Detection and characterisation of Giardia and Cryptosporidium in Hungarian raw, surface and sewage water samples by IFT, PCR and sequence analysis of the SSUrRNA and GDH genes

Environmental surveillance of Cryptosporidium and Giardia in surface supply water and treated sewage intended for reuse from an urban area in Brazil

Environmental monitoring of protozoa, with the potential to trigger diseases, is essential for decision-making by managing authorities and for the control of water surveillance. This study aimed to detect and quantify Cryptosporidium oocysts and Giardia cysts in surface water for drinking water supply and treated sewage for reuse in the city of São Paulo. Samples collected bimonthly for one year were concentrated using the USEPA 1623.1 and 1693 methods for surface water and treated effluents, respectively. Immunofluorescence and nucleic acid amplification techniques were used to detect and quantify (oo)cysts. The cloning technique followed by sequencing and phylogenetic analyses were performed to characterize species and genotypes. The immunofluorescence detected Cryptosporidium spp. and Giardia spp. in 69.2% (9/13) and 100% (13/13) of the surface water samples (0.1-41 oocysts/L and 7.2-354 cysts/L, respectively). In the reuse samples, 85.7% (12/14) were positive for both protozoa and the concentrations varied from 0.4 to 100.6 oocysts/L and 1.2 and 93.5 cysts/L. qPCR assays showed that 100% of surface water (0.1-14.6 oocysts/L and 0.3-639.8 cysts/L) and reused samples (0.1-26.6 oocysts/L and 0.3-92.5 cysts/L) were positive for both protozoa. Species C. parvum, C. hominis, and C. muris were identified using the 18S rRNA gene, demonstrating anthroponotic and zoonotic species in the samples. Multilocus SSU rRNAanalyses of the SSU rRNA, tpi, and gdh genes from Giardia intestinalis identified the AII, BII, and BIV assemblages, revealing that contamination in the different matrices comes from human isolates. The study showed the circulation of these protozoa in the São Paulo city area and the impairment of surface water supply in metropolitan regions impacted by the discharge of untreated or inadequately treated sewage regarding the removal of protozoa, emphasizing the need to implement policies for water safety, to prevent the spread of these protozoa in the population.

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quindío River basin, Colombia

Two zoonotic protozoan pathogens, Giardia duodenalis and Toxoplasma gondii, are important causes of waterborne infections in the Quindío region in Colombia. No previous data exist on how contamination occurs at the source for drinking water consumed by the human population in this region. Our aim was to describe the frequency of G. duodenalis and T. gondii DNA in 11 sampling points during a five-month period in water and adjacent soil at the Quindío River basin (Andean region in the central western part of Colombia). The study employed nested PCR for T. gondii, using the B1 gene as the amplification target, and single-round PCR for G. duodenalis assemblage A and assemblage B, amplifying the gdh gene, followed by DNA sequencing. In 50 soil samples, 28% (14/50) were positive for T. gondii. For G. duodenalis, distribution was in equal parts for assemblage A (8%; 4/50) and assemblage B (8%, 4/50). Genotyping of T. gondii sequences showed two soil samples with type I strain, another two samples of soil with type III strain, but most samples were of unidentified strains. In water samples, T. gondii was detected in 9.1% (5/55), G. duodenalis assemblage A in 34.5% (19/55), and G. duodenalis assemblage B in 12.7% (7/55). T. gondii DNA positivity was associated with lower soil temperature (p = 0.0239). Presence of G. duodenalis and T. gondii was evidenced in soil and water samples in the Quindío River basin, indicating soil as the potential source of contamination for the river that it is destined for human consumption. Monitoring these protozoa in drinking water is necessary to prevent public health risks in human populations.

Survey of the occurrence of Giardia duodenalis cysts and Cryptosporidium spp. oocysts in green leafy vegetables marketed in the city of Valencia (Spain)

The role of vegetables usually consumed without prior culinary treatment is known to contribute to the prevalence of foodborne diseases. Cysts and oocysts can contaminate food, which can then be the source of infection in humans. The aim of the study was to assess the occurrence of Giardia duodenalis and Cryptosporidium spp. (oo)cysts in green leafy vegetables marketed in the city of Valencia (Spain) combining parasitological methods, two real-time qPCRs and light microscopy. An experimental field study was conducted on 129 vegetable samples, 64 from conventional farms and 65 from ecological (organic) farms. The samples were washed with water, and the resulting solution after removing the vegetables, was subjected to 24-hour sedimentation. The concentrated sediment was used for the search for protozoa. A positive result by both real-time PCRs, or a positive result by one qPCR and confirmation by microscopy was established as a positivity criterion. Giardia duodenalis was detected in 23.0 % of the samples, and Cryptosporidium spp. in 7.8 %. G. duodenalis (41.5 %) and Cryptosporidium spp. (20.0 %) were more frequent in ecological crops. The high level of contamination detected in organic vegetables may be due to the type of fertilizers and the quality of the water used for their irrigation and reinforces the need to take extreme hygiene measures in vegetables that are consumed raw.

Detection of Cryptosporidium spp. and Giardia spp. in Environmental Water Samples: A Journey into the Past and New Perspectives

Among the major issues linked with producing safe water for consumption is the presence of the parasitic protozoa Cryptosporidium spp. and Giardia spp. Since they are both responsible for gastrointestinal illnesses that can be waterborne, their monitoring is crucial, especially in water sources feeding treatment plants. Although their discovery was made in the early 1900s and even before, it was only in 1999 that the U.S. Environmental Protection Agency (EPA) published a standardized protocol for the detection of these parasites, modified and named today the U.S. EPA 1623.1 Method. It involves the flow-through filtration of a large volume of the water of interest, the elution of the biological material retained on the filter, the purification of the (oo)cysts, and the detection by immunofluorescence of the target parasites. Since the 1990s, several molecular-biology-based techniques were also developed to detect Cryptosporidium and Giardia cells from environmental or clinical samples. The application of U.S. EPA 1623.1 as well as numerous biomolecular methods are reviewed in this article, and their advantages and disadvantages are discussed guiding the readers, such as graduate students, researchers, drinking water managers, epidemiologists, and public health specialists, through the ever-expanding number of techniques available in the literature for the detection of Cryptosporidium spp. and Giardia spp. in water.

Survey and first report of Acanthamoeba T4 genotype in natural spring water resources in the Black Sea, Turkey

Infection with Acanthamoeba spp. may result in granulomatous amoebic encephalitis and Acanthamoeba keratitis. Water is an important habitat where Acanthamoeba species thrive. Therefore, studying the occurrence of this free-living amoeba in water sources will help understand the infection dynamics. The aim of the study was to survey and report on the presence of Acanthamoeba spp. in water resources from the Ordu and Giresun provinces in Black Sea. Acanthamoeba spp. was found in 1/17 natural spring water samples from Ordu and in 2/18 from Giresun. Acanthamoeba species were not detected in any of the investigated tap water samples. Sequencing of the (SSU) rDNA gene resulted in the identification of haplotype I (Acanthamoeba genotype: KJ094684). T4 (8.6%) was the only isolated genotype in both Ordu and Giresun provinces. This is the first report of Acanthamoeba T4 genotype in natural spring water resources in the Black Sea. The occurrence of Acanthamoeba species in natural spring water sources should be considered as a potential risk for human infection, especially to high-risk populations.

Evaluating the potential for exposure to organisms of public health concern in naturally occurring bathing waters in Europe: A scoping review

Globally, water-based bathing pastimes are important for both mental and physical health. However, exposure to waterborne organisms could present a substantial public health issue. Bathing waters are shown to contribute to the transmission of illness and disease and represent a reservoir and pathway for the dissemination of antimicrobial resistant (AMR) organisms. Current bathing water quality regulations focus on enumeration of faecal indicator organisms and are not designed for detection of specific waterborne organisms of public health concern (WOPHC), such as antimicrobial resistant (AMR)/pathogenic bacteria, or viruses. This investigation presents the first scoping review of the occurrence of waterborne organisms of public health concern (WOPHC) in identified natural bathing waters across the European Union (EU), which aimed to critically evaluate the potential risk of human exposure and to assess the appropriateness of the current EU bathing water regulations for the protection of public health. Accordingly, this review sought to identify and synthesise all literature pertaining to a selection of bacterial (Campylobacter spp., Escherichia coli, Salmonella spp., Shigella spp., Vibrio spp., Pseudomonas spp., AMR bacteria), viral (Hepatitis spp., enteroviruses, rotavirus, adenovirus, norovirus), and protozoan (Giardia spp., and Cryptosporidium spp.) contaminants in EU bathing waters. Sixty investigations were identified as eligible for inclusion and data was extracted. Peer-reviewed investigations included were from 18 countries across the EU, totalling 87 investigations across a period of 35 years, with 30% published between 2011 and 2015. A variety of water bodies were identified, with 27 investigations exclusively assessing coastal waters. Waterborne organisms were classified into three categories; bacteria, viruses, and protozoa; amounting to 58%, 36% and 17% of the total investigations, respectively. The total number of samples across all investigations was 8,118, with detection of one or more organisms in 2,449 (30%) of these. Viruses were detected in 1281 (52%) of all samples where WOPHC were found, followed by bacteria (865(35%)) and protozoa (303(12%)). Where assessed (442 samples), AMR bacteria had a 47% detection rate, emphasising their widespread occurrence in bathing waters. Results of this scoping review highlight the potential public health risk of exposure to WOPHC in bathing waters that normally remain undetected within the current monitoring parameters.

Molecular characterization of the waterborne pathogens Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, Cyclospora cayetanensis and Eimeria spp. in wastewater and sewage in Guangzhou, China

Background

The waterborne pathogens Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Cyclospora cayetanensis can cause intestinal diseases in humans. An understanding of their occurrence and transport in the environment is essential for accurate quantitative microbial risk assessment.

Methods

A total of 238 influent samples were collected from four wastewater treatment plants (WWTPs) and 88 samples from eight sewer locations in Guangzhou, China. PCR-based tools were used to detect and genetically characterize Cryptosporidium spp., G. duodenalis and E. bieneusi. Eimeria spp. and Cyclospora spp. were also analyzed to assess the sources of Cryptosporidium spp., G. duodenalis and E. bieneusi in wastewater.

Results

The overall occurrence rates in the WWTP and sewer samples were 14.3% (34/238) and 13.6% (12/88) for Cryptosporidium spp., 55.5% (132/238) and 33.0% (29/88) for G. duodenalis, 56.3% (134/238) and 26.1% (23/88) for E. bieneusi and 45.4% (108/238) and 47.7% (42/88) for Eimeria spp., respectively. Altogether, 11 Cryptosporidium species and genotypes, six G. duodenalis genotypes, 11 E. bieneusi genotypes and four C. cayetanensis were found, together with the presence of nine Eimeria species. The common occurrence of Cryptosporidium rat genotype IV, C. muris and Eimeria papillata and E. nieschulzi suggested that rodents were significant sources of the enteric pathogens detected in the wastewater samples.

Conclusions

While the dominant Cryptosporidium spp. detected in the raw wastewater sampled in this study are not pathogenic to humans, the widely detected G. duodenalis assemblage A and E. bieneusi genotypes D and Type IV are well-known zoonotic pathogens. Further studies are needed to monitor the occurrence of these waterborne pathogens in WWTPs to better understand their transmission and environmental transport in China.

Surface waters as a potential source of Giardia and Cryptosporidium in Serbia

Giardiasis and cryptosporidiosis are recognized by the WHO as important emerging diseases of the 21st century. Symptoms are similar and include diarrhoea and vomiting, which may be severe, even life-threatening, for the immunocompromised and children under five years of age. Between 2013 and 2017, the Institute for Public Health in Serbia recorded 10 waterborne epidemics that manifested as gastrointestinal disease. Routine testing for enteropathogenic bacteria and viruses did not identify the aetiological agents of these outbreaks. As water is not examined for the presence of protozoa in Serbia, we performed a pilot study to analyse samples from four major rivers and their tributaries using a newly implemented methodology for detection of Giardia and Cryptosporidium, based on the ISO 15553:2006 standard. Using immunofluorescence microscopy, Giardia was detected in 10 out of the 31 samples, Cryptosporidium in five, while two samples were positive for both. Presence of G. duodenalis gDNA was confirmed by amplification of the β-giardin gene in eight samples, of which one and two, respectively, were identified by RFLP as potentially zoonotic assemblages A and B. The results suggest that surface water in Serbia may be a potential source of infection and call for more in-depth studies using sophisticated molecular tools.

Surveillance of Giardia and Cryptosporidium in sewage from an urban area in Brazil

Cryptosporidium and Giardia are protozoan parasites that cause diarrhea in humans and animals. Molecular characterization of these pathogens in sewage may provide insight on their occurrence and prevalence in Brazil. This study aimed to investigate the presence of Giardia and Cryptosporidium in raw and treated sewage from Londrina, Paraná, Brazil. Samples were collected every two weeks during a year. Samples were concentrated, then DNA was extracted and subjected to a nested PCR targeting the Giardia 18S rRNA gene and the Cryptosporidium 18S rRNA gene. Species of Cryptosporidium were characterized by restriction fragment length polymorphism (RFLP). All raw sewage and 76% of the treated sewage were positive for Giardia; 84% of raw sewage samples and 8% of treated sewage were positive for Cryptosporidium. C. muris, C. hominis, C. baileyi, C. parvum and C. suis were detected in 100%, 19%, 9%, 9% and 4% of raw sewage, respectively. C. muris was the only species found in treated sewage. Multiple species of Cryptosporidium were present in 19.04% of the raw sewage. Treated sewage water can pose a threat to human health. The speciation of Cryptosporidium revealed the presence of non-common zoonotic species as C. suis and C. muris.

Review of Cryptosporidium and Giardia in the eastern part of Europe, 2016

This paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results: Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.

Molecular detection and genotyping of pathogenic protozoan parasites in raw and treated water samples from southwest Colombia

BACKGROUND

Protozoan parasites such as Giardia duodenalis, Cryptosporidium spp., Cyclospora cayetanensis, Toxoplasma gondii and Entamoeba histolytica represent a great challenge to the systems producing water for human consumption because their cystic forms are persistent in the environment and resist to the disinfection methods conventionally used for their control. In this study, we investigated the presence of these protozoan pathogens in both raw and treated water samples used for the production of drinking water in Nariño Department, southwest Colombia. We collected 110 water samples (10 lof each sample) and analyzed them with real-time PCR (qPCR). qPCR-positive samples were genotyped with PCR and DNA sequencing.

RESULTS

Giardia duodenalis was detected in 35/110 (31.8%) of the samples and Cryptosporidium spp. in 9/110 (8.2%) of the samples; no sample was positive for T. gondii, E. histolytica or C. cayetanensis. Giardia duodenalis was detected in samples of both raw water (Drinking Water Treatment Plants (DWTP): 47.83%;Drinking Water Rural Plants (DWRP): 18.42%) and water collected either after conventional physicochemical treatment (26.09%) or after disinfection by chlorine (50%), whereas Cryptosporidium spp. were only detected in raw waters (DWTP: 17.39%; DWRP: 13.16%). The two pathogens were detected in both types of treatment plants supplying water to urban areas and to rural zones. Analysis of gdh and tpi markers identified assemblages AI, AII and H of G. duodenalis, while analysis of the small subunit rRNA and gp60 markers of Cryptosporidium-positive samples identified C. parvum (Subtype IIcA5G3c), C. galli, C. molnari, Cryptosporidium sp. genotype II of bats and Cryptosporidium sp. genotype VIII of birds.

CONCLUSIONS

The results obtained demonstrate the presence of protozoan parasites in the water of the study region, and the need to improve the surveillance systems for these pathogens and identify the corresponding sources of contamination.

Occurrence, genotyping, and health risk of Cryptosporidium and Giardia in recreational lakes in Tianjin, China

Cryptosporidium and Giardia are critical parasites in the etiology of diarrhea worldwide, and often cause waterborne outbreaks. The presence of Cryptosporidium and Giardia in recreational lakes was investigated with molecular characterization, and a comprehensive quantitative microbial risk assessment (QMRA) of protozoan infections was performed, considering multiple exposure pathways, differences in age, sex, and disease severity, and the genotypes of the protozoa. Forty-three (82.7%) and 51 (98.1%) water samples were positive for Cryptosporidium oocysts and Giardia cysts, respectively, with average counts of 3.65 oocysts/10 L and 12.58 cysts/10 L, respectively. Six Cryptosporidium species and three Giardia lamblia assemblages were confirmed with molecular analyses. The protozoan concentration was significantly associated with water turbidity, but not with the total coliform numbers. Swimming in the lakes entailed the highest incidence risk of 5.72 × 10^-4 per person per year (pppy) (95% confidence interval (CI): 0.03-43.33 × 10^-4) for Cryptosporidium and 4.04 × 10^-4 pppy (95% CI: 0.01-32.66 × 10^-4) for Giardia, whereas wading entailed the lowest risk (2.20 × 10^-4 and 1.70 × 10^-4 pppy, respectively). The annual burdens attributable to recreational-water-associated cryptosporidiosis and giardiasis were 3.44 (95% CI: 0.04-23.51) and 1.81 (95% CI: 0.01-12.96) disability-adjusted life years per 1,000,000 individuals per year, respectively. Children were more likely to have an individual disease burden than adults, and males were more likely than females. Sensitivity analysis highlighted the great importance of controlling the proportion of exposed individuals and reducing the frequency of exposure. The methodology and results of this study will allow us to better evaluate and reduce the burden of Cryptosporidium and/or Giardia infections associated with recreational water use in China and other countries.

Molecular identification of Blastocystis sp. subtypes in water samples collected from Black sea, Turkey

The aim of this study was to identify the subtypes of Blastocystis sp. and complete a phylogenetic analysis of 268 water samples that were collected from the Samsun, Amasya and Sinop Provinces of the Black Sea in Turkey, between the years 2011 and 2014. Blastocystis sp. was investigated in 48 uncultured sea water samples that were collected from 4 sites within the Sinop Province. A total of 100 river water samples were collected from 37 sites in the Samsun Province and 120 river water samples were collected from 10 sampling sites within the Amasya Province. The small subunit (SSU) rDNA gene Polymerase chain reaction (PCR) were performed for the detection of Blastocytis sp. and the PCR-positive samples were sequenced. Subsequently, the (SSU) rDNA sequences were aligned by Bioedit and phylogenetic trees were constructed for Blastocystis with reference to the genotypes from GenBank. Blastocystis sp. were found in 3 out of the 75 (4%) river water samples that were collected from the Samsun Province. Six of the 120 (5%) river water samples and 1 out of the 48 (2%) seawater samples were positive for Blastocystis in the Amasya and Sinop Provinces. There were two different subtypes (ST; 1 and 3) found from sequencing all of the samples from the investigated sites. Two and one PCR products were found to be positive for ST1 and ST3 from the different samples collected within the Samsun Province. Two and 4 PCR products from the Amasya Province were ST1 and ST3, respectively and only one sample from the Sinop Province was found to be positive for ST1. This is the first report to identify and report the occurrence of Blastocystis subtypes within the Black Sea of Turkey.

Molecular characterization of Cryptosporidium spp. in poultry from Brazil

Cryptosporidiosis is an important zoonotic disease caused by Cryptosporidium. Infections in birds are mainly caused by C. meleagridis, C. baileyi, and C. galli. C. meleagridis is the third most common cause of cryptosporidiosis in humans and the only Cryptosporidium species known to infect both birds and mammals. One hundred and fifty-five fecal specimens from different poultry species (chicken, turkey, ostrich, helmeted guinea fowl, quail, pheasant, and emu) were collected at local markets in the state of Minas Gerais, Brazil. Twenty-three (14.8%) birds (20 chickens, 2 quails, and 1 turkey) were found Cryptosporidium-positive. This constitutes the first report of Cryptosporidium in turkeys from Brazil. Nucleotide sequence analysis identified C. meleagridis in chickens (15), a turkey (1), and a quail (1), C. baileyi in chickens (4) and a quail (1), and a mixed infection C. meleagridis/C. baileyi in a chicken (1). This is the first report of C. meleagridis in turkeys and quails from Brazil. Using the gp60 gene, three subtype families were identified, IIIa, IIIb and IIIg. Within subtype family IIIg, four subtypes were identified in chickens, two novel (IIIgA25G3R1 and IIIgA21G3R1) and two previously reported (IIIgA22G3R1 and IIIgA24G2R1). Within subtype family IIIb two subtypes were identified, IIIbA24G1R1 in a chicken and IIIbA23G1R1 in a quail. A novel subtype in the family IIIa was identified (IIIaA22G3R1) in a turkey. The finding of C. meleagridis subtypes previously identified in humans (IIIgA22G3R1, IIIbA24G1R1 and IIIbA23G1R1) indicates that they can be potentially zoonotic. Further subtyping studies that clarify genetic diversity of C. meleagridis are required to better understand host specificity, source of infection, and transmission dynamics of C. meleagridis.

Occurrence of Cryptosporidium in the water basins of nitra region, slovakia

Cryptosporidium species C. parvum and C. hominis are a common cause of human diarrheal infections worldwide. In this study we attempted to detect these parasites in fish ponds and a water reservoirs in the Nitra region of Slovakia. We identified C. parvum genotype IIaA15G1R1 and genotype IIaA16G1R1 and C. hominis genotype IeA11G3T3 in these locations. Occurrence of the same genotype of C. hominis in two different locations indicates that this parasite is most likely present in the river that connects them. These results indicate a serious threat to public health of humans since these locations are used for fishing and for recreational activities.

Presence and molecular characterization of Cryptosporidium and Giardia in recreational lake water in Tianjin, China: a preliminary study

Little is known about the occurrence of Cryptosporidium and Giardia in recreational water in China. A total of 52 samples were collected from recreational lakes in Tianjin during a high-occurrence season (June-October) for the waterborne cryptosporidiosis and giardiasis, and the occurrence and genotypes of Cryptosporidium and Giardia were investigated. The results showed that 82.7% (43) and 98.1% (51) of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively. The mean concentration of parasites was 3.65 oocysts/10 L and 12.58 cysts/10 L, respectively. Molecular characterization revealed that the presence of Cryptosporidium parvum, C. andersoni, C. hominis, C. meleagridis, C. fragile, C. ubiquitum, and Giardia lamblia assemblage A, B and D. The protozoan contamination in the studied lakes may originate from animal feces on ground, which was washed into the lake by stormwater runoff. Nevertheless, there is a potential risk of infection during recreational activities in the lake because the dominant detected protozoan genotypes are common human pathogens. Moreover, microbial indicators analysis does not adequately indicate the protozoan contamination in recreational water. The information from this study will be valuable for future protozoan source tracking, and any further control interventions against Cryptosporidium and/or Giardia infection associated with recreational water.

Detection of Giardia intestinalis in water samples collected from natural water reservoirs and wells in northern and north-eastern Poland using LAMP, real-time PCR and nested PCR

Giardia intestinalis is a protozoan parasite, transmitted to humans and animals by the faecal-oral route, mainly through contaminated water and food. Knowledge about the distribution of this parasite in surface water in Poland is fragmentary and incomplete. Accordingly, 36 environmental water samples taken from surface water reservoirs and wells were collected in Pomerania and Warmia-Masuria provinces, Poland. The 50 L samples were filtered and subsequently analysed with three molecular detection methods: loop-mediated isothermal amplification (LAMP), real-time polymerase chain reaction (real-time PCR) and nested PCR. Of the samples examined, Giardia DNA was found in 15 (42%) samples with the use of LAMP; in 12 (33%) of these samples, Giardia DNA from this parasite was also detected using real-time PCR; and in 9 (25%) using nested PCR. Sequencing of selected positive samples confirmed that the PCR products were fragments of the Giardia intestinalis small subunit rRNA gene. Genotyping using multiplex real-time PCR indicated the presence of assemblages A and B, with the latter predominating. The results indicate that surface water in Poland, as well as water taken from surface wells, may be a source of Giardia strains which are potentially pathogenic for humans. It was also demonstrated that LAMP assay is more sensitive than the other two molecular assays.

Survey of the Occurrence and Human Infective Potential of Giardia duodenalis and Cryptosporidium spp. in Wastewater and Different Surface Water Sources of Western Romania

From the group of parasitic protozoa, Giardia and Cryptosporidium are the most common pathogens spread in surface water sources, representing a continuous threat to public health and water authorities. The aim of this survey was to assess the occurrence and human infective potential of these pathogens in treated wastewaters and different surface water sources. A total of 76 western Romanian water bodies in four counties (Arad, Bihor, Caraș-Severin and Timiș) were investigated, including the effluents of wastewater treatment plants (n = 11) and brooks (n = 19), irrigation channels (n = 8), lakes (n = 16), and ponds (n = 22). Water samples were collected through polyester microfiber filtration. Giardia cysts and Cryptosporidium oocysts were isolated using immunomagnetic separation, according to the US EPA 1623 method, followed by their identification and counting by immunofluorescence (IF) microscopy. All samples were screened through PCR-based techniques targeting the gdh gene for Giardia spp. and the 18S rRNA gene for Cryptosporidium spp., followed by sequencing of the positive results. Cryptosporidium-positive samples were subtyped based on sequence analysis of the GP60 gene. Giardia spp. was found in all tested water types with a cumulative detection rate of 90.1% in wastewaters, 26.3% in brooks, 37.5% in irrigation channels, 31.2% in lakes, and 36.4% in ponds. Except for ponds, all monitored water bodies harbored the Giardia duodenalis AII subassemblage with human infective potential. In addition, the ruminant origin assemblage E was widely distributed, and the domestic/wild canid-specific assemblage D was also recorded in a pond. Three (27.3%) wastewater samples were Cryptosporidium positive, and the identified species was the zoonotic Cryptosporidium parvum, with IIaA15G2R1 (n = 2) and IIdA18G1 subtypes. The results highlight that this threat to the public health must be brought to the attention of epidemiologists, health officials, and water authorities.

Giardia duodenalis and Cryptosporidium spp. as contaminant protozoa of the main rivers of western Romania: genetic characterization and public health potential of the isolates

The objective of this study was to establish the prevalence, contamination level, and public health significance of Giardia duodenalis and Cryptosporidium spp. in the primary rivers of western Romania. A total of 53 sampling points in the 24 most important western Romanian rivers in four counties (Arad, Bihor, Caraș-Severin, and Timiș) were investigated from March to September 2016. Surface water samples were collected by microfiber filtration. Cryptosporidium and Giardia (oo)cysts were isolated using immunomagnetic separation (IMS) according to the USEPA 1623 method and, after staining with fluorescently labeled (FITC) monoclonal antibodies, were identified and counted under a microscope. The Cryptosporidium and Giardia (oo)cysts were identified to species and assemblage/sub-assemblage level through the nested PCR-RFLP procedure targeting the 18S ribosomal RNA and gdh genes, respectively. PCR-based techniques were utilized for all water samples. Overall, 22 samples (41.5%) were determined to be positive for Giardia cysts (ranging from 0.05 to 300 cysts per liter), and four samples (7.5%) tested positive for Cryptosporidium oocysts (0.17-48 oocysts/l). G. duodenalis was molecularly identified in 13 water samples (24.5%), indicating the presence of the sub-assemblage A-II (n = 12) and assemblage E (n = 1). PCR-RFLP showed that two samples (3.8%) contained Cryptosporidium DNA, and the identified species were Cryptosporidium parvum and Cryptosporidium canis. All positive results were successfully confirmed by DNA sequencing. Subtyping of the zoonotic C. parvum isolate based on sequence analysis of the GP60 gene revealed the occurrence of the IIaA16G1R1 subtype. The results of this study highlight considerable contamination of river waters with pathogenic Giardia spp. and Cryptosporidium spp., suggesting a potential risk for the public and animal health. This report presents the first extended published description of the presence of Giardia spp. and Cryptosporidium spp. in the aquatic environment in Romania.

Occurrence and removal of Giardia spp. cysts and Cryptosporidium spp. oocysts from a municipal wastewater treatment plant in Brazil

Sewage and sewage sludge have been recognized as potential sources of two important waterborne pathogenic protozoa: Giardia spp. and Cryptosporidium spp. Due to the lack of studies about the occurrence of these pathogens in sewage and sludge in Brazil, an investigation was conducted at various stages of a municipal wastewater treatment plant (WWTP) aiming to assess the occurrence of Giardia spp. cysts and Cryptosporidium spp. oocysts, their removal by the treatment processes, which are upflow anaerobic sludge blanket (UASB) reactor and dissolved air flotation process, and also the correlations between protozoa and indicator microorganisms. Significant quantities of cysts were detected in 100% of the analyzed wastewater samples, while oocysts were detected only in 39.0% of all wastewater samples. The overall removal of Giardia spp. cysts from the WWTP was on average 2.03 log, and the UASB reactor was more efficient than flotation. The sludge samples presented high quantities of (oo)cysts, implying the risks of contamination in the case of sludge reuse or inadequate disposal. Giardiasis prevalence was estimated between 2.21% and 6.7% for the population served by the WWTP, while cryptosporidiosis prevalence was much lower. Significant positive correlation was obtained only between cysts and Clostridium spores in anaerobic effluent.

Occurrence of Cryptosporidium and Giardia and the Relationship between Protozoa and Water Quality Indicators in Swimming Pools

A total of 60 samples were collected from 35 swimming pools in Beijing, China, and the presence of Cryptosporidium and Giardia were investigated. The results showed that 16.7% and 15.0% of samples were positive for Cryptosporidium oocyst and Giardia cysts, respectively, with a mean concentration of 0.30 oocysts/10 L and 0.27 cysts/10 L. The oocysts and cysts were found to have higher rates of occurrence in August than in May. Genotyping confirmed the presence of Cryptosporidium hominis, C. parvum, and Giardia assemblages A and B, all of which were associated with human infections. The predominant species/assemblages were C. hominis and Giardia assemblage A. Analyses of the relationships between parasite oocysts/cysts, indicator bacteria, and physical-chemical parameters revealed that there was no correlation between 2 parasites and fecal bacterial indicators, whilst there was a significant correlation between protozoa and urea concentration, which indicates that urea concentration rather than fecal bacterial indicators might be an appropriate index for chlorine-resistant protozoa in swimming pools. This study provides useful information to improve the safety of swimming pool water and deduce the risk of protozoan infections.

Genotyping of Cryptosporidium spp. in environmental water in Turkey

This research was undertaken to study the molecular detection and characterization of Cryptosporidium spp. in environmental water sources at Samsun and Giresun Provinces of The Black Sea in Turkey. Two-hundred forty and one-hundred eighty environmental samples were collected from a total of twenty and twenty-five sampling sites of Giresun and Samsun Provinces. One hundred twenty untreated drinking water samples were also detected for Cryptosporidium spp. in both investigated areas. 101 (%42), 92 (%38.3) of 240 and 74 (41.1%), 70 (38.8%) of 180 environmental samples have been found positive for Cryptosporidium spp. by Loop mediated isothermal amplification (LAMP) targeting the S-adenosyl-L-methionine synthetase (SAM) gene and nested PCR targeting small subunit (SSU)rRNA gene in Samsun and Giresun Provinces, respectively. Of the tested untreated drinking water samples collected from the investigated area, one sample was positive for Cryptosporidium spp. Six and twelve samples were clearly sequenced for the Cryptosporidium (SSU)rRNA gene among the highest positive samples selected from each of the twenty and twenty-five sampling sites of Giresun and Samsun Provinces, respectively. Genetic characterization of Cryptosporidium isolates from water samples represented Cryptosporidium bovis for five samples, Cryptosporidium parvum for six samples and one sample for Cryptosporidium felis in Samsun Province, where C. parvum for five samples and C. bovis for one sample were sequenced in Giresun Province. According to accessible information sources, this is the first research about genotyping of Cryptosporidium spp. in water samples collected from Samsun and Giresun Provinces of Turkey.

Occurency of Giardia duodenalis assemblages in river water sources of Black Sea, Turkey

A total of 420 environmental water samples and 120 drinking water samples from 45 different sampling sites of the Black Sea in Turkey were collected between 2012 and 2014. Genomic DNA was isolated from all the investigated water samples and comparativelly analyzed by Loop-mediated isothermal amplification (LAMP) of the elongation factor 1 Alfa (EF1α) gene, and by nested Polymerase Chain Reaction (nPCR) of the small subunit (SSU) rRNA and semi-nested PCR (snPCR) of the glutamate dehydrogenase gene (GDH). 141 (58.7%), 125 (52.1%) and 120 (50%) samples respectivelly were positive by each method. Out of 240 environmental samples collected from 25 sites of Samsun Province have been found positive for G. duodenalis by LAMP, nPCR and snPCR, respectively. 55 (30.5%), 50 (27.8%) and 47 (26.1%) of 180 environmental samples collected from 20 other sampling sites of Giresun Province were positive for Giardia by LAMP, nPCR and snPCR, respectively. Five PCR products from different samples of the Giresun Province and 10 other samples from the Samsun Province were found positive for G. duodenalis assemblage B. Five PCR products from Giresun Province and 5 samples from Samsun Province were found positive for G. duodenalis assemblage A. This is the first report about G. duodenalis assemblages A and B from water samples investigations in Black Sea of Turkey.

Contribution of environmental media to cryptosporidiosis and giardiasis prevalence in Tehran: a focus on surface waters

The occurrences of Cryptosporidium and Giardia in surface sources of drinking water in Tehran were monitored, using US EPA method 1623.1. The prevalence ratios (PR) of positive samples among other media (animal's stools, vegetables, and human's stools) were also estimated from literature data. The density of Giardia and Cryptosporidium in water samples were 0.129 ± 0.069 cysts/L and 0.005 ± 0.002 oocysts/L, respectively. Estimated PR in vegetables, animal stools, surface waters, and human stools were 6.65, 20.42, 21.05, and 4.28 % for Cryptosporidium and 6.46, 17.13, 73.68, and 15.65 % for Giardia, respectively. These reveal the importance of surface waters' and animal stools' roles in the prevalence of cryptosporidiosis and giardiasis in Tehran's population. Giardia's prevalence in untreated surface waters in Tehran was found 3.5 times as much as Cryptosporidium while this found 2.3 times on a global scale. Moreover, the prevalence of giardiasis to cryptosporidiosis infections in Tehran's human population was 3.65. These values could be a clue to attribute the infections to the occurrence of parasites in surface waters. Significant (p < 0.05) associations were observed between rainfalls and presence of Giardia (r = 0.62) and Cryptosporidium (r = 0.60) in surface waters. In autumn, rainfalls can increase the parasites occurrences in surface waters. Significant (p < 0.05) difference on the density of parasites was found between some seasons using Kruskal-Wallis and multiple comparison tests. A significant correlation (r = 0.86) between Giardia and Cryptosporidium densities also confirms the common sources of pollution in surface waters. Findings suggest that untreated surface waters in Tehran may be a potential route of human exposure to protozoan parasites.

Giardia and Cryptosporidium spp. dissemination during wastewater treatment and comparative detection via immunofluorescence assay (IFA), nested polymerase chain reaction (nested PCR) and loop mediated isothermal amplification (LAMP)

Environmental water samples from the Lower Rhine area in Germany were investigated via immunofluorescence assays (IFAs), nested polymerase chain reaction (nested PCR) and loop-mediated isothermal amplification (LAMP) to detect the presence of Giardia spp. (n=185) and Cryptosporidium spp. (n=227). The samples were concentrated through filtration or flocculation, and oocysts were purified via centrifugation through a sucrose density gradient. For all samples, IFA was performed first, followed by DNA extraction for the nested PCR and LAMP assays. Giardia cysts were detected in 105 samples (56.8%) by IFA, 62 samples (33.5%) by nested PCR and 79 samples (42.7%) by LAMP. Cryptosporidium spp. were detected in 69 samples (30.4%) by IFA, 95 samples (41.9%) by nested PCR and 99 samples (43.6%) by LAMP. According to these results, the three detection methods are complementary for monitoring Giardia and Cryptosporidium in environmental waters.

Assessment of molecular methods as a tool for detecting pathogenic protozoa isolated from water bodies

Several species belong to the Cryptosporidium and Giardia genus, the main parasitic protozoa occurring in water, but only some of them are infectious to humans. We investigated the occurrence of Cryptosporidium and Giardia and identified their species in the water samples collected from natural water bodies in north-western Poland. A total of 600 samples from water bodies used for bathing, sewage discharge, as drinking water sources and watering places for animals were screened. The samples were collected during a 3-year period in each of the four seasons and filtered using Filta-Max (IDEXX Laboratories, USA). Genomic DNA was extracted from all samples and used as a target sequence for polymerase chain reaction (PCR) and TaqMan real-time PCR, as well as for reverse line blotting (RLB) methods. PCR methods seem to be more sensitive to detect Giardia and Cryptosporidium DNA in water samples than RLB methods. All PCR products were sequenced and three were identified as C. parvum and four as G. intestinalis. The overall prevalence of C. parvum (0.5%) and G. intestinalis (0.6%) in the samples suggests that the risk of Cryptosporidium and Giardia infections in north-western Poland is minimal.

Genotyping of Giardia lamblia and Entamoeba spp from river waters in Iran

In this study, DNA from 55 surface and river water samples, which were collected from some water sources of Tehran and the Guilan Province, Iran, were extracted and examined for Entamoeba spp. and Giardia lamblia by PCR and genotyping. Twenty-seven samples, which were concentrated using the immunomagnetic separation technology (IMS) method, were examined for Giardia alone. Twenty-eight samples, which were concentrated using the sucrose flotation (SF) method, were examined for both Giardia and Entamoeba species. The results showed that 27/55 (17/27 and 10/28) (49 %), 4 /28 (14.28 %) and 3/28 (10.7 %) of the samples were positive for Giardia lamblia, Entamoeba spp and mixed infections (Entamoeba spp. and Giardia spp.), respectively. Sixteen out of 55 samples were negative. Entamoeba genus-specific PCR primers in single-round PCR were used to differentiate between the Entamoeba spp. (E. histolytica, E. dispar and E. moshkovskii). With respect to the 7 samples that were positive for Entamoeba, (14.28 %) 4 out of 28 were positive for E. moshkovskii, (7.14 %), 2 out of 28 were positive for E. histolytica and (3.57 %) 1 out of 28 was positive for E. dispar. Genus-specific PCR primers in a semi-nested PCR assay was performed to genotype Giardia species. Of the 27 samples that were positive for Giardia, 10 samples were sequences. All 10 successfully sequenced samples contained assemblage B of Giardia lamblia.This is first study to investigate the G. lamblia genotypes in the water supply of the Tehran and Guilan provinces, and it is the first study to investigate Entamoeba species in the water supplies of Iran. The investigated river water supplies, which are used for agriculture, camping and animal farming, were heavily contaminated by the human pathogenic Entamoeba and Giardia parasites. There is a potential risk of waterborne outbreaks in humans and animals.

Cryptosporidium genotypes and subtypes distribution in river water in Iran

Little is known about the diversity and public health significance of Cryptosporidium species in river waters in Iran. In the present study, we determined the genotype and subtype distribution of Cryptosporidium spp. in river water samples in Iran. A total of 49 surface water samples were collected from rivers and surface water in Guilan and Tehran provinces during 2009-2010. Water samples were filtrated through a 1.2-μm pore size membrane filter or by Filta-Max filter followed by immunomagnetic separation or sucrose purification methods. Genotype and subtype of Cryptosporidium were identified by sequence analysis of the 18S rRNA and 60 kDa glycoprotein (gp60) genes, respectively. A total of 24 (48.97%) water samples were positive for Cryptosporidium species by the 18sRNA-based polymerase chain reaction (PCR)-sequencing technique. DNA sequencing revealed the presence of five species of Cryptosporidium (C. parvum, C. hominis, C. muris, C. andersoni, and C. canis) in the water samples of the study area and, to our knowledge, the first report of C. muris in Iran. The results of GP60 gene analysis showed that all C. parvum and C. hominis isolates belonged to the IId and Id subtype families, respectively. The investigated river water supplies were heavily contaminated by pathogenic species of Cryptosporidium from humans and livestock. There is potential risk of waterborne cryptosporidiosis in humans and animals.

UV irradiation responses in Giardia intestinalis

The response to ultraviolet light (UV) radiation, a natural stressor to the intestinal protozoan parasite Giardia intestinalis, was studied to deepen the understanding of how the surrounding environment affects the parasite during transmission. UV radiation at 10 mJ/cm(2) kills Giardia cysts effectively whereas trophozoites and encysting parasites can recover from UV treatment at 100 mJ/cm(2) and 50 mJ/cm(2) respectively. Staining for phosphorylated histone H2A showed that UV treatment induces double-stranded DNA breaks and flow cytometry analyses revealed that UV treatment of trophozoites induces DNA replication arrest. Active DNA replication coupled to DNA repair could be an explanation to why UV light does not kill trophozoites and encysting cells as efficiently as the non-replicating cysts. We also examined UV-induced gene expression responses in both trophozoites and cysts using RNA sequencing (RNA seq). UV radiation induces small overall changes in gene expression in Giardia but cysts show a stronger response than trophozoites. Heat shock proteins, kinesins and Nek kinases are up-regulated, whereas alpha-giardins and histones are down-regulated in UV treated trophozoites. Expression of variable surface proteins (VSPs) is changed in both trophozoites and cysts. Our data show that Giardia cysts have limited ability to repair UV-induced damage and this may have implications for drinking- and waste-water treatment when setting criteria for the use of UV disinfection to ensure safe water.

Multilocus sequence typing of canine Giardia duodenalis from South Eastern European countries

Giardia duodenalis is a worldwide occurring protozoan that can infect various mammalian hosts. While living conditions are getting closer between pet animals and owners, there is discussion whether dogs may contribute to the transmission of these pathogens to humans. The present study was conducted in order to identify the Giardia assemblages in dogs from South Eastern Europe. For this purpose, 1645 faecal samples of household and shelter dogs from Albania, Bulgaria, Hungary, Macedonia, Romania and Serbia were tested for Giardia coproantigen by enzyme-linked immunosorbent assay (ELISA). A subset of 107 faecal samples demonstrating Giardia cysts by direct immunofluorescence assay (IFA) or microscopy (15-22 per country) plus 26 IFA-positive canine faecal samples from Croatia were used for DNA extraction and multilocus sequence typing with nested PCRs targeting five different gene loci: SSU rRNA, ITS1-5.8S-ITS2, beta giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). One third (33.7%) of the samples tested positive for Giardia antigen in the coproantigen ELISA. Shelter dogs were infected more frequently than household dogs (57.2 vs. 29.7%, p < 0.01). Amplification was obtained in 82.0, 12.8, 11.3, 1.5, and 31.6%, of the investigated samples at the SSU rRNA, bg, gdh and tpi loci and the ITS1-5.8S-ITS2 region, respectively. The dog-specific assemblages C and D were identified in 50 and 68 samples, respectively. The results demonstrate that G. duodenalis should be considered as a common parasite in dogs from South Eastern Europe. However, there was no evidence for zoonotic Giardia assemblages in the investigated canine subpopulation.

Occurrence of Cryptosporidium and Giardia in recycled waters used for irrigation and first description of Cryptosporidium parvum and C. muris in Greece

Here, we present the first time findings regarding the occurrence of Cryptosporidium and Giardia in sewage waters and the first molecular characterization of Cryptosporidium species in Greece. Biological treatment plants from three regions in Greece have been investigated. The detection of Cryptosporidium oocysts was by modified Ziehl-Neelsen acid fast (MZN-AF) and by immunofluorescence microscopy (IFT) for Cryptosporidium and Giardia (oo)cysts, whereas nested PCR based on the SSU rDNA assay was used for molecular detection of Cryptosporidium followed by sequencing for the genetic characterization of the species. In total, 73 samples (37 raw sewage samples and 38 of treated water samples) were collected and analyzed. Of the 73 water samples, 4 samples were Cryptosporidium-positive by IFT and staining, 12 samples were Cryptosporidium-positive by nested PCR; 9 samples were Giardia-positive by IFT. We showed that Cryptosporidium cysts are found both in the input and the discharge of the biological treatment plants. Molecular characterization of Cryptosporidium based on the small subunit ribosomal DNA gene resulted in the determination of Cryptosporidium parvum and Cryptosporidium muris Greek isolates. This is the first report of Cryptosporidium and Giardia occurrence in wastewaters and the first molecular identification of Cryptosporidium species in Greek environments. As the treated water is used for irrigation, or it is discharged into the sea, our findings indicate that biological treatment facilities constitute a possible risk for public health because the related species are prevalent in humans; the results invite for further epidemiological investigations to evaluate the real public health risk in Greece.

Genetic diversity of Giardia duodenalis: multilocus genotyping reveals zoonotic potential between clinical and environmental sources in a metropolitan region of Brazil

BACKGROUND

Giardia duodenalis is a flagellate protozoan that parasitizes humans and several other mammals. Protozoan contamination has been regularly documented at important environmental sites, although most of these studies were performed at the species level. There is a lack of studies that correlate environmental contamination and clinical infections in the same region. The aim of this study is to evaluate the genetic diversity of a set of clinical and environmental samples and to use the obtained data to characterize the genetic profile of the distribution of G. duodenalis and the potential for zoonotic transmission in a metropolitan region of Brazil.

METHODOLOGY/PRINCIPAL FINDINGS

The genetic assemblages and subtypes of G. duodenalis isolates obtained from hospitals, a veterinary clinic, a day-care center and important environmental sites were determined via multilocus sequence-based genotyping using three unlinked gene loci. Cysts of Giardia were detected at all of the environmental sites. Mixed assemblages were detected in 25% of the total samples, and an elevated number of haplotypes was identified. The main haplotypes were shared among the groups, and new subtypes were identified at all loci. Ten multilocus genotypes were identified: 7 for assemblage A and 3 for assemblage B.

CONCLUSIONS/SIGNIFICANCE

There is persistent G. duodenalis contamination at important environmental sites in the city. The identified mixed assemblages likely represent mixed infections, suggesting high endemicity of Giardia in these hosts. Most Giardia isolates obtained in this study displayed zoonotic potential. The high degree of genetic diversity in the isolates obtained from both clinical and environmental samples suggests that multiple sources of infection are likely responsible for the detected contamination events. The finding that many multilocus genotypes (MLGs) and haplotypes are shared by different groups suggests that these sources of infection may be related and indicates that there is a notable risk of human infection caused by Giardia in this region.

Final opportunity to rehabilitate an urban river as a water source for Mexico City

The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973-2010), along with the physicochemical and bacteriological attributes, documenting the evolution of these variables over the course of five years (2008-2012) in both dry and rainy seasons. The analyses show that the flow regime has been significantly altered. The physicochemical variables show significant differences between the natural area, where the river originates, and the urban area, where the river receives untreated wastewater. Nutrient and conductivity concentrations in the river were equivalent to domestic wastewater. Fecal pollution indicators and various pathogens were present in elevated densities, demonstrating a threat to the population living near the river. Estimates of the value of the water lost as a result of mixing clean and contaminated water are presented. This urban river should be rehabilitated as a sustainability practice, and if possible, these efforts should be replicated in other areas. Because of the public health issues and in view of the population exposure where the river flows through the city, the river should be improved aesthetically and should be treated to allow its ecosystem services to recover. This river represents an iconic case for Mexico City because it connects the natural and urban areas in a socio-ecological system that can potentially provide clean water for human consumption. Contaminated water could be treated and reused for irrigation in one of the green areas of the city. Wastewater treatment plants and the operation of the existing purification plants are urgent priorities that could lead to better, more sustainable water use practices in Mexico City.

Detection of Cryptosporidium and Giardia in agricultural and water environments in the Qinghai area of China by IFT and PCR

Qinghai Province in northwest China is strongly influenced by agricultural activities and is an important source of food and drinking water. Here, we present findings regarding the occurrence and molecular epidemiology of Cryptosporidium and Giardia species based on a large-scale investigation of areas of Qinghai Province. The diagnosis and molecular detection of Cryptosporidium oocysts and Giardia cysts was carried out using immunofluorescence microscopy (IFT), whereas nested polymerase chain reaction (PCR) in fecal smears and water samples was used for the detection and molecular characterization of the species. In total, 561 samples (260 water samples and 301 fecal samples from animals) were collected and analyzed. Of the 260 water samples, 66 samples were Cryptosporidium-positive by IFT and 71 samples were positive by nested PCR; in addition, 39 samples were Giardia-positive by IFT and 40 samples were positive by nested PCR. Of the 301 fecal samples from animals, 98 samples were Cryptosporidium-positive by IFT and 61 samples were positive by nested PCR, whereas 52 samples were Giardia-positive by IFT and 31 samples were positive by nested PCR. We showed that the water supplies and animals investigated contained Cryptosporidium and Giardia (oo)cysts. Thus, we recommend that the Chinese Government and Chinese health authorities undertake control measures to protect the food and drinking water sources in Qinghai from these pathogenic protozoa.

Detection and genotype analysis of Giardia duodenalis from asymptomatic Hungarian inhabitants and comparative findings in three distinct locations

The transmission route of giardiasis not yet understood and why some infected individuals remain asymptomatic while others become quite ill. The drinking water quality is supposedly responsible for the prevalence of asymptomatic Giardia duodenalis infections in different areas, therefore asymptomatic giardiasis has been investigated in three water supply areas of Hungary: three hundred stool samples from inhabitants of Budapest, Füzér and Mátrafüred were examined by immunological and molecular methods for the presence of G. duodenalis infections. Individuals were asked to fill out a validated questionnaire at the time of stool collection and the interview covered demographic data, family life, education and travel history.In Budapest and in Mátrafüred in one stool sample G. duodenalis Assemblage A, whereas in Füzér once G. duodenalis Assemblage A, once Assemblage B and twice mixed infection were detected. We found higher prevalence rate of 4% of G. duodenalis infections of asymptomatic people in the village Füzér, where the removal of the Giardia cysts of the drinking water treatment plant was not effective. This study throws a light the need to look into the possibility of other risks of Giardia infections such as water transmission routes. To our knowledge, this is the first study evaluating the prevalence of G. duodenalis infections in asymptomatic persons in Hungary.

[Cryptosporidium and Giardia as water contaminant pathogens in Hungary]

INTRODUCTION

Many species of Cryptosporidium, and two assemlages of Giardia duodenalis cause typically acute diaorrhoea in human. The oocysts and cysts of these parasites excreted in faeces are capable of infecting other hosts and those are environmentally stable.

AIM

The aims of the study were to evaluate the prevalence and genotypes of Cryptosporidium and Giardia species from different water sources as well as to monitor and characterize the (oo)cyst contamination sources in watersheds. In addition, an epidemiological study was performed in three selected settlements.

METHOD

Wide range of modern epidemiological and molecular detection methods have been applied.

RESULTS

(Oo)cysts densities were associated with water receiving effluents of sewage treatment plants or originating from a forest environment. It was confirmed, that cattle can be a source of Cryptosporidium oocysts at watersheds and aquatic birds can play a role in the environmental dissemination of these protozoa. The epidemiological study demonstrated a specific epidemiological situation, giving essential evidence about giardiasis in asymptomatic carriers. The applied novel detection technology was found to be cost effective and simple procedure for screening catchments to identify those that require further treatment and more detailed microscopic counts.

CONCLUSIONS

The presented results contribute to a better understanding the epidemiology and relevance of waterborne parasites, their surveillance and performance of future control measures to prevent waterborne infections in Hungary.

Detection of Cryptosporidium and Giardia (oo)cysts by IFA, PCR and LAMP in surface water from Rasht, Iran

BACKGROUND

Cryptosporidium and Giardia in water supplies is acknowledged as a public health problem. In the present study, we applied immunofluorescence assay (IFA), PCR and loop-mediated isothermal amplification (LAMP) for the detection of the two protozoa.

METHODS

Over a period of 12 months, surface water samples were collected from two rivers in the north of Iran, and filtrated by 142 mm membrane filters. At each sampling point 10 L water were used for IFT and the10 L were analysed using molecular methods.

RESULTS

In 15/40 samples, (oo)cysts were detected by one of the IFA, PCR or LAMP methods. Five samples that were Cryptosporidium-negative by IFA were positive by LAMP. A total of 10 out of 13 samples that were Giardia-positive by IFA were also positive by PCR. IFA revealed high levels of Giardia, with 1-1800 cysts and 1-16 Cryptosporidium oocysts detected per 10 L.

CONCLUSION

The study reveals that the investigated water supplies were contaminated by Cryptosporidium and Giardia. The LAMP assay has advantages for detection and screening of these protozoa at relatively low concentration in water samples. The three assays applied are complimentary but no single one will give the true prevalence of these parasites in surface water samples. However, each method has its own advantages and disadvantages dependent of the aim and the study design; a combination of detection methods should be applied to discover whether water is, or is not, contaminated with (oo)cysts. This is the first report on the occurrence of (oo)cysts in Iranian surface waters to compare the results of parasite detection obtained with the different methods.

Occurrence and potential health risk of Cryptosporidium and Giardia in the Three Gorges Reservoir, China

The Three Gorges Reservoir (TGR) is the biggest lake in the world and a major water source in China. There is no information about occurrence and impact of Cryptosporidium and Giardia on the aquatic ecosystem. 61 surface water samples from 23 monitoring sites and 5 treated effluent samples were collected and analyzed. Cryptosporidium oocysts and Giardia cysts were found, respectively, in 86.4% and 65.2% of a total of 66 water samples, with high concentrations in treated effluent. The mean percent recovery was 29.14% for oocysts and 34.86% for cysts. A seasonal pattern was observed, with positive samples for Cryptosporidium more frequent in flood period and positive samples for Giardia more frequent in impounding period. Counts of enterococci, fecal coliforms and total coliforms, and turbidity were significantly associated with Cryptosporidium concentration in backwater (water in a main river which is backed up by the Three Gorges Dam) areas of tributaries but not Giardia. High associations were also found between oocyst and cyst in backwater areas of tributaries and cities. The risks of infection and illness due to water consumption in four different exposure routes were estimated. The results showed that swimming in the TGR has the highest infection risk with 1.39 × 10(-3) per time (95% confidence interval (CI): 0.05-600.3 × 10(-5)) for Cryptosporidium and 2.08 × 10(-4) per time (95% CI: 0.05-878.87 × 10(-6)) for Giardia, while directly drinking unboiled tap water treated with the conventional process has the highest morbidity with 524.98 per 100,000 population per year (95% CI: 10.35-2040.26) for Cryptosporidium and 5.89 per 100,000 population per year (95% CI: 0.08-22.67) for Giardia. This study provides new useful information for drinking water plants, health care workers and managers to improve the safety of tap water and deduce the risk of surface water contamination in China.

Detection of Cryptosporidium species in the sea and tap water samples of Black Sea, Turkey

The aim of this study was to evaluate Cryptosporidium spp. contamination of sea and tap water samples from Sinop and Ordu Provinces, Black Sea, Turkey. The samples (10 L) were collected in spring, summer, autumn, and winter in 2011. A total of 128 water samples was analyzed using an immunofluorescence test (IFT), as well as loop-mediated isothermal amplification (LAMP) and nested polymerase chain reaction (PCR). Cryptosporidium spp. oocysts were detected by IFT in 43 of the 70 samples (61.4%; 1-40 oocysts per 0.5 L) and 35 of the 58 samples (60.3%; 1-23 oocysts per 0.5 L) in the sea water samples from Ordu and Sinop, respectively. The highest number of oocysts by IFT were detected in spring and winter in Ordu and Sinop, respectively. The results of the S-adenosylmethionine synthetase (SAM) gene LAMP assays were 65.5% positive for Cryptosporidium parvum , Cryptosporidium hominis , and Cryptosporidium meleagridis in all examined samples, while the SSUrRNA gene nested PCR assay was 31.0% positive. Six C. parvum nested PCR products from all positive samples were successfully sequenced.

Population-based analyses of Giardia duodenalis is consistent with the clonal assemblage structure

Background

Giardia duodenalis is a common protozoan parasite of humans and animals. Genetic characterization of single loci indicates the existence of eight groups called assemblages, which differ in their host distribution. Molecular analyses challenged the idea that G. duodenalis is a strictly clonal diplomonad by providing evidence of recombination within and between assemblages. Particularly, inter-assemblage recombination events would complicate the interpretation of multi-locus genotyping data from field isolates: where is a host infected with multiple Giardia genotypes or with a single, recombined Giardia genotype.

Methods

Population genetic analyses on the single and multiple-locus level on an extensive dataset of G. duodenalis isolates from humans and animals were performed.

Results

Our analyses indicate that recombination between isolates from different assemblages are apparently very rare or absent in the natural population of Giardia duodenalis. At the multi-locus level, our statistical analyses are more congruent with clonal reproduction and can equally well be explained with the presence of multiple G. duodenalis genotypes within one field isolate.

Conclusions

We conclude that recombination between G. duodenalis assemblages is either very rare or absent. Recombination between genotypes from the same assemblage and genetic exchange between the nuclei of a single cyst needs further investigation.

Investigations and comparative detection of Cryptosporidium species by microscopy, nested PCR and LAMP in water supplies of Ordu, Middle Black Sea, Turkey

A total of 70 water samples, including tap, river, fountain and well water were collected in the Ordu province, Middle Black Sea, Turkey and investigated for the detection of Cryptosporidium oocysts. The samples were directly screened microscopically for Cryptosporidium oocysts' detection by immunofluorescence test and subsequently DNA was extracted for the molecular detection by loop-mediated isothermal amplification (LAMP) and nested polymerase chain reaction (PCR). Eighteen out of the 70 (25·7%) water samples were found positive for Cryptosporidium spp. by immunofluorescence test and 19 (27·1%) were found positive by LAMP. Nested PCR products were not generated in any of the investigated water samples. A total of 16 randomly selected pellets were spiked with 10 Cryptosporidium oocysts to test the efficiency of the applied method. All the samples were found positive by LAMP for the presence of Cryptosporidium DNA, while the nested PCR assay was positive in only seven (43·75%) out of the 16 examined spiked samples. This is the first report on the occurrence of Cryptosporidium species in environmental and drinking water supplies in the Black Sea area.

Occurrence, source, and human infection potential of cryptosporidium and Giardia spp. in source and tap water in shanghai, china

Genotyping studies on the source and human infection potential of Cryptosporidium oocysts in water have been almost exclusively conducted in industrialized nations. In this study, 50 source water samples and 30 tap water samples were collected in Shanghai, China, and analyzed by the U.S. Environmental Protection Agency (EPA) Method 1623. To find a cost-effective method to replace the filtration procedure, the water samples were also concentrated by calcium carbonate flocculation (CCF). Of the 50 source water samples, 32% were positive for Cryptosporidium and 18% for Giardia by Method 1623, whereas 22% were positive for Cryptosporidium and 10% for Giardia by microscopy of CCF concentrates. When CCF was combined with PCR for detection, the occurrence of Cryptosporidium (28%) was similar to that obtained by Method 1623. Genotyping of Cryptosporidium in 17 water samples identified the presence of C. andersoni in 14 water samples, C. suis in 7 water samples, C. baileyi in 2 water samples, C. meleagridis in 1 water sample, and C. hominis in 1 water sample. Therefore, farm animals, especially cattle and pigs, were the major sources of water contamination in Shanghai source water, and most oocysts found in source water in the area were not infectious to humans. Cryptosporidium oocysts were found in 2 of 30 tap water samples. The combined use of CCF for concentration and PCR for detection and genotyping provides a less expensive alternative to filtration and fluorescence microscopy for accurate assessment of Cryptosporidium contamination in water, although the results from this method are semiquantitative.

Zoonotic potential and molecular epidemiology of Giardia species and giardiasis

Molecular diagnostic tools have been used recently in assessing the taxonomy, zoonotic potential, and transmission of Giardia species and giardiasis in humans and animals. The results of these studies have firmly established giardiasis as a zoonotic disease, although host adaptation at the genotype and subtype levels has reduced the likelihood of zoonotic transmission. These studies have also identified variations in the distribution of Giardia duodenalis genotypes among geographic areas and between domestic and wild ruminants and differences in clinical manifestations and outbreak potentials of assemblages A and B. Nevertheless, our efforts in characterizing the molecular epidemiology of giardiasis and the roles of various animals in the transmission of human giardiasis are compromised by the lack of case-control and longitudinal cohort studies and the sampling and testing of humans and animals living in the same community, the frequent occurrence of infections with mixed genotypes and subtypes, and the apparent heterozygosity at some genetic loci for some G. duodenalis genotypes. With the increased usage of multilocus genotyping tools, the development of next-generation subtyping tools, the integration of molecular analysis in epidemiological studies, and an improved understanding of the population genetics of G. duodenalis in humans and animals, we should soon have a better appreciation of the molecular epidemiology of giardiasis, the disease burden of zoonotic transmission, the taxonomy status and virulences of various G. duodenalis genotypes, and the ecology of environmental contamination.

Contribution of treated wastewater to the microbiological quality of Seine River in Paris

Urban part of Seine River serving as drinking water supply in Paris can be heavily contaminated by Cryptosporidium spp. and Giardia duodenalis. In the absence of agricultural practice in this highly urbanized area, we investigated herein the contribution of treated wastewater to the microbiological quality of this river focusing on these two parasites. Other microorganisms such as faecal bacterial indicators, enteroviruses and oocysts of Toxoplasma gondii were assessed concurrently. Raw wastewaters were heavily contaminated by Cryptosporidium and Giardia (oo)cysts, whereas concentrations of both protozoa in treated wastewater were lower. Treated wastewater, flowed into Seine River, had a parasite concentration closed to the one found along the river, in particular at the entry of a drinking water plant (DWP). Even if faecal bacteria were reliable indicators of a reduction in parasite concentrations during the wastewater treatment, they were not correlated to protozoal contamination of wastewater and river water. Oocysts of T. gondii were not found in both raw and treated wastewater, or in Seine River. Parasitic contamination was shown to be constant in the Seine River up to 40 km upstream Paris. Altogether, these results strongly suggest that treated wastewater does not contribute to the main parasitic contamination of the Seine River usually observed in this urbanized area.