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Masoori L, Khalaf AK, Ezzatkhah F, Balaña-Fouce R, Mahmoudvand H. Promising effects of 1,8 Cineole to control Giardia lamblia infection: Targeting the inflammation, oxidative stress, and infectivity. Acta Trop 2024; 255:107201. [PMID: 38604329 DOI: 10.1016/j.actatropica.2024.107201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/13/2024]
Abstract
Reportedly, synthetic drugs such as metronidazole, furazolidone, tinidazole, and quinacrine are used for the treatment of giardiasis but are associated with adverse effects. In this study, we aimed to investigate the in vitro and in vivo effects of eucalyptol (ECT, 1,8 cineole) alone and in combination with metronidazole (MNZ) on Giardia lamblia. The effects of ECT on cell viability, plasma membrane permeability, and gene expression levels of adenylate cyclase (AK) and extracellular signal kinases 1 and 2 (ERK1 and ERK2) in trophozoites of G. lamblia were assessed. In vivo, the effects of ECT alone and in combination with MNZ were assessed on mice infected with G. lamblia. In addition, the gene expression of inflammatory genes (e.g., TNF-α, IL-1β, and IL-10) and antioxidant genes (catalase (CAT), superoxide dismutase 1 (SOD1), glutathione peroxidase 2 (GPX2)) was determined by real-time PCR. The IC50 values of ECT, MNZ, and ECT+MNZ on trophozoites were 30.2 µg/mL, 21.6 µg/mL, and 8.5 µg/mL, respectively. The estimated Fractional inhibitory concentration index (FICI) values for ECT and MNZ were 0.28 and 0.39, respectively. The application of ECT on G. lamblia trophozoites resulted in a dose-dependent increase in plasma membrane permeability, particularly at concentrations of ½ IC50 and IC50 (P < 0.05). The treatment of infected mice with various doses of ECT, mainly in combination with MNZ for 7 days, resulted in a significant decrease (P < 0.001) in the average number and viability of cysts. ECT, especially when combined with MNZ, caused a significant (P < 0.001) reduction in the expression of TNF-α and IL-6 genes, and an increase (P < 0.05) in the expression of IL-10 genes. ECT alone and mainly in combination with MNZ leads to a significant (P < 0.001) increase in the gene expression of CAT, SOD, and GPX genes. These findings demonstrate that the use of ECT in these doses, even for 14 days, does not have any toxic effects on the function of vital liver and kidney tissues. The study findings confirmed the promising effects of ECT against G. lamblia infection both in vitro and in vivo. Considering the possible mechanisms, ECT increases plasma membrane permeability and reduces the expression levels of infectivity-related genes. In addition, ECT suppresses inflammation and oxidative stress, controlling giardiasis in mice. More studies are needed to clarify these findings.
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Affiliation(s)
- Leila Masoori
- Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Amal Khudair Khalaf
- Department of Microbiology, College of Medicine, University of Thiqar, Thiqar, Iraq
| | - Fatemeh Ezzatkhah
- Department of Laboratory Sciences, Sirjan School of Medical Sciences, Sirjan, Iran
| | - Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Instituto de Biomedicina (IBIOMED), Campus de Vegazana s/n, Universidad de León 24071 León, Spain
| | - Hossein Mahmoudvand
- Nutritional Health Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.
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Yarlett N, Jarroll EL, Morada M, Lloyd D. Protists: Eukaryotic single-celled organisms and the functioning of their organelles. Adv Microb Physiol 2024; 84:243-307. [PMID: 38821633 DOI: 10.1016/bs.ampbs.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
Organelles are membrane bound structures that compartmentalize biochemical and molecular functions. With improved molecular, biochemical and microscopy tools the diversity and function of protistan organelles has increased in recent years, providing a complex panoply of structure/function relationships. This is particularly noticeable with the description of hydrogenosomes, and the diverse array of structures that followed, having hybrid hydrogenosome/mitochondria attributes. These diverse organelles have lost the major, at one time, definitive components of the mitochondrion (tricarboxylic cycle enzymes and cytochromes), however they all contain the machinery for the assembly of Fe-S clusters, which is the single unifying feature they share. The plasticity of organelles, like the mitochondrion, is therefore evident from its ability to lose its identity as an aerobic energy generating powerhouse while retaining key ancestral functions common to both aerobes and anaerobes. It is interesting to note that the apicoplast, a non-photosynthetic plastid that is present in all apicomplexan protozoa, apart from Cryptosporidium and possibly the gregarines, is also the site of Fe-S cluster assembly proteins. It turns out that in Cryptosporidium proteins involved in Fe-S cluster biosynthesis are localized in the mitochondrial remnant organelle termed the mitosome. Hence, different organisms have solved the same problem of packaging a life-requiring set of reactions in different ways, using different ancestral organelles, discarding what is not needed and keeping what is essential. Don't judge an organelle by its cover, more by the things it does, and always be prepared for surprises.
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Affiliation(s)
- Nigel Yarlett
- Haskins Laboratories, Pace University, New York, NY, United States; The Department of Chemistry and Physical Sciences, Pace University, New York, NY, United States.
| | - Edward L Jarroll
- Department of Biological Sciences, CUNY-Lehman College, Bronx, NY, United States
| | - Mary Morada
- Haskins Laboratories, Pace University, New York, NY, United States
| | - David Lloyd
- Schools of Biosciences and Engineering, Cardiff University, Wales, United Kingdom
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Abstract
Giardia duodenalis captured the attention of Leeuwenhoek in 1681 while he was examining his own diarrheal stool, but, ironically, it did not really gain attention as a human pathogen until the 1960s, when outbreaks were reported. Key technological advances, including in vitro cultivation, genomic and proteomic databases, and advances in microscopic and molecular approaches, have led to an understanding that this is a eukaryotic organism with a reduced genome rather than a truly premitochondriate eukaryote. This has included the discovery of mitosomes (vestiges of mitochondria), a transport system with many of the features of the Golgi apparatus, and even evidence for a sexual or parasexual cycle. Cell biology approaches have led to a better understanding of how Giardia survives with two nuclei and how it goes through its life cycle as a noninvasive organism in the hostile environment of the lumen of the host intestine. Studies of its immunology and pathogenesis have moved past the general understanding of the importance of the antibody response in controlling infection to determining the key role of the Th17 response. This work has led to understanding of the requirement for a balanced host immune response that avoids the extremes of an excessive response with collateral damage or one that is unable to clear the organism. This understanding is especially important in view of the remarkable ranges of early manifestations, which range from asymptomatic to persistent diarrhea and weight loss, and longer-term sequelae that include growth stunting in children who had no obvious symptoms and a high frequency of postinfectious irritable bowel syndrome (IBS).
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Weisz F, Lalle M, Nohynkova E, Sannella AR, Dluhošová J, Cacciò SM. Testing the impact of Whole Genome Amplification on genome comparison using the polyploid flagellated Giardia duodenalis as a model. Exp Parasitol 2019; 207:107776. [PMID: 31628895 DOI: 10.1016/j.exppara.2019.107776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/03/2019] [Accepted: 10/13/2019] [Indexed: 11/27/2022]
Abstract
The availability of high quality genomic DNA in sufficient amounts to perform Next Generation Sequencing (NGS) experiments is challenging for pathogens that cannot be cultivated in vitro, as is the case for many parasites. Therefore, Whole Genome Amplification (WGA) of genomic DNA is used to overcome this limitation. In this study, we evaluated the effect of WGA using the intestinal flagellated protozoan Giardia duodenalis as a model, due to its genome compactness (12 Mb), the presence of two diploid nuclei with variable levels of allelic sequence heterogeneity (ASH), and the availability of reference genomes. We selected one isolate (ZX15) belonging to the same genetic group of the reference isolate WB, namely Assemblage A, sub-Assemblage AI. Genomic DNA from the ZX15 isolate (GEN dataset) and that obtained by WGA of 1 ng of the same genomic DNA (WGA dataset) were sequenced on a HiSeq Illumina platform. Trimmed reads from the GEN and WGA experiments were mapped against the WB reference genome, showing the presence of a very small number of mutations (846 and 752, respectively). The difference in the number of mutations is largely accounted by local variation in coverage and not by bias introduced by WGA. No significant difference were observed in the distribution of mutations in coding and non-coding regions, in the proportion of heterozygous mutations (ASH), or in the transition/transversion ratio of Single Nucleotide Variants within coding sequences. We conclude that the quantitative and qualitative impact of WGA on the identification of mutations is limited, and that this technique can be used to conduct comparative genomics studies.
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Affiliation(s)
- Filip Weisz
- Institute of Immunology and Microbiology, First Faculty of Medicine and General University Hospital, Charles University in Prague, Czech Republic; Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Marco Lalle
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Eva Nohynkova
- Institute of Immunology and Microbiology, First Faculty of Medicine and General University Hospital, Charles University in Prague, Czech Republic
| | - Anna Rosa Sannella
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Jana Dluhošová
- Institute of Immunology and Microbiology, First Faculty of Medicine and General University Hospital, Charles University in Prague, Czech Republic
| | - Simone M Cacciò
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy.
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Rousseau A, La Carbona S, Dumètre A, Robertson LJ, Gargala G, Escotte-Binet S, Favennec L, Villena I, Gérard C, Aubert D. Assessing viability and infectivity of foodborne and waterborne stages (cysts/oocysts) of Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii: a review of methods. ACTA ACUST UNITED AC 2018; 25:14. [PMID: 29553366 PMCID: PMC5858526 DOI: 10.1051/parasite/2018009] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 02/09/2018] [Indexed: 11/14/2022]
Abstract
Giardia duodenalis, Cryptosporidium spp. and Toxoplasma gondii are protozoan parasites that have been highlighted as emerging foodborne pathogens by the Food and Agriculture Organization of the United Nations and the World Health Organization. According to the European Food Safety Authority, 4786 foodborne and waterborne outbreaks were reported in Europe in 2016, of which 0.4% were attributed to parasites including Cryptosporidium, Giardia and Trichinella. Until 2016, no standardized methods were available to detect Giardia, Cryptosporidium and Toxoplasma (oo)cysts in food. Therefore, no regulation exists regarding these biohazards. Nevertheless, considering their low infective dose, ingestion of foodstuffs contaminated by low quantities of these three parasites can lead to human infection. To evaluate the risk of protozoan parasites in food, efforts must be made towards exposure assessment to estimate the contamination along the food chain, from raw products to consumers. This requires determining: (i) the occurrence of infective protozoan (oo)cysts in foods, and (ii) the efficacy of control measures to eliminate this contamination. In order to conduct such assessments, methods for identification of viable (i.e. live) and infective parasites are required. This review describes the methods currently available to evaluate infectivity and viability of G. duodenalis cysts, Cryptosporidium spp. and T. gondii oocysts, and their potential for application in exposure assessment to determine the presence of the infective protozoa and/or to characterize the efficacy of control measures. Advantages and limits of each method are highlighted and an analytical strategy is proposed to assess exposure to these protozoa.
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Affiliation(s)
- Angélique Rousseau
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France - ACTALIA Food Safety Department, 310 Rue Popielujko, 50000 Saint-Lô, France - EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | | | - Aurélien Dumètre
- Aix Marseille Univ, IRD (Dakar, Marseille, Papeete), AP-HM, IHU-Méditerranée Infection, UMR Vecteurs - Infections Tropicales et Méditerranéennes (VITROME), Marseille, France
| | - Lucy J Robertson
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, PO Box 8146 Dep., 0033, Oslo, Norway
| | - Gilles Gargala
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | - Sandie Escotte-Binet
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
| | - Loïc Favennec
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Rouen, 76183 Rouen Cedex, France
| | - Isabelle Villena
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
| | - Cédric Gérard
- Food Safety Microbiology, Nestlé Research Center, PO Box 44, CH-1000 Lausanne 26, Switzerland
| | - Dominique Aubert
- EA 3800, Protozooses transmises par l'alimentation, Laboratoire de Parasitologie Mycologie, Université de Reims Champagne Ardenne, Faculté de Médecine, SFR Cap Santé Fed 4231, 51 Rue Cognacq Jay, 51096 Reims, France
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Garcia LS, Arrowood M, Kokoskin E, Paltridge GP, Pillai DR, Procop GW, Ryan N, Shimizu RY, Visvesvara G. Practical Guidance for Clinical Microbiology Laboratories: Laboratory Diagnosis of Parasites from the Gastrointestinal Tract. Clin Microbiol Rev 2018; 31:e00025-17. [PMID: 29142079 PMCID: PMC5740970 DOI: 10.1128/cmr.00025-17] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This Practical Guidance for Clinical Microbiology document on the laboratory diagnosis of parasites from the gastrointestinal tract provides practical information for the recovery and identification of relevant human parasites. The document is based on a comprehensive literature review and expert consensus on relevant diagnostic methods. However, it does not include didactic information on human parasite life cycles, organism morphology, clinical disease, pathogenesis, treatment, or epidemiology and prevention. As greater emphasis is placed on neglected tropical diseases, it becomes highly probable that patients with gastrointestinal parasitic infections will become more widely recognized in areas where parasites are endemic and not endemic. Generally, these methods are nonautomated and require extensive bench experience for accurate performance and interpretation.
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Affiliation(s)
| | - Michael Arrowood
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Foodborne, Waterborne, and Environmental Diseases, Waterborne Disease Prevention Branch, Atlanta, Georgia, USA
| | - Evelyne Kokoskin
- Public Health Ontario, Ottawa, Ontario, Canada
- Public Health Laboratories-Ottawa, Ottawa, Ontario, Canada
| | | | - Dylan R Pillai
- Calgary Laboratory Services, Diagnostic and Scientific Centre, Calgary, Alberta, Canada
| | - Gary W Procop
- Enterprise Test Utilization and Pathology Consultative Services, Cleveland, Ohio, USA
- Molecular Microbiology, Parasitology, and Mycology Laboratories, Cleveland Clinic Lerner College of Medicine, Cleveland, Ohio, USA
| | - Norbert Ryan
- Bacteriology and Parasitology, Victorian Infectious Diseases Reference Laboratory, Peter Doherty Institute, Melbourne, Victoria, Australia
| | | | - Govinda Visvesvara
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Foodborne, Waterborne, and Environmental Diseases, Waterborne Disease Prevention Branch, Atlanta, Georgia, USA
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Tysnes KR, Robertson LJ. Establishment of Canine-DerivedGiardia duodenalisIsolates in Culture. J Parasitol 2016; 102:342-8. [DOI: 10.1645/15-910] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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8
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Sphingolipids, Lipid Rafts, and Giardial Encystation: The Show Must Go On. CURRENT TROPICAL MEDICINE REPORTS 2015; 2:136-143. [PMID: 26587369 DOI: 10.1007/s40475-015-0052-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Sphingolipids are sphingosine-based phospholipids, which are present in the plasma and endomembranes of many eukaryotic cells. These lipids are involved in various cellular functions, including cell growth, differentiation, and apoptosis. In addition, sphingolipid and cholesterol-enriched membrane microdomains (also called "lipid rafts") contain a set of proteins and lipids, which take part in the signaling process in response to intra- or extracellular stimuli. Recent findings suggest that sphingolipids, especially glucosylceramide, play a critical role in inducing encystation and maintaining the cyst viability in Giardia. Similarly, the assembly/disassembly of lipid rafts modulates the encystation and cyst production of this ubiquitous enteric parasite. In this review article, we discuss the overall progress in the field and examine whether sphingolipids and lipid rafts can be used as novel targets for designing therapies to control infection by Giardia, which is rampant in developing countries, where children are especially vulnerable.
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Meehan CJ, Beiko RG. A phylogenomic view of ecological specialization in the Lachnospiraceae, a family of digestive tract-associated bacteria. Genome Biol Evol 2014; 6:703-13. [PMID: 24625961 PMCID: PMC3971600 DOI: 10.1093/gbe/evu050] [Citation(s) in RCA: 503] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Several bacterial families are known to be highly abundant within the human microbiome, but their ecological roles and evolutionary histories have yet to be investigated in depth. One such family, Lachnospiraceae (phylum Firmicutes, class Clostridia) is abundant in the digestive tracts of many mammals and relatively rare elsewhere. Members of this family have been linked to obesity and protection from colon cancer in humans, mainly due to the association of many species within the group with the production of butyric acid, a substance that is important for both microbial and host epithelial cell growth. We examined the genomes of 30 Lachnospiraceae isolates to better understand the origin of butyric acid capabilities and other ecological adaptations within this group. Butyric acid production-related genes were detected in fewer than half of the examined genomes with the distribution of this function likely arising in part from lateral gene transfer (LGT). An investigation of environment-specific functional signatures indicated that human gut-associated Lachnospiraceae possess genes for endospore formation, whereas other members of this family lack key sporulation-associated genes, an observation supported by analysis of metagenomes from the human gut, oral cavity, and bovine rumen. Our analysis demonstrates that adaptation to an ecological niche and acquisition of defining functional roles within a microbiome can arise through a combination of both habitat-specific gene loss and LGT.
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Affiliation(s)
- Conor J Meehan
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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Axenic in vitro culture and molecular characterization of Giardia duodenalis from red deer (Cervus elaphus) and Thomson's gazelle (Gazella thomsonii). Acta Parasitol 2014; 59:763-6. [PMID: 25236290 DOI: 10.2478/s11686-014-0279-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/04/2014] [Accepted: 05/20/2014] [Indexed: 11/20/2022]
Abstract
Giardia duodenalis is an ubiquitous flagellate that infects humans and many species of animals. This species exhibits great biotypic and genetic diversity. In the present study, we established short- and long-term in vitro cultures of G. duodenalis trophozoites originating from red deer and Thomson's gazelle (artiodactyls) and genetically characterised the isolates by their glutamate dehydrogenase and triose phosphate isomerase gene sequences. The G. duodenalis isolates from red deer and the gazelle represented assemblages A (AIII sub-assemblage) and B. In conclusion, G. duodenalis assemblages and sub-assemblages can be associated with differences in growth rate in vitro cultures.
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Klotz C, Aebischer T, Seeber F. Stem cell-derived cell cultures and organoids for protozoan parasite propagation and studying host–parasite interaction. Int J Med Microbiol 2012; 302:203-9. [DOI: 10.1016/j.ijmm.2012.07.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Abstract
In this review, the current status of genomic and proteomic research on Giardia is examined in terms of evolutionary biology, phylogenetic relationships and taxonomy. The review also describes how characterising genetic variation in Giardia from numerous hosts and endemic areas has provided a better understanding of life cycle patterns, transmission and the epidemiology of Giardia infections in humans, domestic animals and wildlife. Some progress has been made in relating genomic information to the phenotype of Giardia, and as a consequence, new information has been obtained on aspects of developmental biology and the host-parasite relationship. However, deficiencies remain in our understanding of pathogenesis and host specificity, highlighting the limitations of currently available genomic datasets.
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Alum A, Sbai B, Asaad H, Rubino JR, Khalid Ijaz M. ECC-RT-PCR: a new method to determine the viability and infectivity of Giardia cysts. Int J Infect Dis 2012; 16:e350-3. [PMID: 22390842 DOI: 10.1016/j.ijid.2012.01.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 01/03/2012] [Accepted: 01/11/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Giardia sp is a major cause of diarrheal illness worldwide, and millions of people are infected each year. Rapid methods to determine the infectivity and virulence of isolates are critical for the development of intervention strategies to control the transmission of Giardia sp cysts, which occurs through contaminated surfaces, food, and water. However, determining the viability, infectivity, and virulence of Giardia sp cysts using molecular methods is a technical challenge because of the lack of a cell culture model. METHOD This study was designed to evaluate mRNA expression in trophozoites and to assess trophozoite attachment to cell monolayer and changes in transcellular resistance as an indicator of Giardia sp viability and infectivity. Heat shock mRNA in Giardia cysts and variant-specific protein (VSP) mRNA in trophozoites were quantified by reverse transcription polymerase chain reaction (RT-PCR). C2bb (Caco-2) cells were grown on transwell chambers to study the attachment of trophozoites, changes in transcellular resistance, and expression of VSP in trophozoites. RESULTS The results of these molecular and cell culture studies indicate a direct linear correlation between the viability and infectivity of fresh stocks of Giardia sp cysts. The attachment of trophozoites to cell monolayer, expression of VSP, and change in the transcellular resistance was directly correlated with their infectivity in neonatal mice. PCR was successfully combined with the electrophysiological analysis of cell culture (ECC-RT-PCR) post-trophozoite attachment. CONCLUSION This study shows that the ECC-RT-PCR, a new integrated cell culture assay, can be used as a rapid and cost-effective tool for assessing the viability and infectivity of environmental isolates of Giardia sp cysts.
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Affiliation(s)
- Absar Alum
- Arizona State University, Department of Civil & Environmental Engineering, Tempe, Arizona, USA; DH Laboratory, Chandler, Arizona, USA
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Carpenter ML, Assaf ZJ, Gourguechon S, Cande WZ. Nuclear inheritance and genetic exchange without meiosis in the binucleate parasite Giardia intestinalis. J Cell Sci 2012; 125:2523-32. [PMID: 22366460 DOI: 10.1242/jcs.103879] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The protozoan parasite Giardia intestinalis (also known as Giardia lamblia) is a major waterborne pathogen. During its life cycle, Giardia alternates between the actively growing trophozoite, which has two diploid nuclei with low levels of allelic heterozygosity, and the infectious cyst, which has four nuclei and a tough outer wall. Although the formation of the cyst wall has been studied extensively, we still lack basic knowledge about many fundamental aspects of the cyst, including the sources of the four nuclei and their distribution during the transformation from cyst into trophozoite. In this study, we tracked the identities of the nuclei in the trophozoite and cyst using integrated nuclear markers and immunofluorescence staining. We demonstrate that the cyst is formed from a single trophozoite by a mitotic division without cytokinesis and not by the fusion of two trophozoites. During excystation, the cell completes cytokinesis to form two daughter trophozoites. The non-identical nuclear pairs derived from the parent trophozoite remain associated in the cyst and are distributed to daughter cells during excystation as pairs. Thus, nuclear sorting (such that each daughter cell receives a pair of identical nuclei) does not appear to be a mechanism by which Giardia reduces heterozygosity between its nuclei. Rather, we show that the cyst nuclei exchange chromosomal genetic material, perhaps as a way to reduce heterozygosity in the absence of meiosis and sex, which have not been described in Giardia. These results shed light on fundamental aspects of the Giardia life cycle and have implications for our understanding of the population genetics and cell biology of this binucleate parasite.
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Affiliation(s)
- Meredith L Carpenter
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Alvarado ME, Wasserman M. Calmodulin expression during Giardia intestinalis differentiation and identification of calmodulin-binding proteins during the trophozoite stage. Parasitol Res 2011; 110:1371-80. [DOI: 10.1007/s00436-011-2637-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 09/02/2011] [Indexed: 11/28/2022]
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Manning G, Reiner DS, Lauwaet T, Dacre M, Smith A, Zhai Y, Svard S, Gillin FD. The minimal kinome of Giardia lamblia illuminates early kinase evolution and unique parasite biology. Genome Biol 2011; 12:R66. [PMID: 21787419 PMCID: PMC3218828 DOI: 10.1186/gb-2011-12-7-r66] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Revised: 05/04/2011] [Accepted: 07/25/2011] [Indexed: 01/23/2023] Open
Abstract
Background The major human intestinal pathogen Giardia lamblia is a very early branching eukaryote with a minimal genome of broad evolutionary and biological interest. Results To explore early kinase evolution and regulation of Giardia biology, we cataloged the kinomes of three sequenced strains. Comparison with published kinomes and those of the excavates Trichomonas vaginalis and Leishmania major shows that Giardia's 80 core kinases constitute the smallest known core kinome of any eukaryote that can be grown in pure culture, reflecting both its early origin and secondary gene loss. Kinase losses in DNA repair, mitochondrial function, transcription, splicing, and stress response reflect this reduced genome, while the presence of other kinases helps define the kinome of the last common eukaryotic ancestor. Immunofluorescence analysis shows abundant phospho-staining in trophozoites, with phosphotyrosine abundant in the nuclei and phosphothreonine and phosphoserine in distinct cytoskeletal organelles. The Nek kinase family has been massively expanded, accounting for 198 of the 278 protein kinases in Giardia. Most Neks are catalytically inactive, have very divergent sequences and undergo extensive duplication and loss between strains. Many Neks are highly induced during development. We localized four catalytically active Neks to distinct parts of the cytoskeleton and one inactive Nek to the cytoplasm. Conclusions The reduced kinome of Giardia sheds new light on early kinase evolution, and its highly divergent sequences add to the definition of individual kinase families as well as offering specific drug targets. Giardia's massive Nek expansion may reflect its distinctive lifestyle, biphasic life cycle and complex cytoskeleton.
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Affiliation(s)
- Gerard Manning
- Razavi Newman Center for Bioinformatics, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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17
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Giardia taxonomy, phylogeny and epidemiology: Facts and open questions. Int J Hyg Environ Health 2010; 213:321-33. [DOI: 10.1016/j.ijheh.2010.06.005] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 05/25/2010] [Accepted: 06/02/2010] [Indexed: 11/18/2022]
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18
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Síntesis de las enzimas de piruvato, oxidorreductasa de ferredoxina y deshidrogenasa E de alcohol durante el desenquistamiento (excystacion) de Giardia intestinalis. BIOMEDICA 2010. [DOI: 10.7705/biomedica.v30i1.150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Mitra BN, Pradel G, Frevert U, Eichinger D. Compounds of the upper gastrointestinal tract induce rapid and efficient excystation of Entamoeba invadens. Int J Parasitol 2009; 40:751-60. [PMID: 20018192 DOI: 10.1016/j.ijpara.2009.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/24/2009] [Accepted: 11/25/2009] [Indexed: 11/20/2022]
Abstract
The infective stage of Entamoeba parasites is an encysted form. This stage can be readily generated in vitro, which has allowed identification of stimuli that trigger the differentiation of the parasite trophozoite stage into the cyst stage. Studies of the second differentiation event, emergence of the parasite from the cyst upon infection of a host, have been hampered by the lack of an efficient means to excyst the parasite and complete the life cycle in vitro. We have determined that a combination of exposures to water, bicarbonate and bile induces rapid excystment of Entamoeba invadens cysts. The high efficiency of this method has allowed the visualization of the dynamics of the process by electron and confocal microscopy, and should permit the analysis of stage-specific gene expression and high-throughput screening of inhibitory compounds.
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Affiliation(s)
- Biswa Nath Mitra
- Department of Medical Parasitology, New York University School of Medicine, NY 10010, USA
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20
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Alvarado ME, Wasserman M. Analysis of phosphorylated proteins and inhibition of kinase activity during Giardia intestinalis excystation. Parasitol Int 2009; 59:54-61. [PMID: 19861170 DOI: 10.1016/j.parint.2009.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2009] [Revised: 10/08/2009] [Accepted: 10/10/2009] [Indexed: 11/24/2022]
Abstract
The parasite Giardia intestinalis undergoes a differentiation process that allows it to infect its mammal host. That process is excystation. We examined the importance of protein phosphorylation during the passage from cyst to trophozoite. Cysts obtained from patients with giardiasis were excysted in vitro and the soluble cytoplasmic proteins were analyzed during the three phases of the process, using a specific staining for phosphoproteins. We found two phosphorylated proteins and identified them with MALDI-TOF as 14-3-3 and Hsp70. Modifications were detected in both proteins, which could indicate a role in differentiation of the parasite. In addition, the inhibition of serine-threonine kinases during excystation specifically affected the cytokinesis of the excyzoite, thus inhibiting the completion of trophozoite formation.
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Affiliation(s)
- Magda E Alvarado
- Laboratorio de Investigaciones Básicas en Bioquímica, Departamento de Química, Universidad Nacional de Colombia, Bogotá calle 44 No 45-67 Bloque 10 nivel 4 Unidad Camilo Torres, Colombia
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21
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Bertrand I, Maux M, Helmi K, Hoffmann L, Schwartzbrod J, Cauchie HM. Quantification of Giardia transcripts during in vitro excystation: interest for the estimation of cyst viability. WATER RESEARCH 2009; 43:2728-2738. [PMID: 19395061 DOI: 10.1016/j.watres.2009.03.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 03/11/2009] [Accepted: 03/14/2009] [Indexed: 05/27/2023]
Abstract
The aim of the present study was to evaluate the potential of transcript quantification as an indicator of Giardia cyst viability. The variations of beta-giardin, EF1A and ADHE mRNAs were quantified during excystation by real-time RT-PCR assays and compared with the percentages of viability estimated using propidium iodide staining and in vitro excystation. The first experiments were performed with purified G. duodenalis assemblage B cysts. When 55% of excysting protozoa were observed, the increase of the selected transcripts ranged from 0.40+/-0.13 to 0.97+/-0.11 log10 after 1h of incubation in excystation medium. Purified cysts were also stored at 4 degrees C for up to 56 days and analysed at several sampling times. Significant correlations were observed between the variations of the selected mRNAs and the percentages of viability estimated with staining and excystation methods. Among the three transcripts, beta-giardin appeared to be the most appropriate to study the viability of Giardia cysts concentrated from wastewater samples.
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Affiliation(s)
- Isabelle Bertrand
- Centre de Recherche Public-Gabriel Lippmann, Department of Environment and Agro-biotechnologies (EVA), 41 rue du Brill, L-4422 Belvaux, Luxembourg.
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22
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Melo SP, Gómez V, Castellanos IC, Alvarado ME, Hernández PC, Gallego A, Wasserman M. Transcription of meiotic-like-pathway genes in Giardia intestinalis. Mem Inst Oswaldo Cruz 2008; 103:347-50. [PMID: 18660988 DOI: 10.1590/s0074-02762008000400006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Accepted: 06/12/2008] [Indexed: 11/22/2022] Open
Abstract
The reproductive mechanism of Giardia intestinalis, considered one of the earliest divergent eukaryotes, has not been fully defined yet. Some evidence supports the hypothesis that Giardia is an exclusively asexual organism with a clonal population structure. However, the high genetic variability, the variation in ploidy during its life cycle, the low heterozygosity and the existence of genes involved in the meiotic-like recombination pathway in the parasite's genome cast doubt on exclusively asexual nature of Giardia. In this work, semiquantitative RT-PCR analysis was used to assess the transcription pattern of three meiosis-like-specific genes involved in homologues recombination: dmc1, hop1 and spo11. The mRNAs were amplified during the parasite's differentiation processes, encystation and excystation, and expression was found at each stage of its life cycle. A semiquantitative assessment also suggests that expression of some of the genes is regulated during encystation process.
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Affiliation(s)
- Sandra P Melo
- Departamento de Química, Facultad de Ciencias, Laboratorio de Investigaciones Básicas en Bioquímica, Universidad Nacional de Colombia, Bogotá, Colombia
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23
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Singh DK, Rastogi A, Sakhuja P, Gondal R. Giardiasis diagnosed on esophageal brush smears in a case of chronic alcoholic liver disease with esophageal candidiasis. Diagn Cytopathol 2008; 36:846-7. [PMID: 18831025 DOI: 10.1002/dc.20930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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24
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Gallego E, Alvarado M, Wasserman M. Identification and expression of the protein ubiquitination system in Giardia intestinalis. Parasitol Res 2007; 101:1-7. [PMID: 17252268 DOI: 10.1007/s00436-007-0458-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2006] [Accepted: 01/08/2007] [Indexed: 10/23/2022]
Abstract
Giardia intestinalis is a single-cell eukaryotic microorganism, regarded as one of the earliest divergent eukaryotes and thus an attractive model to study the evolution of regulatory systems. Giardia has two different forms throughout its life cycle, cyst and trophozoite, and changes from one to the other in response to environmental signals. The two differentiation processes involve a differential gene expression as well as a quick and specific protein turnover that may be mediated by the ubiquitin/proteasome system. The aim of this work was to search for unreported components of the ubiquitination system and to experimentally demonstrate their expression in the parasite and during the two differentiation processes. We found activity of protein ubiquitination in G. intestinalis trophozoites and analyzed the transcription of the ubiquitin gene, as well as that of the activating (E1), conjugating (E2), and ligase (E3) ubiquitin enzymes during encystation and excystation. A constant ubiquitin expression persisted during the parasite's differentiation processes, whereas variation in transcription was observed in the other genes under study.
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Affiliation(s)
- Eva Gallego
- Laboratorio de Investigaciones Básicas en Bioquímica, Facultad de Ciencias, Universidad Nacional de Colombia, Unidad Camilo Torres Cra 50 No 27-70 Bloque 10 nivel 4, Bogota, Colombia
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25
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Chávez-Munguía B, Omaña-Molina M, González-Lázaro M, González-Robles A, Cedillo-Rivera R, Bonilla P, Martínez-Palomo A. Ultrastructure of cyst differentiation in parasitic protozoa. Parasitol Res 2007; 100:1169-75. [PMID: 17252271 DOI: 10.1007/s00436-006-0447-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Accepted: 12/14/2006] [Indexed: 11/29/2022]
Abstract
Cysts represent a phase in the life cycle of biphasic parasitic protozoa that allow them to survive under adverse environmental conditions. Two events are required for the morphological differentiation from trophozoite to cyst and from cyst to trophozoite: the encystation and excystation processes. In this paper, we present a review of the ultrastructure of the encystation and excystation processes in Entamoeba invadens, Acanthamoeba castellanii, and Giardia lamblia. The comparative electron microscopical observations of these events here reported provide a morphological background to better understand recent advances in the biochemistry and molecular biology of the differentiation phenomena in these microorganisms.
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Affiliation(s)
- Bibiana Chávez-Munguía
- Department of Experimental Pathology, Center for Research and Advanced Studies, Av. IPN 2508, Zacatenco, 07360, Mexico City, Mexico.
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26
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Lee JH, Lee J, Park SJ, Yong TS, Hwang UW. Detection and genotyping of Giardia intestinalis isolates using intergenic spacers(IGS)-based PCR. THE KOREAN JOURNAL OF PARASITOLOGY 2007; 44:343-53. [PMID: 17170576 PMCID: PMC2559131 DOI: 10.3347/kjp.2006.44.4.343] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Giardia intestinalis infections arise primarily from contaminated food or water. Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was performed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176 bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.
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Affiliation(s)
- Jong-Ho Lee
- Department of Parasitology and Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul, Korea
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27
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Abstract
This paper discusses the most important parasites that inhabit the human small intestine. Beginning with the protozoa and proceeding through the various species of cestodes, nematodes, and trematodes that inhabit the human small bowel, the most important organisms are presented. Possible future developments are discussed along with pathophysiology and treatment in this phylogenic approach. Zoonotic illnesses, those diseases that by their rarity are of little import, and diseases without significant clinical or social implications are beyond the scope of this article and are not discussed.
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Affiliation(s)
- Theodore W Schafer
- Division of Gastroenterology, Naval Medical Center, 620 John Paul Jones Cir., Portsmouth, VA 23708, USA.
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28
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Abstract
This paper discusses the most important parasites that inhabit the human small intestine. Beginning with the protozoa and proceeding through the various species of cestodes, nematodes, and trematodes that inhabit the human small bowel, the most important organisms are presented. Possible future developments are discussed along with pathophysiology and treatment in this phylogenic approach. Zoonotic illnesses, those diseases that by their rarity are of little import, and diseases without significant clinical or social implications are beyond the scope of this article and are not discussed.
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Affiliation(s)
- Theodore W Schafer
- Division of Gastroenterology, Naval Medical Center,620 John Paul Jones Cir., Portsmouth, VA 23708, USA.
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29
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Alvarado ME, Wasserman M. Quick and efficient purification of Giardia intestinalis cysts from fecal samples. Parasitol Res 2006; 99:300-2. [PMID: 16565815 DOI: 10.1007/s00436-006-0143-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 02/06/2006] [Indexed: 10/24/2022]
Abstract
Giardia intestinalis is an intestinal parasite that has sparked considerable interest because of the public health problem it creates and because it is regarded as one of the earliest divergent eukaryotes. The present report describes a new method for quick, clean, and effective isolation of G. intestinalis cysts from fecal samples. The isolated cysts have the quality required for biochemical studies of the excystation process.
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Affiliation(s)
- M E Alvarado
- Laboratorio de Investigaciones Básicas en Bioquímica LIBBIQ, Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia.
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30
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Makioka A, Kumagai M, Kobayashi S, Takeuchi T. Effect of artificial gastrointestinal fluids on the excystation and metacystic development of Entamoeba invadens. Parasitol Res 2006; 98:443-6. [PMID: 16416121 DOI: 10.1007/s00436-005-0025-7] [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] [Received: 05/05/2005] [Accepted: 09/20/2005] [Indexed: 10/25/2022]
Abstract
The effect of artificial gastric fluid (AGF), containing 0.5% pepsin and 0.6% hydrochloric acid, pH 1.8, in distilled water, on the excystation and metacystic development of Entamoeba invadens was examined. Excystation, which was assessed by counting the number of metacystic amoebae after inducing excystation, was enhanced by pretreatment of cysts with AGF for 30 to 60 min at 37 degrees C but not 26 degrees C. Longer exposure of cysts to AGF significantly reduced their viability. Significant enhancement of excystation was observed by pretreatment of cysts with distilled water only at 37 degrees C. In addition, 0.6% hydrochloric acid had a comparable enhancing effect on excystation to AGF. Metacystic development, when determined by the number of nuclei in amoeba, was slightly enhanced by pretreatment with AGF. An artificial intestinal fluid (AIF), containing 1% pancreatin, 1% sodium bicarbonate, and 5% ox bile, pH 8.0, in distilled water, had a significant toxic effect on cysts, where 1% pancreatin had neither an enhancing effect on excystation nor a toxic effect on cysts, whereas 5% ox bile had a toxic effect on cysts. Pretreatment of cysts with AGF followed by AIF had a similar toxic effect on cysts to that by AIF only. These results suggest that gastric fluid but not intestinal fluid at 37 degrees C contributes to enhancing excystation for Entamoeba infection.
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Affiliation(s)
- Asao Makioka
- Department of Tropical Medicine, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo, 105-8461, Japan.
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31
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Hernandez PC, Wasserman M. Do genes from the cholesterol synthesis pathway exist and express in Giardia intestinalis? Parasitol Res 2005; 98:194-9. [PMID: 16323024 DOI: 10.1007/s00436-005-0039-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2005] [Accepted: 09/26/2005] [Indexed: 10/25/2022]
Abstract
Giardia intestinalis undergo biochemical and morphological changes to survive under extreme environmental conditions. One of these changes is encystation. The trophozoites colonizing the upper part of the small intestine differentiate into a cyst, the infective form of the parasite. In in vitro cultures, the formation of cysts is induced by the depletion of cholesterol. It was reported that Giardia cannot synthesize cholesterol de novo. However, through bioinformatic studies, we found the genes that codify for the enzymes in the cholesterol biosynthesis pathway. We were able to verify the existence and define the transcription of four genes in the trophozoite and in parasites subjected to the encystation and excystation processes.
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Affiliation(s)
- Paula C Hernandez
- Laboratorio de Investigaciones Básicas en Bioquímica (LIBBIQ), Departamento de Química, Universidad Nacional de Colombia, Ciudad Universitaria, Bogotá, Colombia
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32
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de Souza W, Lanfredi-Rangel A, Campanati L. Contribution of microscopy to a better knowledge of the biology of Giardia lamblia. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2004; 10:513-527. [PMID: 15525427 DOI: 10.1017/s1431927604040954] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2002] [Indexed: 05/24/2023]
Abstract
Giardia lamblia is a flagellated protozoan of great medical and biological importance. It is the causative agent of giardiasis, one of the most prevalent diarrheal disease both in developed and third-world countries. Morphological studies have shown that G. lamblia does not present structures such as peroxisomes, mitochondria, and a well-elaborated Golgi complex. In this review, special emphasis is given to the contribution made by various microscopic techniques to a better knowledge of the biology of the protozoan. The application of video microscopy, immunofluorescence confocal laser scanning microscopy, and several techniques associated with transmission electron microscopy (thin section, enzyme cytochemistry, freeze-fracture, deep-etching, fracture-flip) to the study of the cell surface, peripheral vesicles, endoplasmic reticulum-Golgi complex system, and of the encystation vesicles found in trophozoites and during the process of trophozoite-cyst transformation are discussed.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS-Bloco G, 21949-900, Rio de Janeiro-RJ, Brazil.
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Paget T, Maroulis S, Mitchell A, Edwards MR, Jarroll EL, Lloyd D. Menadione kills trophozoites and cysts of Giardia intestinalis. MICROBIOLOGY-SGM 2004; 150:1231-1236. [PMID: 15133085 DOI: 10.1099/mic.0.26836-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Production of reactive oxygen species by redox cycling in the presence of low levels of oxygen has been studied as a possible approach to anti-protozoal chemotherapeutic strategy. Incubation of the diplomonad flagellate Giardia intestinalis with 2-methy-1,4-naphthoquinone (menadione), under anaerobic conditions, gave UV absorption changes characteristic of reduction to menadiol; partial reversal was observed on admitting O(2). Under microaerobic conditions, similar to those on the surface of the jejunal mucosa, trophozoites consumed O(2) rapidly in the presence of menadione; reaction products included singlet O(2) (monitored by single photon counting of O(2)-dependent low-level chemiluminescence) and H(2)O(2) (measured by the formation of Complex I of microperoxidase). Trophozoites became swollen and incapable of regulatory volume control; these irreversible responses led to loss of motility, cessation of flagellar activity and cell death. Comparison of the sensitivities of trophozoites to metronidazole and menadione gave LC(50) values ( microg x ml(-1)) of 1.2 and 0.7, respectively; corresponding values for cysts (measured by in vitro excystation capacities) were >50 and 1.3. Menadione (LD(50) in mice, 0.5 g kg(-1)) is therefore a potentially more useful and general anti-giardial agent than metronidazole, as it is active against cysts as well as trophozoites.
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Affiliation(s)
- Timothy Paget
- Department of Applied Biology, University of Hull, UK
| | - Sarah Maroulis
- School of Biotechnology and Bio-molecular Sciences, University of New South Wales, Sydney, Australia
| | - Andrew Mitchell
- School of Biotechnology and Bio-molecular Sciences, University of New South Wales, Sydney, Australia
| | - Michael R Edwards
- School of Biotechnology and Bio-molecular Sciences, University of New South Wales, Sydney, Australia
| | - Edward L Jarroll
- Department of Biology, Northeastern University, Boston, MA 02115, USA
| | - David Lloyd
- Microbiology Group (BIOSI 1, Main Building), Cardiff University, PO Box 915, Cardiff CF10 3TL, UK
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Niño CA, Wasserman M. Transcription of metabolic enzyme genes during the excystation of Giardia lamblia. Parasitol Int 2004; 52:291-8. [PMID: 14665385 DOI: 10.1016/s1383-5769(03)00032-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study evaluates the expression of genes of Giardia lamblia, one of the most simple and most early diverging eukaryotes, that encode the metabolic enzymes pyruvate: ferredoxin oxidoreductase (PFOR), acetyl-CoA synthetase (ACS), alcohol dehydrogenase E (ADHE) and glutamate dehydrogenase (GDH) and the cyst wall protein (CWP1) gene in trophozoites, cysts and during the excystation process. Primers were designed to amplify mRNA fragments through quantitative reverse-transcriptase-polymerase-chain-reaction. In trophozoites, all transcripts of the enzymes studied were present. In cysts, three of the transcripts were detected: CWP1, GDH and ACS; but the relative levels of the mRNA of GDH and ACS were very different between trophozoites and cysts. During excystation, PFOR and ADHE transcripts appeared after the first induction phase, and the mRNAs of ACS and GDH increased throughout the process.
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Affiliation(s)
- Carlos A Niño
- Laboratorio de Investigaciones Básicas en Bioquímica, Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota, Colombia
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35
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Chávez-Munguía B, Cedillo-Rivera R, Martínez-Palomo A. The Ultrastructure of the Cyst Wall of Giardia lamblia. J Eukaryot Microbiol 2004; 51:220-6. [PMID: 15134259 DOI: 10.1111/j.1550-7408.2004.tb00549.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Giardiasis is the most common human protozoal infection. In their cystic phase, giardias are protected from the environment by a filamentous cyst wall made up of carbohydrates, proteins, and by two outer membranes separated from the plasma membrane of the parasite by a peripheral space. The present transmission electron microscope observations of G. lamblia cysts of human origin suggest that the extracellular peritrophic space originates from the growth, elongation, and fusion of large cytoplasmic vacuoles. As the large clear vacuoles grew in size, flattening against the inner face of the plasma membrane, they formed a single vacuole that surrounded the body of the parasite, eventually forming two outer membranes. In mature Giardia cysts, the original plasma membrane of the trophozoite becomes the outermost membrane of the cyst wall (CM1). The large vacuoles form a second membrane surrounding the cyst (CM2), and also form a third membrane (CM3), that becomes the new plasma membrane of the trophozoite. During excystation CM1 and CM2 attach to each other and fragment, leaving abundant membrane residues in the peritrophic space. Knowledge of the biochemical composition and functional properties of the complex outer membranous system of G. lamblia cysts here described will be of use to understand the survival of Giardia cysts in the environment, a major factor responsible for the high prevalence of giardiasis worldwide.
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Affiliation(s)
- Bibiana Chávez-Munguía
- Department of Experimental Pathology, Center for Research and Advanced Studies, Av. IPN 2508, Zacatenco, 07360 Mexico City, Mexico
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36
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Rocha MO, Gomes MA, Costa AO, Furst C, Silva EF. Molecular characterization of Brazilian human Giardia duodenalis isolates using isoenzyme and random amplified polymorphic DNA analysis. Diagn Microbiol Infect Dis 2003; 46:273-8. [PMID: 12944019 DOI: 10.1016/s0732-8893(03)00083-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Isoenzymes and RAPD (random amplified polymorphic DNA) analysis were used to characterize three Brazilian human isolates of Giardia duodenalis and its clones. The Portland-1 strain (ATCC 30888) was included in the study as a reference pattern. Both methods divided the isolates into two main groups, one represented by the Portland-1 strain, the other constituted by the Brazilian isolates, which, in turn, were divided into 2 subgroups. The dendogram constructed with the RAPD data, using seven primers, revealed a great heterogeneity between Brazilian isolates and the Portland-1 strain. There was no relationship to the clinical characteristics of the isolates. Although a lot of similarity has been observed among Brazilian isolates and its clones, individual polymorphism was detected, which could be related to the clonal reproduction of this protozoan.
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Affiliation(s)
- Míriam O Rocha
- School of Pharmacy, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
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37
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Sun CH, McCaffery JM, Reiner DS, Gillin FD. Mining the Giardia lamblia genome for new cyst wall proteins. J Biol Chem 2003; 278:21701-8. [PMID: 12686559 DOI: 10.1074/jbc.m302023200] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Giardia lamblia cyst wall (CW), which is required for survival outside the host and infection, is a primitive extracellular matrix. Because of the importance of the CW, we queried the Giardia Genome Project Database with the coding sequences of the only two known CW proteins, which are cysteine-rich and contain leucine-rich repeats (LRRs). We identified five new LRR-containing proteins, of which only one (CWP3) is up-regulated during encystation and incorporated into the cyst wall. Sequence comparison with CWP1 and -2 revealed conservation within the LRRs and the 44-amino-acid N-flanking region, although CWP3 is more divergent. Interestingly, all 14 cysteine residues of CWP3 are positionally conserved with CWP1 and -2. During encystation, C-terminal epitope-tagged CWP3 was transported to the wall of water-resistant cysts via the novel regulated secretory pathway in encystation-secretory vesicles (ESVs). Deletion analysis revealed that the four LRRs are each essential to target CWP3 to the ESVs and cyst wall. In a deletion of the most C-terminal region, fewer ESVs were stained in encysting cells, and there was no staining in cysts. In contrast, deletion of the 44 amino acids between the signal sequence and the LRRs or the region just C-terminal to the LRRs only decreased the number of cells with CWP3 targeting to ESVs and cyst wall by approximately 50%. Our studies indicate that virtually every portion of the CWP3 protein is needed for efficient targeting to the regulated secretory pathway and incorporation into the cyst wall. Further, these data demonstrate the power of genomics in combination with rigorous functional analyses to verify annotation.
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Affiliation(s)
- Chin-Hung Sun
- Department of Pathology, School of Medicine, University of California at San Diego, 214 Dickinson Street, San Diego, CA 92103-8416, USA
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Reiner DS, Hetsko ML, Meszaros JG, Sun CH, Morrison HG, Brunton LL, Gillin FD. Calcium signaling in excystation of the early diverging eukaryote, Giardia lamblia. J Biol Chem 2003; 278:2533-40. [PMID: 12397071 DOI: 10.1074/jbc.m208033200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Excystation of Giardia lamblia, which initiates infection, is a poorly understood but dramatic differentiation induced by physiological signals from the host. Our data implicate a central role for calcium homeostasis in excystation. Agents that alter cytosolic Ca(2+) levels (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-tetra(acetyloxymethyl) ester, a Ca(2+) channel blocker, Ca(2+) ionophores, and thapsigargin) strongly inhibit excystation. Treatment of Giardia with thapsigargin raised intracellular Ca(2+) levels, and peak Ca(2+) responses increased with each stage of excystation, consistent with the kinetics of inhibition. Fluorescent thapsigargin localized to a likely Ca(2+) storage compartment in cysts. The ability to sequester ions in membrane-bounded compartments is a hallmark of the eukaryotic cell. These studies support the existence of a giardial thapsigargin-sensitive Ca(2+) storage compartment resembling the sarcoplasmic/endoplasmic reticulum calcium ATPase pump-leak system and suggest that it is important in regulation of differentiation and appeared early in the evolution of eukaryotic cells. Calmodulin antagonists also blocked excystation. The divergent giardial calmodulin localized to the eight flagellar basal bodies/centrosomes, like protein kinase A. Inhibitor kinetics suggest that protein kinase A signaling triggers excystation, whereas calcium signaling is mainly required later, for parasite activation and emergence. Thus, the basal bodies may be a cellular control center to coordinate the resumption of motility and cytokinesis in excystation.
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Affiliation(s)
- David S Reiner
- Department of Pathology, University of California, San Diego, 92103, USA
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Svärd SG, Hagblom P, Palm JED. Giardia lamblia -- a model organism for eukaryotic cell differentiation. FEMS Microbiol Lett 2003; 218:3-7. [PMID: 12583890 DOI: 10.1111/j.1574-6968.2003.tb11490.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Giardia lamblia is a binucleated, flagellated protozoan parasite that inhabits the upper small intestine of its vertebrate hosts. The entire life cycle, which can be completed in vitro, is simple with cycling between a vegetative trophozoite and a highly resistant cystic form. The parasite is one of the earliest diverging eukaryotes known and more than 95% of the genome is sequenced. This makes Giardia an excellent model system for studies of basic eukaryotic processes like cell differentiation. In this review we will discuss recent data concerning Giardia differentiation with a focus on DNA replication and cytokinesis.
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Affiliation(s)
- Staffan G Svärd
- Microbiology and Tumour Biology Center, Karolinska Institutet, Box 280, 171 77, Stockholm, Sweden.
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Clark CG, Diamond LS. Methods for cultivation of luminal parasitic protists of clinical importance. Clin Microbiol Rev 2002; 15:329-41. [PMID: 12097242 PMCID: PMC118080 DOI: 10.1128/cmr.15.3.329-341.2002] [Citation(s) in RCA: 292] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cultivation of luminal protistan parasites has a long history. In this review we discuss the methods and media that are most widely used for the establishment and maintenance of the following organisms in culture: Entamoeba histolytica, Giardia intestinalis, Trichomonas vaginalis, Dientamoeba fragilis, Blastocystis hominis, and Balantidium coli. While cultivation is of limited importance in the diagnostic laboratory, it is essential to most research laboratories, and it is toward the latter that this review is primarily aimed.
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Affiliation(s)
- C Graham Clark
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, Great Britain.
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Quintero-Betancourt W, Peele ER, Rose JB. Cryptosporidium parvum and Cyclospora cayetanensis: a review of laboratory methods for detection of these waterborne parasites. J Microbiol Methods 2002; 49:209-24. [PMID: 11869786 DOI: 10.1016/s0167-7012(02)00007-6] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Cryptosporidium and Cyclospora are obligate, intracellular, coccidian protozoan parasites that infest the gastrointestinal tract of humans and animals causing severe diarrhea illness. In this paper, we present an overview of the conventional and more novel techniques that are currently available to detect Cryptosporidium and Cyclospora in water. Conventional techniques and new immunological and genetic/molecular methods make it possible to assess the occurrence, prevalence, virulence (to a lesser extent), viability, levels, and sources of waterborne protozoa. Concentration, purification, and detection are the three key steps in all methods that have been approved for routine monitoring of waterborne oocysts. These steps have been optimized to such an extent that low levels of naturally occurring Cryptosporidium oocysts can be efficiently recovered from water. The filtration systems developed in the US and Europe trap oocysts more effectively and are part of the standard methodologies for environmental monitoring of Cryptosporidium oocysts in source and treated water. Purification techniques such as immunomagnetic separation and flow cytometry with fluorescent activated cell sorting impart high capture efficiency and selective separation of oocysts from sample debris. Monoclonal antibodies with higher avidity and specificity to oocysts in water concentrates have significantly improved the detection and enumeration steps. To date, PCR-based detection methods allow us to differentiate the human pathogenic Cryptosporidium parasites from those that do not infect humans, and to track the source of oocyst contamination in the environment. Cell culture techniques are now used to examine oocyst viability. While fewer studies have focused on Cyclospora cayetanensis, the parasite has been successfully detected in drinking water and wastewater using current methods to recover Cryptosporidium oocysts. More research is needed for monitoring of Cyclospora in the environment. Meanwhile, molecular methods (e.g. molecular markers such as intervening transcribed spacer regions), which can identify different genotypes of C. cayetanensis, show good promise for detection of this emerging coccidian parasite in water.
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Affiliation(s)
- Walter Quintero-Betancourt
- Water Pollution Microbiology, College of Marine Science, University of South Florida, 140 7th Avenue South, St. Petersburg, FL 33701, USA
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Reiner DS, McCaffery JM, Gillin FD. Reversible interruption of Giardia lamblia cyst wall protein transport in a novel regulated secretory pathway. Cell Microbiol 2001; 3:459-72. [PMID: 11437832 DOI: 10.1046/j.1462-5822.2001.00129.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To survive in the environment and infect a new host, Giardia lamblia secretes an extracellular cyst wall using a poorly understood pathway. The two cyst wall proteins (CWPs) form disulphide-bonded heterodimers and are exported via novel encystation-specific secretory vesicles (ESVs). Exposure of eukaryotic cells to dithiothreitol (DTT) blocks the formation of disulphide bonds in nascent proteins that accumulate in the endoplasmic reticulum (ER) and induces an unfolded protein response (UPR). Proteins that have exited the ER are not susceptible. Exposure to DTT inhibits ESV formation by > 85%. Addition of DTT to encysting cells causes rapid (t1/2 < 10 min), reversible disappearance of ESVs, correlated with reduction of CWPs to monomers and reformation of CWP oligomers upon removal of DTT. Neither CWPs nor ESVs are affected by mercaptoethanesulphonic acid, a strong reducing agent that does not penetrate cells. DTT does not inhibit the overall protein secretory pathway, and recovery does not require new protein synthesis. We found evidence of protein disulphide isomerases in the ESV and the surface of encysting cells, in which they may catalyse initial CWP folding and recovery from DTT. This is the first suggestion of non-CWP proteins in ESVs and of enzymes on the giardial surface. DTT treatment did not stimulate a UPR, suggesting that Giardia may have diverged before the advent of this conserved form of ER quality control.
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Affiliation(s)
- D S Reiner
- Department of Pathology, Division of Infectious Diseases, University of California San Diego, School of Medicine, San Diego, CA 92103-8416, USA
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Abstract
Giardia lamblia is a common cause of diarrhea in humans and other mammals throughout the world. It can be distinguished from other Giardia species by light or electron microscopy. The two major genotypes of G. lamblia that infect humans are so different genetically and biologically that they may warrant separate species or subspecies designations. Trophozoites have nuclei and a well-developed cytoskeleton but lack mitochondria, peroxisomes, and the components of oxidative phosphorylation. They have an endomembrane system with at least some characteristics of the Golgi complex and encoplasmic reticulum, which becomes more extensive in encysting organisms. The primitive nature of the organelles and metabolism, as well as small-subunit rRNA phylogeny, has led to the proposal that Giardia spp. are among the most primitive eukaryotes. G. lamblia probably has a ploidy of 4 and a genome size of approximately 10 to 12 Mb divided among five chromosomes. Most genes have short 5' and 3' untranslated regions and promoter regions that are near the initiation codon. Trophozoites exhibit antigenic variation of an extensive repertoire of cysteine-rich variant-specific surface proteins. Expression is allele specific, and changes in expression from one vsp gene to another have not been associated with sequence alterations or gene rearrangements. The Giardia genome project promises to greatly increase our understanding of this interesting and enigmatic organism.
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Affiliation(s)
- R D Adam
- Department of Medicine, University of Arizona College of Medicine, 1501N. Campbell, Tucson, AZ 85724-5049, USA.
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Abstract
Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine.
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Affiliation(s)
- T B Gardner
- Division of Infectious Diseases, University of Connecticut Health Center, Farmington, Connecticut 06030-3212, USA
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Yong TS, Park SJ, Hwang UW, Yang HW, Lee KW, Min DY, Rim HJ, Wang Y, Zheng F. Genotyping of Giardia lamblia isolates from humans in China and Korea using ribosomal DNA Sequences. J Parasitol 2000; 86:887-91. [PMID: 10958483 DOI: 10.1645/0022-3395(2000)086[0887:goglif]2.0.co;2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Genetic characterization of a total of 15 Giardia lamblia isolates, 8 from Anhui Province, China (all from purified cysts) and 7 from Seoul, Korea (2 from axenic cultures and 5 from purified cysts), was performed by polymerase chain reaction amplification and sequencing of a 295-bp region near the 5' end of the small subunit ribosomal DNA (eukaryotic 16S rDNA). Phylogenetic analyses were subsequently conducted using sequence data obtained in this study, as well as sequences published from other Giardia isolates. The maximum parsimony method revealed that G. lamblia isolates from humans in China and Korea are divided into 2 major lineages, assemblages A and B. All 7 Korean isolates were grouped into assemblage A, whereas 4 Chinese isolates were grouped into assemblage A and 4 into assemblage B. Two Giardia microti isolates and 2 dog-derived Giardia isolates also grouped into assemblage B, whereas Giardia ardeae and Giardia muris were unique.
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Affiliation(s)
- T S Yong
- Department of Parasitology and Institute of Tropical Medicine, Yonsei University College of Medicine, Seoul, Korea
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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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Abstract
Giardiasis is the intestinal infection resulting from infestation with the human parasite Giardia intestinalis, also called Giardia lamblia. The infection may be asymptomatic or present with a variety of symptoms such as diarrhoea, weight loss, abdominal cramps, and failure to thrive. Giardiasis is most often diagnosed after recent travel or in day care centres. The organism has two stages in its life cycle. It is usually ingested as a cyst with as few as 10-25 cysts being sufficient to cause infection. After excystation, the organism is a replicative trophozoite which may attach to the small bowel wall. Giardia intestinalis does not invade the bowel wall. Trophozoites may encyst and be shed in faeces for future ingestion by another host. Diagnosis of infection is by stool examination which may also eliminate other possible infectious agents. Small bowel biopsy may be necessary in difficult individual cases or to rule out non-infectious illnesses, and stool ELISA may serve for large population screening examinations. The mainstay of treatment is metronidazole 250-400 mg three times per day by mouth for 5 days.
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Affiliation(s)
- C J Vesy
- Department of Internal Medicine, University of Texas South-Western Medical Center and Medical Service, Department of Veterans Affairs Medical Center, Dallas, TX, USA
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