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Hassan EM, Örmeci B, DeRosa MC, Dixon BR, Sattar SA, Iqbal A. A review of Cryptosporidium spp. and their detection in water. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 83:1-25. [PMID: 33460403 DOI: 10.2166/wst.2020.515] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cryptosporidium spp. are one of the most important waterborne pathogens worldwide and a leading cause of mortality from waterborne gastrointestinal diseases. Detection of Cryptosporidium spp. in water can be very challenging due to their low numbers and the complexity of the water matrix. This review describes the biology of Cryptosporidium spp. and current methods used in their detection with a focus on C. parvum and C. hominis. Among the methods discussed and compared are microscopy, immunology-based methods using monoclonal antibodies, molecular methods including PCR (polymerase chain reaction)-based assays, and emerging aptamer-based methods. These methods have different capabilities and limitations, but one common challenge is the need for better sensitivity and specificity, particularly in the presence of contaminants. The application of DNA aptamers in the detection of Cryptosporidium spp. oocysts shows promise in overcoming these challenges, and there will likely be significant developments in aptamer-based sensors in the near future.
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Affiliation(s)
- Eman M Hassan
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail:
| | - Banu Örmeci
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail:
| | - Maria C DeRosa
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Canada, K1S 5B6
| | - Brent R Dixon
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, Canada, K1A 0K9
| | - Syed A Sattar
- Department of Civil and Environmental Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, K1S 5B6, Canada E-mail: ; C.R.E.M. Co Labs, Units 1-2, 3403 American Drive, Mississauga, ON, Canada, L4V 1T4
| | - Asma Iqbal
- C.R.E.M. Co Labs, Units 1-2, 3403 American Drive, Mississauga, ON, Canada, L4V 1T4
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Toebe K. Whole cell hybridisation for monitoring harmful marine microalgae. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2013; 20:6816-6823. [PMID: 23835584 DOI: 10.1007/s11356-012-1416-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 12/09/2012] [Indexed: 06/02/2023]
Abstract
Fluorescence in situ hybridisation (FISH) is a powerful molecular biological tool to detect and enumerate harmful microorganism in the marine environment. Different FISH methods are available, and especially in combination with automated counting techniques, the potential for a routine monitoring of harmful marine microalgae is attainable. Various oligonucleotide probes are developed for detecting harmful microalgae. However, FISH-based methods are not yet regularly included in monitoring programmes tracking the presence of harmful marine microalgae. A limitation factor of the FISH technique is the currently available number of suited fluorochromes attached to the FISH probes to detect various harmful species in one environmental sample at a time. However, coupled automated techniques, like flow cytometry or solid-phase cytometry, can facilitate the analysis of numerous field samples and help to overcome this drawback. A great benefit of FISH in contrast to other molecular biological detection methods for harmful marine microalgae is the direct visualisation of the hybridised target cells, which are not permitted in cell free formats, like DNA depending analysis methods. Therefore, an additional validation of the FISH-generated results is simultaneously given.
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Affiliation(s)
- Kerstin Toebe
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany,
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Weigum SE, Castellanos-Gonzalez A, White AC, Richards-Kortum R. Amplification-free detection of Cryptosporidium parvum nucleic acids with the use of DNA/RNA-directed gold nanoparticle assemblies. J Parasitol 2013; 99:923-6. [PMID: 23617738 DOI: 10.1645/12-132.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This study describes the development and evaluation of an amplification-free molecular assay for detection of Cryptosporidium parvum oocysts. The assay employed a pair of oligonucleotide-functionalized gold nanoparticle (AuNP) probes that were complementary to adjacent sequences on C. parvum 18s rRNA. Hybridization of the probes to the target RNA resulted in the assembly of AuNPs into target-linked networks, which were detected both visibly and spectroscopically, by a redshift in the wavelength of light scattered by the gold nanoparticles. The limit of detection was between 4 × 10(5) and 4 × 10(6) copies of RNA per microliter reaction mix, when a short synthetic target or full-length in vitro transcribed target was employed. With total nucleic acids purified from C. parvum oocysts spiked into 100-mg stool, as few as 670 oocysts/μl reaction mix were detected. The ability to detect the nucleic acids of C. parvum oocysts in stool, without the need for complex amplification, offers unique advantages for such AuNP aggregation assays to be extended toward use in resource-limited settings where protozoan detection is needed most.
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Affiliation(s)
- S E Weigum
- Department of Biology, Texas State University, San Marcos, Texas 78666
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Double-color fluorescence in situ hybridization (FISH) for the detection of Bacillus anthracis spores in environmental samples with a novel permeabilization protocol. J Microbiol Methods 2013; 93:177-84. [PMID: 23523967 DOI: 10.1016/j.mimet.2013.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 03/10/2013] [Accepted: 03/10/2013] [Indexed: 11/22/2022]
Abstract
For anti-bioterrorism measures against the use of Bacillus anthracis, a double-color fluorescence in situ hybridization (FISH) is proposed, for the rapid and specific detection of B. anthracis. The probes were designed based on the differences in 16S and 23S rRNA genes of B. cereus group. A new permeabilization protocol was developed to enhance the permeability of FISH probes into B. anthracis spores. The highest detection rate (90.8 ± 0.69) of B. anthracis spores by FISH was obtained with successive incubation steps with 50% ethanol at 80 °C, a mixture of SDS/DTT solution (10mg/ml SDS, 50mM DTT) at 65 °C and finally in a lysozyme solution (20mg/ml) at 37 °C for 30 min each. This protocol was evaluated for the detection of B. anthracis spores in soil and air samples after adding formalin-fixed spores at different densities. The results have proven the success of double-color FISH in detecting B. anthracis spores in air samples in the range of 10(3) spores/m(3) and above. Conversely, for detecting B. anthracis spores in a soil sample, the lowest detection limit was found to be 10(7) spores/g dry soils. These results confirm the applicability of the developed permeabilization protocol, combined with the double-color FISH technique in specific detection of B. anthracis in soil and air samples.
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Lawson TS, Connally RE, Vemulpad S, Piper JA. Optimization of a two-step permeabilization fluorescence in situ hybridization (FISH) assay for the detection of Staphylococcus aureus. J Clin Lab Anal 2012; 25:359-65. [PMID: 21919072 DOI: 10.1002/jcla.20486] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Aspects of the fluorescence in situ hybridization (FISH) method for the detection of clinically important bacteria, such as Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli, were investigated for optimization. METHODS Various approaches to optimizing the FISH procedure were taken and different methods were compared. To save time, hybridization and washing buffers were prepared beforehand and stored at -20 °C and mixed to their final formamide and NaCl concentrations just before use. The use of 50-ml tubes for hybridization incubation reduced drying out, reagent wastage, and reaction times. RESULTS A two-step permeabilization FISH assay was developed that used phosphate-buffered saline as a buffer for lysostaphin. It could detect bacteria with DNA probes conjugated to fluorophores with a higher signal intensity and the less expensive biotinylated DNA probes with minimal cell lysis in 1 hr. CONCLUSIONS The two-step assay might be used when the FISH signal is weak, bacterial numbers are low or if there is a need to use other reporter molecules.
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Affiliation(s)
- Thomas S Lawson
- Macquarie University, Faculty of Science, Sydney, New South Wales, Australia.
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Morin-Adeline V, Foster C, Šlapeta J. Identification of Chromera velia by fluorescence in situ hybridization. FEMS Microbiol Lett 2012; 328:144-9. [DOI: 10.1111/j.1574-6968.2011.02489.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/19/2011] [Accepted: 12/19/2011] [Indexed: 11/26/2022] Open
Affiliation(s)
| | - Christie Foster
- Faculty of Veterinary Science; University of Sydney; Sydney; NSW; Australia
| | - Jan Šlapeta
- Faculty of Veterinary Science; University of Sydney; Sydney; NSW; Australia
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Luquin E, Pérez-Lorenzo E, Aymerich MS, Mengual E. Two-color fluorescence labeling in acrolein-fixed brain tissue. J Histochem Cytochem 2010; 58:359-68. [PMID: 20051381 DOI: 10.1369/jhc.2009.954495] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acrolein is a potent fixative that provides both excellent preservation of ultrastructural morphology and retention of antigenicity, thus it is frequently used for immunocytochemical detection of antigens at the electron microscopic level. However, acrolein is not commonly used for fluorescence microscopy because of concerns about possible autofluorescence and destruction of the luminosity of fluorescent dyes. Here we describe a simple protocol that allows fine visualization of two fluorescent markers in 40-mum sections from acrolein-perfused rat brain. Autofluorescence was removed by pretreatment with 1% sodium borohydride for 30 min, and subsequent incubation in a 50% ethanol solution containing 0.3% hydrogen peroxide enhanced fluorescence labeling. Thus, fluorescence labeling can be used for high-quality detection of markers in tissue perfused with acrolein. Furthermore, adjacent acrolein-fixed sections from a single experiment can be processed to produce high-quality results for electron microscopy or fluorescence labeling.
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Affiliation(s)
- Esther Luquin
- Center for Applied Medical Research (CIMA), Area de Neurociencias, Universidad de Navarra, Pamplona, Spain
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Robertson LJ, Gjerde B. Development and use of a pepsin digestion method for analysis of shellfish for Cryptosporidium oocysts and Giardia cysts. J Food Prot 2008; 71:959-66. [PMID: 18522030 DOI: 10.4315/0362-028x-71.5.959] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Investigation of shellfish for Cryptosporidium oocysts and Giardia cysts is of public health interest because shellfish may concentrate these pathogens in their bodies, and because shellfish are frequently eaten raw or lightly cooked. To date, the methods used for the analysis of shellfish for these parasites are based on those originally designed for water concentrates or fecal samples; the reported recovery efficiencies are frequently relatively low and the amount of sample examined is small. Here, we describe the development and use of a pepsin digestion method for analyzing shellfish samples for these parasites. The conditions of the isolation method did not affect subsequent parasite detection by immunofluorescent antibody test, and allowed examination of 3-g samples of shellfish homogenate, with recovery efficiencies from blue mussel homogenates of between 70 and 80%, and similar recoveries from horse mussel and oyster homogenates. Although exposure of the parasites to the conditions used in the technique affected their viability, as assessed by vital dyes, the maximum reduction in viability after 1-h incubation in digestion solution was 20%. In a preliminary survey of shellfish collected from the Norwegian coast, Cryptosporidium oocysts were detected in blue mussel homogenates in 6 (43%) of 14 batches and Giardia cysts in 7 (50%) of these batches. However, this relatively high occurrence, compared with other surveys, may be due to the higher recovery efficiency of the new method, and the relatively large sample size analyzed. A more comprehensive study of the occurrence of these parasites in shellfish would be of pertinence to the Norwegian shellfish industry.
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Affiliation(s)
- L J Robertson
- Parasitology Laboratory, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, 0033 Oslo, Norway.
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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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Montemayor M, Galofré B, Ribas F, Lucena F. Comparative study between two laser scanning cytometers and epifluorescence microscopy for the detection ofCryptosporidium oocysts in water. Cytometry A 2007; 71:163-9. [PMID: 17279570 DOI: 10.1002/cyto.a.20373] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Cryptosporidium detection in water and environmental samples has increased during the last years, largely due to an increase in the number of reported waterborne outbreaks of cryptosporidiosis and the implementation of new regulations about Cryptosporidium monitoring in water supplies. The aim of this study was to validate and compare the capacity of two laser scanning cytometers commercially available (LSC and ChemScanRDI), against manual microscopic enumeration of Cryptosporidium oocysts in surface water and reference material samples. METHODS Reference material and surface water samples were analysed by two laser scanning cytometers methodologies and by manual epifluorescence microscopy. Two mAbs from commercial suppliers were used to evaluate background reduction. RESULTS Highly significant correlations were obtain between both cytometers (R(2) = 0.99) and with manual microscopy (R(2) = 0.98), showing that oocysts counts made by cytometers were equivalent to those obtained with conventional methods. We observed a variability in oocysts counts when different antibodies where used with laser scanning cytometers and manual microscopy. CONCLUSIONS This study showed the efficacy of the laser scanning technology (LSC and ChemScanRDI), as an automated and a more standardized alternative to manual epifluorescence microscopy examination, for Cryptosporidium detection in water samples. High quality antibodies are needed for automated enumeration as well as for manual microscope observations.
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Affiliation(s)
- Michel Montemayor
- Department of Microbiology, University of Barcelona, Barcelona, Spain
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Chvala S, Fragner K, Hackl R, Hess M, Weissenböck H. Cryptosporidium infection in domestic geese (Anser anser f. domestica) detected by in-situ hybridization. J Comp Pathol 2006; 134:211-8. [PMID: 16615936 DOI: 10.1016/j.jcpa.2005.11.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Accepted: 11/03/2005] [Indexed: 11/17/2022]
Abstract
An in-situ hybridization (ISH) procedure was developed for the detection of Cryptosporidium sp. in paraffin wax-embedded tissues with a digoxigenin-labelled probe targeting the 18S rRNA. This technique was used in addition to traditional methods, such as haematoxylin and eosin staining, periodic acid-Schiff reaction, transmission electron microscopy and the polymerase chain reaction, to examine the bursa of Fabricius (BF), conjunctiva and other tissues from 20 domestic geese aged 16-36 days for the presence of cryptosporidia. Positive signals were found to a moderate or marked extent in both conjunctival samples (89%) and BF samples (88%) but not in other tissues. Sequencing of the PCR amplification product revealed identity with Cryptosporidium baileyi. The infected geese showed no clinical signs and only scanty histological lesions. These results confirm reports showing that young waterfowl are especially vulnerable to cryptosporidium infection and indicate that the BF and conjunctiva are the preferred sites for the presence of the protozoon. ISH proved a good method for detecting and identifying even small numbers of cryptosporidia in tissue sections.
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Affiliation(s)
- S Chvala
- Department of Pathobiology, Institute of Pathology and Forensic Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria
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Miller WA, Gardner IA, Atwill ER, Leutenegger CM, Miller MA, Hedrick RP, Melli AC, Barnes NM, Conrad PA. Evaluation of methods for improved detection of Cryptosporidium spp. in mussels (Mytilus californianus). J Microbiol Methods 2006; 65:367-79. [PMID: 16181691 DOI: 10.1016/j.mimet.2005.08.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Revised: 08/04/2005] [Accepted: 08/16/2005] [Indexed: 11/24/2022]
Abstract
Bivalve molluscs concentrate Cryptosporidium oocysts from fecal-contaminated aquatic environments and are therefore useful in monitoring water quality. A real-time TaqMan polymerase chain reaction (PCR) system was developed to allow for large scale quantitative detection of Cryptosporidium spp. in mussels (Mytilus californianus). The TaqMan sensitivity and specificity were compared to conventional PCR and direct immunofluorescent antibody (DFA) assays, with and without immunomagnetic separation (IMS), to identify the best method for parasite detection in mussel hemolymph, gill washings and digestive glands. TaqMan PCR and two conventional PCR systems all detected 1 or more oocysts spiked into 1 ml hemolymph samples. The minimum oocyst detection limit in spiked 5 ml gill wash and 1 g digestive gland samples tested by TaqMan PCR and DFA was 100 oocysts, with a 1 log(10) improvement when samples were first processed by IMS. For tank exposed mussels, TaqMan and conventional PCR methods detected C. parvum in <5% of hemolymph samples. No gill washings from these same mussels tested positive by TaqMan PCR or DFA analysis even with IMS concentration. All methods detected the highest prevalence of C. parvum-positive samples in digestive gland tissues of exposed mussels. In conclusion, the most sensitive method for the detection of C. parvum in oocyst-exposed mussels was IMS concentration with DFA detection: 80% of individual and 100% of pooled digestive gland samples tested positive. TaqMan PCR was comparable to conventional PCR for detection of C. parvum oocysts in mussels and additionally allowed for automated testing, high throughput, and semi-quantitative results.
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Affiliation(s)
- Woutrina A Miller
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, 95616, USA
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Ferrari BC, Tujula N, Stoner K, Kjelleberg S. Catalyzed reporter deposition-fluorescence in situ hybridization allows for enrichment-independent detection of microcolony-forming soil bacteria. Appl Environ Microbiol 2006; 72:918-22. [PMID: 16391135 PMCID: PMC1352241 DOI: 10.1128/aem.72.1.918-922.2006] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Advances in the growth of hitherto unculturable soil bacteria have emphasized the requirement for rapid bacterial identification methods. Due to the slow-growing strategy of microcolony-forming soil bacteria, successful fluorescence in situ hybridization (FISH) requires an rRNA enrichment step for visualization. In this study, catalyzed reporter deposition (CARD)-FISH was employed as an alternative method to rRNA enhancement and was found to be superior to conventional FISH for the detection of microcolonies that are cultivated by using the soil substrate membrane system. CARD-FISH enabled real-time identification of oligophilic microcolony-forming soil bacteria without the requirement for enrichment on complex media and the associated shifts in community composition.
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Affiliation(s)
- Belinda C Ferrari
- Department of Chemistry and Biomolecular Sciences, Division of Environmental and Life Sciences, Macquarie University, Sydney, NSW 2109, Australia.
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Davies CM, Altavilla N, Krogh M, Ferguson CM, Deere DA, Ashbolt NJ. Environmental inactivation of Cryptosporidium oocysts in catchment soils. J Appl Microbiol 2005; 98:308-17. [PMID: 15659185 DOI: 10.1111/j.1365-2672.2004.02459.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To generate field-relevant inactivation rates for Cryptosporidium oocysts in soil that may serve as parameter values in models to predict the terrestrial fate and transport of oocysts in catchments. METHODS AND RESULTS The inactivation of Cryptosporidium oocysts in closed soil microcosms over time was monitored using fluorescence in situ hybridization (FISH) as an estimate of oocyst 'viability'. Inactivation rates for Cryptosporidium in two soils were determined under a range of temperature, moisture and biotic status regimes. Temperature and soil type emerged as significantly influential factors (P < 0.05) for Cryptosporidium inactivation. In particular, temperatures as high as 35 degrees C may result in enhanced inactivation. CONCLUSIONS When modelling the fate of Cryptosporidium oocysts in catchment soils, the use of inactivation rates that are appropriate for the specific catchment climate and soil types is essential. FISH was considered cost-effective and appropriate for determining oocyst inactivation rates in soil. SIGNIFICANCE AND IMPACT OF THE STUDY Previous models for predicting the fate of pathogens in catchments have either made nonvalidated assumptions regarding inactivation of Cryptosporidium in the terrestrial environment or have not considered it at all. Field-relevant inactivation data are presented, with significant implications for the management of catchments in warm temperate and tropical environments.
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Affiliation(s)
- C M Davies
- Centre for Water and Waste Technology, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW, Australia.
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Szostakowska B, Kruminis-Lozowska W, Racewicz M, Knight R, Tamang L, Myjak P, Graczyk TK. Cryptosporidium parvum and Giardia lamblia recovered from flies on a cattle farm and in a landfill. Appl Environ Microbiol 2004; 70:3742-4. [PMID: 15184182 PMCID: PMC427780 DOI: 10.1128/aem.70.6.3742-3744.2004] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 03/04/2004] [Indexed: 11/20/2022] Open
Abstract
Filth flies associated with a cattle barn and a municipal landfill were tested positive by combined immunofluorescent antibody and fluorescent in situ hybridization for Cryptosporidium parvum and Giardia lamblia on their exoskeletons and in their guts. More pathogens were carried by flies from the cattle barn than from the landfill; 81% of C. parvum and 84% of G. lamblia pathogens were presumptively viable.
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Affiliation(s)
- Beata Szostakowska
- Department of Tropical Parasitology, Interfaculty Institute of Maritime and Tropical Medicine, Medical University of Gdansk, 81-519 Gdynia, Poland
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Yokouchi H, Takeyama H, Miyashita H, Maruyama T, Matsunaga T. In situ identification of symbiotic dinoflagellates, the genus Symbiodinium with fluorescence-labeled rRNA-targeted oligonucleotide probes. J Microbiol Methods 2003; 53:327-34. [PMID: 12689710 DOI: 10.1016/s0167-7012(02)00250-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Fluorescence in situ hybridization has been used for the identification and analysis of populations of the dinoflagellate Symbiodinium that lives symbiotically in marine invertebrates. Conditions for in situ hybridization of Symbiodinium were optimized and used to identify the clade to which the isolate belongs using specific probes. The optimized in situ hybridization procedure used a combination of chlorophyll removal and permeabilization with hot ethanol. Incubation of the cells in 50% ethanol at 80 degrees C for 20 min rendered the cell wall permeable to Cy3-labeled probes. Symbiodinium clade-specific probes were designed based on 18S rRNA sequences. Symbiodinium A, B and C were distinguished by in situ hybridization with the specific probes SymA, SymB and SymC, respectively. The hybridization results using clade-specific probes corresponded with results obtained using restriction fragment length polymorphism (RFLP) analysis. Symbiodinium isolated from jellyfish Cassiopea sp. and sea anemone Aiptasia sp. were classified as belonging to clades A and B using the FISH procedure established in this study.
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Affiliation(s)
- Hiroko Yokouchi
- Department of Biotechnology, Tokyo University of Agriculture and Technology 2-24-16, Naka-cho, Koganei, Japan
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Fang Q, Brockmann S, Botzenhart K, Wiedenmann A. Improved detection of Salmonella spp. in foods by fluorescent in situ hybridization with 23S rRNA probes: a comparison with conventional culture methods. J Food Prot 2003; 66:723-31. [PMID: 12747677 DOI: 10.4315/0362-028x-66.5.723] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report describes a new technique for the detection and identification of Salmonella species in food with the use of fluorescent in situ hybridization (FISH) with 23S rRNA-targeted oligonucleotide probes. Two species-specific 23S rRNA-targeted oligonucleotide probes (Sal-1 and Sal-3) were selected, and one (Sal-544) was newly designed. The relative specificities of these probes were compared with those of bacterial 23S rRNA sequences from the GenBank database and tested by in situ hybridization with bacterial cell smears of pure cultures. Fifty-one tested reference strains of Salmonella serovars belonging to subspecies I (enterica) hybridized with these probes. No cross-reactions with 46 other strains of the family Enterobacteriaceae or with another 14 bacterial strains from other families were observed. Storage of a Salmonella Panama test strain under various environmental conditions (2, 5, and 15% NaC1; -20 degrees C, 4 degrees C, and room temperature; pHs of 3.3 to 7.4) did not adversely affect the FISH method. No matrix effects were observed with 18 different kinds of foods. FISH was able to detect Salmonella spp. in 52 (probe Sal-1), 56 (probe Sal-3), and 35 (probe Sal-544) of 225 naturally contaminated food samples after 16 h of incubation in a preenrichment broth. When conventional culture and detection methods were used, Salmonella could be isolated from only 30 of these 225 samples. In contrast, FISH failed to identify Salmonella in only two of the culture-positive samples when Sal-1 and Sal-3 were used and in only three of the culture-positive samples when Sal-544 was used.
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Affiliation(s)
- Qiang Fang
- Eberhard Karls-University of Tübingen, Institute of General and Environmental Hygiene, Wilhelmstrasse 31, 72074 Tuebingen, Germany
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Ferrari BC, Veal D. Analysis-only detection of Giardia by combining immunomagnetic separation and two-color flow cytometry. Cytometry A 2003; 51:79-86. [PMID: 12541282 DOI: 10.1002/cyto.a.10009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Giardia is a protozoan parasite of concern to water utilities. Giardia detection relies on cyst isolation and confirmation with the use of fluorescence microscopy. It is of interest to develop a flow cytometric (FCM) method that reliably detects one cyst in 10 L of water. To date all available antibodies have targeted the same epitope on the cyst wall. To achieve a reliable method, two independent probes are required. METHODS Giardia cysts were spiked into a backwash water sample with and without prior hybridization to peptide nucleic acid (PNA) probes. Immunomagnetic separation (IMS) as a pre-enrichment step was compared with filtration of the water sample. Cysts were recovered with two-color FCM. Those cysts hybridized with PNA and fluorescein isothiocyanate (FITC) were dual stained with monoclonal antibody (mAb) conjugated to phycoerythrin (PE); those not hybridized to PNA were dual stained with mAb-FITC and mAb-PE. RESULTS A fourfold increase in fluorescent signal intensity was obtained when combining the mAb-PE and PNA probe compared with two-color antibody staining. When combined with IMS, Giardia was successfully identified by FCM, with no false positives detected. CONCLUSIONS Analysis-only FCM detection of Giardia in water is feasible. Further method development incorporating PNA probe hybridization after IMS is necessary.
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Affiliation(s)
- Belinda C Ferrari
- Centre for Fluorometric Applications in Biotechnology, School of Biological Sciences, Macquarie University, Sydney, Australia.
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Graczyk TK, Bosco-Nizeyi J, Ssebide B, Thompson RCA, Read C, Cranfield MR. Anthropozoonotic Giardia duodenalis genotype (assemblage) a infections in habitats of free-ranging human-habituated gorillas, Uganda. J Parasitol 2002; 88:905-9. [PMID: 12435128 DOI: 10.1645/0022-3395(2002)088[0905:agdgaa]2.0.co;2] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
To facilitate ecotourism and research, free-ranging mountain gorillas of Uganda have been habituated to humans. Testing of fecal samples of gorillas (n = 100), people sharing gorilla habitats (n = 62). and local pre- and postweaned cattle (n = 50) having access to these habitats with fluorescein isothiocyanate-conjugated monoclonal antibodies revealed Giardia duodenalis cysts at prevalences of 2, 5, and 10%, respectively. The identification of G. duodenalis was confirmed by fluorescent in situ hybridization with 2 species-specific 18-bp oligonucleotide probes conjugated to hexachlorinated 6-carboxyfluorescein. The mean pathogen concentration was 2.5, 2.8, and 0.2 x 10(4) cysts/g of the gorilla, people, and cattle feces, respectively. All cyst isolates aligned with genotype (assemblage) A, as confirmed by polymerase chain reaction amplification and sequencing of a 130-bp region near the 5' end of the small subunit-ribosomal RNA gene. A single genotype (assemblage) A recovered from 3 genetically distant but geographically united host groups indicates anthropozoonotic transmission of G. duodenalis. A large percentage of the local community does not follow park regulations regarding the disposal of their fecal waste, as self-reported in a questionnaire. This genotype may have been introduced into gorilla populations through habituation activities and may have then been sustained in their habitats by anthropozoonotic transmission.
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Affiliation(s)
- Thaddeus K Graczyk
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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Abstract
Molecular techniques are increasingly being used to study the ecology of a variety of organisms. These techniques represent important tools for the study of the systematics, population genetics, biogeography and ecology of parasites. Here, we review the techniques that have been employed to study the ecology and systematics of parasites (including bacteria and viruses). Particular emphasis is placed on the techniques of isoenzyme electrophoresis, in situ hybridisation and nucleic acid amplification to characterise parasite/microbial communities. The application of these techniques will be exemplified using ticks, bacterial endosymbionts and parasitic protozoa.
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Affiliation(s)
- Paul T Monis
- Microbiology Unit, Australian Water Quality Centre, Private Mail Bag 3, South Australia 5108, Salisbury, Australia.
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21
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Dorsch MR, Veal DA. Oligonucleotide probes for specific detection of Giardia lamblia cysts by fluorescent in situ hybridization. J Appl Microbiol 2001; 90:836-42. [PMID: 11348446 DOI: 10.1046/j.1365-2672.2001.01325.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Our study focused on the design of oligonucleotide probes and a suitable hybridization protocol that would allow rapid and specific identification of potentially viable cysts of the waterborne parasite Giardia lamblia. METHODS AND RESULTS Comparative analysis of ribosomal RNA (rRNA) sequences of Giardia lamblia and a number of closely and more distantly related species identified six regions that appear to be specific for the G. lamblia 16S rRNA. Fluorescently labelled probes targeting these regions were produced and employed in fluorescent in situ hybridization (FISH) experiments. Two of the six probes tested successfully. CONCLUSION Our study provides the first reported probes for specific FISH detection of G. lamblia. The method depends on sufficient amounts of intact rRNA in the target organism, which is unlikely to be present in nonviable cysts that have been exposed to the environment for a prolonged period. SIGNIFICANCE AND IMPACT OF THE STUDY Currently, detection of G. lamblia cysts is largely based on immunofluorescence assays (IFA) targeting cyst wall surface antigens. These assays lack specificity and will detect species others than G. lamblia. Further, IFA will detect nonviable cysts and cyst wall fragments that do not pose a public health risk. In contrast, FISH probes allow specific detection and are likely to only detect viable, infectious cysts.
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Affiliation(s)
- M R Dorsch
- Centre for Fluorimetric Applications in Biotechnology, Department of Biological Sciences, Macquarie University, NSW, Australia.
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Jenkins MC, Trout J, Abrahamsen MS, Lancto CA, Higgins J, Fayer R. Estimating viability of Cryptosporidium parvum oocysts using reverse transcriptase-polymerase chain reaction (RT-PCR) directed at mRNA encoding amyloglucosidase. J Microbiol Methods 2000; 43:97-106. [PMID: 11121608 DOI: 10.1016/s0167-7012(00)00198-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of the present study was to determine if reverse transcriptase-polymerase chain reaction (RT-PCR) directed at mRNA encoding the enzyme amyloglucosidase (CPAG) could serve as a indicator for C. parvum oocyst viability. Oocysts were stored for 1-11 months in the refrigerator and at monthly intervals extracted for total RNA for RT-PCR analysis. An aliquot of these C. parvum oocysts was inoculated into neonatal mice which were necropsied 4 days later for ileal tissue that was analyzed by semi-quantitative PCR to determine the level of parasite replication. The CPAG RT-PCR assay detected RNA from as few as 10(3) C. parvum oocysts. An effect of storage time on both RT-PCR signal and mouse infectivity was observed. RNA from oocysts stored for 1-7 months, unlike oocysts stored for 9 or 11 months, contained CPAG mRNA that was detectable by RT-PCR. A gradual decrease in the RT-PCR signal intensity was observed between 5 and 7 months storage. The intensity of RT-PCR product from oocysts and the signal from semi-quantitative PCR of ileal tissue DNA from mice infected with these same aged oocysts were comparable. The RT-PCR assay of CPAG mRNA in cultured cells infected with viable C. parvum oocysts first detected expression at 12 h with highest expression levels observed at 48 h post-infection. These results indicate that CPAG RT-PCR may be useful for differentiating viable from non-viable C. parvum oocysts and for studying the expression of the gene for amyloglucosidase in vitro.
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Affiliation(s)
- M C Jenkins
- Immunology and Disease Resistance Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705, USA
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23
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Veal DA, Deere D, Ferrari B, Piper J, Attfield PV. Fluorescence staining and flow cytometry for monitoring microbial cells. J Immunol Methods 2000; 243:191-210. [PMID: 10986415 DOI: 10.1016/s0022-1759(00)00234-9] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Large numbers of microbiological samples are analysed annually using traditional culture-based techniques. These techniques take hours to days to yield a result, are tedious and are not suitable for non-culturable microorganisms. Further, culture-based techniques do not provide real-time information on the physiological status of the organism in situ which is important in the industrial manufacture of many microbial products. Flow cytometry offers the prospect of real-time microbial analysis of individual microorganisms, without dependency on microbial culture. However, flow cytometry has not been extensively used as a tool for routine microbial analysis. This has been mainly due to the high cost and complexity of instrumentation, the need for trained flow cytometrists and the lack of assay kits with appropriate biological reagents for specific applications. Many modern instruments are now relatively simple to operate, due to improvements in the user-interface, and no longer need a specialist operator. However, most cytometers are still reliant on analogue technology first developed 20-30 years ago. The incorporation of modern, solid state opto-electronics combined with micro-fabrication and digital signal processing technology offers the prospect of simple to use, low cost and robust instruments suitable for microbial analyses. Advances are being made in the development of a range of biological reagents and these are now being formulated into simple to use kits for microbiological applications. Currently, these kits are largely restricted to simple analyses, for example to assay for total or viable numbers of microorganisms present. However, technologies are available to selectively label specific types of microorganisms. For example, fluorescent antibodies can be used to label microorganisms according to expression of particular antigens, fluorescent in situ hybridisation to label according to phylogeny and fluorogenic enzymatic substrates to label according to expression of specific enzyme activities. Reagents are also available that stain viruses sufficiently brightly to enable their direct detection in environments such as sea water. Microorganisms need to be detected in a variety of different matrices (e.g., water, mud, food, and beverages) and these matrices may be highly variable in nature (e.g., tap water compared to river water). Many matrices have high background autofluorescence (e.g., algae and minerals in water samples) or may bind non-specifically to the fluorescent biological reagents used (e.g., protein micelles in milk). Formulation of biological reagents and sample pre-treatments are critical to the development of suitable microbiological assays. Here, developments in instrumentation and biological reagents for microbiological applications are reviewed with specific examples from environmental or industrial microbiology. The broader considerations for the development of microbial assays for flow cytometry are also considered.
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Affiliation(s)
- D A Veal
- Centre for Development of Fluorimetric Applications in Biotechnology, Department of Biological Sciences, Macquarie University, 2109, Sydney, NSW, Australia.
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Geoffroy MC, Guyard C, Quatannens B, Pavan S, Lange M, Mercenier A. Use of green fluorescent protein to tag lactic acid bacterium strains under development as live vaccine vectors. Appl Environ Microbiol 2000; 66:383-91. [PMID: 10618252 PMCID: PMC91834 DOI: 10.1128/aem.66.1.383-391.2000] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/1999] [Accepted: 10/26/1999] [Indexed: 11/20/2022] Open
Abstract
The lactic acid bacteria (LAB) are safe microorganisms which are mainly used for the preparation of fermented foods and for probiotic applications. The potential of LAB as live vehicles for the production and delivery of therapeutic molecules such as antigens is also being actively investigated today. However, very little is known about the fate of live LAB when administered in vivo and about the interaction of these microorganisms with the nasal or gastrointestinal ecosystem. For future applications, it is essential to be able to discriminate the biotherapeutic strain from the endogenous microflora and to unravel the mechanisms underlying the postulated health-beneficial effect. We therefore started to investigate both aspects in a mouse model with two LAB species presently under development as live vaccine vectors, i.e., Lactococcus lactis and Lactobacillus plantarum. We have constructed different expression vectors carrying the gfp (green fluorescent protein [GFP]) gene from the jellyfish Aequoria victoria, and we found that this visible marker was best expressed when placed under the control of the inducible strong nisA promoter from L. lactis. Notably, a threshold amount of GFP was necessary to obtain a bright fluorescent phenotype. We further demonstrated that fluorescent L. plantarum NCIMB8826 can be enumerated and sorted by flow cytometry. Moreover, tagging of this strain with GFP allowed us to visualize its phagocytosis by macrophages in vitro and ex vivo and to trace it in the gastrointestinal tract of mice upon oral administration.
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Affiliation(s)
- M C Geoffroy
- Département de Microbiologie des Ecosystèmes, Institut Pasteur de Lille, Lille Cedex 59019, France
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Neumann NF, Gyürek LL, Gammie L, Finch GR, Belosevic M. Comparison of animal infectivity and nucleic acid staining for assessment of Cryptosporidium parvum viability in water. Appl Environ Microbiol 2000; 66:406-12. [PMID: 10618255 PMCID: PMC91837 DOI: 10.1128/aem.66.1.406-412.2000] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cryptosporidium parvum oocysts were stained with the fluorogenic dyes SYTO-9 and SYTO-59 and sorted by flow cytometry in order to determine whether the fluorescent staining intensity correlated with the ability of oocysts to infect neonatal CD-1 mice. Oocysts that did not fluoresce or that displayed weak fluorescent intensity when stained with SYTO-9 or SYTO-59 readily established infections in mice, whereas those oocysts that fluoresced brightly did not. Although fluorescent staining profiles varied among different batches of oocysts, a relative cutoff in fluorescent staining intensity that correlated with animal infectivity was observed for all batches.
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Affiliation(s)
- N F Neumann
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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