were pathogenic and three (30%) were non-pathogenic. The observed frequency of Acanthamoeba spp. was compared with available literature worldwide. Conclusion:This study is the first report showing the distribution of Acanthamoeba in various water sources in the central region of Saudi Arabia and confirms that the high percentage presence of pathogenic strains in recreational water could threat contact lens wearers. Further research works are required to identify the prevalence of pathogenic Acanthamoeba from various water sources in Saudi Arabia.

Satellite monitoring of cyanobacterial harmful algal bloom frequency in recreational waters and drinking water sources

Cyanobacterial harmful algal blooms (cyanoHAB) cause extensive problems in lakes worldwide, including human and ecological health risks, anoxia and fish kills, and taste and odor problems. CyanoHABs are a particular concern in both recreational waters and drinking water sources because of their dense biomass and the risk of exposure to toxins. Successful cyanoHAB assessment using satellites may provide an indicator for human and ecological health protection. In this study, methods were developed to assess the utility of satellite technology for detecting cyanoHAB frequency of occurrence at locations of potential management interest. The European Space Agency's MEdium Resolution Imaging Spectrometer (MERIS) was evaluated to prepare for the equivalent series of Sentinel-3 Ocean and Land Colour Imagers (OLCI) launched in 2016 as part of the Copernicus program. Based on the 2012 National Lakes Assessment site evaluation guidelines and National Hydrography Dataset, the continental United States contains 275,897 lakes and reservoirs >1ha in area. Results from this study show that 5.6% of waterbodies were resolvable by satellites with 300m single-pixel resolution and 0.7% of waterbodies were resolvable when a three by three pixel (3×3-pixel) array was applied based on minimum Euclidian distance from shore. Satellite data were spatially joined to U.S. public water surface intake (PWSI) locations, where single-pixel resolution resolved 57% of the PWSI locations and a 3×3-pixel array resolved 33% of the PWSI locations. Recreational and drinking water sources in Florida and Ohio were ranked from 2008 through 2011 by cyanoHAB frequency above the World Health Organization’s (WHO) high threshold for risk of 100,000 cells mL−1. The ranking identified waterbodies with values above the WHO high threshold, where Lake Apopka, FL (99.1%) and Grand Lake St. Marys, OH (83%) had the highest observed bloom frequencies per region. The method presented here may indicate locations with high exposure to cyanoHABs and therefore can be used to assist in prioritizing management resources and actions for recreational and drinking water sources.

Bioaccumulation of Toxoplasma and Cryptosporidium by the freshwater crustacean Gammarus fossarum: Involvement in biomonitoring surveys and trophic transfer

The protozoa Toxoplasma gondii and Cryptosporidium parvum are public health priorities because their oocysts can persist in recreational, surface, drinking, river, and sea water sources for a long time. To evaluate the capacity of the freshwater crustacean Gammarus fossarum to accumulate T. gondii and C. parvum oocysts, gammarids were exposed to 200, 2000 or 20,000 oocysts per gammarid and per day for 21 days followed by 5 days of depuration. C. parvum DNA was detected by qPCR in G. fossarum in only one out of four pools for the highest concentration and after 14 days of exposure, and T. gondii DNA was detected after 7 days of exposure to the two highest concentrations. Our results document the capacity of G. fossarum to accumulate T. gondii in its tissues proportionally to the ambient concentration; the maximum number of oocysts was detected in gammarid tissues after exposure to 20,000 oocysts per day. Mean values of 3.26 (±3), 21.71 (±15.18), and 17.41 (±10.89) oocysts were detected in gammarids after 7, 14, and 21 days, respectively, and after 5 days of depuration, T. gondii oocysts were still present in gammarid tissues. These results show for the first time that a freshwater crustacean can bioaccumulate T. gondii oocysts, suggesting that G. fossarum is a potential effective bioindicator of protozoan contamination in biomonitoring studies. Moreover, due to its key position in freshwater food webs, G. fossarum could also play a role in the trophic transfer of protozoa.

Distribution of Acanthamoeba Genotypes Isolated from Recreational and Therapeutic Geothermal Water Sources in Southwestern Iran.

A comprehensive survey was conducted along 10 km of geothermal rivers in southwestern Iran. A total of 40 water samples were tested for the presence of Acanthamoeba spp., and genotypes were determined by targeting the diagnostic fragment 3 region of the 18S rRNA gene. The pathogenic potential of all positive isolates was also identified using tolerance ability test. High occurrences of Acanthamoeba (50%) were detected in the sampling areas. Based on sequencing analysis, isolates belonging to T4 (93.7%) and T2 (6.25%) genotypes were reported. Thermo- and osmotolerance tests revealed that five strains are highly pathogenic. Since every collection site of this study was associated with high human activity, posting of warning signs, monitoring of recreational water sources, and awareness of high-risk people are of utmost importance. To the best of our knowledge, the present research is the first to report T2 genotype from geothermal water sources in Iran.