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Jia L, Zhao Q, Zhu S, Han H, Zhao H, Yu Y, Yang J, Dong H. Proteomic Analysis of Fractionated Eimeria tenella Sporulated Oocysts Reveals Involvement in Oocyst Wall Formation. Int J Mol Sci 2023; 24:17051. [PMID: 38069374 PMCID: PMC10707475 DOI: 10.3390/ijms242317051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 11/26/2023] [Indexed: 12/18/2023] Open
Abstract
Eimeria tenella is the most pathogenic intracellular protozoan parasite of the Eimeria species. Eimeria oocyst wall biogenesis appears to play a central role in oocyst transmission. Proteome profiling offers insights into the mechanisms governing the molecular basis of oocyst wall formation and identifies targets for blocking parasite transmission. Tandem mass tags (TMT)-labeled quantitative proteomics was used to analyze the oocyst wall and sporocysts of E. tenella. A combined total of 2865 E. tenella proteins were identified in the oocyst wall and sporocyst fractions; among these, 401 DEPs were identified, of which 211 were upregulated and 190 were downregulated. The 211 up-regulated DEPs were involved in various biological processes, including DNA replication, fatty acid metabolism and biosynthesis, glutathione metabolism, and propanoate metabolism. Among these proteins, several are of interest for their likely role in oocyst wall formation, including two tyrosine-rich gametocyte proteins (EtGAM56, EtSWP1) and two cysteine-rich proteins (EtOWP2, EtOWP6). Concurrently, 96 uncharacterized proteins may also participate in oocyst wall formation. The present study significantly expands our knowledge of the proteome of the oocyst wall of E. tenella, thereby providing a theoretical basis for further understanding of the biosynthesis and resilience of the E. tenella oocyst wall.
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Affiliation(s)
| | | | | | | | | | | | | | - Hui Dong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Minhang, Shanghai 200241, China; (L.J.); (Q.Z.); (S.Z.); (H.H.); (H.Z.); (Y.Y.); (J.Y.)
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2
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Cruz-Bustos T, Dolezal M, Feix AS, Ruttkowski B, Hummel K, Razzazi-Fazeli E, Joachim A. Unravelling the sexual developmental biology of Cystoisospora suis, a model for comparative coccidian parasite studies. Front Cell Infect Microbiol 2023; 13:1271731. [PMID: 37953800 PMCID: PMC10635411 DOI: 10.3389/fcimb.2023.1271731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 09/28/2023] [Indexed: 11/14/2023] Open
Abstract
Introduction The apicomplexan parasite Cystoisospora suis has global significance as an enteropathogen of suckling piglets. Its intricate life cycle entails a transition from an asexual phase to sexual development, ultimately leading to the formation of transmissible oocysts. Methods To advance our understanding of the parasite's cellular development, we complemented previous transcriptome studies by delving into the proteome profiles at five distinct time points of in vitro cultivation through LC/MS-MS analysis. Results A total of 1,324 proteins were identified in the in vitro developmental stages of C. suis, and 1,082 proteins were identified as significantly differentially expressed. Data are available via ProteomeXchange with identifier PXD045050. We performed BLAST, GO enrichment, and KEGG pathway analyses on the up- and downregulated proteins to elucidate correlated events in the C. suis life cycle. Our analyses revealed intriguing metabolic patterns in macromolecule metabolism, DNA- and RNA-related processes, proteins associated with sexual stages, and those involved in cell invasion, reflecting the adaptation of sexual stages to a nutrient-poor and potentially stressful extracellular environment, with a focus on enzymes involved in metabolism and energy production. Discussion These findings have important implications for understanding the developmental biology of C. suis as well as other, related coccidian parasites, such as Eimeria spp. and Toxoplasma gondii. They also support the role of C. suis as a new model for the comparative biology of coccidian tissue cyst stages.
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Affiliation(s)
- Teresa Cruz-Bustos
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Marlies Dolezal
- Platform for Bioinformatics and Biostatistics, Department of Biomedical Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Anna Sophia Feix
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Bärbel Ruttkowski
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Karin Hummel
- VetCore Facility (Proteomics), University of Veterinary Medicine Vienna, Vienna, Austria
| | - Ebrahim Razzazi-Fazeli
- VetCore Facility (Proteomics), University of Veterinary Medicine Vienna, Vienna, Austria
| | - Anja Joachim
- Department of Pathobiology, Institute of Parasitology, University of Veterinary Medicine Vienna, Vienna, Austria
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Sena F, Cancela S, Bollati-Fogolín M, Pagotto R, Francia ME. Exploring Toxoplasma gondii´s Biology within the Intestinal Epithelium: intestinal-derived models to unravel sexual differentiation. Front Cell Infect Microbiol 2023; 13:1134471. [PMID: 37313339 PMCID: PMC10258352 DOI: 10.3389/fcimb.2023.1134471] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 04/25/2023] [Indexed: 06/15/2023] Open
Abstract
A variety of intestinal-derived culture systems have been developed to mimic in vivo cell behavior and organization, incorporating different tissue and microenvironmental elements. Great insight into the biology of the causative agent of toxoplasmosis, Toxoplasma gondii, has been attained by using diverse in vitro cellular models. Nonetheless, there are still processes key to its transmission and persistence which remain to be elucidated, such as the mechanisms underlying its systemic dissemination and sexual differentiation both of which occur at the intestinal level. Because this event occurs in a complex and specific cellular environment (the intestine upon ingestion of infective forms, and the feline intestine, respectively), traditional reductionist in vitro cellular models fail to recreate conditions resembling in vivo physiology. The development of new biomaterials and the advances in cell culture knowledge have opened the door to a next generation of more physiologically relevant cellular models. Among them, organoids have become a valuable tool for unmasking the underlying mechanism involved in T. gondii sexual differentiation. Murine-derived intestinal organoids mimicking the biochemistry of the feline intestine have allowed the generation of pre-sexual and sexual stages of T. gondii for the first time in vitro, opening a window of opportunity to tackling these stages by "felinizing" a wide variety of animal cell cultures. Here, we reviewed intestinal in vitro and ex vivo models and discussed their strengths and limitations in the context of a quest for faithful models to in vitro emulate the biology of the enteric stages of T. gondii.
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Affiliation(s)
- Florencia Sena
- Laboratory of Apicomplexan Biology, Institut Pasteur Montevideo, Montevideo, Uruguay
- Laboratorio de Bioquímica, Departamento de Biología Vegetal, Universidad de la República, Montevideo, Uruguay
| | - Saira Cancela
- Cell Biology Unit, Institut Pasteur Montevideo, Montevideo, Uruguay
- Molecular, Cellular, and Animal Technology Program (ProTeMCA), Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Mariela Bollati-Fogolín
- Cell Biology Unit, Institut Pasteur Montevideo, Montevideo, Uruguay
- Molecular, Cellular, and Animal Technology Program (ProTeMCA), Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Romina Pagotto
- Cell Biology Unit, Institut Pasteur Montevideo, Montevideo, Uruguay
| | - María E. Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur Montevideo, Montevideo, Uruguay
- Departamento de Parasitología y Micología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
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4
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Lodoen MB, Smith NC, Soldati-Favre D, Ferguson DJP, van Dooren GG. Nanos gigantium humeris insidentes: old papers informing new research into Toxoplasma gondii. Int J Parasitol 2021; 51:1193-1212. [PMID: 34736901 PMCID: PMC10538201 DOI: 10.1016/j.ijpara.2021.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/25/2022]
Abstract
Since Nicolle, Manceaux and Splendore first described Toxoplasma gondii as a parasite of rodents and rabbits in the early 20th century, a diverse and vigorous research community has been built around studying this fascinating intracellular parasite. In addition to its importance as a pathogen of humans, livestock and wildlife, modern researchers are attracted to T. gondii as a facile experimental system to study many aspects of evolutionary biology, cellular biology, host-microbe interactions, and host immunity. For new researchers entering the field, the extensive literature describing the biology of the parasite, and the interactions with its host, can be daunting. In this review, we examine four foundational studies that describe various aspects of T. gondii biology, presenting a 'journal club'-style analysis of each. We have chosen a paper that established the beguiling life cycle of the parasite (Hutchison et al., 1971), a paper that described key features of its cellular biology that the parasite shares with related organisms (Gustafson et al., 1954), a paper that characterised the origin of the unique compartment in which the parasite resides within host cells (Jones and Hirsch, 1972), and a paper that established a key mechanism in the host immune response to parasite infection (Pfefferkorn, 1984). These interesting and far-reaching studies set the stage for subsequent research into numerous facets of parasite biology. As well as providing new researchers with an entry point into the literature surrounding the parasite, revisiting these studies can remind us of the roots of our discipline, how far we have come, and the new directions in which we might head.
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Affiliation(s)
- Melissa B Lodoen
- Institute for Immunology, University of California, Irvine, Irvine, CA, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, California, USA
| | - Nicholas C Smith
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia; Research School of Biology, Australian National University, Canberra, ACT 2600, Australia
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland
| | - David J P Ferguson
- Nuffield Department of Clinical Laboratory Science, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK; Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK
| | - Giel G van Dooren
- Research School of Biology, Australian National University, Canberra, ACT 2600, Australia.
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5
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Identification of Oocyst-Driven Toxoplasma gondii Infections in Humans and Animals through Stage-Specific Serology-Current Status and Future Perspectives. Microorganisms 2021; 9:microorganisms9112346. [PMID: 34835471 PMCID: PMC8618849 DOI: 10.3390/microorganisms9112346] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022] Open
Abstract
The apicomplexan zoonotic parasite Toxoplasma gondii has three infective stages: sporozoites in sporulated oocysts, which are shed in unsporulated form into the environment by infected felids; tissue cysts containing bradyzoites, and fast replicating tachyzoites that are responsible for acute toxoplasmosis. The contribution of oocysts to infections in both humans and animals is understudied despite being highly relevant. Only a few diagnostic antigens have been described to be capable of discriminating which parasite stage has caused an infection. Here we provide an extensive overview of the antigens and serological assays used to detect oocyst-driven infections in humans and animals according to the literature. In addition, we critically discuss the possibility to exploit the increasing knowledge of the T. gondii genome and the various 'omics datasets available, by applying predictive algorithms, for the identification of new oocyst-specific proteins for diagnostic purposes. Finally, we propose a workflow for how such antigens and assays based on them should be evaluated to ensure reproducible and robust results.
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6
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Tomasina R, Francia ME. The Structural and Molecular Underpinnings of Gametogenesis in Toxoplasma gondii. Front Cell Infect Microbiol 2020; 10:608291. [PMID: 33365279 PMCID: PMC7750520 DOI: 10.3389/fcimb.2020.608291] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 11/04/2020] [Indexed: 01/18/2023] Open
Abstract
Toxoplasma gondii is a widely prevalent protozoan parasite member of the phylum Apicomplexa. It causes disease in humans with clinical outcomes ranging from an asymptomatic manifestation to eye disease to reproductive failure and neurological symptoms. In farm animals, and particularly in sheep, toxoplasmosis costs the industry millions by profoundly affecting their reproductive potential. As do all the parasites in the phylum, T. gondii parasites go through sexual and asexual replication in the context of an heteroxenic life cycle involving members of the Felidae family and any warm-blooded vertebrate as definitive and intermediate hosts, respectively. During sexual replication, merozoites differentiate into female and male gametes; their combination gives rise to a zygotes which evolve into sporozoites that encyst and are shed in cat's feces as environmentally resistant oocysts. During zygote formation T. gondii parasites are diploid providing the parasite with a window of opportunity for genetic admixture making this a key step in the generation of genetic diversity. In addition, oocyst formation and shedding are central to dissemination and environmental contamination with infectious parasite forms. In this minireview we summarize the current state of the art on the process of gametogenesis. We discuss the unique structures of macro and microgametes, an insight acquired through classical techniques, as well as the more recently attained molecular understanding of the routes leading up to these life forms by in vitro and in vivo systems. We pose a number of unanswered questions and discuss these in the context of the latest findings on molecular cues mediating stage switching, and the implication for the field of newly available in vitro tools.
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Affiliation(s)
- Ramiro Tomasina
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - María E Francia
- Laboratory of Apicomplexan Biology, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Department of Parasitology and Mycology, School of Medicine, Universidad de la Republica, Montevideo, Uruguay
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7
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Marciano MAM, Silva RA, Barbosa ML, Ferreira ARS, Pereira-Chioccola VL. Determination of the viability of Toxoplasma gondii oocysts by PCR real-time after treatment with propidium monoazide. Rev Inst Med Trop Sao Paulo 2020; 62:e84. [PMID: 33146312 PMCID: PMC7608075 DOI: 10.1590/s1678-9946202062084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/01/2020] [Indexed: 11/23/2022] Open
Abstract
This study aimed to investigate a methodology for discriminating viable and non-viable T. gondii oocysts in water. Analyses included two steps: (i) microscopic investigation with vital dyes; (ii) molecular investigation, using a real time PCR (qPCR), after parasite treatment (or not) with propidium monoazide (PMA). The method was called qPCR-PMA. Oocyst aliquots were incubated (15 min) at 25 ºC or 100 ºC and analyzed by microscopy, after trypan blue and neutral red staining. Microscopic investigation determined viable and non-viable oocysts. For the molecular investigation, both aliquots of oocysts were treated with PMA. Non-viable oocysts, after PMA treatment, exhibited an inhibition of DNA amplification by qPCR. Although analyses were carried out with oocysts treated experimentally, these results suggest that qPCR-PMA can be a useful strategy to distinguish viable and non-viable T. gondii oocysts in water safety testing, showing if water is safe to drink.
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Affiliation(s)
| | | | - Maria Luisa Barbosa
- Instituto Adolfo Lutz , Núcleo de Morfologia e Microscopia , São Paulo , São Paulo , Brazil
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8
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Abbas IE, El-Alfy E, Al-Araby M, Al-Kappany Y, El-Seadawy R, Dubey JP. Prevalence of Eimeria Species in Camels (Camelus dromedarius) from Egypt and Variability in Structure of Eimeria cameli Oocysts. J Parasitol 2019. [DOI: 10.1645/18-201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- I. E. Abbas
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - E. El-Alfy
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - M. Al-Araby
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - Y. Al-Kappany
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - R. El-Seadawy
- Parasitology Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, 35516, Egypt
| | - J. P. Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland 20705-2350
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9
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Differential Roles for Inner Membrane Complex Proteins across Toxoplasma gondii and Sarcocystis neurona Development. mSphere 2017; 2:mSphere00409-17. [PMID: 29062899 PMCID: PMC5646244 DOI: 10.1128/msphere.00409-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 09/29/2017] [Indexed: 12/30/2022] Open
Abstract
The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative alveolin domain-containing IMC proteins across developmental stages. Our work shows universal but distinct roles for IMC1, -3, and -7 during Toxoplasma asexual division but more specialized functions for these proteins during gametogenesis. In addition, we find that IMC15 is involved in daughter formation in both Toxoplasma and Sarcocystis tachyzoites, bradyzoites, and sporozoites. IMC14 and IMC15 function in limiting the number of Toxoplasma offspring per division. Furthermore, IMC7, -12, and -14, which are recruited in the G1 cell cycle stage, are required for stress resistance of extracellular tachyzoites. Thus, although the roles of the different IMC proteins appear to overlap, stage- and development-specific behaviors indicate that their functions are uniquely tailored to each life stage requirement. The inner membrane complex (IMC) of apicomplexan parasites contains a network of intermediate filament-like proteins. The 14 alveolin domain-containing IMC proteins in Toxoplasma gondii fall into different groups defined by their distinct spatiotemporal dynamics during the internal budding process of tachyzoites. Here, we analyzed representatives of different IMC protein groups across all stages of the Toxoplasma life cycle and during Sarcocystis neurona asexual development. We found that across asexually dividing Toxoplasma stages, IMC7 is present exclusively in the mother’s cytoskeleton, whereas IMC1 and IMC3 are both present in mother and daughter cytoskeletons (IMC3 is strongly enriched in daughter buds). In developing macro- and microgametocytes, IMC1 and -3 are absent, whereas IMC7 is lost in early microgametocytes but retained in macrogametocytes until late in their development. We found no roles for IMC proteins during meiosis and sporoblast formation. However, we observed that IMC1 and IMC3, but not IMC7, are present in sporozoites. Although the spatiotemporal pattern of IMC15 and IMC3 suggests orthologous functions in Sarcocystis, IMC7 may have functionally diverged in Sarcocystis merozoites. To functionally characterize IMC proteins, we knocked out IMC7, -12, -14, and -15 in Toxoplasma. IMC14 and -15 appear to be involved in switching between endodyogeny and endopolygeny. In addition, IMC7, -12, and -14, which are all recruited to the cytoskeleton outside cytokinesis, are critical for the structural integrity of extracellular tachyzoites. Altogether, stage- and development-specific roles for IMC proteins can be discerned, suggesting different niches for each IMC protein across the entire life cycle. IMPORTANCE The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative alveolin domain-containing IMC proteins across developmental stages. Our work shows universal but distinct roles for IMC1, -3, and -7 during Toxoplasma asexual division but more specialized functions for these proteins during gametogenesis. In addition, we find that IMC15 is involved in daughter formation in both Toxoplasma and Sarcocystis. IMC14 and IMC15 function in limiting the number of Toxoplasma offspring per division. Furthermore, IMC7, -12, and -14, which are recruited in the G1 cell cycle stage, are required for stress resistance of extracellular tachyzoites. Thus, although the roles of the different IMC proteins appear to overlap, stage- and development-specific behaviors indicate that their functions are uniquely tailored to each life stage requirement.
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Impact of environmental factors on the emergence, transmission and distribution of Toxoplasma gondii. Parasit Vectors 2016; 9:137. [PMID: 26965989 PMCID: PMC4785633 DOI: 10.1186/s13071-016-1432-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 03/05/2016] [Indexed: 11/10/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan that poses a great threat to human health and economic well-being worldwide. The effects of environmental factors such as changing climate and human activities on the ecology of this protozoan are being discovered. Accumulated evidence shows that changes of these environmental factors can exert influence on the occurrence, transmission and distribution of T. gondii. This article reviews studies from different geographical regions with varying climates, social cultures and animal welfare standards. It aims to illustrate how these environmental factors work, highlighting their importance in influencing the ecology of T. gondii, as well as providing clues which may contribute to preventing transmission of this important zoonotic pathogen.
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11
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Targeting Toxoplasma tubules: tubulin, microtubules, and associated proteins in a human pathogen. EUKARYOTIC CELL 2014; 14:2-12. [PMID: 25380753 DOI: 10.1128/ec.00225-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that causes serious opportunistic infections, birth defects, and blindness in humans. Microtubules are critically important components of diverse structures that are used throughout the Toxoplasma life cycle. As in other eukaryotes, spindle microtubules are required for chromosome segregation during replication. Additionally, a set of membrane-associated microtubules is essential for the elongated shape of invasive "zoites," and motility follows a spiral trajectory that reflects the path of these microtubules. Toxoplasma zoites also construct an intricate, tubulin-based apical structure, termed the conoid, which is important for host cell invasion and associates with proteins typically found in the flagellar apparatus. Last, microgametes specifically construct a microtubule-containing flagellar axoneme in order to fertilize macrogametes, permitting genetic recombination. The specialized roles of these microtubule populations are mediated by distinct sets of associated proteins. This review summarizes our current understanding of the role of tubulin, microtubule populations, and associated proteins in Toxoplasma; these components are used for both novel and broadly conserved processes that are essential for parasite survival.
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12
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de Muno RM, Moura MA, de Carvalho LC, Seabra SH, Barbosa HS. Spontaneous cystogenesis of Toxoplasma gondii in feline epithelial cells in vitro. Folia Parasitol (Praha) 2014. [DOI: 10.14411/fp.2014.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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McGovern KE, Wilson EH. Dark side illuminated: imaging of Toxoplasma gondii through the decades. Parasit Vectors 2013; 6:334. [PMID: 24267350 PMCID: PMC4176259 DOI: 10.1186/1756-3305-6-334] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Accepted: 11/15/2013] [Indexed: 11/29/2022] Open
Abstract
In the more than 100 years since its discovery, our knowledge of Toxoplasma biology has improved enormously. The evolution of molecular biology, immunology and genomics has had profound influences on our understanding of this ubiquitous bug. However, it could be argued that in science today the adage "seeing is believing" has never been truer. Images are highly influential and in the time since the first description of T. gondii, advances in microscopy and imaging technology have been and continue to be dramatic. In this review we recount the discovery of T. gondii and the contribution of imaging techniques to elucidating its life cycle, biology and the immune response of its host.
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Affiliation(s)
- Kathryn E McGovern
- School of Medicine, Division of Biomedical Sciences, University of California, Riverside, CA 92521-0129, USA.
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14
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Abstract
The ability of microorganisms to survive under extreme conditions is closely related to the physicochemical properties of their wall. In the ubiquitous protozoan parasite Toxoplasma gondii, the oocyst stage possesses a bilayered wall that protects the dormant but potentially infective parasites from harsh environmental conditions until their ingestion by the host. None of the common disinfectants are effective in killing the parasite because the oocyst wall acts as a primary barrier to physical and chemical attacks. Here, we address the structure and chemistry of the wall of the T. gondii oocyst by combining wall surface treatments, fluorescence imaging, EM, and measurements of its mechanical characteristics by using atomic force microscopy. Elasticity and indentation measurements indicated that the oocyst wall resembles common plastic materials, based on the Young moduli, E, evaluated by atomic force microscopy. Our study demonstrates that the inner layer is as robust as the bilayered wall itself. Besides wall mechanics, our results suggest important differences regarding the nonspecific adhesive properties of each layer. All together, these findings suggest a key biological role for the oocyst wall mechanics in maintaining the integrity of the T. gondii oocysts in the environment or after exposure to disinfectants, and therefore their potential infectivity to humans and animals.
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15
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VanWormer E, Fritz H, Shapiro K, Mazet JAK, Conrad PA. Molecules to modeling: Toxoplasma gondii oocysts at the human-animal-environment interface. Comp Immunol Microbiol Infect Dis 2013; 36:217-31. [PMID: 23218130 PMCID: PMC3779781 DOI: 10.1016/j.cimid.2012.10.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 10/17/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
Environmental transmission of extremely resistant Toxoplasma gondii oocysts has resulted in infection of diverse species around the world, leading to severe disease and deaths in human and animal populations. This review explores T. gondii oocyst shedding, survival, and transmission, emphasizing the importance of linking laboratory and landscape from molecular characterization of oocysts to watershed-level models of oocyst loading and transport in terrestrial and aquatic systems. Building on discipline-specific studies, a One Health approach incorporating tools and perspectives from diverse fields and stakeholders has contributed to an advanced understanding of T. gondii and is addressing transmission at the rapidly changing human-animal-environment interface.
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Affiliation(s)
- Elizabeth VanWormer
- One Health Institute, School of Veterinary Medicine, University of California-Davis, 1 Shields Avenue, Davis, CA 95616, USA.
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Wendte JM, Gibson AK, Grigg ME. Population genetics of Toxoplasma gondii: new perspectives from parasite genotypes in wildlife. Vet Parasitol 2011; 182:96-111. [PMID: 21824730 PMCID: PMC3430134 DOI: 10.1016/j.vetpar.2011.07.018] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Toxoplasma gondii, a zoonotic protozoal parasite, is well-known for its global distribution and its ability to infect virtually all warm-blooded vertebrates. Nonetheless, attempts to describe the population structure of T. gondii have been primarily limited to samples isolated from humans and domesticated animals. More recent studies, however, have made efforts to characterize T. gondii isolates from a wider range of host species and geographic locales. These findings have dramatically changed our perception of the extent of genetic diversity in T. gondii and the relative roles of sexual recombination and clonal propagation in the parasite's lifecycle. In particular, identification of novel, disease-causing T. gondii strains in wildlife has raised concerns from both a conservation and public health perspective as to whether distinct domestic and sylvatic parasite gene pools exist. If so, overlap of these cycles may represent regions of high probability of disease emergence. Here, we attempt to answer these key questions by reviewing recent studies of T. gondii infections in wildlife, highlighting those which have advanced our understanding of the genetic diversity and population biology of this important zoonotic pathogen.
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Affiliation(s)
- Jered M. Wendte
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA
- Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, OK, 74074, USA
| | - Amanda K. Gibson
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA
| | - Michael E. Grigg
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-0425, USA
- Department of Veterinary Pathobiology, Oklahoma State University Center for Veterinary Health Sciences, Stillwater, OK, 74074, USA
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Colegrove KM, Grigg ME, Carlson-Bremer D, Miller RH, Gulland FMD, Ferguson DJP, Rejmanek D, Barr BC, Nordhausen R, Melli AC, Conrad PA. Discovery of three novel coccidian parasites infecting California sea lions (Zalophus californianus), with evidence of sexual replication and interspecies pathogenicity. J Parasitol 2011; 97:868-77. [PMID: 21495828 DOI: 10.1645/ge-2756.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Enteric protozoal infection was identified in 5 stranded California sea lions (Zalophus californianus). Microscopically, the apical cytoplasm of distal jejunal enterocytes contained multiple stages of coccidian parasites, including schizonts with merozoites and spherical gametocytes, which were morphologically similar to coccidians. By histopathology, organisms appeared to be confined to the intestine and accompanied by only mild enteritis. Using electron microscopy, both sexual (microgametocytes, macrogamonts) and asexual (schizonts, merozoites) coccidian stages were identified in enterocytes within parasitophorous vacuoles, consistent with apicomplexan development in a definitive host. Serology was negative for tissue cyst-forming coccidians, and immunohistochemistry for Toxoplasma gondii was inconclusive and negative for Neospora caninum and Sarcocystis neurona. Analysis of ITS-1 gene sequences amplified from frozen or formalin-fixed paraffin-embedded intestinal sections identified DNA sequences with closest homology to Neospora sp. (80%); these novel sequences were referred to as belonging to coccidian parasites "A," "B," and "C." Subsequent molecular analyses completed on a neonatal harbor seal (Phoca vitulina) with protozoal lymphadenitis, hepatitis, myocarditis, and encephalitis showed that it was infected with a coccidian parasite bearing the "C" sequence type. Our results indicate that sea lions likely serve as definitive hosts for 3 newly described coccidian parasites, at least 1 of which is pathogenic in a marine mammal intermediate host species.
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Affiliation(s)
- Kathleen M Colegrove
- Zoological Pathology Program, College of Veterinary Medicine at Urbana-Champaign, Loyola University Medical Center, 2160 South First Avenue, Maywood, Illinois 60153, USA.
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Grigg ME, Sundar N. Sexual recombination punctuated by outbreaks and clonal expansions predicts Toxoplasma gondii population genetics. Int J Parasitol 2009; 39:925-33. [PMID: 19217909 PMCID: PMC2713429 DOI: 10.1016/j.ijpara.2009.02.005] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 01/31/2009] [Accepted: 02/01/2009] [Indexed: 10/21/2022]
Abstract
The cosmopolitan parasitic pathogen Toxoplasma gondii is capable of infecting essentially any warm-blooded vertebrate worldwide, including most birds and mammals, and establishes chronic infections in one-third of the globe's human population. The success of this highly prevalent zoonosis is largely the result of its ability to propagate both sexually and clonally. Frequent genetic exchanges via sexual recombination among extant parasite lineages that mix in the definitive felid host produces new lines that emerge to expand the parasite's host range and cause outbreaks. Highly successful lines spread clonally via carnivorism and in some cases sweep to pandemic levels. The extent to which sexual reproduction versus clonal expansion shapes Toxoplasma's current, global population genetic structure is the central question this review will attempt to answer.
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Affiliation(s)
- Michael E Grigg
- Molecular Parasitology Unit, Laboratory of Parasitic Diseases, NIAID, NIH, Bethesda, MD 20815, USA.
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MORN1 has a conserved role in asexual and sexual development across the apicomplexa. EUKARYOTIC CELL 2008; 7:698-711. [PMID: 18310354 DOI: 10.1128/ec.00021-08] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The gene encoding the membrane occupation and recognition nexus protein MORN1 is conserved across the Apicomplexa. In Toxoplasma gondii, MORN1 is associated with the spindle poles, the anterior and posterior rings of the inner membrane complex (IMC). The present study examines the localization of MORN1 during the coccidian development of T. gondii and three Eimeria species (in the definitive host) and erythrocytic schizogony of Plasmodium falciparum. During asexual proliferation, MORN1 is associated with the posterior ring of the IMCs of the multiple daughters forming during T. gondii endopolygeny and schizogony in Eimeria and P. falciparum. Furthermore, the expression of P. falciparum MORN1 protein peaked in late schizogony. These data fit a model with a conserved role for MORN1 during IMC assembly in all variations of asexual development. An important new observation is the reactivity of MORN1 antibody with certain sexual stages in T. gondii and Eimeria species. Here MORN1 is organized as a ring-like structure where the microgametes bud from the microgametocyte while in mature microgametes it is present near the flagellar basal bodies and mitochondrion. These observations suggest a conserved role for MORN1 in both asexual and sexual development across the Apicomplexa.
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Ferguson DJP, Henriquez FL, Kirisits MJ, Muench SP, Prigge ST, Rice DW, Roberts CW, McLeod RL. Maternal inheritance and stage-specific variation of the apicoplast in Toxoplasma gondii during development in the intermediate and definitive host. EUKARYOTIC CELL 2005; 4:814-26. [PMID: 15821140 PMCID: PMC1087807 DOI: 10.1128/ec.4.4.814-826.2005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The structure and location of Toxoplasma gondii apicoplasts were examined in intermediate and definitive hosts and shown to vary in a stage-specific manner. Immunocytochemistry and electron microscopy studies were used to identify changes in the morphology of apicoplasts and in their enoyl reductase (ENR) content during asexual and sexual development. Apicoplasts in tachyzoites were small, multimembraned organelles anterior to nuclei that divided and segregated with the nuclei during endodyogeny. In nonproliferating bradyzoites within mature tissue cysts (1 to 24 months), apicoplasts had high levels of ENR. During coccidian development, asexual multiplication (endopolygeny), resulting in simultaneous formation of up to 30 daughters (merozoites), involved an initial growth phase associated with repeated nuclear divisions during which apicoplasts appeared as single, elongated, branched structures with increased levels of ENR. At initiation of merozoite formation, enlarged apicoplasts divided simultaneously, with constrictions, into portions that segregated to developing daughters. In sexual stages, apicoplast division did not occur during microgametogony, and apicoplasts were absent from the microgametes that were formed. In contrast, during macrogametogony, the apicoplast appeared as a large, branched, perinuclear structure that had very high levels of ENR in the absence of nuclear division. Marked increases in the size of apicoplasts and levels of ENR may be related to requirements of the macrogametocytes to synthesize and store all components necessary for oocyst formation and subsequent extracellular sporulation. Thus, it is shown that apicoplasts are present and contain ENR in all T. gondii life cycle stages except microgametes, which will result in maternal inheritance of the organelle.
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Affiliation(s)
- David J P Ferguson
- Department of Pathology, University of Oxford, John Radcliffe Hospital, United Kingdom
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Abstract
Detection of Toxoplasma gondii oocysts in environmental samples is a great challenge for researchers as this coccidian parasite can be responsible for severe infections in humans and in animals via ingestion of a single oocyst from contaminated water, soil, fruits or vegetables. Despite field investigations, oocysts have been rarely recovered from the environment due to the lack of sensitive methods. Immunomagnetic separation, fluorescence-activated cell sorting, and polymerase chain reaction have recently shown promising use in detection of protozoa from complex matrices. Such procedures could be applied to T. gondii detection, if studies on the antigenic and biochemical composition of the oocyst wall are completed. Using such methods, it will be possible to assess the occurrence, prevalence, viability and virulence of T. gondii oocysts in environmental matrices and specify sources of human and animal contamination.
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Affiliation(s)
- Aurélien Dumètre
- UPRES EA 3174, Neuroparasitologie et Neuroépidémiologie Tropicale, Faculté de Médecine, 2 Rue du Dr Marcland, F-87025 Limoges, France
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Dzbenski TH, Michalak T, Plonka WS. Electron microscopic and radioisotopic studies on cap formation in Toxoplasma gondii. Infect Immun 1976; 14:1196-201. [PMID: 789242 PMCID: PMC415514 DOI: 10.1128/iai.14.5.1196-1201.1976] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Trophozoites of Toxoplasma gondii from mouse peritoneal exudate are capable of shedding antibodies with which they have been previously coated. The antibodies are first moved towards the anterior pole of the parasite, at which they form a "cap". From the pole they are shed into the environment in the form of antigen-antibody complexes. An internalization of the accumulated material has never been encountered. Most probably, the observed phenomenon reflects a mechanism by which the parasite evades the host's immune response.
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