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Piro F, Masci S, Kannan G, Focaia R, Schultz TL, Thaprawat P, Carruthers VB, Di Cristina M. A Toxoplasma gondii putative amino acid transporter localizes to the plant-like vacuolar compartment and controls parasite extracellular survival and stage differentiation. mSphere 2024; 9:e0059723. [PMID: 38051073 PMCID: PMC10871165 DOI: 10.1128/msphere.00597-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 12/07/2023] Open
Abstract
Toxoplasma gondii is a protozoan parasite that infects a broad spectrum of hosts and can colonize many organs and cell types. The ability to reside within a wide range of different niches requires substantial adaptability to diverse microenvironments. Very little is known about how this parasite senses various milieus and adapts its metabolism to survive, replicate during the acute stage, and then differentiate to the chronic stage. T. gondii possesses a lysosome-like organelle known as the plant-like vacuolar compartment (PLVAC), which serves various functions, including digestion, ion storage and homeostasis, endocytosis, and autophagy. Lysosomes are critical for maintaining cellular health and function by degrading waste materials and recycling components. To supply the cell with the essential building blocks and energy sources required for the maintenance of its functions and structures, the digested solutes generated within the lysosome are transported into the cytosol by proteins embedded in the lysosomal membrane. Currently, a limited number of PLVAC transporters have been characterized, with TgCRT being the sole potential transporter of amino acids and small peptides identified thus far. To bridge this knowledge gap, we used lysosomal amino acid transporters from other organisms as queries to search the T. gondii proteome. This led to the identification of four potential amino acid transporters, which we have designated as TgAAT1-4. Assessing their expression and sub-cellular localization, we found that one of them, TgAAT1, localized to the PLVAC and is necessary for normal parasite extracellular survival and bradyzoite differentiation. Moreover, we present preliminary data showing the possible involvement of TgAAT1 in the PLVAC transport of arginine.IMPORTANCEToxoplasma gondii is a highly successful parasite infecting a broad range of warm-blooded organisms, including about one-third of all humans. Although Toxoplasma infections rarely result in symptomatic disease in individuals with a healthy immune system, the incredibly high number of persons infected, along with the risk of severe infection in immunocompromised patients and the potential link of chronic infection to mental disorders, makes this infection a significant public health concern. As a result, there is a pressing need for new treatment approaches that are both effective and well tolerated. The limitations in understanding how Toxoplasma gondii manages its metabolism to adapt to changing environments and triggers its transformation into bradyzoites have hindered the discovery of vulnerabilities in its metabolic pathways or nutrient acquisition mechanisms to identify new therapeutic targets. In this work, we have shown that the lysosome-like organelle plant-like vacuolar compartment (PLVAC), acting through the putative arginine transporter TgAAT1, plays a pivotal role in regulating the parasite's extracellular survival and differentiation into bradyzoites.
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Affiliation(s)
- Federica Piro
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Silvia Masci
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Geetha Kannan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Riccardo Focaia
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Tracey L. Schultz
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Pariyamon Thaprawat
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
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Piro F, Masci S, Kannan G, Focaia R, Schultz TL, Carruthers VB, Di Cristina M. A Toxoplasma gondii putative arginine transporter localizes to the plant-like vacuolar compartment and controls parasite extracellular survival and stage differentiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555807. [PMID: 37693549 PMCID: PMC10491228 DOI: 10.1101/2023.08.31.555807] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Toxoplasma gondii is a protozoan parasite that infects a broad spectrum of hosts and can colonize many organs and cell types. The ability to reside within a wide range of different niches requires substantial adaptability to diverse microenvironments. Very little is known about how this parasite senses various milieus and adapts its metabolism to survive, replicate during the acute stage, and then differentiate to the chronic stage. Most eukaryotes, from yeast to mammals, rely on a nutrient sensing machinery involving the TORC complex as master regulator of cell growth and cell cycle progression. The lysosome functions as a signaling hub where TORC complex assembles and is activated by transceptors, which both sense and transport amino acids, including the arginine transceptor SLC38A9. While most of the TORC components are lost in T. gondii , indicating the evolution of a distinct nutrient sensing mechanism, the parasite's lysosomal plant-like vacuolar compartment (PLVAC) may still serve as a sensory platform for controlling parasite growth and differentiation. Using SLC38A9 to query the T. gondii proteome, we identified four putative amino acid transporters, termed TgAAT1-4, that structurally resemble the SLC38A9 arginine transceptor. Assessing their expression and sub-cellular localization, we found that one of them, TgAAT1, localized to the PLVAC and is necessary for normal parasite extracellular survival and bradyzoite differentiation. Moreover, we show that TgAAT1 is involved in the PLVAC efflux of arginine, an amino acid playing a key role in T. gondii differentiation, further supporting the hypothesis that TgAAT1 might play a role in nutrient sensing. IMPORTANCE T. gondii is a highly successful parasite infecting a broad range of warm-blood organisms including about one third of all humans. Although Toxoplasma infections rarely result in symptomatic disease in individuals with a healthy immune system, the incredibly high number of persons infected along with the risk of severe infection in immunocompromised patients and the potential link of chronic infection to mental disorders make this infection a significant public health concern. As a result, there is a pressing need for new treatment approaches that are both effective and well-tolerated. The limitations in understanding how Toxoplasma gondii manages its metabolism to adapt to changing environments and triggers its transformation into bradyzoites have hindered the discovery of vulnerabilities in its metabolic pathways or nutrient acquisition mechanisms to identify new therapeutic targets. In this work, we have shown that the lysosome-like organelle PLVAC, acting through the putative arginine transporter TgAAT1, plays a pivotal role in regulating the parasite's extracellular survival and differentiation into bradyzoites.
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Chen Y, Wu Y, Qin H, Xu H, Zhang L. Prevalence of Cryptosporidium infection in children from China: a systematic review and meta-analysis. Acta Trop 2023; 244:106958. [PMID: 37257675 DOI: 10.1016/j.actatropica.2023.106958] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/24/2023] [Accepted: 05/28/2023] [Indexed: 06/02/2023]
Abstract
Cryptosporidium is an important zoonotic pathogen that causes diarrhea in humans and animals, and a leading cause of diarrhea morbidity and mortality in children under 5 years old. However, the meta-analysis of Cryptosporidium infection in children in China has not been published. We searched the databases for articles published on the prevalence of Cryptosporidium infection in children in China since the inception of these databases to 31 October 2022. The prevalence of Cryptosporidium infection in children was estimated using a random effects model. The results showed that 111 datasets from 24 provinces were selected for the final quantitative analysis. The estimated pooled Cryptosporidium infection prevalence in children in China was 2.9% (3300/126,381). The highest prevalence rate was in southwestern China (4.8%, 365/7766). Subgroup analysis indicated that the Cryptosporidium infection rate in children aged < 3 years (4.9%, 330/8428) was significantly higher than that in children aged 3-6 years (2.5%, 609/26,080) and >6 years (2.6%, 647/27,586). Six Cryptosporidium species were detected in children in China from the selected studies. C. hominis was the dominant species (77.1%, 145/188) and the proportions of subgenotype IaA14R4 of C. hominis was highest (42.8%, 62/145). The findings suggest that Chinese children is in a low level of Cryptosporidium infection, however, the geographical distribution of the infection is extensive. We suggest that measures should be taken to ensure the healthy growth of Chinese children by improving the water environment, increasing public health facilities, strengthening children's health education, and developing sound Cryptosporidium infection control programs.
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Affiliation(s)
- Yuancai Chen
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, P. R. China; International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou 450046, P. R. China; Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou 450046, China
| | - Yayun Wu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, P. R. China; International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou 450046, P. R. China; Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou 450046, China
| | - Huikai Qin
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, P. R. China; International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou 450046, P. R. China; Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou 450046, China
| | - Huiyan Xu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, P. R. China; International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou 450046, P. R. China; Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou 450046, China
| | - Longxian Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, P. R. China; International Joint Research Laboratory for Zoonotic Diseases of Henan, Zhengzhou 450046, P. R. China; Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou 450046, China.
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Matsubayashi M, Teramoto I, Urakami I, Naohara J, Sasai K, Kido Y, Kaneko A. Evaluation of Cryptosporidium parvum oocyst inactivation following exposure to ultraviolet light-emitting diodes by in vitro excystation and dye staining assays. Parasitol Int 2022; 88:102557. [DOI: 10.1016/j.parint.2022.102557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/28/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022]
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Kim M, Shapiro K, Rajal VB, Packham A, Aguilar B, Rueda L, Wuertz S. Quantification of viable protozoan parasites on leafy greens using molecular methods. Food Microbiol 2021; 99:103816. [PMID: 34119101 DOI: 10.1016/j.fm.2021.103816] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 03/23/2021] [Accepted: 04/14/2021] [Indexed: 12/01/2022]
Abstract
Protozoan contamination in produce is of growing importance due to their capacity to cause illnesses in consumers of fresh leafy greens. Viability assays are essential to accurately estimate health risk caused by viable parasites that contaminate food. We evaluated the efficacy of reverse transcription quantitative PCR (RT-qPCR), propidium monoazide coupled with (q)PCR, and viability staining using propidium iodide through systematic laboratory spiking experiments for selective detection of viable Cryptosporidium parvum, Giardia enterica, and Toxoplasma gondii. In the presence of only viable protozoa, the RT-qPCR assays could accurately detect two to nine (oo)cysts/g spinach (in 10 g processed). When different proportions of viable and inactivated parasite were spiked, mRNA concentrations correlated with increasing proportions of viable (oo)cysts, although low levels of false-positive mRNA signals were detectable in the presence of high amounts of inactivated protozoa. Our study demonstrated that among the methods tested, RT-qPCR performed more effectively to discriminate viable from inactivated C. parvum, G. enterica and T. gondii on spinach. This application of viability methods on leafy greens can be adopted by the produce industry and regulatory agencies charged with protection of human public health to screen leafy greens for the presence of viable protozoan pathogen contamination.
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Affiliation(s)
- Minji Kim
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA; Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Karen Shapiro
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Verónica B Rajal
- Facultad de Ingeniería and Instituto de Investigaciones para la Industria Química (INIQUI), CONICET - Universidad Nacional de Salta (UNSa), Av. Bolivia 5150, Salta, 4400, Argentina; Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore (NTU), 60 Nanyang Drive, 637551, Singapore
| | - Andrea Packham
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Beatriz Aguilar
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Lezlie Rueda
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Stefan Wuertz
- Department of Civil and Environmental Engineering, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA; Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore (NTU), 60 Nanyang Drive, 637551, Singapore; School of Civil and Environmental Engineering, NTU, 50 Nanyang Avenue, 649798, Singapore.
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Sammarro Silva KJ, Sabogal-Paz LP. Cryptosporidium spp. and Giardia spp. (oo)cysts as target-organisms in sanitation and environmental monitoring: A review in microscopy-based viability assays. WATER RESEARCH 2021; 189:116590. [PMID: 33166919 DOI: 10.1016/j.watres.2020.116590] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/22/2020] [Accepted: 10/31/2020] [Indexed: 06/11/2023]
Abstract
Cysts and (oo)cysts are the infective forms of parasitic protozoa, as Giardia and Cryptosporidium, which are widespread and associated to worldwide waterborne diseases outbreaks. These microorganisms pose a challenge to public health, as they are resistant to conventional disinfection methods, which make them important parameters when evaluating inactivation efficiency. However, when (oo)cysts are targets, it is challenging to infer inactivation efficacy, as it may require infectivity tests that are not often an option for laboratory routine analysis. In this scene, (oo)cyst viability based on induced excystation, membrane integrity and enzyme activity evaluated by dye inclusion and/or exclusion, as well as fluorescence reduction consist on microscopy-based techniques that may be options to estimate inactivation in the environmental context. This scoping review presents applications, advantages and limitations of these methodologies for viability assessment, in order to shed light on the (oo)cyst viability topic and provide insight strategies for choosing protocols in the environmental and sanitation field, in laboratory applications and novel research.
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Affiliation(s)
- Kamila Jessie Sammarro Silva
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-carlense 400, São Carlos, São Paulo, 13566-590, Brazil
| | - Lyda Patricia Sabogal-Paz
- Department of Hydraulics and Sanitation, São Carlos School of Engineering, University of São Paulo, Avenida Trabalhador São-carlense 400, São Carlos, São Paulo, 13566-590, Brazil.
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Wang W, Gong QL, Zeng A, Li MH, Zhao Q, Ni HB. Prevalence of Cryptosporidium in pigs in China: A systematic review and meta-analysis. Transbound Emerg Dis 2020; 68:1400-1413. [PMID: 32815651 DOI: 10.1111/tbed.13806] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/28/2020] [Accepted: 08/13/2020] [Indexed: 12/23/2022]
Abstract
Cryptosporidium is an important zoonotic parasite that can infect a variety of hosts, including pigs and humans, through water and food. Many studies on Cryptosporidium infection in pigs have been reported worldwide. However, the meta-analysis of Cryptosporidium infection in pigs in China has not been published. This study retrieved articles related to Cryptosporidium in pigs in China by using four databases: Chinese National Knowledge Infrastructure (CNKI), PubMed, VIP Chinese journal database and Wanfang Data. We retrieved 40 studies related to Cryptosporidium infection in China, and those articles were harvested from the inception to 1 January 2020. We estimated that the overall prevalence of pigs with Cryptosporidium in the selected period was 12.2% (4,349/30,404). In the sampling year subgroup, the prevalence rate after 2010 was the lowest at 8.7% (2,087/18,100). In Northern China, the Cryptosporidium prevalence was 47.9% (34/71). By contrast, the prevalence of Cryptosporidium in Southwestern China was only 6.9% (778/6,445). The infection rate of Cryptosporidium in diarrhoea pigs of 15.6% (74/384) was higher than that in non-diarrhoea pigs at 10.8% (378/2,840). Among the four age groups, the prevalence of weaning pigs of 16.2% (530/3,243) was the highest, and the difference was significant (p < .05). The prevalence of Cryptosporidium in extensive farming was 25.7% (660/3,121), which was significantly higher than in intensive farming 8.7% (566/6,336), and the prevalence of infection was related to the farming modes (p < .05). We also analysed the impact of different geographic factor subgroups (longitude, latitude, precipitation, temperature, humidity, climate and altitude) on the prevalence of pigs. The results showed that cryptosporidiosis was widespread in pigs in China. We suggest that appropriate control schemes should be developed according to the differences in breeding patterns and geographic conditions in different regions, and effective management measures should be developed to reduce the spread between pigs.
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Affiliation(s)
- Wei Wang
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, PR China.,College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, PR China
| | - Qing-Long Gong
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Ao Zeng
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing, PR China
| | - Ming-Han Li
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Quan Zhao
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, PR China
| | - Hong-Bo Ni
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao, PR China
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Jaskiewicz JJ, Sevenler D, Swei AA, Widmer G, Toner M, Tzipori S, Sandlin RD. Cryopreservation of infectious Cryptosporidium parvum oocysts achieved through vitrification using high aspect ratio specimen containers. Sci Rep 2020; 10:11711. [PMID: 32678171 PMCID: PMC7366687 DOI: 10.1038/s41598-020-68643-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/16/2020] [Indexed: 01/11/2023] Open
Abstract
Infection with protozoa of the genus Cryptosporidium is a leading cause of child morbidity and mortality associated with diarrhea in the developing world. Research on this parasite has been impeded by many technical limitations, including the lack of cryopreservation methods. While cryopreservation of Cryptosporidium oocysts by vitrification was recently achieved, the method is restricted to small sample volumes, thereby limiting widespread implementation of this procedure. Here, a second-generation method is described for cryopreservation of C. parvum oocysts by vitrification using custom high aspect ratio specimen containers, which enable a 100-fold increase in sample volume compared to previous methods. Oocysts cryopreserved using the described protocol exhibit high viability, maintain in vitro infectivity, and are infectious to interferon-gamma (IFN-γ) knockout mice. Importantly, the course of the infection is comparable to that observed in mice infected with unfrozen oocysts. Vitrification of C. parvum oocysts in larger volumes will expedite progress of research by enabling the sharing of isolates among different laboratories and the standardization of clinical trials.
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Affiliation(s)
- Justyna J Jaskiewicz
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA
| | - Derin Sevenler
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospitals for Children, Boston, MA, USA
| | - Anisa A Swei
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospitals for Children, Boston, MA, USA
| | - Giovanni Widmer
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA
| | - Mehmet Toner
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospitals for Children, Boston, MA, USA
| | - Saul Tzipori
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA, USA.
| | - Rebecca D Sandlin
- Center for Engineering in Medicine, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, and Shriners Hospitals for Children, Boston, MA, USA.
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Pignata C, Bonetta S, Bonetta S, Cacciò SM, Sannella AR, Gilli G, Carraro E. Cryptosporidium Oocyst Contamination in Drinking Water: A Case Study in Italy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E2055. [PMID: 31185673 PMCID: PMC6604028 DOI: 10.3390/ijerph16112055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 06/04/2019] [Accepted: 06/05/2019] [Indexed: 11/30/2022]
Abstract
The aim of this study was to evaluate the occurrence of Cryptosporidium oocysts in a drinking water treatment plant (DWTP) located in a rural area of northern Italy. Influent and effluent samples were collected at the DWTP over three years (2013-2016). In parallel, tap water samples from a public drinking fountain were collected as well. All samples were analyzed for the presence of Cryptosporidium spp. oocysts by a common method based on an immunomagnetic separation (IMS)/immunofluorescence assay (IFA), complemented by 4,6-diamidino-2-phenylindole (DAPI) staining. A reverse transcriptase-PCR (RT-PCR) protocol was added to evaluate oocyst viability. The results highlighted a high variability of oocyst concentrations across all samples (mean 4.3 ± 5.8/100 L) and a high variability in the percentage of DAPI-positive specimens (mean 48.2% ± 40.3%). Conversely, RT-PCR did not reveal the presence of viable C. parvum and C. hominis oocysts. A nested PCR targeting Cryptosporidium 18S ribosomal DNA, carried out in two water samples, confirmed the presence of a Cryptosporidium genotype associated with wild animals in the river and in tap water. The results obtained underline the vulnerability of the investigated surface water to Cryptosporidium spp. contamination. Although the recovered Cryptosporidium genotype is not a human pathogen, its presence demonstrates the existence of a potential pathogen Cryptosporidium spp. contamination risk. Moreover, these results underline the importance of also considering unconventional (not bacterial) biological contaminations (protozoa) in water resources in rural areas, including those of developed countries.
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Affiliation(s)
- Cristina Pignata
- Department of Public Health and Pediatrics, University of Torino, Via Santena 5bis, 10126 Torino, Italy.
| | - Silvia Bonetta
- Department of Public Health and Pediatrics, University of Torino, Via Santena 5bis, 10126 Torino, Italy.
| | - Sara Bonetta
- Department of Public Health and Pediatrics, University of Torino, Via Santena 5bis, 10126 Torino, Italy.
| | - Simone M Cacciò
- Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
| | - Anna R Sannella
- Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
| | - Giorgio Gilli
- Department of Public Health and Pediatrics, University of Torino, Via Santena 5bis, 10126 Torino, Italy.
| | - Elisabetta Carraro
- Department of Public Health and Pediatrics, University of Torino, Via Santena 5bis, 10126 Torino, Italy.
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Rousseau A, Villena I, Dumètre A, Escotte-Binet S, Favennec L, Dubey JP, Aubert D, La Carbona S. Evaluation of propidium monoazide–based qPCR to detect viable oocysts of Toxoplasma gondii. Parasitol Res 2019; 118:999-1010. [DOI: 10.1007/s00436-019-06220-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/17/2019] [Indexed: 01/03/2023]
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Cryopreservation of infectious Cryptosporidium parvum oocysts. Nat Commun 2018; 9:2883. [PMID: 30038430 PMCID: PMC6056504 DOI: 10.1038/s41467-018-05240-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/19/2018] [Indexed: 11/09/2022] Open
Abstract
Cryptosporidiosis in an enteric infection caused by Cryptosporidium parasites and is a major cause of acute infant diarrhea in the developing world. A major bottleneck to research progress is the lack of methods to cryopreserve Cryptosporidium oocysts, thus requiring routine propagation in laboratory animals. Here, we report a method to cryopreserve C. parvum oocysts by ultra-fast cooling. Cryopreserved oocysts exhibit high viability and robust in vitro excystation, and are infectious to interferon-γ knockout mice. The course of the infection is comparable to what we observe with unfrozen oocysts. Oocyst viability and infectivity is not visibly changed after several weeks of cryogenic storage. Cryopreservation will facilitate the sharing of oocysts from well-characterized isolates and transgenic strains among different laboratories.
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