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Backer HD, Derlet RW, Hill VR. Wilderness Medical Society Clinical Practice Guidelines on Water Treatment for Wilderness, International Travel, and Austere Situations: 2024 Update. Wilderness Environ Med 2024; 35:45S-66S. [PMID: 38379474 PMCID: PMC10961906 DOI: 10.1177/10806032231218722] [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] [Indexed: 02/22/2024]
Abstract
To provide guidance to medical providers, wilderness users, and travelers, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for treating water in situations where the potability of available water is not assured, including wilderness and international travel, areas impacted by disaster, and other areas without adequate sanitation. The guidelines present the available methods for reducing or eliminating microbiological contamination of water for individuals, groups, or households; evaluation of their effectiveness; and practical considerations. The evidence base includes both laboratory and clinical publications. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians.
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Affiliation(s)
| | - Robert W. Derlet
- Emergency Department, University of California, Davis, Sacramento, CA
| | - Vincent R. Hill
- Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA
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Hassanein F, Masoud IM, Awwad ZM, Abdel-Salam H, Salem M, Shehata AI. Microbial bowel infections-induced biochemical and biological abnormalities and their effects on young Egyptian swimmers. Sci Rep 2023; 13:4597. [PMID: 36944683 PMCID: PMC10030829 DOI: 10.1038/s41598-023-31708-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 03/16/2023] [Indexed: 03/23/2023] Open
Abstract
Swimmers' personal hygiene affects the spread of microbes in pools. The present study aimed to determine the incidence of microbial infections among young Egyptian swimmers and its impact on swimmers' scores. From January 2020 to June 2021, 528 public club swimmers were examined cross-sectionally. Swimmers were divided into two groups according to their star tests and their scores in the competition (group 1 with a high score and group 2 with a low score). Stool samples, biochemical and biological parameters were assessed. Microbial infections were 54% for intestinal parasitosis and 2.8% for Helicobacter pylori. The rate of intestinal parasitosis was higher among Gp2 as compared to Gp1. The results also revealed higher prevalence of Cryptosporidium spp., Giardia lamblia, Entameba histolytica, and Cyclospora among Gp2 than Gp1. Swimming frequency, and duration influenced the infectious status that induced anemia, abnormal blood pressure, and heart rate. Infected swimmers with cryptosporidiosis had higher alanine transaminase levels, white blood cells, and differential cells but lower aspartate transaminase levels. Giardiasis showed higher reduction in the biochemical markers including ferritin, lactoferrin, iron, and transferrin among Gp 2, compared to Gp 1 and thus affected the swimmers' scores. Thus, raising swimmers' hygiene awareness and targeting health education is obliged.
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Affiliation(s)
- Faika Hassanein
- Department of Microbiology and Immunology, Faculty of Dentistry, Pharos University in Alexandria, Alexandria, Egypt.
| | - Inas M Masoud
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Pharos University in Alexandria, Alexandria, Egypt
| | - Zeinab M Awwad
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Pharos University in Alexandria, Alexandria, Egypt
| | - Hussin Abdel-Salam
- Department of Water Sports Training, Faculty of Fitness Education, Alexandria University, Alexandria, Egypt
| | - Mohamed Salem
- Department of Water Sports Training, Faculty of Fitness Education, Alexandria University, Alexandria, Egypt
| | - Amany I Shehata
- Department of Tropical Health, High Institute of Public Health, Alexandria University, Alexandria, Egypt
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Gupta V, Shekhawat SS, Kulshreshtha NM, Gupta AB. A systematic review on chlorine tolerance among bacteria and standardization of their assessment protocol in wastewater. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:261-291. [PMID: 35906907 DOI: 10.2166/wst.2022.206] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Though chlorine is a cost-effective disinfectant for water and wastewaters, the bacteria surviving after chlorination pose serious public health and environmental problems. This review critically assesses the mechanism of chlorine disinfection as described by various researchers; factors affecting chlorination efficacy; and the re-growth potential of microbial contaminations in treated wastewater post chlorination to arrive at meaningful doses for ensuring health safety. Literature analysis shows procedural inconsistencies in the assessment of chlorine tolerant bacteria, making it extremely difficult to compare the tolerance characteristics of different reported tolerant bacteria. A comparison of logarithmic reduction after chlorination and the concentration-time values for prominent pathogens led to the generation of a standard protocol for the assessment of chlorine tolerance. The factors that need to be critically monitored include applied chlorine doses, contact time, determination of chlorine demands of the medium, and the consideration of bacterial counts immediately after chlorination and in post chlorinated samples (regrowth). The protocol devised here appropriately assesses the chlorine-tolerant bacteria and urges the scientific community to report the regrowth characteristics as well. This would increase the confidence in data interpretation that can provide a better understanding of chlorine tolerance in bacteria and aid in formulating strategies for effective chlorination.
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Affiliation(s)
- Vinayak Gupta
- Alumnus, Department of Civil and Environmental Engineering, National University of Singapore, Singapore; School of Environment and Society, Tokyo Institute of Technology, Tokyo, Japan
| | - Sandeep Singh Shekhawat
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail: ; School of Life and Basic Sciences, SIILAS Campus, Jaipur National University Jaipur, India
| | - Niha Mohan Kulshreshtha
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail:
| | - Akhilendra Bhushan Gupta
- Department of Civil Engineering, Malaviya National Institute of Technology, Jaipur, India E-mail:
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Pharmacokinetics and pharmacodynamics of clofazimine for treatment of cryptosporidiosis. Antimicrob Agents Chemother 2021; 66:e0156021. [PMID: 34748385 PMCID: PMC8765308 DOI: 10.1128/aac.01560-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Infection with Cryptosporidium spp. can cause severe diarrhea, leading to long-term adverse impacts and even death in malnourished children and immunocompromised patients. The only FDA-approved drug for treating cryptosporidiosis, nitazoxanide, has limited efficacy in the populations impacted the most by the diarrheal disease, and safe, effective treatment options are urgently needed. Initially identified by a large-scale phenotypic screening campaign, the antimycobacterial therapeutic clofazimine demonstrated great promise in both in vitro and in vivo preclinical models of Cryptosporidium infection. Unfortunately, a phase 2a clinical trial in HIV-infected adults with cryptosporidiosis did not identify any clofazimine treatment effect on Cryptosporidium infection burden or clinical outcomes. To explore whether clofazimine’s lack of efficacy in the phase 2a trial may have been due to subtherapeutic clofazimine concentrations, a pharmacokinetic/pharmacodynamic modeling approach was undertaken to determine the relationship between clofazimine in vivo concentrations and treatment effects in multiple preclinical infection models. Exposure-response relationships were characterized using Emax and logistic models, which allowed predictions of efficacious clofazimine concentrations for the control and reduction of disease burden. After establishing exposure-response relationships for clofazimine treatment of Cryptosporidium infection in our preclinical model studies, it was unmistakable that the clofazimine levels observed in the phase 2a study participants were well below concentrations associated with anti-Cryptosporidium efficacy. Thus, despite a dosing regimen above the highest doses recommended for mycobacterial therapy, it is very likely the lack of treatment effect in the phase 2a trial was at least partially due to clofazimine concentrations below those required for efficacy against cryptosporidiosis. It is unlikely that clofazimine will provide a remedy for the large number of cryptosporidiosis patients currently without a viable treatment option unless alternative, safe clofazimine formulations with improved oral absorption are developed. (This study has been registered in ClinicalTrials.gov under identifier NCT03341767.)
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de Oliveira AGL, Sudré AP, Bergamo do Bomfim TC, Santos HLC. Molecular characterization of Cryptosporidium spp. in dogs and cats in the city of Rio de Janeiro, Brazil, reveals potentially zoonotic species and genotype. PLoS One 2021; 16:e0255087. [PMID: 34343188 PMCID: PMC8330930 DOI: 10.1371/journal.pone.0255087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 07/12/2021] [Indexed: 12/04/2022] Open
Abstract
Intestinal cryptosporidiosis is a diarrheal disease caused by protists of genus Cryptosporidium that infect a wide variety of hosts, primarily vertebrates. Due to the close contact between humans and their companion animals, especially dogs and cats, there is concern about the potential for zoonotic transmission of this enteric protozoan parasite by infected animals. This study aimed to perform a microscopic and molecular diagnosis of Cryptosporidium spp. in fecal samples from domiciled dogs and cats. One hundred and nineteen fecal samples were processed using sugar centrifugal flotation followed by molecular detection of Cryptosporidium spp. DNA using nested PCR. Subtyping of isolates positive for C. parvum was performed by sequence analysis of the 60 kDa glycoprotein gene (GP60). Cryptosporidium oocysts were detected in 7.8% (5/64) and 5.4% (3/55) of the fecal samples from dogs and cats, respectively. Cryptosporidium canis (n = 3) and C. parvum (n = 2) were the main species found in dogs, whereas C. felis (n = 3) was prevalent in cats. Subtype IIaA17G2R2 (potentially zoonotic) was identified in samples positive for C. parvum. Despite the low prevalence of Cryptosporidium observed in the domiciled dogs and cats, the presence of potentially zoonotic C. parvum in dogs evidences a public health concern. Further research is needed to better understand the epidemiology, source, and potential impacts of Cryptosporidium infection in cats and dogs.
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Affiliation(s)
- Amanda Gleyce Lima de Oliveira
- Universidade Federal Rural do Rio de Janeiro–Departamento de Parasitologia–Instituto de Veterinária–Instituto de Veterinária, Seropédica, Rio de Janeiro, Brazil
| | - Adriana Pittella Sudré
- Universidade Federal Fluminense–Departamento de Microbiologia e Parasitologia, Instituto Biomédico, Niterói, Rio de Janeiro, Brazil
| | - Teresa Cristina Bergamo do Bomfim
- Universidade Federal Rural do Rio de Janeiro–Departamento de Parasitologia–Instituto de Veterinária–Instituto de Veterinária, Seropédica, Rio de Janeiro, Brazil
- * E-mail: ,
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Cell Culture Infectivity to Assess Chlorine Disinfection of Cryptosporidium Oocysts in Water. Methods Mol Biol 2020; 2052:283-302. [PMID: 31452168 DOI: 10.1007/978-1-4939-9748-0_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This chapter provides a detailed protocol to assess disinfection efficacy of chlorine against Cryptosporidium oocysts including the core chlorine disinfection assay, the in vitro cell culture infectivity assay, and microscopy analysis and data interpretation.
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Backer HD, Derlet RW, Hill VR. Wilderness Medical Society Clinical Practice Guidelines for Water Disinfection for Wilderness, International Travel, and Austere Situations. Wilderness Environ Med 2019; 30:S100-S120. [PMID: 31668519 PMCID: PMC10961709 DOI: 10.1016/j.wem.2019.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 05/18/2019] [Accepted: 06/14/2019] [Indexed: 11/23/2022]
Abstract
To provide guidance to clinicians, the Wilderness Medical Society convened experts to develop evidence-based guidelines for water disinfection in situations where the potability of available water is not ensured, including wilderness and international travel, areas affected by disaster, and other areas without adequate sanitation. The guidelines present the available methods for reducing or eliminating microbiologic contamination of water for individuals, groups, or households; evaluation of their effectiveness; and practical considerations. The evidence evaluation includes both laboratory and clinical publications. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks or burdens, according to the criteria published by the American College of Chest Physicians.
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Affiliation(s)
- Howard D Backer
- California Emergency Medical Services Authority, Racho Cordova, CA.
| | - Robert W Derlet
- Emergency Department, University of California, Davis, Sacramento, CA
| | - Vincent R Hill
- Division of Foodborne, Waterborne and Environmental Diseases, Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, Atlanta, GA
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Shedding of Cryptosporidium in calves and dams: evidence of re-infection and shedding of different gp60 subtypes. Parasitology 2019; 146:1404-1413. [PMID: 31327324 DOI: 10.1017/s0031182019000829] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
One of the most common causes of calf diarrhoea is the parasite Cryptosporidium parvum. Two longitudinal studies were carried out on a dairy farm Scotland to determine the prevalence of Cryptosporidium species and subtypes in a group of calves and to determine whether dams were a possible source of calfhood infection. Fecal samples were collected from 25 calves from birth to 12 months in the first year. In the second year, fecal samples were collected from pregnant cows (n = 29) and their calves (n = 30) from birth to 6 months. The samples were tested for Cryptosporidium and speciated. Cryptosporidium parvum-positive samples were subtyped by GP60 fragment analysis. All calves in both studies shed Cryptosporidium during the study period. Cryptosporidium parvum was the predominant species detected in calves ⩽6 weeks of age and at 6 months of age, C. bovis and C. ryanae were detected in calves older than 4 weeks of age but ⩽6 months of age. The prevalence of Cryptosporidium was higher in younger animals than in older animals. GP60 subtyping revealed two subtypes in calves on this farm (IIaA15G2R1 and IIaA19G2R1) that differed in frequency by age. Adult cattle also shed C. parvum, of four gp60 genotypes.
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Chinello E, Modestino MA, Schüttauf JW, Coulot L, Ackermann M, Gerlich F, Faes A, Psaltis D, Moser C. A comparative performance analysis of stand-alone, off-grid solar-powered sodium hypochlorite generators. RSC Adv 2019; 9:14432-14442. [PMID: 35519297 PMCID: PMC9064146 DOI: 10.1039/c9ra02221j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 04/18/2019] [Indexed: 11/21/2022] Open
Abstract
Sodium hypochlorite (NaClO) is a chemical commodity widely employed as a disinfection agent in water treatment applications. Its production commonly follows electrochemical routes in an undivided reactor. Powering the process with photovoltaic (PV) electricity holds the potential to install stand-alone, independent generators and reduce the NaClO production cost. This study reports the comparative assessment of autonomous, solar-powered sodium hypochlorite generators employing different photovoltaic (PV) technologies: silicon hetero-junction (SHJ) and multi-junction (MJ) solar cells. For Si hetero-junctions, the series connection of either four or five SHJ (4SHJ and 5SHJ, respectively) cells was implemented to obtain the reaction potential required. MJ cells were illuminated by a novel planar solar concentrator that guarantees solar tracking with minimal linear displacements. The three solar-hypochlorite generators were tested under real atmospheric conditions, demonstrating solar-to-chemical conversion efficiencies (SCE) of 9.8% for 4SHJ, 14.2% for 5SHJ and 25.1% for MJ solar cells, respectively. Simulations based on weather databases allowed us to assess efficiencies throughout the entire model year and resulted in specific sodium hypochlorite yearly production rates between 7.2-28 gNaClO cm-2 (referred to the PV surface), depending on the considered PV technology, location, and deployment of electronics converters. The economic viability and competitiveness of solar hypochlorite generators have been investigated and compared with an analog disinfection system deploying ultraviolet lamps. Our study demonstrates the feasibility of off-grid, solar-hypochlorite generators, and points towards the implementation of SHJ solar cells as a reliable technology for stand-alone solar-chemical devices.
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Affiliation(s)
- E Chinello
- School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) Station 18 1015 Lausanne Switzerland +41 21 69 35171
| | - M A Modestino
- Tandon School of Engineering, New York University (NYU) Rogers Halls 600A Brooklyn 11201 NY New York
| | - J W Schüttauf
- Swiss Center for Electronics and Microtechnology (CSEM) Rue Jacquet-Droz 1 CH 2002 Neuchâtel Switzerland
| | - L Coulot
- Insolight SA Chemin de la Raye 13, Ecublens (VD) CH 1015 Lausanne Switzerland
| | - M Ackermann
- Insolight SA Chemin de la Raye 13, Ecublens (VD) CH 1015 Lausanne Switzerland
| | - F Gerlich
- Insolight SA Chemin de la Raye 13, Ecublens (VD) CH 1015 Lausanne Switzerland
| | - A Faes
- Swiss Center for Electronics and Microtechnology (CSEM) Rue Jacquet-Droz 1 CH 2002 Neuchâtel Switzerland
| | - D Psaltis
- School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) Station 18 1015 Lausanne Switzerland +41 21 69 35171
| | - C Moser
- School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL) Station 18 1015 Lausanne Switzerland +41 21 69 35171
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Kumar N, Hu Y, Singh S, Mizaikoff B. Emerging biosensor platforms for the assessment of water-borne pathogens. Analyst 2018; 143:359-373. [PMID: 29271425 DOI: 10.1039/c7an00983f] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Pathogens are key contaminants in water that are responsible for the generation of various water-borne diseases, and include viruses, fungi, bacteria, and protozoan parasites. The pathogenic effects of these species in water depend on their shape, size, composition, and structure. The resulting water-borne diseases are a serious threat to the environment, including to humans and animals, and are directly responsible for environmental deterioration and pollution. The potential presence of these pathogens requires sensitive, powerful, efficient, and ideally real-time monitoring methods for their reproducible quantification. Conventional methods for pathogen detection mainly rely on time-consuming enrichment steps followed by biochemical identification strategies, which require assay times ranging from 24 h to up to a week. However, in recent years, significant efforts have been made towards the development of biosensing technologies enabling rapid and close-to-real-time detection of water-borne pathogens. This review summarizes recent developments in biosensors and sensing systems based on a variety of transducer technologies for water-quality monitoring, with specific focus on rapid pathogen detection.
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Affiliation(s)
- Nishant Kumar
- CSIR-Central Scientific Instruments Organisation, Chandigarh, India.
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Soliman A, El-Adawy A, Abd El-Aal AA, Elmallawany MA, Nahnoush RK, Eiaghni ARA, Negm MS, Mohsen A. Usefulness of Sunlight and Artificial UV Radiation Versus Chlorine for the Inactivation of Cryptosporidium Oocysts: An in Vivo Animal Study. Open Access Maced J Med Sci 2018; 6:975-981. [PMID: 29983787 PMCID: PMC6026424 DOI: 10.3889/oamjms.2018.180] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 03/24/2018] [Accepted: 03/25/2018] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Cryptosporidium is an important waterborne protozoan. AIM The aim of this study was to investigate the effect of sunlight being the natural source of UV and artificial UV irradiation on Cryptosporidium oocysts versus the effect of chlorination, being the traditional method of water disinfection and to provide an insight into the viability and degree of infectivity of Cryptosporidium oocysts, using an animal model. METHODS An experimental study including 300 neonatal mice was carried out to investigate the effect of artificial ultraviolet (UV) irradiation and sunlight being the natural source of UV irradiation versus chlorine, the traditionally used water disinfectant on the infectivity of Cryptosporidium oocysts present in water. For each item, nine different exposure times were investigated. Parasitological assessment (Modified Ziehl Neelsen stained stool smears) and histopathological assessment of the excised segments of the small intestine (stained by both Haematoxylin & Eosin and ZN stain) of mice were used to verify the inactivation of oocysts. RESULTS Cryptosporidium oocysts failed to induce any noticeable infection after 4 hours of artificial UV exposure that provided a UV dose of 10mJ/cm2 and after an 8 hours exposure to sunlight, whereas they showed resistance to disinfection by chlorine. CONCLUSION The results of the study demonstrate the important role of an 8 hours sunlight exposure of potable water in plastic bottles in achieving complete inactivation of any contaminating Cryptosporidium oocysts, thus offering an applicable, economical and convenient method for the control of cryptosporidiosis especially in developing countries.
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Affiliation(s)
- Amany Soliman
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Azza El-Adawy
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Medical Parasitology, Armed Forces College of Medicine, Cairo, Egypt
| | - Amany A. Abd El-Aal
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
- Department of Medical Parasitology, Armed Forces College of Medicine, Cairo, Egypt
| | - Marwa A. Elmallawany
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Reham K. Nahnoush
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Asmaa R. Abd Eiaghni
- Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | - Amira Mohsen
- Community Medicine Department, National Research Centre, Cairo, Egypt
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Silva Novaes R, Pires MS, Sudré AP, Bergamo do Bomfim TC. Captive-bred neotropical birds diagnosed with Cryptosporidium Avian genotype III. Acta Trop 2018; 178:297-302. [PMID: 29221852 DOI: 10.1016/j.actatropica.2017.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 07/23/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
Currently, there are only three valid species of Cryptosporidium infecting avian hosts, namely, Cryptosporidium meleagridis, Cryptosporidium baileyi, Cryptosporidium galli and Cryptosporidium avium in addition to 12 genotypes of unknown species status. The objectives of this study were to microscopically diagnose the presence of Cryptosporidium in birds from a commercial aviary located in Rio de Janeiro, Brazil; genotypically characterize species and/or genotypes of genus Cryptosporidum; and conduct sequencing and phylogenetic analyses to compare the obtained DNA sequences with those deposited in GenBank. A total of 85 fecal samples were collected from wild captive-bred birds: 48 of family Psittacidae and 37 of family Ramphastidae. Initially, a search for the presence of Cryptosporidium sp. oocysts was conducted using the centrifugal-flotation in saturated sugar solution technique, after that, the collected samples were analyzed microscopically. Cryptosporidium infections were only detected in 24.32% of samples belonging to the family Ramphastidae. DNA was extracted from positive samples and molecular diagnostics was applied targeting the 18S rRNA gene, followed by sequencing and phylogenetic analysis. The Cryptosporidium Avian genotype III was diagnosed in this study more closely related to the gastric species. This is the first record of Cryptosporidium Avian genotype III in order Piciformes and family Ramphastidae, where three host species (Ramphastus toco, Ramphastus tucanus, and Pteroglossus bailloni) were positive for the etiologic agent. Based on the molecular data obtained, these wild birds raised in captivity do not represent a source of human cryptosporidiosis, considering that Cryptosporidium Avian genotype III does not constitute a zoonosis.
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Aquino de Carvalho N, Stachler EN, Cimabue N, Bibby K. Evaluation of Phi6 Persistence and Suitability as an Enveloped Virus Surrogate. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8692-8700. [PMID: 28657725 DOI: 10.1021/acs.est.7b01296] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Recent outbreaks involving enveloped viruses, such as Ebola virus, have raised questions regarding the persistence of enveloped viruses in the water environment. Efforts have been made to find enveloped virus surrogates due to challenges investigating viruses that require biosafety-level 3 or 4 handling. In this study, the enveloped bacteriophage Phi6 was evaluated as a surrogate for enveloped waterborne viruses. The persistence of Phi6 was tested in aqueous conditions chosen based on previously published viral persistence studies. Our results demonstrated that the predicted T90 (time for 90% inactivation) of Phi6 under the 12 evaluated conditions varied from 24 min to 117 days depending on temperature, biological activity, and aqueous media composition. Phi6 persistence was then compared with persistence values from other enveloped viruses reported in the literature. The apparent suitability of Phi6 as an enveloped virus surrogate was dependent on the temperature and composition of the media tested. Of evaluated viruses, 33%, including all conditions considered, had T90 values greater than the 95% confidence interval for Phi6. Ultimately, these results highlight the variability of enveloped virus persistence in the environment and the value of working with the virus of interest for environmental persistence studies.
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Affiliation(s)
- Nathalia Aquino de Carvalho
- Department of Civil and Environmental Engineering, and ‡Department of Computational and Systems Biology, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Elyse N Stachler
- Department of Civil and Environmental Engineering, and ‡Department of Computational and Systems Biology, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Nicole Cimabue
- Department of Civil and Environmental Engineering, and ‡Department of Computational and Systems Biology, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Kyle Bibby
- Department of Civil and Environmental Engineering, and ‡Department of Computational and Systems Biology, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
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Ryan U, Lawler S, Reid S. Limiting swimming pool outbreaks of cryptosporidiosis - the roles of regulations, staff, patrons and research. JOURNAL OF WATER AND HEALTH 2017; 15:1-16. [PMID: 28151435 DOI: 10.2166/wh.2016.160] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Cryptosporidium is the leading cause of swimming pool outbreaks of gastroenteritis. Transmission occurs through the ingestion of oocysts that are passed in the faeces of an infected person or animal when an accidental faecal release event occurs. Cryptosporidium parasites present specific challenges for infection control as oocysts are highly resistant to chlorine levels used for pool disinfection, infected individuals can shed large numbers of oocysts, there is a long incubation period and shedding of oocysts occurs even after symptom resolution. The purposes of this review are to identify key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis and to outline needs for research and collaboration to advance co-ordinated management practices. We reviewed swimming pool-associated cryptosporidiosis outbreaks, disinfection teachniques, current regulations and the role of staff and patrons. Key barriers to limiting swimming pool-associated outbreaks of cryptosporidiosis are a lack of uniform national and international standards, poor adherence and understanding of regulations governing staff and patron behaviour, and low levels of public knowledge and awareness.
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Affiliation(s)
- Una Ryan
- School of Veterinary and Life Sciences, Murdoch University, Perth, Australia E-mail:
| | - Sheleigh Lawler
- The University of Queensland, School of Public Health, Herston, Queensland 4006, Australia
| | - Simon Reid
- The University of Queensland, School of Public Health, Herston, Queensland 4006, Australia
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Nasser AM. Removal of Cryptosporidium by wastewater treatment processes: a review. JOURNAL OF WATER AND HEALTH 2016; 14:1-13. [PMID: 26837825 DOI: 10.2166/wh.2015.131] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cryptosporidium is a protozoan parasite that infects humans and various animal species. The environmental stability and the low infectious dose of Cryptosporidium facilitate its transmission by water and food. Discharge of untreated wastewater may result in waterborne or foodborne Cryptosporidium outbreaks, therefore a suitable treatment may prevent its dissemination. Most studies on the prevalence of Cryptosporidium oocysts in wastewater have reported a concentration range between 10 and 200 oocysts/L and a prevalence of 6 to 100%. Activated sludge has been found to be ineffective for the removal of Cryptosporidium oocysts. Stabilization ponds and constructed wetlands are efficient for the reduction of Cryptosporidium from wastewater, especially when the retention time is longer than 20 days at suitable sunlight and temperature. High rate filtration and chlorine disinfection are inefficient for the reduction of Cryptosporidium from effluents, whereas ultrafiltration and UV irradiation were found to be very efficient for the reduction of Cryptosporidium oocysts. Adequate tertiary treatment may result in high quality effluent with low risk of Cryptosporidium for unrestricted irrigation and other non-potable applications.
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Affiliation(s)
- Abidelfatah M Nasser
- Water Quality Research Laboratory, Ministry of Health, Ben Zvi Rd 69, Tel Aviv, Israel E-mail:
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Lu P, Amburgey JE. A pilot-scale study of Cryptosporidium-sized microsphere removals from swimming pools via sand filtration. JOURNAL OF WATER AND HEALTH 2016; 14:109-120. [PMID: 26837835 DOI: 10.2166/wh.2015.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Cryptosporidium species are the most common cause of gastrointestinal illness in treated recreational water venues. In order to protect public health during swimming, Cryptosporidium-sized microsphere removals by high-rate sand filtration with six coagulants were evaluated with a 5.5 m(3) pilot-scale swimming pool. A sand filter without coagulation removed 20-63% of Cryptosporidium-sized microspheres. Cryptosporidium-sized microsphere removals exceeded 98% by sand filtration with five of the six tested coagulants. Continuously feeding coagulants A, B, and F (i.e., organic polymers) led to coagulant accumulation in the system and decreased removals over time (<2 days). Coagulant E (polyaluminum chloride) consistently removed more than 90% of microspheres at 30 m/h while the removals dropped to approximately 50% at a filtration rate of 37 m/h. Coagulant C was a chitosan-based product that removed fewer microspheres compared with other products, <75%, under the studied conditions. Results indicated aluminum-based coagulants (coagulants D and E) had an overall performance advantage over the organic polymer based coagulants primarily in terms of their tendency not to accumulate in the water and cease to be effective at improving filter efficiency.
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Affiliation(s)
- Ping Lu
- Department of Environmental Science and Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China E-mail: ; Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - James E Amburgey
- Civil and Environmental Engineering, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
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Cryptosporidium Lactate Dehydrogenase Is Associated with the Parasitophorous Vacuole Membrane and Is a Potential Target for Developing Therapeutics. PLoS Pathog 2015; 11:e1005250. [PMID: 26562790 PMCID: PMC4642935 DOI: 10.1371/journal.ppat.1005250] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 10/06/2015] [Indexed: 12/27/2022] Open
Abstract
The apicomplexan, Cryptosporidium parvum, possesses a bacterial-type lactate dehydrogenase (CpLDH). This is considered to be an essential enzyme, as this parasite lacks the Krebs cycle and cytochrome-based respiration, and mainly–if not solely, relies on glycolysis to produce ATP. Here, we provide evidence that in extracellular parasites (e.g., sporozoites and merozoites), CpLDH is localized in the cytosol. However, it becomes associated with the parasitophorous vacuole membrane (PVM) during the intracellular developmental stages, suggesting involvement of the PVM in parasite energy metabolism. We characterized the biochemical features of CpLDH and observed that, at lower micromolar levels, the LDH inhibitors gossypol and FX11 could inhibit both CpLDH activity (Ki = 14.8 μM and 55.6 μM, respectively), as well as parasite growth in vitro (IC50 = 11.8 μM and 39.5 μM, respectively). These observations not only reveal a new function for the poorly understood PVM structure in hosting the intracellular development of C. parvum, but also suggest LDH as a potential target for developing therapeutics against this opportunistic pathogen, for which fully effective treatments are not yet available. Cryptosporidians are unique among the apicomplexans in regards to their parasitic life style (e.g., they are intracellular, but undergo extracytoplasmic development within a host membrane-derived structure termed parasitophorous vacuole membrane, PVM) and their metabolism (e.g., they are incapable of de novo nutrient synthesis and rely on glycolysis for the synthesis of ATP). We discovered that the Cryptosporidium parvum bacterial-type L-lactate dehydrogenase (CpLDH) enzyme is cytosolic during the parasite’s motile, extracellular, stages (sporozoites and merozoites), but becomes associated with the PVM during intracellular development, indicating the involvement of the PVM in lactate fermentation. We also observed that micromolar concentrations of the LDH inhibitors gossypol and FX11 inhibit both CpLDH activity and the growth of C. parvum in vitro, suggesting that CpLDH is a potential target for the development of anti-cryptosporidial therapeutics.
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Review of Risk Status of Groundwater Supply Wells by Tracing the Source of Coliform Contamination. WATER 2015. [DOI: 10.3390/w7073878] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Biotin- and Glycoprotein-Coated Microspheres as Surrogates for Studying Filtration Removal of Cryptosporidium parvum in a Granular Limestone Aquifer Medium. Appl Environ Microbiol 2015; 81:4277-83. [PMID: 25888174 DOI: 10.1128/aem.00885-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/10/2015] [Indexed: 11/20/2022] Open
Abstract
Members of the genus Cryptosporidium are waterborne protozoa of great health concern. Many studies have attempted to find appropriate surrogates for assessing Cryptosporidium filtration removal in porous media. In this study, we evaluated the filtration of Cryptosporidium parvum in granular limestone medium by the use of biotin- and glycoprotein-coated carboxylated polystyrene microspheres (CPMs) as surrogates. Column experiments were carried out with core material taken from a managed aquifer recharge site in Adelaide, Australia. For the experiments with injection of a single type of particle, we observed the total removal of the oocysts and glycoprotein-coated CPMs, a 4.6- to 6.3-log10 reduction of biotin-coated CPMs, and a 2.6-log10 reduction of unmodified CPMs. When two different types of particles were simultaneously injected, glycoprotein-coated CPMs showed a 5.3-log10 reduction, while the uncoated CPMs displayed a 3.7-log10 reduction, probably due to particle-particle interactions. Our results confirm that glycoprotein-coated CPMs are the most accurate surrogates for C. parvum; biotin-coated CPMs are slightly more conservative, while unmodified CPMs are markedly overly conservative for predicting C. parvum removal in granular limestone medium. The total removal of C. parvum observed in our study suggests that granular limestone medium is very effective for the filtration removal of C. parvum and could potentially be used for the pretreatment of drinking water and aquifer storage recovery of recycled water.
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Suzuki Y, Takida T. Concentration of Cryptosporidium oocysts from river water by coagulation and foam separation combined with acid dissolution of ferric flocs. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2015; 50:311-316. [PMID: 25594124 DOI: 10.1080/10934529.2015.981121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cryptosporidium is an extremely virulent microorganism; contamination of water works systems by Cryptosporidium oocysts is a serious issue in public health. However, a great deal of effort is required to detect oocysts in source water for drinking, because the oocysts have to be concentrated from a large volume of water before detection. In this study, the concentration of oocysts in oocyst-polluted artificial river water was examined by coagulation and foam separation. The oocysts concentrated in the foam water were purified using immunomagnetic separation and assessed using epifluorescence microscopy. When ferric coagulation was performed prior to foam separation, oocysts were effectively removed from the river water and concentrated in the foam within 10 min. The removal efficiency was greater than 96% at the optimum iron and casein concentrations of 5 mg-Fe L(-1) and 20 mg L(-1), respectively. Furthermore, the number of recovered oocysts in the solution obtained by the dissolution of the collected ferric flocs from foam water was the same as that obtained using the Japanese standard procedure for detection of Cryptosporidium in water using membrane filtration. This is a novel method of concentrating Cryptosporidium oocysts for detection in river water using a coagulation and foam separation combined with acid dissolution of ferric flocs; the method is easy to use, rapid, and efficient.
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Affiliation(s)
- Yoshihiro Suzuki
- a Faculty of Engineering , University of Miyazaki , Miyazaki , Japan
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Daniels ME, Hogan J, Smith WA, Oates SC, Miller MA, Hardin D, Shapiro K, Los Huertos M, Conrad PA, Dominik C, Watson FGR. Estimating environmental conditions affecting protozoal pathogen removal in surface water wetland systems using a multi-scale, model-based approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 493:1036-1046. [PMID: 25016109 DOI: 10.1016/j.scitotenv.2014.06.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 06/13/2014] [Accepted: 06/13/2014] [Indexed: 06/03/2023]
Abstract
Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii are waterborne protozoal pathogens distributed worldwide and empirical evidence suggests that wetlands reduce the concentrations of these pathogens under certain environmental conditions. The goal of this study was to evaluate how protozoal removal in surface water is affected by the water temperature, turbidity, salinity, and vegetation cover of wetlands in the Monterey Bay region of California. To examine how protozoal removal was affected by these environmental factors, we conducted observational experiments at three primary spatial scales: settling columns, recirculating wetland mesocosm tanks, and an experimental research wetland (Molera Wetland). Simultaneously, we developed a protozoal transport model for surface water to simulate the settling columns, the mesocosm tanks, and the Molera Wetland. With a high degree of uncertainty expected in the model predictions and field observations, we developed the model within a Bayesian statistical framework. We found protozoal removal increased when water flowed through vegetation, and with higher levels of turbidity, salinity, and temperature. Protozoal removal in surface water was maximized (~0.1 hour(-1)) when flowing through emergent vegetation at 2% cover, and with a vegetation contact time of ~30 minutes compared to the effects of temperature, salinity, and turbidity. Our studies revealed that an increase in vegetated wetland area, with water moving through vegetation, would likely improve regional water quality through the reduction of fecal protozoal pathogen loads.
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Affiliation(s)
- Miles E Daniels
- Division of Science and Environmental Policy, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA; Veterinary Medicine and Epidemiology Department, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Jennifer Hogan
- Veterinary Medicine and Epidemiology Department, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Woutrina A Smith
- Veterinary Medicine and Epidemiology Department, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Stori C Oates
- Marine Wildlife Veterinary Care and Research Center, California Department of Fish and Wildlife, Santa Cruz, CA, 95062, USA
| | - Melissa A Miller
- Marine Wildlife Veterinary Care and Research Center, California Department of Fish and Wildlife, Santa Cruz, CA, 95062, USA
| | - Dane Hardin
- Applied Marine Sciences and Central Coast Long-Term Environmental Assessment Network, Santa Cruz, CA, 95062, USA
| | - Karen Shapiro
- Veterinary Medicine and Epidemiology Department, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Marc Los Huertos
- Division of Science and Environmental Policy, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA
| | - Patricia A Conrad
- Veterinary Medicine and Epidemiology Department, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Clare Dominik
- Applied Marine Sciences and Central Coast Long-Term Environmental Assessment Network, Santa Cruz, CA, 95062, USA
| | - Fred G R Watson
- Division of Science and Environmental Policy, California State University, Monterey Bay, 100 Campus Center, Seaside, CA, 93955, USA
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Frequencies and spatial distributions of Cryptosporidium in livestock animals and children in the Ismailia province of Egypt. Epidemiol Infect 2014; 143:1208-18. [PMID: 25084317 DOI: 10.1017/s0950268814001824] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Faecal samples from 804 cattle and buffaloes and 165 diarrhoeal children of Ismailia province were investigated by an immunochromatographic screening test and PCR to determine prevalences and distributions of Cryptosporidium spp. Results were analysed statistically for clustering of animal and human cases. Cryptosporidium herd prevalence was 73·3% and individual animal prevalence 32·3%. C. parvum was the dominant species in animals (65·7%). Young calves watered with canal or underground water were at particular risk of infection. Detection rates were higher when calves showed diarrhoea, fever and dehydration. Human Cryptosporidium prevalence was 49·1%. C. hominis dominated in humans (60·5%), followed by C. parvum (38·3%). Living in villages, drinking underground water and having contact with animals were risk factors. Cluster analysis revealed differences in the distribution of infections between animals and humans and suggests different transmission dynamics.
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Maas AK. Considerations and conditions involving protozoal inhabitation of the reptilian gastrointestinal tract. Vet Clin North Am Exot Anim Pract 2014; 17:263-97. [PMID: 24767746 DOI: 10.1016/j.cvex.2014.01.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In mammals, gastrointestinal protozoal organism inhabitation has been well studied, with hundreds of species defined as parasites. While the mammalian protozoal relationships have been identified and categorized by anatomy, tropism, pathogenicity, and life cycles, relatively few species of protozoal organism relationships have been categorized in reptiles. Species of parasites are still being segregated from each other, and conflicting information needs to be clarified to completely understand the data already available. This article presents the information available to help reptile practitioners make evidence-based decisions regarding both the determination of a pathologic parasitic condition and direct appropriate treatment of patients.
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Affiliation(s)
- Adolf K Maas
- ZooVet Consulting, PLLC, PO Box 1007, Bothell, WA 98041, USA.
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Cacciabue DG, Juárez MM, Poma HR, Garcé B, Rajal VB. Cuantificación y evaluación de la estacionalidad de elementos parasitarios en ambientes acuáticos recreativos de la provincia de Salta, Argentina. Rev Argent Microbiol 2014; 46:150-60. [DOI: 10.1016/s0325-7541(14)70064-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/22/2014] [Indexed: 11/27/2022] Open
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26
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Jex AR, Gasser RB. Diagnostic and analytical mutation scanning ofCryptosporidium: utility and advantages. Expert Rev Mol Diagn 2014; 9:179-85. [DOI: 10.1586/14737159.9.2.179] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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27
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[Intestinal parasitoses in Argentina: major causal agents found in the population and in the environment]. Rev Argent Microbiol 2013; 45:191-204. [PMID: 24165144 DOI: 10.1016/s0325-7541(13)70024-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Intestinal parasitic diseases are widely spread in the world, with the highest prevalence in developing countries. Children are mainly affected, showing a decrease in physical and mental development, as well as the expected manifestations of the disease. This situation can be greatly enhanced in children with poor nutritional status. The World Health Organization considers intestinal parasitic diseases a major cause of morbidity, closely linked to poverty and poor personal hygiene, inappropriate handling of raw food, lack of sanitation, lack of potable water supply, and environmental fecal contamination. Some parasitic diseases are cosmopolitan while others have variable geographic distribution, due to different factors such as the presence of exclusive intermediate hosts. In the past few years, globalization allowed the spread of certain parasites from endemic to non-endemic regions. Even though people's customs influence on the frequency of certain parasites, environmental conditions are a determinant factor for parasite survival. In our country, due to the variety of soils and climatic conditions, several causative agents of these parasitoses can be found. The aim of this work was to review the literature on the intestinal parasitic agents found in Argentina in human fecal samples and its environment, as parasitic contamination constitutes a direct indicator of the infection risk by intestinal parasites.
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Laczka O, Skillman L, Ditcham WG, Hamdorf B, Wong DK, Bergquist P, Sunna A. Application of an ELISA-type screen printed electrode-based potentiometric assay to the detection of Cryptosporidium parvum oocysts. J Microbiol Methods 2013; 95:182-5. [DOI: 10.1016/j.mimet.2013.08.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/09/2013] [Accepted: 08/09/2013] [Indexed: 11/28/2022]
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Abeywardena H, Jex AR, von Samson-Himmelstjerna G, Haydon SR, Stevens MA, Gasser RB. First molecular characterisation of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) in Victoria, Australia. INFECTION GENETICS AND EVOLUTION 2013; 20:96-102. [PMID: 23886616 DOI: 10.1016/j.meegid.2013.07.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 07/14/2013] [Accepted: 07/16/2013] [Indexed: 12/15/2022]
Abstract
We conducted a molecular epidemiological survey of Cryptosporidium and Giardia from Bubalus bubalis (water buffalo) on two extensive farms (450 km apart) in Victoria, Australia. Faecal samples (n=476) were collected from different age groups of water buffalo at two time points (six months apart) and tested using a PCR-based mutation scanning-targeted sequencing-phylogenetic approach, employing markers within the small subunit of ribosomal RNA (designated pSSU) and triose phosphate isomerase (ptpi) genes. Based on pSSU data, Cryptosporidium parvum, Cryptosporidium bovis and Cryptosporidium genotypes 1, 2 (each 99% similar genetically to Cryptosporidium ryanae) and 3 (99% similar to Cryptosporidium suis) were detected in two (0.4%), one (0.2%), 38 (8.0%), 16 (3.4%) and one (0.2%) of the 476 samples tested, respectively. Using ptpi, Giardia duodenalis assemblages A and E were detected in totals of 56 (11.8%) and six (1.3%) of these samples, respectively. Cryptosporidium was detected on both farms, whereas Giardia was detected only on farm B, and both genera were detected in 1.5% of all samples tested. The study showed that water buffaloes on these farms excreted C. parvum and/or G. duodenalis assemblage A, which are consistent with those found in humans, inferring that these particular pathogens are of zoonotic significance. Future work should focus on investigating, in a temporal and spatial manner, the prevalence and intensity of such infections in water buffaloes in various geographical regions in Australia and in other countries.
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Affiliation(s)
- Harshanie Abeywardena
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia
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Nolan MJ, Jex AR, Koehler AV, Haydon SR, Stevens MA, Gasser RB. Molecular-based investigation of Cryptosporidium and Giardia from animals in water catchments in southeastern Australia. WATER RESEARCH 2013; 47:1726-1740. [PMID: 23357792 DOI: 10.1016/j.watres.2012.12.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Revised: 12/10/2012] [Accepted: 12/14/2012] [Indexed: 06/01/2023]
Abstract
There has been no large-scale systematic molecular epidemiological investigation of the waterborne protozoans, Cryptosporidium or Giardia, in southeastern Australia. Here, we explored, for the first time, the genetic composition of these genera in faecal samples from animals in nine Melbourne Water reservoir areas, collected over a period of two-years. We employed PCR-based single-strand conformation polymorphism (SSCP) and phylogenetic analyses of loci (pSSU and pgp60) in the small subunit (SSU) of ribosomal RNA and 60-kDa glycoprotein (gp60) genes to detect and characterise Cryptosporidium, and another locus (ptpi) in the triose-phosphate isomerase (tpi) gene to identify and characterise Giardia. Cryptosporidium was detected in 2.8% of the 2009 samples examined; the analysis of all amplicons defined 14 distinct sequence types for each of pSSU and pgp60, representing Cryptosporidium hominis (genotype Ib - subgenotype IbA10G2R2), Cryptosporidium parvum (genotype IIa - subgenotypes IIaA15G2R1, IIaA19G2R1, IIaA19G3R1, IIaA19G4R1, IIaA20G3R1, IIaA20G4R1, IIaA20G3R2 and IIaA21G3R1), Cryptosporidium cuniculus (genotype Vb - subgenotypes VbA22R4, VbA23R3, VbA24R3, VbA25R4 and VbA26R4), and Cryptosporidium canis, Cryptosporidium fayeri, Cryptosporidium macropodum and Cryptosporidium ubiquitum as well as six new pSSU sequence types. In addition, Giardia was identified in 3.4% of the samples; all 28 distinct ptpi sequence types defined were linked to assemblage A of Giardia duodenalis. Of all 56 sequence types characterised, eight and one have been recorded previously in Cryptosporidium and Giardia, respectively, from humans. In contrast, nothing is known about the zoonotic potential of 35 new genotypes of Cryptosporidium and Giardia recorded here for the first time. Future work aims to focus on estimating the prevalence of Cryptosporidium and Giardia genotypes in humans and a wide range of animals in Victoria and elsewhere in Australia. (Nucleotide sequences reported in this paper are available in the GenBank database under accession nos. KC282952-KC283005).
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Affiliation(s)
- Matthew J Nolan
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Sunna A, Chi F, Bergquist PL. Efficient capture of pathogens with a zeolite matrix. Parasitol Res 2013; 112:2441-52. [DOI: 10.1007/s00436-013-3405-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Accepted: 03/15/2013] [Indexed: 10/27/2022]
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McGuigan KG, Conroy RM, Mosler HJ, du Preez M, Ubomba-Jaswa E, Fernandez-Ibañez P. Solar water disinfection (SODIS): a review from bench-top to roof-top. JOURNAL OF HAZARDOUS MATERIALS 2012; 235-236:29-46. [PMID: 22906844 DOI: 10.1016/j.jhazmat.2012.07.053] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Revised: 07/27/2012] [Accepted: 07/28/2012] [Indexed: 05/12/2023]
Abstract
Solar water disinfection (SODIS) has been known for more than 30 years. The technique consists of placing water into transparent plastic or glass containers (normally 2L PET beverage bottles) which are then exposed to the sun. Exposure times vary from 6 to depending on the intensity of sunlight and sensitivity of the pathogens. Its germicidal effect is based on the combined effect of thermal heating of solar light and UV radiation. It has been repeatedly shown to be effective for eliminating microbial pathogens and reduce diarrhoeal morbidity including cholera. Since 1980 much research has been carried out to investigate the mechanisms of solar radiation induced cell death in water and possible enhancement technologies to make it faster and safer. Since SODIS is simple to use and inexpensive, the method has spread throughout the developing world and is in daily use in more than 50 countries in Asia, Latin America, and Africa. More than 5 million people disinfect their drinking water with the solar disinfection (SODIS) technique. This review attempts to revise all relevant knowledge about solar disinfection from microbiological issues, laboratory research, solar testing, up to and including real application studies, limitations, factors influencing adoption of the technique and health impact.
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Abeywardena H, Jex AR, Nolan MJ, Haydon SR, Stevens MA, McAnulty RW, Gasser RB. Genetic characterisation of Cryptosporidium and Giardia from dairy calves: discovery of species/genotypes consistent with those found in humans. INFECTION GENETICS AND EVOLUTION 2012; 12:1984-93. [PMID: 22981927 DOI: 10.1016/j.meegid.2012.08.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/31/2012] [Accepted: 08/01/2012] [Indexed: 10/27/2022]
Abstract
Cryptosporidium and Giardia are important genera of parasitic protists that can cause significant diarrhoeal diseases in humans and other animals. Depending on the species/genotype of parasite, human infection may be acquired via anthroponotic or zoonotic transmission routes. Here, we undertook a molecular epidemiological investigation of these two genera of parasites in pre- and post-weaned calves from eight locations in Canterbury, New Zealand, by PCR-coupled sequencing and phylogenetic analysis of sequence data for regions in the 60 kDa glycoprotein (pgp60) gene of Cryptosporidium and/or the triose-phosphate isomerase (ptpi) gene of Giardia. The pgp60 and ptpi regions were specifically amplified from 15 (8.3%) and 11 (6.1%) of the 180 individual faecal samples, respectively. The sequences derived from all of the amplicons were aligned with homologous reference sequences and subjected to phylogenetic analysis by Bayesian inference. For Cryptosporidium, three samples contained Cryptosporidium parvum genotype IIa, subgenotypes IIaA15G3R1, IIaA19G3R1 and IIaA23G4. Twelve samples contained Cryptosporidium hominis genotype Ib, subgenotype IbA10G2R2. While subgenotypes IIaA15G3R1 and IIaA23G4 are new records, IIaA19G3R1 and IbA10G2R2 are commonly found in humans in various countries. For Giardia, two samples contained Giardia duodenalis assemblage A, also common in humans. In contrast, nine samples contained G. duodenalis assemblage E, which is the first report of this assemblage in cattle in New Zealand. Therefore, the present results indicate that dairy calves on the South Island of New Zealand harbour 'zoonotic' genotypes of Cryptosporidium and Giardia, which is likely to have significant public health implications.
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Affiliation(s)
- Harshanie Abeywardena
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia
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Criteria for selection of surrogates used to study the fate and control of pathogens in the environment. Appl Environ Microbiol 2012; 78:1969-77. [PMID: 22247166 DOI: 10.1128/aem.06582-11] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This article defines the term surrogate as an organism, particle, or substance used to study the fate of a pathogen in a specific environment. Pathogenic organisms, nonpathogenic organisms, and innocuous particles have been used as surrogates for a variety of purposes, including studies on survival and transport as well as for method development and as "indicators" of certain conditions. This article develops a qualitative surrogate attribute prioritization process and allows investigators to select a surrogate by systematically detailing the experimental process and prioritizing attributes. The results are described through the use of case studies of various laboratories that have used this process. This article also discusses the history of surrogate and microbial indicator use and outlines the method by which surrogates can be used when conducting a quantitative microbial risk assessment. The ultimate goal of selecting a sufficiently representative surrogate is to improve public health through a health-based risk assessment framework. Under- or overestimating the resistance, inactivation, or movement may negatively impact risk assessments that, in turn, will impact health assessments and estimated safety levels. Reducing uncertainty in a risk assessment is one of the objectives of using surrogates and the ultimate motive for any experiment investigating potential exposure of a pathogen.
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Kishida N, Miyata R, Furuta A, Izumiyama S, Tsuneda S, Sekiguchi Y, Noda N, Akiba M. Quantitative detection of Cryptosporidium oocyst in water source based on 18S rRNA by alternately binding probe competitive reverse transcription polymerase chain reaction (ABC-RT-PCR). WATER RESEARCH 2012; 46:187-194. [PMID: 22088270 DOI: 10.1016/j.watres.2011.10.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/19/2011] [Accepted: 10/21/2011] [Indexed: 05/31/2023]
Abstract
We describe an assay for simple and cost-effective quantification of Cryptosporidium oocysts in water samples using a recently developed quantification method named alternately binding probe competitive PCR (ABC-PCR). The assay is based on the detection of 18S rRNA specific for Cryptosporidium oocysts. The standard curve of the ABC-PCR assay had a good fitting to a rectangular hyperbola with a correlation coefficient (R) of 0.9997. Concentrations of Cryptosporidium oocysts in real river water samples were successfully quantified by the ABC-reverse transcription (RT)-PCR assay. The quantified values by the ABC-RT-PCR assay very closely resemble those by the real-time RT-PCR assay. In addition, the quantified concentration in most water samples by the ABC-RT-PCR assay was comparable to that by conventional microscopic observation. Thus, Cryptosporidium oocysts in water samples can be accurately and specifically determined by the ABC-RT-PCR assay. As the only equipment that is needed for this end-point fluorescence assay is a simple fluorometer and a relatively inexpensive thermal cycler, this method can markedly reduce time and cost to quantify Cryptosporidium oocysts and other health-related water microorganisms.
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Affiliation(s)
- Naohiro Kishida
- Division of Water Management, Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351 0197, Japan.
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Metge DW, Harvey RW, Aiken GR, Anders R, Lincoln G, Jasperse J, Hill MC. Effects of sediment-associated extractable metals, degree of sediment grain sorting, and dissolved organic carbon upon Cryptosporidium parvum removal and transport within riverbank filtration sediments, Sonoma County, California. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:5587-5595. [PMID: 21634424 DOI: 10.1021/es200544p] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Oocysts of the protozoan pathogen Cryptosporidium parvum are of particular concern for riverbank filtration (RBF) operations because of their persistence, ubiquity, and resistance to chlorine disinfection. At the Russian River RBF site (Sonoma County, CA), transport of C. parvum oocysts and oocyst-sized (3 μm) carboxylate-modified microspheres through poorly sorted (sorting indices, σ(1), up to 3.0) and geochemically heterogeneous sediments collected between 2 and 25 m below land surface (bls) were assessed. Removal was highly sensitive to variations in both the quantity of extractable metals (mainly Fe and Al) and degree of grain sorting. In flow-through columns, there was a log-linear relationship (r(2) = 0.82 at p < 0.002) between collision efficiency (α, the probability that colloidal collisions with grain surfaces would result in attachment) and extractable metals, and a linear relationship (r(2) = 0.99 at p < 0.002) between α and σ(1). Collectively, variability in extractable metals and grain sorting accounted for ∼83% of the variability in α (at p < 0.0002) along the depth profiles. Amendments of 2.2 mg L(-1) of Russian River dissolved organic carbon (DOC) reduced α for oocysts by 4-5 fold. The highly reactive hydrophobic organic acid (HPOA) fraction was particularly effective in re-entraining sediment-attached microspheres. However, the transport-enhancing effects of the riverine DOC did not appear to penetrate very deeply into the underlying sediments, judging from high α values (∼1.0) observed for oocysts being advected through unamended sediments collected at ∼2 m bls. This study suggests that in evaluating the efficacy of RBF operations to remove oocysts, it may be necessary to consider not only the geochemical nature and size distribution of the sediment grains, but also the degrees of sediment sorting and the concentration, reactivity, and penetration of the source water DOC.
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Affiliation(s)
- David W Metge
- National Research Program, US Geological Survey, 3215 Marine Street, Boulder, Colorado 80303, United States.
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Khaldi S, Ratajczak M, Gargala G, Fournier M, Berthe T, Favennec L, Dupont JP. Intensive exploitation of a karst aquifer leads to Cryptosporidium water supply contamination. WATER RESEARCH 2011; 45:2906-2914. [PMID: 21477840 DOI: 10.1016/j.watres.2011.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 03/03/2011] [Accepted: 03/08/2011] [Indexed: 05/30/2023]
Abstract
Groundwater from karst aquifers is an important source of drinking water worldwide. Outbreaks of cryptosporidiosis linked to surface water and treated public water are regularly reported. Cryptosporidium oocysts are resistant to conventional drinking water disinfectants and are a major concern for the water industry. Here, we examined conditions associated with oocyst transport along a karstic hydrosystem, and the impact of intensive exploitation on Cryptosporidium oocyst contamination of the water supply. We studied a well-characterized karstic hydrosystem composed of a sinkhole, a spring and a wellbore. Thirty-six surface water and groundwater samples were analyzed for suspended particulate matter, turbidity, electrical conductivity, and Cryptosporidium and Giardia (oo)cyst concentrations. (Oo)cysts were identified and counted by means of solid-phase cytometry (ChemScan RDI(®)), a highly sensitive method. Cryptosporidium oocysts were detected in 78% of both surface water and groundwater samples, while Giardia cysts were found in respectively 22% and 8% of surface water and groundwater samples. Mean Cryptosporidium oocyst concentrations were 29, 13 and 4/100 L at the sinkhole, spring and wellbore, respectively. Cryptosporidium oocysts were transported from the sinkhole to the spring and the wellbore, with respective release rates of 45% and 14%, suggesting that oocysts are subject to storage and remobilization in karst conduits. Principal components analysis showed that Cryptosporidium oocyst concentrations depended on variations in hydrological forcing factors. All water samples collected during intensive exploitation contained oocysts. Control of Cryptosporidium oocyst contamination during intensive exploitation is therefore necessary to ensure drinking water quality.
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Affiliation(s)
- S Khaldi
- UMR CNRS 6143, M2C, University of Rouen, Mont-Saint-Aignan, France.
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Abstract
Food- and water-borne infections have afflicted mankind since the earliest days of human development and preceded the emergence of civilization. Despite current knowledge of microbial pathogenicity, modern methods of food production and rigorous industrial hygiene, these infections are still commonplace and exact significant health and economic tolls on human populations in all parts of the globe. This review uses data derived from new surveillance networks to survey the current epidemiology of bacterial, protozoan and viral pathogens transmitted by food and water. In addition, we will discuss clinical features of human disease caused by pathogens of current and emerging relevance.
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Recognition and prevention of hospital-associated enteric infections in the intensive care unit. Crit Care Med 2010; 38:S324-34. [PMID: 20647790 DOI: 10.1097/ccm.0b013e3181e69f05] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The objectives of this article were to review the causes and extent of hospital-associated infectious diarrhea and associated risks in the general hospital ward and intensive care unit (ICU), to compare microorganisms with similar symptoms to aid in recognition that will lead to timely and appropriate treatment and control measures, and to propose infection prevention protocols that could decrease human process errors in the ICU. This literature review describes epidemiology, comparison of microbial characteristics for potential hospital-associated enteric pathogens, diagnosis, and prevention, especially if important in the ICU, and particularly in regard to Clostridium difficile. Enteric organisms that most commonly cause hospital-associated infectious diarrhea in acute care settings and the ICU are C. difficile, rotavirus, and norovirus, although others may also be important, particularly in developing countries. To recognize and control infectious diarrhea successfully in the ICU, intensivists should be aware that epidemiology, risks, and prevention measures may differ between these microorganisms. In addition, intensivists should be ready to implement systems changes related to notification, isolation precautions and prevention, and environmental cleaning in the ICU.
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Jex AR, Gasser RB. Genetic richness and diversity in Cryptosporidium hominis and C. parvum reveals major knowledge gaps and a need for the application of "next generation" technologies--research review. Biotechnol Adv 2010; 28:17-26. [PMID: 19699288 DOI: 10.1016/j.biotechadv.2009.08.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 08/07/2009] [Accepted: 08/08/2009] [Indexed: 11/26/2022]
Abstract
Cryptosporidium species (apicomplexan protists) are a major cause of diarrhoeal disease (= cryptosporidiosis) in humans worldwide. The impact of cryptosporidiosis is also compounded by the spread of HIV/AIDS and a lack of cost-effective anti-cryptosporidial chemotherapeutics or vaccines. Mitigation of the impact of cryptosporidiosis in humans needs to focus on prevention and control strategies, built on a sound understanding of the epidemiology of Cryptosporidium species. Refined epidemiological studies rely on the use of molecular tools employing informative genetic markers. Currently, the 60-kDa glycoprotein gene (gp60) is the most suitable and widely used genetic marker for Cryptosporidium species infecting humans. Here, we undertake an analysis of all publicly-available gp60 sequence data and associated literature for C. hominis and C. parvum, and yield useful insights into the richness, diversity and distribution of genetic variants, and link these variants to human cryptosporidiosis. This global analysis reveals that, despite high genetic richness in Cryptosporidium isolates from humans, there is a surprisingly low diversity. It also highlights limited knowledge about the genetics of cryptosporidiosis in developing nations and in many animals that might act as infection sources. Clearly, there is a major need for more comprehensive studies of Cryptosporidium infecting humans and other animals in Africa and Asia. As molecular technologies improve and become affordable, future studies should utilize "next generation" sequencing and bioinformatic platforms to conduct comparative 'genome sequence surveys' to test the validity of current genetic classifications based on gp60 data. Complemented by in vitro and in vivo investigations, these biotechnological advances will also assist significantly in the search for new intervention strategies against human cryptosporidiosis.
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Affiliation(s)
- Aaron R Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria 3030, Australia.
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Water disinfection in the mountains – state of the art recommendation paper of the Union Internationale des Associations d'Alpinisme Medical Commission. Travel Med Infect Dis 2009; 7:7-14. [DOI: 10.1016/j.tmaid.2008.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2008] [Revised: 11/06/2008] [Accepted: 11/17/2008] [Indexed: 01/22/2023]
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High resolution melting-curve (HRM) analysis for the diagnosis of cryptosporidiosis in humans. Mol Cell Probes 2008; 23:10-5. [PMID: 19013516 DOI: 10.1016/j.mcp.2008.10.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 10/16/2008] [Accepted: 10/20/2008] [Indexed: 11/23/2022]
Abstract
Cryptosporidiosis of humans is an intestinal disease caused predominantly by infection with Cryptosporidium hominis or C. parvum. This disease is transmitted mainly via the faecal-oral route (water or food) and has major socioeconomic impact globally. The diagnosis and genetic characterization of the main species and population variants (also called "genotypes" and "subgenotypes") of Cryptosporidium infecting humans is central to the prevention, surveillance and control of cryptosporidiosis, particularly as there is presently no cost effective anti-cryptosporidial chemotherapeutic regimen or vaccine available. In the present study, we established a polymerase chain reaction (PCR)-coupled high resolution melting-curve (HRM) analysis method, utilizing the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker, for the diagnosis of Cryptosporidium hominis, C. parvum or C. meleagridis infection. An evaluation of the method revealed intra- and inter-assay variabilities of <1.5 and 3.5%, respectively. Cryptosporidium hominis, C. parvum and C. meleagridis were detected in 97, 44 and 2, respectively, of the 143 Cryptosporidium oocyst DNA samples originating from Australians with clinical cryptosporidiosis. The melting profiles characterized by peaks of 72.47+/-0.33 degrees C and 74.19+/-0.45 degrees C (profile 1), 72.17+/-0.32 degrees C (profile 2) and 73.33+/-0.03 degrees C (profile 3) genetically identified as C. hominis, C. parvum and C. meleagridis, respectively. In conclusion, PCR-coupled melting analysis of ITS-2 achieved the diagnosis of Cryptosporidium hominis, C. parvum or C. meleagridis infection. This approach is well suited for the rapid screening of large numbers of Cryptosporidium oocyst DNA samples and, although qualitative, is significantly less time-consuming to carry out than electrophoretic analysis and has the added advantage of data storage and analysis capabilities in silico. This method provides a useful tool for investigating the epidemiology and outbreaks of cryptosporidiosis, and could be applicable to species of Cryptosporidium other than those investigated herein.
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Jex AR, Smith HV, Monis PT, Campbell BE, Gasser RB. Cryptosporidium--biotechnological advances in the detection, diagnosis and analysis of genetic variation. Biotechnol Adv 2008; 26:304-17. [PMID: 18430539 DOI: 10.1016/j.biotechadv.2008.02.003] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Revised: 01/29/2008] [Accepted: 02/14/2008] [Indexed: 11/19/2022]
Abstract
Cryptosporidiosis is predominantly a gastrointestinal disease of humans and other animals, caused by various species of protozoan parasites representing the genus Cryptosporidium. This disease, transmitted mainly via the faecal-oral route (in water or food), is of major socioeconomic importance worldwide. The diagnosis and genetic characterization of the different species and population variants (usually recognised as "genotypes" or "subgenotypes") of Cryptosporidium is central to the prevention, surveillance and control of cryptosporidiosis, particularly given that there is presently no broadly applicable treatment regimen for this disease. Although traditional phenotypic techniques have had major limitations in the specific diagnosis of cryptosporidiosis, there have been major advances in the development of molecular analytical and diagnostic tools. This article provides a concise account of Cryptosporidium and cryptosporidiosis, and focuses mainly on recent advances in nucleic acid-based approaches for the diagnosis of cryptosporidiosis and analysis of genetic variation within and among species of Cryptosporidium. These advances represent a significant step toward an improved understanding of the epidemiology as well as the prevention and control of cryptosporidiosis.
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Affiliation(s)
- A R Jex
- Department of Veterinary Science, The University of Melbourne, Werribee, Victoria, Australia.
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Jex AR, Ryan UM, Ng J, Campbell BE, Xiao L, Stevens M, Gasser RB. Specific and genotypic identification of Cryptosporidium from a broad range of host species by nonisotopic SSCP analysis of nuclear ribosomal DNA. Electrophoresis 2007; 28:2818-25. [PMID: 17702061 DOI: 10.1002/elps.200600772] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The accurate identification of Cryptosporidium (Protozoa: Apicomplexa) species and genotypes is central to the understanding of the transmission and to the diagnosis and control of cryptosporidiosis. In this study, we demonstrate the effectiveness of nonisotopic SSCP analysis of a approximately 300 bp region of the small subunit (pSSU) of ribosomal DNA for the specific identification of and delineation among 18 different Cryptosporidium species and genotypes from a wide range of hosts. This mutation scanning approach allowed the rapid and reliable differentiation between species/genotypes differing by as little as 1.3% in the pSSU sequence, with the capacity to detect point mutations. The present findings confirm the usefulness of this tool for the rapid genetic screening of Cryptosporidium samples from any host species, providing a foundation for detailed systematic, epidemiological and ecological studies. Although applied herein to pSSU, this low cost approach should be applicable to a wide range of genetic loci for population genetic investigations of Cryptosporidium.
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Affiliation(s)
- Aaron R Jex
- Department of Veterinary Science, The University of Melbourne, Victoria, Australia.
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Maruyama H, Tanaka M, Hashimoto M, Inoue M, Sasahara T. The suppressive effect of Mekabu fucoidan on an attachment of Cryptosporidium parvum oocysts to the intestinal epithelial cells in neonatal mice. Life Sci 2007; 80:775-81. [PMID: 17157323 DOI: 10.1016/j.lfs.2006.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Revised: 10/06/2006] [Accepted: 11/03/2006] [Indexed: 11/24/2022]
Abstract
The present study was done to investigate the effects of fucoidan and de-sulfated fucoidan isolated from the sporophyll of Undaria pinnatifida on the C. parvum adhesion to the cultured human intestinal cells and on the C. parvum infection in neonatal mice. The C. parvum adhesion to human Intestinal 407 cells was significantly suppressed by a low dose (1 micro g/ml) of Mekabu fucoidan (1 micro g/ml) (approx. 20.5 oocysts, p<0.0001), but not by de-sulfated fucoidan (approx. 138.2 oocysts), as compared with that (approx. 121.0 oocysts) of phosphate-buffered saline (PBS). The in vivo experiments presented here revealed that C. parvum oocysts in the fucoidan-treated mice was reduced nearly one fifth (approx. 5.4x10(4) oocysts, p<0.02) of the total number of oocysts (approx. 3.0x10(5)) in mice treated with PBS, but no significant effect of de-sulfated fucoidan was observed. These results show that (i) fucoidan effectively inhibits the growth of C. parvum in mice; and (ii) the ester sulfate of fucoidan is an active site to prevent the adhesion of C. parvum to the intestinal epithelial cells. Finally, we concluded that fucoidan might inhibit cryptosporidiosis through the direct binding of fucoidan to the C. parvum-derived functional mediators in the intestinal epithelial cells in neonatal mice.
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Affiliation(s)
- Hiroko Maruyama
- Department of Pathology, School of Allied Health Sciences, Kitasato University, Kitasato 1-15-1, Sagamihara, Kanagawa, Japan.
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Lepesteur M, McComb AJ, Moore SA. Do we all face the same risk when bathing in the estuary? WATER RESEARCH 2006; 40:2787-95. [PMID: 16814839 PMCID: PMC7172320 DOI: 10.1016/j.watres.2006.04.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Revised: 03/07/2006] [Accepted: 04/24/2006] [Indexed: 05/10/2023]
Abstract
With the development of coastal areas, microbial water quality is an emerging public health issue though few studies have focused on risks according to age. A survey was undertaken of faecal contamination in relation to recreational activities in the Peel Harvey estuarine system, Western Australia. Levels of exposure to contaminated water were estimated though social surveys. Follow-up was also conducted to estimate the incidence of disease associated with bathing in the estuary. Pathogen levels exceeded the guideline values recommended by the World Health Organisation (WHO) at most locations throughout the year. The social survey provided information about exposure of the population in age groups. Only 31% of the recreational users belonged to the healthy adult group upon which the WHO quantitative microbial risk assessment model is based. A correlation was established between microbial water quality and incidence of respiratory diseases for children as well as for adults. Exposure to recreational water increased the incidence of respiratory illnesses for the whole population almost by a factor 2. Behaviours which resulted in increased exposures were associated with increased incidence of illnesses were observed, particularly among children aged 11-15 yr, who exhibited the highest odd ratio (OR 4.23 [2.44-6.01], CI 95%, p=0.05). There is a need for combining epidemiology studies with risk assessment processes and complementing them with social surveys for understanding the risk of recreational activities to public health.
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Affiliation(s)
- Muriel Lepesteur
- School of Environmental Science, Murdoch University, Murdoch, WA 6150, Australia.
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Insulander M, Lebbad M, Stenström TA, Svenungsson B. An outbreak of cryptosporidiosis associated with exposure to swimming pool water. ACTA ACUST UNITED AC 2005; 37:354-60. [PMID: 16051572 DOI: 10.1080/00365540410021072] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
An outbreak of cryptosporidiosis among visitors to a public swimming pool occurred in the late summer of 2002. We performed a retrospective cohort study, including 3 cohorts, A) 178 school-children who visited the pool on a single occasion, B) 263 arbitrarily chosen school children, aged 6-12 y, and their household members, living within the municipality where the outbreak occurred, and C) an additional 28 individuals with laboratory confirmed cryptosporidiosis. The outbreak lasted 4 weeks and affected an estimated 800-1000 individuals. The primary attack rate was 40-50%. The median incubation period was 5 d (range 2-13 d). The secondary attack rate was 8-10%. Diarrhoea was reported by 93% of the patients, abdominal pain 89%, nausea 73%, and fever 40%. Fifty-four percent had<5 loose stools and 20% had>10 loose stools per d. The duration of symptoms was 4-10 d for 52% and>10 d for 34% of the cases. This is the first reported outbreak of pool associated cryptosporidiosis in Sweden and emphasizes the importance of proper control routines of swimming pools with continuous assessment of the quality of the water sources and filtration processes.
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Affiliation(s)
- Mona Insulander
- Department of Communicable Disease Control and Prevention, Karolinska University Hospital, Stockholm, Sweden.
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Craun GF, Calderon RL, Craun MF. Outbreaks associated with recreational water in the United States. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2005; 15:243-62. [PMID: 16175741 DOI: 10.1080/09603120500155716] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
In this article, we review the causes of outbreaks associated with recreational water during 1971-2000. A bacterial or protozoan etiology was identified in three-quarters of the outbreaks; 23% of the outbreaks were of undetermined etiology. The most frequently identified agents were Cryptosporidium (15%), Pseudomonas (14%), Shigella (13%), Naegleria (11%), Giardia (6%), and toxigenic E. coli (6%). Outbreaks attributed to Shigella, E. coli O157:H7, and Naegleria were primarily associated with swimming in fresh waters such as lakes, ponds, and rivers. In contrast, outbreaks caused by Cryptosporidium and Giardia were primarily associated with treated water in swimming and wading pools. Important sources of contamination for both treated and untreated recreational waters were the bathers themselves. Contamination from sewage discharges and wild or domestic animals were also important sources for untreated waters. Contributing factors in swimming-pool outbreaks were inadequate attention to maintenance, operation, disinfection, and filtration. Although not all waterborne outbreaks are recognized nor reported, the national surveillance of these outbreaks has helped identify important sources of contamination of recreational waters and the etiologic agents. This information can affect prevention recommendations and research priorities that may lead to improved water quality guidelines.
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Affiliation(s)
- Gunther F Craun
- Gunther F. Craun & Associates, 101 West Frederick Street, Suite 205, Staunton, VA 24401, USA.
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Abstract
Of 155 species of mammals reported to be infected with Cryptosporidium parvum or C. parvum-like organisms most animals are found in the Orders Artiodactyla, Primates, and Rodentia. Because Cryptosporidium from most of these animals have been identified by oocyst morphology alone with little or no host specificity and/or molecular data to support identification it is not known how many of the reported isolates are actually C. parvum or other species. Cryptosporidiosis is a cause of morbidity and mortality in animals and humans, resulting primarily in diarrhea, and resulting in the most severe infections in immune-compromised individuals. Of 15 named species of Cryptosporidium infectious for nonhuman vertebrate hosts C. baileyi, C. canis, C. felis, C. hominis, C. meleagridis, C. muris, and C. parvum have been reported to also infect humans. Humans are the primary hosts for C. hominis, and except for C. parvum, which is widespread amongst nonhuman hosts and is the most frequently reported zoonotic species, the remaining species have been reported primarily in immunocompromised humans. The oocyst stage can remain infective under cool, moist conditions for many months, especially where water temperatures in rivers, lakes, and ponds remain low but above freezing. Surveys of surface water, groundwater, estuaries, and seawater have dispelled the assumption that Cryptosporidium oocysts are present infrequently and in geographically isolated locations. Numerous reports of outbreaks of cryptosporidiosis related to drinking water in North America, the UK, and Japan, where detection methods are in place, indicate that water is a major vehicle for transmission of cryptosporidiosis.
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Affiliation(s)
- Ronald Fayer
- United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA.
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Abstract
Cryptosporidium was first recognized in humans in 1976 and came to prominence in the 1980s and 1990s as a cause of severe diarrheal illness in patients with AIDS. Its hardy, chlorine-resistant oocysts, tiny size, low infectious dose, fully infectious development when shed and zoonotic potential make it a threat in drinking and recreational water, contaminated food, day care centers, hospitals, and in persons with exposure to animals or unsanitary conditions, with potentially huge, long-term impact in malnourished children, as reviewed herein.
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Affiliation(s)
- Rebecca A Dillingham
- Division of Geographic and International Medicine, University of Virginia School of Medicine, Health Sciences Center, P.O. Box 801379, Charlottesville, VA 22908-1379, USA
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