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Warschkau D, Klein S, Schadt E, Doellinger J, Schares G, Seeber F. Proteomic identification of a Toxoplasma gondii sporozoite-specific antigen using HDAC3 inhibitor-treated tachyzoites as surrogate. FEMS MICROBES 2024; 6:xtae034. [PMID: 39802703 PMCID: PMC11719624 DOI: 10.1093/femsmc/xtae034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2024] [Revised: 11/26/2024] [Accepted: 12/19/2024] [Indexed: 01/16/2025] Open
Abstract
The apicomplexan parasite Toxoplasma gondii has a complex life cycle. Access to sexual stages and sporozoite-containing oocysts, essential for studying the parasite's environmental transmission, is limited and requires animal experiments with cats. Thus, alternatives and resource-efficient methods are needed. Several molecular factors and transcriptional switches responsible for differentiation have been identified in recent years. In tachyzoites, drug-induced inhibition of the histone deacetylase HDAC3, or genetic depletion of transcription factors regulating HDAC3, leads to the expression of genes that are specific to sexual stages and oocysts. Here, we applied this concept and showed that the commercially available HDAC3 inhibitor apicidin could be used to identify the hitherto unknown antigen of the sporozoite-specific monoclonal antibody G1/19 in tachyzoites. Using mass spectrometry of immunoprecipitated G1/19 target protein from apicidin-treated cultures, we identified it as SporoSAG. In addition, for the much less abundant sporozoite-specific protein LEA860, apicidin treatment was still sufficient to induce a detectable protein level in immunofluorescence microscopy. We also discuss further applications and the limitations of this approach. This allows to overcome issues with the paucity of material of sexual stages and oocysts from T. gondii to some extent without the need for cat-derived material.
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Affiliation(s)
- David Warschkau
- FG16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany
- Humboldt-Universität zu Berlin, Department of Biology, 10099 Berlin, Germany
| | - Sandra Klein
- FG16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany
| | - Ella Schadt
- FG16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany
| | - Joerg Doellinger
- ZBS6: Proteomics and Spectroscopy, Robert Koch Institute, 13353 Berlin, Germany
| | - Gereon Schares
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, National Reference Laboratory for Toxoplasmosis, 17493 Greifswald-Insel Riems, Germany
| | - Frank Seeber
- FG16: Mycotic and Parasitic Agents and Mycobacteria, Robert Koch Institute, 13353 Berlin, Germany
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Kanakapura Sundararaj B, Goyal M, Samuelson J. Cellulose binding and the timing of expression influence protein targeting to the double-layered cyst wall of Acanthamoeba. mSphere 2024; 9:e0046624. [PMID: 39136454 PMCID: PMC11423589 DOI: 10.1128/msphere.00466-24] [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: 05/29/2024] [Accepted: 07/22/2024] [Indexed: 09/26/2024] Open
Abstract
The cyst wall of the eye pathogen Acanthamoeba castellanii contains cellulose and has ectocyst and endocyst layers connected by conical ostioles. Cyst walls contain families of lectins that localize to the ectocyst layer (Jonah) or the endocyst layer and ostioles (Luke and Leo). How lectins and an abundant laccase bind cellulose and why proteins go to locations in the wall are not known and are the focus of the studies here. Structural predictions identified β-jelly-roll folds (BJRFs) of Luke and sets of four disulfide knots (4DKs) of Leo, each of which contains linear arrays of aromatic amino acids, also present in carbohydrate-binding modules of bacterial and plant endocellulases. Ala mutations showed that these aromatics are necessary for cellulose binding and proper localization of Luke and Leo in the Acanthamoeba cyst wall. BJRFs of Luke, 4DKs of Leo, a single β-helical fold (BHF) of Jonah, and a copper oxidase domain of the laccase each bind to glycopolymers in both layers of deproteinated cyst walls. Promoter swaps showed that ectocyst localization does not just correlate with but is caused by early encystation-specific expression, while localization in the endocyst layer and ostioles is caused by later expression. Evolutionary studies showed distinct modes of assembly of duplicated domains in Luke, Leo, and Jonah lectins and suggested Jonah BHFs originated from bacteria, Luke BJRFs share common ancestry with slime molds, while 4DKs of Leo are unique to Acanthamoeba.IMPORTANCEAcanthamoebae is the only human parasite with cellulose in its cyst wall and conical ostioles that connect its inner and outer layers. Cyst walls are important virulence factors because they make Acanthamoebae resistant to surface disinfectants, hand sanitizers, contact lens sterilizers, and antibiotics applied to the eye. The goal here was to understand better how proteins are targeted to specific locations in the cyst wall. To this end, we identified three new proteins in the outer layer of the cyst wall, which may be targets for diagnostic antibodies in corneal scrapings. We used structural predictions and mutated proteins to show linear arrays of aromatic amino acids of two unrelated wall proteins are necessary for binding cellulose and proper wall localization. We showed early expression during encystation causes proteins to localize to the outer layer, while later expression causes proteins to localize to the inner layer and the ostioles.
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Affiliation(s)
- Bharath Kanakapura Sundararaj
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA
| | - Manish Goyal
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA
| | - John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA
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Wang L, Liu D, Zhu Y, Wang F, Cai W, Feng Q, Su S, Hou Z, Xu J, Hu J, Tao J. Comparative proteomic analysis of wall-forming bodies and oocyst wall reveals the molecular basis underlying oocyst wall formation in Eimeria necatrix. Parasit Vectors 2023; 16:460. [PMID: 38111000 PMCID: PMC10729351 DOI: 10.1186/s13071-023-06076-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND The durable oocyst wall formed from the contents of wall-forming bodies (WFBs) protects Eimeria parasites from harsh conditions and enhances parasite transmission. Comprehending the contents of WFBs and proteins involved in oocyst wall formation is pivotal to understanding the mechanism of the oocyst wall formation and the search for novel targets to disrupt parasite transmission. METHODS Total proteins extracted from WFBs and the oocyst wall of Eimeria necatrix were subjected to comparative proteomic analysis using tandem mass tag in conjunction with liquid chromatography tandem-mass spectrometry techniques. After functional clustering analysis of the identified proteins, three proteins, including E. necatrix disulfide isomerase (EnPDI), thioredoxin (EnTrx) and phosphoglycerate kinase (EnPGK), were selected for further study to confirm their potential roles in oocyst wall formation. RESULTS A total of 3009 and 2973 proteins were identified from WFBs and the oocyst wall of E. necatrix, respectively. Among these proteins, 1102 were identified as differentially expressed proteins, of which 506 were upregulated and 596 downregulated in the oocyst wall compared to the WFBs. A total of 108 proteins, including compositional proteins of the oocyst wall, proteases, oxidoreductases, proteins involved in glycosylation, proteins involved in synthesis of the acid-fast lipid layer and proteins related to transport, were proposed to be involved in oocyst wall formation. The approximate molecular sizes of native EnPDI, EnTrx and EnPGK proteins were 55, 50 and 45 kDa, respectively. EnPDI was present in both type 1 and type 2 WFBs, EnTrx was present only in type 2 WFB2 and EnPGK was present only in type 1 WFBs, whereas all of them were localized to the outer layer of the oocyst wall, indicating that all of them participate in the formation of the oocyst wall. CONCLUSIONS To the best of our knowledge, this is the first report on the proteomes of WFBs and the oocyst wall of E. necatrix. The data obtained from this study form a basis for deciphering the molecular mechanisms underlying oocyst wall formation of Eimeria parasites. They also provide valuable resources for future studies on the development of novel therapeutic agents and vaccines aimed at combating coccidian transmission.
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Affiliation(s)
- Lele Wang
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Dandan Liu
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Yu Zhu
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Feiyan Wang
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Weimin Cai
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Qianqian Feng
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Shijie Su
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Zhaofeng Hou
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Jinjun Xu
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China
| | - Junjie Hu
- School of Ecology and Environmental Sciences and Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming, 650091, People's Republic of China
| | - Jianping Tao
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China.
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, 225009, People's Republic of China.
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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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López-Ureña NM, Calero-Bernal R, Koudela B, Cherchi S, Possenti A, Tosini F, Klein S, San Juan-Casero C, Jara-Herrera S, Jokelainen P, Regidor-Cerrillo J, Ortega-Mora LM, Spano F, Seeber F, Álvarez-García G. Limited value of current and new in silico predicted oocyst-specific proteins of Toxoplasma gondii for source-attributing serology. FRONTIERS IN PARASITOLOGY 2023; 2:1292322. [PMID: 39816825 PMCID: PMC11731929 DOI: 10.3389/fpara.2023.1292322] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/01/2023] [Indexed: 01/18/2025]
Abstract
Toxoplasma gondii is a zoonotic parasite infecting all warm-blooded animals, including humans. The contribution of environmental contamination by T. gondii oocysts to infections is understudied. The aim of the current work was to explore T. gondii serology as a means of attributing the source of infection using a robust stepwise approach. We identified in silico thirty-two promising oocyst-specific antigens from T. gondii ´omics data, recombinantly expressed and purified them and validated whether serology based on these proteins could discriminate oocyst- from tissue cyst-driven experimental infections. For this, three well-characterized serum panels, sampled from 0 to 6 weeks post-infection, from pigs and sheep experimentally infected with T. gondii oocysts or tissue cysts, were used. Candidate proteins were initially screened by Western blot with sera from pigs or sheep, infected for different times, either with oocysts or tissue cysts, as well as non-infected animals. Only the recombinant proteins TgCCp5A and TgSR1 provoked seroconversion upon infection and appeared to discriminate between oocyst- and tissue cyst-driven infections with pig sera. They were subsequently used to develop an enzyme-linked immunosorbent assay test for pigs. Based on this assay and Western blot analyses, a lack of stage specificity and low antigenicity was observed with all pig sera. The same was true for proteins TgERP, TgSporoSAG, TgOWP1 and TgOWP8, previously described as source-attributing antigens, when analyzed using the whole panels of sera. We conclude that there is currently no antigen that allows the discrimination of T. gondii infections acquired from either oocysts or tissue cysts by serological tests. This work provides robust new knowledge that can inform further research and development toward source-attributing T. gondii serology.
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Affiliation(s)
- Nadia-María López-Ureña
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
| | - Rafael Calero-Bernal
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
| | - Bretislav Koudela
- Central European Institute of Technology (CEITEC), University of Veterinary Sciences, Brno, Czechia
- Faculty of Veterinary Medicine, University of Veterinary Sciences, Brno, Czechia
- Veterinary Research Institute, Brno, Czechia
| | - Simona Cherchi
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Alessia Possenti
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Fabio Tosini
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Sandra Klein
- FG16, Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Carmen San Juan-Casero
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
| | - Silvia Jara-Herrera
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
| | - Pikka Jokelainen
- Infectious Disease Preparedness, Statens Serum Institut, Copenhagen, Denmark
| | | | - Luis-Miguel Ortega-Mora
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
| | - Furio Spano
- Unit of Foodborne and Neglected Parasitic Diseases, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Frank Seeber
- FG16, Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Gema Álvarez-García
- Salud Veterinaria y Zoonosis (SALUVET), Animal Health Department, Veterinary Faculty, Complutense University of Madrid, Madrid, Spain
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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: 4] [Impact Index Per Article: 2.0] [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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Wang F, Ye Z, Liu Y, Wang L, Su S, Hou Z, Xu J, Tao J, Liu D. Characterization of the novel glucose-methanol-choline (GMC) oxidoreductase EnOXIO1 in Eimeria necatrix. Vet Parasitol 2023; 321:110002. [PMID: 37567028 DOI: 10.1016/j.vetpar.2023.110002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/29/2023] [Accepted: 07/30/2023] [Indexed: 08/13/2023]
Abstract
Eimeria species are intracellular obligate parasites, among the most common pathogens affecting the intensive poultry industry. Oxidoreductases are members of a class of proteins with redox activity and are widely found in apicomplexan protozoans. However, there have been few reports related to Eimeria species. In this study, total RNA was extracted from the gametocytes of E. necatrix Yangzhou strain to amplify the EnOXIO1 gene using reverse-transcription polymerase chain reaction. After cloning and sequence analysis, the prokaryotic expression vector pET-28a(+)-EnOXIO1 was constructed and transformed into Escherichia coli BL21(DE3), and the recombinant protein rEnOXIO1 was expressed by induction with isopropyl ß-D-1-thiogalactopyranoside. The full length EnOXIO1 gene was 2535 bp encoding 844 amino acids, and the EnOXIO1 protein had a molecular weight of about 100 kDa and was mainly expressed in inclusion bodies. Western blot analysis indicated that the rEnOXIO1 protein had good antigenicity and cross-reactivity and was specifically recognized by a 6 ×HIS labeled monoclonal antibody, mouse anti-recombinant protein polyclonal antibody, and recovery serum from chickens infected with E. necatrix, E. acervulina, and E. tenella sporulated oocysts. The results of laser confocal immunofluorescence localization showed that the EnOXIO1 protein was mainly located on the wall-forming bodies in gametocytes and played an important role in the formation of the oocyst wall. Quantitative PCR analysis revealed that transcript levels of EnOXIO1 were highest in the gametocyte stage. Protein expression levels of EnOXIO1 were higher in the gametocyte stage than in other developmental stages according to western blot analysis. Vaccination of chickens against E. necatrix was achieved with recombinant protein rEnOXIO1, which triggered humoral immunity and antibody production, increased average body weight gain, reduced oocyst output and alleviated lesions after E. necatrix infection. The highest ACI value (172.36) was observed in chickens that received 200 μg rEnOXIO1 compared with other immunization groups.
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Affiliation(s)
- Feiyan Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Zhuang Ye
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Yue Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Lele Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Shijie Su
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Zhaofeng Hou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Jinjun Xu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Jianping Tao
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Dandan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
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8
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Late Embryogenesis Abundant Proteins Contribute to the Resistance of Toxoplasma gondii Oocysts against Environmental Stresses. mBio 2023; 14:e0286822. [PMID: 36809045 PMCID: PMC10128015 DOI: 10.1128/mbio.02868-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Toxoplasma gondii oocysts, which are shed in large quantities in the feces from infected felines, are very stable in the environment, resistant to most inactivation procedures, and highly infectious. The oocyst wall provides an important physical barrier for sporozoites contained inside oocysts, protecting them from many chemical and physical stressors, including most inactivation procedures. Furthermore, sporozoites can withstand large temperature changes, even freeze-thawing, as well as desiccation, high salinity, and other environmental insults; however, the genetic basis for this environmental resistance is unknown. Here, we show that a cluster of four genes encoding Late Embryogenesis Abundant (LEA)-related proteins are required to provide Toxoplasma sporozoites resistance to environmental stresses. Toxoplasma LEA-like genes (TgLEAs) exhibit the characteristic features of intrinsically disordered proteins, explaining some of their properties. Our in vitro biochemical experiments using recombinant TgLEA proteins show that they have cryoprotective effects on the oocyst-resident lactate dehydrogenase enzyme and that induced expression in E. coli of two of them leads to better survival after cold stress. Oocysts from a strain in which the four LEA genes were knocked out en bloc were significantly more susceptible to high salinity, freezing, and desiccation compared to wild-type oocysts. We discuss the evolutionary acquisition of LEA-like genes in Toxoplasma and other oocyst-producing apicomplexan parasites of the Sarcocystidae family and discuss how this has likely contributed to the ability of sporozoites within oocysts to survive outside the host for extended periods. Collectively, our data provide a first molecular detailed view on a mechanism that contributes to the remarkable resilience of oocysts against environmental stresses. IMPORTANCE Toxoplasma gondii oocysts are highly infectious and may survive in the environment for years. Their resistance against disinfectants and irradiation has been attributed to the oocyst and sporocyst walls by acting as physical and permeability barriers. However, the genetic basis for their resistance against stressors like changes in temperature, salinity, or humidity, is unknown. We show that a cluster of four genes encoding Toxoplasma Late Embryogenesis Abundant (TgLEA)-related proteins are important for this resistance to environmental stresses. TgLEAs have features of intrinsically disordered proteins, explaining some of their properties. Recombinant TgLEA proteins show cryoprotective effects on the parasite's lactate dehydrogenase, an abundant enzyme in oocysts, and expression in E. coli of two TgLEAs has a beneficial effect on growth after cold stress. Moreover, oocysts from a strain lacking all four TgLEA genes were more susceptible to high salinity, freezing, and desiccation compared to wild-type oocysts, highlighting the importance of the four TgLEAs for oocyst resilience.
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Feix AS, Cruz-Bustos T, Ruttkowski B, Joachim A. Inhibition of sexual stage-specific proteins results in reduced numbers of sexual stages and oocysts of Cystoisospora suis (Apicomplexa: Coccidia) in vitro. Int J Parasitol 2022; 52:829-841. [PMID: 36270547 DOI: 10.1016/j.ijpara.2022.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/05/2022]
Abstract
Parasites of the order Coccidia (phylum: Alveolata, subphylum: Apicomplexa) have sophisticated life cycles that include a switch from asexual to sexual development, characterised by distinct cell types. During the development of gametes (gamogony), substantial changes occur at the cellular and subcellular levels, leading to cell fusion of micro- and microgametes, and the development of a zygote that forms a protective outer layer for environmental survival as an oocyst, the transmissible stage. Studies on the porcine coccidian Cystoisospora suis already identified changes in transcription profiles during different time points in the parasite's development and identified proteins with potential roles in the sexual development of this parasite. Here, we focus on three proteins that are possibly involved in the sexual development of C. suis. Enkurin and hapless protein 2 (HAP2) play important roles in signal transduction and gamete fusion during the fertilisation process, and oocyst wall forming protein 1 (OWP1) is a homologue of oocyst wall forming proteins of related parasites. We evaluated their locations in the different life cycle stages of C. suis and their inhibition by specific antibodies in vitro. Immunolocalization detected enkurin in merozoites and sporulated oocysts, HAP2 in merozoites and microgamonts, and OWP2 in merozoites, macrogamonts, oocysts and sporozoites. Up to 100% inhibition of the development of sexual stages and oocyst formation with purified chicken immunoglobulin IgY sera against recombinant enkurin, HAP2, and especially OWP1, were demonstrated. We conclude that the three investigated sexual stage-specific proteins constitute targets for in vivo intervention strategies to interrupt parasite development and transmission to susceptible hosts.
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Affiliation(s)
- Anna Sophia Feix
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna A-1210, Austria.
| | - Teresa Cruz-Bustos
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna A-1210, Austria
| | - Bärbel Ruttkowski
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna A-1210, Austria
| | - Anja Joachim
- Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna A-1210, Austria
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10
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Wang L, Wang Y, Cui Z, Li D, Li X, Zhang S, Zhang L. Enrichment and proteomic identification of Cryptosporidium parvum oocyst wall. Parasit Vectors 2022; 15:335. [PMID: 36151578 PMCID: PMC9508764 DOI: 10.1186/s13071-022-05448-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Accepted: 08/22/2022] [Indexed: 11/12/2022] Open
Abstract
Background Cryptosporidium parvum is a zoonotic parasitic protozoan that can infect a variety of animals and humans and is transmitted between hosts via oocysts. The oocyst wall provides strong protection against hostile environmental factors; however, research is limited concerning the oocyst wall at the proteomic level. Methods A comprehensive analysis of the proteome of oocyst wall of C. parvum was performed using label-free qualitative high-performance liquid chromatography (HPLC) fractionation and mass spectrometry-based qualitative proteomics technologies. Among the identified proteins, a surface protein (CpSP1) encoded by the C. parvum cgd7_5140 (Cpcgd7_5140) gene was predicted to be located on the surface of the oocyst wall. We preliminarily characterized the sequence and subcellular localization of CpSP1. Results A total of 798 proteins were identified, accounting for about 20% of the CryptoDB proteome. By using bioinformatic analysis, functional annotation and subcellular localization of the identified proteins were examined for better understanding of the characteristics of the oocyst wall. To verify the localization of CpSP1, an indirect immunofluorescent antibody assay demonstrated that the protein was localized on the surface of the oocyst wall, illustrating the potential usage as a marker for C. parvum detection in vitro. Conclusion The results provide a global framework about the proteomic composition of the Cryptosporidium oocyst wall, thereby providing a theoretical basis for further study of Cryptosporidium oocyst wall formation as well as the selection of targets for Cryptosporidium detection. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05448-8.
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Affiliation(s)
- Luyang Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China.,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China
| | - Yuexin Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China.,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China
| | - Zhaohui Cui
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China.,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China
| | - Dongfang Li
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China.,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China
| | - Xiaoying Li
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China.,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China.,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China
| | - Sumei Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. .,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China. .,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China.
| | - Longxian Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, 450002, China. .,International Joint Research Center of National Animal Immunology, Zhengzhou, 450046, China. .,Key Laboratory of Quality and Safety Control of Poultry Products (Zhengzhou), Ministry of Agriculture and Rural Affairs, Zhengzhou, People's Republic of China.
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11
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Possenti A, Di Cristina M, Nicastro C, Lunghi M, Messina V, Piro F, Tramontana L, Cherchi S, Falchi M, Bertuccini L, Spano F. Functional Characterization of the Thrombospondin-Related Paralogous Proteins Rhoptry Discharge Factors 1 and 2 Unveils Phenotypic Plasticity in Toxoplasma gondii Rhoptry Exocytosis. Front Microbiol 2022; 13:899243. [PMID: 35756016 PMCID: PMC9218915 DOI: 10.3389/fmicb.2022.899243] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
To gain access to the intracellular cytoplasmic niche essential for their growth and replication, apicomplexan parasites such as Toxoplasma gondii rely on the timely secretion of two types of apical organelles named micronemes and rhoptries. Rhoptry proteins are key to host cell invasion and remodeling, however, the molecular mechanisms underlying the tight control of rhoptry discharge are poorly understood. Here, we report the identification and functional characterization of two novel T. gondii thrombospondin-related proteins implicated in rhoptry exocytosis. The two proteins, already annotated as MIC15 and MIC14, were renamed rhoptry discharge factor 1 (RDF1) and rhoptry discharge factor 2 (RDF2) and found to be exclusive of the Coccidia class of apicomplexan parasites. Furthermore, they were shown to have a paralogous relationship and share a C-terminal transmembrane domain followed by a short cytoplasmic tail. Immunofluorescence analysis of T. gondii tachyzoites revealed that RDF1 presents a diffuse punctate localization not reminiscent of any know subcellular compartment, whereas RDF2 was not detected. Using a conditional knockdown approach, we demonstrated that RDF1 loss caused a marked growth defect. The lack of the protein did not affect parasite gliding motility, host cell attachment, replication and egress, whereas invasion was dramatically reduced. Notably, while RDF1 depletion did not result in altered microneme exocytosis, rhoptry discharge was found to be heavily impaired. Interestingly, rhoptry secretion was reversed by spontaneous upregulation of the RDF2 gene in knockdown parasites grown under constant RDF1 repression. Collectively, our results identify RDF1 and RDF2 as additional key players in the pathway controlling rhoptry discharge. Furthermore, this study unveils a new example of compensatory mechanism contributing to phenotypic plasticity in T. gondii.
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Affiliation(s)
- Alessia Possenti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Manlio Di Cristina
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Chiara Nicastro
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Matteo Lunghi
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Valeria Messina
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Piro
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Lorenzo Tramontana
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Simona Cherchi
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Mario Falchi
- National AIDS Center, Istituto Superiore di Sanità, Rome, Italy
| | | | - Furio Spano
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
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12
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The transcriptome from asexual to sexual in vitro development of Cystoisospora suis (Apicomplexa: Coccidia). Sci Rep 2022; 12:5972. [PMID: 35396557 PMCID: PMC8993856 DOI: 10.1038/s41598-022-09714-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 03/15/2022] [Indexed: 11/08/2022] Open
Abstract
The apicomplexan parasite Cystoisospora suis is an enteropathogen of suckling piglets with woldwide distribution. As with all coccidian parasites, its lifecycle is characterized by asexual multiplication followed by sexual development with two morphologically distinct cell types that presumably fuse to form a zygote from which the oocyst arises. However, knowledge of the sexual development of C. suis is still limited. To complement previous in vitro studies, we analysed transcriptional profiles at three different time points of development (corresponding to asexual, immature and mature sexual stages) in vitro via RNASeq. Overall, transcription of genes encoding proteins with important roles in gametes biology, oocyst wall biosynthesis, DNA replication and axonema formation as well as proteins with important roles in merozoite biology was identified. A homologue of an oocyst wall tyrosine rich protein of Toxoplasma gondii was expressed in macrogametes and oocysts of C. suis. We evaluated inhibition of sexual development in a host-free culture for C. suis by antiserum specific to this protein to evaluate whether it could be exploited as a candidate for control strategies against C. suis. Based on these data, targets can be defined for future strategies to interrupt parasite transmission during sexual development.
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13
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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: 2.3] [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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14
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Liu L, Wang P, Jiang SQ, Zhong ZR, Zhan TZ, Yang ZY, Zhang YN, Li C, Xu J, Xia CM. Seasonal variations and public search interests in Toxoplasma: a 16-year retrospective analysis of big data on Google Trends. Trans R Soc Trop Med Hyg 2021; 115:878-885. [PMID: 33241272 DOI: 10.1093/trstmh/traa147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/06/2020] [Accepted: 11/06/2020] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND This study aims to understand whether there is a seasonal change in the internet search interest for Toxoplasma by using the data derived from Google Trends (GT). METHODS The present study searched for the relative search volume (RSV) for the search term 'Toxoplasma' in GT within six major English-speaking countries (Australia, New Zealand [Southern Hemisphere] and Canada, Ireland, the UK and the USA [Northern Hemisphere] from 1 January 2004 to 31 December 2019, utilizing the category of 'health'. Data regarding the RSV of Toxoplasma was obtained and further statistical analysis was performed in R software using the 'season' package. RESULTS There were significantly seasonal patterns for the RSV of the search term 'Toxoplasma' in five countries (all p<0.05), except for the UK. A peak in December-March and a trough in July-September (Canada, Ireland, the UK and the USA) were observed, while a peak in June/August and a trough in December/February (Australia, New Zealand) were also found. Moreover, the presence of seasonal patterns regarding RSV for 'Toxoplasma' between the Southern and Northern Hemispheres was also found (both p<0.05), with a reversed meteorological month. CONCLUSIONS Overall, our study revealed the seasonal variation for Toxoplasma in using internet search data from GT, providing additional evidence on seasonal patterns in Toxoplasma.
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Affiliation(s)
- Lei Liu
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Peng Wang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Su-Qin Jiang
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Zi-Rong Zhong
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Ting-Zheng Zhan
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Zi-Yin Yang
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Ya-Nan Zhang
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Chen Li
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Jing Xu
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
| | - Chao-Ming Xia
- Department of Parasitology, Medical College of Soochow University, 199 Renai Road, Suzhou, 215123, Jiangsu, China
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15
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Multimodal regulation of encystation in Giardia duodenalis revealed by deep proteomics. Int J Parasitol 2021; 51:809-824. [PMID: 34331939 DOI: 10.1016/j.ijpara.2021.01.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/24/2020] [Accepted: 01/07/2021] [Indexed: 12/21/2022]
Abstract
Cyst formation in the parasitic protist Giardia duodenalis is critical to its transmission. Existing proteomic data quantifies only 17% of coding genes transcribed during encystation and does not cover the complete process from trophozoite to mature cyst. Using high-resolution mass spectrometry, we have quantified proteomic changes across encystation and compared this with published transcriptomic data. We reproducibly identified 3863 (64.5% of Giardia proteins) and quantified 3382 proteins (56.5% of Giardia proteins) over standard trophozoite growth (TY), during low-bile encystation priming (LB), 16 h into encystation (EC), and at cyst maturation (C). This work provides the first known expanded observation of encystation at the proteomic level and triples the coverage of previous encystation proteomes. One-third (1169 proteins) of the quantified proteome is differentially expressed in the mature cyst relative to the trophozoite, including proteasomal machinery, metabolic pathways, and secretory proteins. Changes in lipid metabolism indicated a shift in lipid species dependency during encystation. Consistent with this, we identified the first, putative lipid transporters in this species, representing the steroidogenic acute regulatory protein-related lipid transfer (StARkin), oxysterol binding protein related protein (ORP/Osh) and glycosphingolipid transfer protein (GLTP) families, and follow their differential expression over cyst formation. Lastly, we undertook correlation analyses of the transcriptome and proteome of trophozoites and cysts, and found evidence of post-transcriptional regulation of key protein classes (RNA binding proteins) and stage-specific genes (encystation markers) implicating translation-repression in encystation. We provide the most extensive proteomic analysis of encystation in Giardia to date and the first known exploration across its complete duration. This work identifies encystation as highly coordinated, involving major changes in proteostasis, metabolism and membrane dynamics, and indicates a potential role for post-transcriptional regulation, mediated through RNA-binding proteins. Together our work provides a valuable resource for Giardia research and the development of transmission-blocking anti-giardials.
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Progression of asexual to sexual stages of Cystoisospora suis in a host cell-free environment as a model for Coccidia. Parasitology 2021; 148:1475-1481. [PMID: 34193323 PMCID: PMC8426156 DOI: 10.1017/s0031182021001074] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract
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Expanding the Known Repertoire of C-Type Lectin Receptors Binding to Toxoplasma gondii Oocysts Using a Modified High-Resolution Immunofluorescence Assay. mSphere 2021; 6:6/2/e01341-20. [PMID: 33789945 PMCID: PMC8546727 DOI: 10.1128/msphere.01341-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The environmental stage of the apicomplexan Toxoplasma gondii oocyst is vital to its life cycle but largely understudied. Because oocysts are excreted only by infected felids, their availability for research is limited. We report the adaptation of an agarose-based method to immobilize minute amounts of oocysts to perform immunofluorescence assays. Agarose embedding allows high-resolution confocal microscopy imaging of antibodies binding to the oocyst surface as well as unprecedented imaging of intracellular sporocyst structures with Maclura pomifera agglutinin after on-slide permeabilization of the immobilized oocysts. To identify new possible molecules binding to the oocyst surface, we used this method to screen a library of C-type lectin receptor (CLR)-human IgG constant region fusion proteins from the group of related CLRs called the Dectin-1 cluster against oocysts. In addition to CLEC7A that was previously reported to decorate T. gondii oocysts, we present experimental evidence for specific binding of three additional CLRs to the surface of this stage. We discuss how these CLRs, known to be expressed on neutrophils, dendritic cells, or macrophages, could be involved in the early immune response by the host, such as oocyst antigen uptake in the intestine. In conclusion, we present a modified immunofluorescence assay technique that allows material-saving immunofluorescence microscopy with T. gondii oocysts in a higher resolution than previously published, which allowed us to describe three additional CLRs binding specifically to the oocyst surface. IMPORTANCE Knowledge of oocyst biology of Toxoplasma gondii is limited, not the least due to its limited availability. We describe a method that permits us to process minute amounts of oocysts for immunofluorescence microscopy without compromising their structural properties. This method allowed us to visualize internal structures of sporocysts by confocal microscopy in unprecedented quality. Moreover, the method can be used as a low- to medium-throughput method to screen for molecules interacting with oocysts, such as antibodies, or compounds causing structural damage to oocysts (i.e., disinfectants). Using this method, we screened a small library of C-type lectin receptors (CLRs) present on certain immune cells and found three CLRs able to decorate the oocyst wall of T. gondii and which were not known before to bind to oocysts. These tools will allow further study into oocyst wall composition and could also provoke experiments regarding immunological recognition of oocysts.
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Martorelli Di Genova B, Knoll LJ. Comparisons of the Sexual Cycles for the Coccidian Parasites Eimeria and Toxoplasma. Front Cell Infect Microbiol 2020; 10:604897. [PMID: 33381466 PMCID: PMC7768002 DOI: 10.3389/fcimb.2020.604897] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/12/2020] [Indexed: 12/11/2022] Open
Abstract
Toxoplasma gondii and Eimeria spp. are widely prevalent Coccidian parasites that undergo sexual reproduction during their life cycle. T. gondii can infect any warm-blooded animal in its asexual cycle; however, its sexual cycle is restricted to felines. Eimeria spp. are usually restricted to one host species, and their whole life cycle is completed within this same host. The literature reviewed in this article comprises the recent findings regarding the unique biology of the sexual development of T. gondii and Eimeria spp. The molecular basis of sex in these pathogens has been significantly unraveled by new findings in parasite differentiation along with transcriptional analysis of T. gondii and Eimeria spp. pre-sexual and sexual stages. Focusing on the metabolic networks, analysis of these transcriptome datasets shows enrichment for several different metabolic pathways. Transcripts for glycolysis enzymes are consistently more abundant in T. gondii cat infection stages than the asexual tachyzoite stage and Eimeria spp. merozoite and gamete stages compared to sporozoites. Recent breakthroughs in host-pathogen interaction and host restriction have significantly expanded the understating of the unique biology of these pathogens. This review aims to critically explore advances in the sexual cycle of Coccidia parasites with the ultimate goal of comparing and analyzing the sexual cycle of Eimeria spp. and T. gondii.
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Affiliation(s)
| | - Laura J. Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, United States
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19
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Polyphyletic origin, intracellular invasion, and meiotic genes in the putatively asexual agamococcidians (Apicomplexa incertae sedis). Sci Rep 2020; 10:15847. [PMID: 32985520 PMCID: PMC7522995 DOI: 10.1038/s41598-020-72287-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/28/2020] [Indexed: 12/30/2022] Open
Abstract
Agamococcidians are enigmatic and poorly studied parasites of marine invertebrates with unexplored diversity and unclear relationships to other sporozoans such as the human pathogens Plasmodium and Toxoplasma. It is believed that agamococcidians are not capable of sexual reproduction, which is essential for life cycle completion in all well studied parasitic apicomplexans. Here, we describe three new species of agamococcidians belonging to the genus Rhytidocystis. We examined their cell morphology and ultrastructure, resolved their phylogenetic position by using near-complete rRNA operon sequences, and searched for genes associated with meiosis and oocyst wall formation in two rhytidocystid transcriptomes. Phylogenetic analyses consistently recovered rhytidocystids as basal coccidiomorphs and away from the corallicolids, demonstrating that the order Agamococcidiorida Levine, 1979 is polyphyletic. Light and transmission electron microscopy revealed that the development of rhytidocystids begins inside the gut epithelial cells, a characteristic which links them specifically with other coccidiomorphs to the exclusion of gregarines and suggests that intracellular invasion evolved early in the coccidiomorphs. We propose a new superorder Eococcidia for early coccidiomorphs. Transcriptomic analysis demonstrated that both the meiotic machinery and oocyst wall proteins are preserved in rhytidocystids. The conservation of meiotic genes and ultrastructural similarity of rhytidocystid trophozoites to macrogamonts of true coccidians point to an undescribed, cryptic sexual process in the group.
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Sousa S, Almeida A, Delgado L, Conceição A, Marques C, da Costa JMC, Castro A. rTgOWP1-f, a specific biomarker for Toxoplasma gondii oocysts. Sci Rep 2020; 10:7947. [PMID: 32409659 PMCID: PMC7224171 DOI: 10.1038/s41598-020-64590-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 04/16/2020] [Indexed: 01/26/2023] Open
Abstract
Toxoplasma gondii oocyst wall protein 1 (TgOWP1) integrates a family of seven proteins, consensually assumed as specific antigens of Toxoplasma gondii oocyst stage, located in the outer layer of the oocyst wall. Herein, we notice the expression of a recombinant antigen, rTgOWP1-f, derived from a fragment selected on basis of its structural homology with Plasmodium MSP1-19. Rabbit polyclonal antibodies anti-rTgOWP1-f evidence ability for specific identification of environmental T. gondii oocysts. We assume, rTgOWP1-f, as a possible biomarker of oocysts. In addition, we present findings supporting this vision, including the development of an immunodetection method for T. gondii oocysts identification.
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Affiliation(s)
- Susana Sousa
- Center for Parasite Biology and Immunology, National Institute of Health Dr Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal.
- Center for the Study of Animal Science (CECA)/Institute for Agricultural and Agro-Alimentary Science and Technology (ICETA), University of Porto, Porto, Portugal.
- LAQV, REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Porto, Portugal.
| | - André Almeida
- Center for the Study of Animal Science (CECA)/Institute for Agricultural and Agro-Alimentary Science and Technology (ICETA), University of Porto, Porto, Portugal
| | - Lurdes Delgado
- Center for Parasite Biology and Immunology, National Institute of Health Dr Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal
| | | | - Cláudia Marques
- Center for Parasite Biology and Immunology, National Institute of Health Dr Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal
- Center for the Study of Animal Science (CECA)/Institute for Agricultural and Agro-Alimentary Science and Technology (ICETA), University of Porto, Porto, Portugal
| | - José Manuel Correia da Costa
- Center for Parasite Biology and Immunology, National Institute of Health Dr Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal
- Center for the Study of Animal Science (CECA)/Institute for Agricultural and Agro-Alimentary Science and Technology (ICETA), University of Porto, Porto, Portugal
| | - António Castro
- Center for Parasite Biology and Immunology, National Institute of Health Dr Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055, Porto, Portugal
- Center for the Study of Animal Science (CECA)/Institute for Agricultural and Agro-Alimentary Science and Technology (ICETA), University of Porto, Porto, Portugal
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Feix AS, Cruz-Bustos T, Ruttkowski B, Joachim A. Characterization of Cystoisospora suis sexual stages in vitro. Parasit Vectors 2020; 13:143. [PMID: 32188507 PMCID: PMC7079422 DOI: 10.1186/s13071-020-04014-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/10/2020] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND The porcine coccidium Cystoisospora suis is characterized by a complex life-cycle during which asexual multiplication is followed by sexual development with two morphologically distinct cell types, the micro- and macrogametes. Genes related to the sexual stages and cell cycle progression were previously identified in related Apicomplexa. Dynein light chain type 1 and male gamete fusion factor HAP2 are restricted to microgametes. Tyrosine-rich proteins and oocyst wall proteins are a part of the oocyst wall. The Rad51/Dmc1-like protein and Nima-related protein kinases are associated with the cell cycle and fertilization process. Here, the sexual stages of C. suis were characterized in vitro morphologically and for temporal expression changes of the mentioned genes to gain insight into this poorly known phase of coccidian development. METHODS Sexual stages of C. suis developing in vitro in porcine intestinal epithelial cells were examined by light and electron microscopy. The transcriptional levels of genes related to merozoite multiplication and sexual development were evaluated by quantitative real-time PCR at different time points of cultivation. Transcription levels were compared for parasites in culture supernatants at 6-9 days of cultivation (doc) and intracellular parasites at 6-15 doc. RESULTS Sexual stage of C. suis was detected during 8-11 doc in vitro. Microgamonts (16.8 ± 0.9 µm) and macrogamonts (16.6 ± 1.1 µm) are very similar in shape and size. Microgametes had a round body (3.5 ± 0.5 µm) and two flagella (11.2 ± 0.5 µm). Macrogametes were spherical with a diameter of 12.1 ± 0.5 µm. Merozoite gene transcription peaked on 10 doc and then declined. Genes related to the sexual stages and cell cycle showed an upregulation with a peak on 13 doc, after which they declined. CONCLUSIONS The present study linked gene expression changes to the detailed morphological description of C. suis sexual development in vitro, including fertilization, meiosis and oocyst formation in this unique model for coccidian parasites. Following this process at the cellular and molecular level will elucidate details on potential bottlenecks of C. suis development (applicable for coccidian parasites in general) which could be exploited as a novel target for control.
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Affiliation(s)
- Anna Sophia Feix
- Institute for Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, 1210 Austria
| | - Teresa Cruz-Bustos
- Institute for Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, 1210 Austria
| | - Bärbel Ruttkowski
- Institute for Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, 1210 Austria
| | - Anja Joachim
- Institute for Parasitology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, Vienna, 1210 Austria
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Freppel W, Ferguson DJ, Shapiro K, Dubey JP, Puech PH, Dumètre A. Structure, composition, and roles of the Toxoplasma gondii oocyst and sporocyst walls. Cell Surf 2019; 5:100016. [PMID: 32743133 PMCID: PMC7389338 DOI: 10.1016/j.tcsw.2018.100016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 12/03/2018] [Accepted: 12/14/2018] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii is a coccidian parasite with the cat as its definitive host but any warm-blooded animal, including humans, may act as intermediate hosts. It has a worldwide distribution where it may cause acute and chronic toxoplasmosis. Infection can result from ingestion either of tissue cysts in infected meat of intermediate hosts or oocysts found in cat faeces via contaminated water or food. In this review, we highlight how the oocyst and sporocyst walls sustain the persistence and transmission of infective T. gondii parasites from terrestrial and aquatic environments to the host. We further discuss why targeting the oocyst wall structure and molecules may reduce the burden of foodborne and waterborne T. gondii infections.
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Shapiro K, Bahia-Oliveira L, Dixon B, Dumètre A, de Wit LA, VanWormer E, Villena I. Environmental transmission of Toxoplasma gondii: Oocysts in water, soil and food. Food Waterborne Parasitol 2019; 15:e00049. [PMID: 32095620 PMCID: PMC7033973 DOI: 10.1016/j.fawpar.2019.e00049] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/19/2019] [Accepted: 03/19/2019] [Indexed: 12/11/2022] Open
Abstract
Toxoplasma gondii is a zoonotic protozoan parasite that can cause morbidity and mortality in humans, domestic animals, and terrestrial and aquatic wildlife. The environmentally robust oocyst stage of T. gondii is fundamentally critical to the parasite's success, both in terms of its worldwide distribution as well as the extensive range of infected intermediate hosts. Despite the limited definitive host species (domestic and wild felids), infections have been reported on every continent, and in terrestrial as well as aquatic environments. The remarkable resistance of the oocyst wall enables dissemination of T. gondii through watersheds and ecosystems, and long-term persistence in diverse foods such as shellfish and fresh produce. Here, we review the key attributes of oocyst biophysical properties that confer their ability to disseminate and survive in the environment, as well as the epidemiological dynamics of oocyst sources including domestic and wild felids. This manuscript further provides a comprehensive review of the pathways by which T. gondii oocysts can infect animals and people through the environment, including in contaminated foods, water or soil. We conclude by identifying critical control points for reducing risk of exposure to oocysts as well as opportunities for future synergies and new directions for research aimed at reducing the burden of oocyst-borne toxoplasmosis in humans, domestic animals, and wildlife.
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Affiliation(s)
- Karen Shapiro
- Department of Pathology, Microbiology & Immunology, School of Veterinary Medicine, One Shields Ave, 4206 VM3A, University of California, Davis, CA 95616-5270, USA
| | - Lillian Bahia-Oliveira
- Laboratory of Immunoparasitology, Federal University of Rio de Janeiro, Macaé, RJ, Brazil
| | - Brent Dixon
- Bureau of Microbial Hazards, Food Directorate, Health Canada, 251 Sir Frederick Banting Driveway, A.L. 2204E, Ottawa, ON K1A 0K9, Canada
| | - Aurélien Dumètre
- Aix Marseille Univ, IRD 257, AP-HM, SSA, VITROME, IHU-Méditerranée Infection, Marseille, France
| | - Luz A. de Wit
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, 130 McAllister Way, Santa Cruz, CA 95050, USA
| | - Elizabeth VanWormer
- School of Veterinary Medicine and Biomedical Sciences, School of Natural Resources, University of Nebraska-Lincoln, VBS 111, Lincoln, NE 68583, USA
| | - Isabelle Villena
- EA 7510, UFR Medicine, University Reims Champagne-Ardenne, National Reference Center on Toxoplasmosis, Hospital Maison Blanche, Reims, France
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Mirza Alizadeh A, Jazaeri S, Shemshadi B, Hashempour-Baltork F, Sarlak Z, Pilevar Z, Hosseini H. A review on inactivation methods of Toxoplasma gondii in foods. Pathog Glob Health 2018; 112:306-319. [PMID: 30346249 PMCID: PMC6381540 DOI: 10.1080/20477724.2018.1514137] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Toxoplasmosis is an infection caused by Toxoplasma gondii, a widespread zoonotic protozoan which poses a great threat to human health and economic well-being worldwide. It is usually acquired by ingestion of water contaminated with oocysts from the feces of infected cats or by the ingestion of raw or undercooked foodstuff containing tissue cysts. The oocyst can contaminate irrigation water and fresh edible produce. It is estimated that approximately one-third of the human population worldwide harbor this parasite. Infection with T. gondii is an important cause of diseases of the central nervous system and the eye in immunocompromised and immunocompetent individuals. The purpose of this study was to evaluate the efficacy and applicability of thermal (heating, cooking, freezing and low temperature), non-thermal (high pressure processing, ionizing irradiation and curing) and chemical and biochemical (disinfection, essential oils and biochemical methods such as enzymes, nanoparticles, antibiotics and immune response) treatments for the inactivation, inhabitation or to kill T. gondii in foodstuff intended for public consumption and under experimental conditions.
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Affiliation(s)
- Adel Mirza Alizadeh
- Student Research Committee, Department of Food Technology, Faculty of Nutrition Sciences and Food Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sahar Jazaeri
- Department of Food Science and Technology, Faculty of Nutrition Science, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahar Shemshadi
- Department of Parasitology, Faculty of Veterinary Medicine, Islamic Azad University, Garmsar Branch, Garmsar, Iran
| | - Fataneh Hashempour-Baltork
- Student Research Committee, Department of Food Technology, Faculty of Nutrition Sciences and Food Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Sarlak
- Student Research Committee, Department of Food Technology, Faculty of Nutrition Sciences and Food Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zahra Pilevar
- Student Research Committee, Department of Food Technology, Faculty of Nutrition Sciences and Food Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hedayat Hosseini
- Department of Food Science and Technology, Faculty of Nutrition Science, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Su S, Hou Z, Liu D, Jia C, Wang L, Xu J, Tao J. Comparative transcriptome analysis of Eimeria necatrix third-generation merozoites and gametocytes reveals genes involved in sexual differentiation and gametocyte development. Vet Parasitol 2018; 252:35-46. [PMID: 29559148 DOI: 10.1016/j.vetpar.2018.01.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/20/2018] [Accepted: 01/22/2018] [Indexed: 11/17/2022]
Abstract
Eimeria necatrix is one of the most pathogenic parasites causing high mortality in chicken older than 8 weeks. Eimeria spp. possess a coccidian lifecycle including both sexual and asexual stages. Sexual differentiation and development occupies a central place in the life cycle of the Eimeria parasite. However, our knowledge of the sexual differentiation and gametocyte development of Eimeria is very limited. Here using RNA sequencing, we conducted a comparative transcriptome analysis between third-generation merozoites (MZ-3) and gametocytes (GAM) of E. necatrix to identify genes with functions related to sexual differentiation and gametocyte development. Approximately 4267 genes were differentially expressed between MZ-3 and GAM. Compared with MZ-3, 2789 genes were upregulated and 1478 genes were downregulated in GAM. Approximately 329 genes in MZ-3 and 1289 genes in GAM were further analyzed in the evaluation of stage-specific genes. Gene Ontology (GO) classification and KEGG analysis revealed that 953 upregulated gametocyte genes were annotated with 170 GO assignments, and 405 upregulated genes were associated with 231 signaling pathways. We also predicted a further 83 upregulated gametocyte genes, of which 53 were involved in the biosynthesis of the oocyst wall, and 30 were involved in microgametocyte development. This information offers insights into the mechanisms governing the sexual development of E. necatrix and may potentially allow the identification of targets for blocking parasite transmission.
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Affiliation(s)
- Shijie Su
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Zhaofeng Hou
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Dandan Liu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Chuanli Jia
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Lele Wang
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Jinjun Xu
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
| | - Jianping Tao
- College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China.
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Wiedmer S, Buder U, Bleischwitz S, Kurth M. Distribution and Processing of Eimeria nieschulzi
OWP13, a New Protein of the COWP Family. J Eukaryot Microbiol 2018; 65:518-530. [DOI: 10.1111/jeu.12498] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 12/14/2017] [Accepted: 12/14/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Stefanie Wiedmer
- Faculty of Biology; Institute of Zoology; Technische Universität Dresden; Zellescher Weg 20 B Dresden 01217 Germany
| | - Ulrike Buder
- Faculty of Biology; Institute of Zoology; Technische Universität Dresden; Zellescher Weg 20 B Dresden 01217 Germany
| | - Sinja Bleischwitz
- Faculty of Biology; Institute of Zoology; Technische Universität Dresden; Zellescher Weg 20 B Dresden 01217 Germany
| | - Michael Kurth
- Faculty of Biology; Institute of Zoology; Technische Universität Dresden; Zellescher Weg 20 B Dresden 01217 Germany
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Harito JB, Campbell AT, Tysnes KR, Robertson LJ. Use of lectin-magnetic separation (LMS) for detecting Toxoplasma gondii oocysts in environmental water samples. WATER RESEARCH 2017; 127:68-76. [PMID: 29031801 DOI: 10.1016/j.watres.2017.10.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 09/30/2017] [Accepted: 10/06/2017] [Indexed: 06/07/2023]
Abstract
Proof-of-principle of lectin-magnetic separation (LMS) for isolating Toxoplasma oocysts (pre-treated with 0.5% acidified pepsin (AP)) from water for subsequent detection by microscopy or molecular methods has been shown. However, application of this technique in the routine water-analysis laboratory requires that the method is tested, modified, and optimized. The current study describes attempts to apply the LMS technique on supernatants from water samples previously analyzed for contamination with Cryptosporidium and Giardia using standard methods, and the supernatant following immunomagnetic separation (IMS) retained. Experiments on AP-treatment of Toxoplasma oocysts in situ in such samples demonstrated that overnight incubation at 37 °C was adequate, but excess AP had to be removed before continuing to LMS; neutralization in sodium hydroxide and a single wash step was found to be suitable. Mucilaginous material in post-IMS samples that had been stored at room temperature without washing, which was found to be probably an exudate from bacterial and fungal overgrowth, hampered the isolation of T. gondii oocysts by LMS beads. For detection, microscopy was successful only for clean samples, as debris occluded viewing in dirtier samples. Although qPCR was successful, for some samples non-specific inhibition occurred, as demonstrated by inhibition of an internal amplification control in the qPCR reaction. For some, but not all, samples this could be addressed by dilution. Finally, the optimized methodology was used for a pilot project in which 23 post-IMS water sample concentrates were analyzed. Of these, only 20 provided interpretable results (without qPCR inhibition) of which one sample was positive, and confirmed by sequencing of PCR product, indicating that Toxoplasma oocysts occur in Norwegian drinking water samples. In conclusion, we suggest that post-IMS samples may be suitable for analysis for Toxoplasma oocysts using LMS, only if freshly processed or washed before being refrigerated. In addition, application of AP treatment requires a neutralization step before proceeding to LMS. For detection, qPCR, rather than microscopy, is the most appropriate approach, although some inhibition may still occur, and therefore inclusion of an internal amplification control is important. Our study indicates that, despite some limitations, this approach would be appropriate for further large-scale analysis of samples of raw and treated drinking water.
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Affiliation(s)
- Jemere Bekele Harito
- Parasitology, Section for Microbiology, Immunology and Parasitology, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Adamstuen Campus, P.O. Box 8146 Dep, N-0033 Oslo, Norway; College of Veterinary Medicine, Hawassa University, P.O. Box 1337, Hawassa, Ethiopia
| | | | - Kristoffer R Tysnes
- Parasitology, Section for Microbiology, Immunology and Parasitology, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Adamstuen Campus, P.O. Box 8146 Dep, N-0033 Oslo, Norway
| | - Lucy J Robertson
- Parasitology, Section for Microbiology, Immunology and Parasitology, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Adamstuen Campus, P.O. Box 8146 Dep, N-0033 Oslo, Norway.
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Zhou DH, Wang ZX, Zhou CX, He S, Elsheikha HM, Zhu XQ. Comparative proteomic analysis of virulent and avirulent strains of Toxoplasma gondii reveals strain-specific patterns. Oncotarget 2017; 8:80481-80491. [PMID: 29113319 PMCID: PMC5655214 DOI: 10.18632/oncotarget.19077] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/18/2017] [Indexed: 12/31/2022] Open
Abstract
Research exploring the proteome of Toxoplasma gondii oocysts has gained momentum over the past few years. However, little is known about the oocyst's protein repertoires that contribute to differential virulence among T. gondii strains. Here, we used isobaric tag for relative and absolute quantitation-based proteomic analysis of oocysts of two T. gondii strains exhibiting the virulent PYS (ToxoDB#9) phenotype versus the less virulent PRU (Type II, ToxoDB#1) phenotype. Our aim was to determine protein expression patterns that contribute to the virulence of a particular phenotype. A total of 2,551 proteins were identified, of which 374 were differentially expressed proteins (DEPs) (|log2 fold change| ≥ 0.58 and P < 0.05). DEPs included 192 increased and 182 decreased proteins. Gene Ontology and KEGG pathway analyses revealed a large number of DEPs enriched in various metabolic processes. Protein interaction network analysis using STRING identified inosine monophosphate dehydrogenase (IMPDH), Bifunctional GMP synthase/glutamine amidotransferase protein, Glucose-6-phosphate 1-dehydrogenase, and Citrate synthase as the top four hubs. Of the 22 virulence proteins commonly expressed in the oocysts of the two strains, 13 and 2 proteins were increased in PYS strain and PRU strain, respectively. Also, 10 and 3 of the 22 identified oocyst wall proteins showed higher expression in oocysts of PRU strain and PYS strain, respectively. These findings revealed new proteomic differences in the oocysts of T. gondii strains of different genotypic backgrounds.
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Affiliation(s)
- Dong-Hui Zhou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Ze-Xiang Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Chun-Xue Zhou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
- Department of Parasitology, Shandong University School of Basic Medicine, Jinan, Shandong Province, 250012, PR China
| | - Shuai He
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
- College of Animal Science and Technology, Anhui Agricultural University, Hefei, Anhui Province, 230036, PR China
| | - Hany M. Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
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Evaluation of novel oocyst wall protein candidates of Toxoplasma gondii. Parasitol Int 2017; 66:643-651. [DOI: 10.1016/j.parint.2017.05.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/17/2017] [Accepted: 05/23/2017] [Indexed: 11/21/2022]
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Guiton PS, Sagawa JM, Fritz HM, Boothroyd JC. An in vitro model of intestinal infection reveals a developmentally regulated transcriptome of Toxoplasma sporozoites and a NF-κB-like signature in infected host cells. PLoS One 2017; 12:e0173018. [PMID: 28362800 PMCID: PMC5376300 DOI: 10.1371/journal.pone.0173018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/12/2017] [Indexed: 01/13/2023] Open
Abstract
Toxoplasmosis is a zoonotic infection affecting approximately 30% of the world’s human population. After sexual reproduction in the definitive feline host, Toxoplasma oocysts, each containing 8 sporozoites, are shed into the environment where they can go on to infect humans and other warm-blooded intermediate hosts. Here, we use an in vitro model to assess host transcriptomic changes that occur in the earliest stages of such infections. We show that infection of rat intestinal epithelial cells with mature sporozoites primarily results in higher expression of genes associated with Tumor Necrosis Factor alpha (TNFα) signaling via NF-κB. Furthermore, we find that, consistent with their biology, these mature, invaded sporozoites display a transcriptome intermediate between the previously reported day 10 oocysts and that of their tachyzoite counterparts. Thus, this study uncovers novel host and pathogen factors that may be critical for the establishment of a successful intracellular niche following sporozoite-initiated infection.
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Affiliation(s)
- Pascale S. Guiton
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Janelle M. Sagawa
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Heather M. Fritz
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - John C. Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- * E-mail:
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Wang ZT, Verma SK, Dubey JP, Sibley LD. The aromatic amino acid hydroxylase genes AAH1 and AAH2 in Toxoplasma gondii contribute to transmission in the cat. PLoS Pathog 2017; 13:e1006272. [PMID: 28288194 PMCID: PMC5363998 DOI: 10.1371/journal.ppat.1006272] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/23/2017] [Accepted: 03/06/2017] [Indexed: 01/08/2023] Open
Abstract
The Toxoplasma gondii genome contains two aromatic amino acid hydroxylase genes, AAH1 and AAH2 encode proteins that produce L-DOPA, which can serve as a precursor of catecholamine neurotransmitters. It has been suggested that this pathway elevates host dopamine levels thus making infected rodents less fearful of their definitive Felidae hosts. However, L-DOPA is also a structural precursor of melanins, secondary quinones, and dityrosine protein crosslinks, which are produced by many species. For example, dityrosine crosslinks are abundant in the oocyst walls of Eimeria and T. gondii, although their structural role has not been demonstrated, Here, we investigated the biology of AAH knockout parasites in the sexual reproductive cycle within cats. We found that ablation of the AAH genes resulted in reduced infection in the cat, lower oocyst yields, and decreased rates of sporulation. Our findings suggest that the AAH genes play a predominant role during infection in the gut of the definitive feline host.
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Affiliation(s)
- Zi T. Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Shiv K. Verma
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland, United States of America
| | - Jitender P. Dubey
- United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Animal Parasitic Diseases Laboratory, Beltsville, Maryland, United States of America
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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Importance of serological cross-reactivity among Toxoplasma gondii, Hammondia spp., Neospora spp., Sarcocystis spp. and Besnoitia besnoiti. Parasitology 2017; 144:851-868. [PMID: 28241894 PMCID: PMC5471829 DOI: 10.1017/s0031182017000063] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Toxoplasma gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and Besnoitia besnoiti are genetically related cyst-forming coccidia. Serology is frequently used for the identification of T. gondii, Neospora spp. and B. besnoiti-exposed individuals. Serologic cross-reactions occur in different tests among animals infected with T. gondii and H. hammondi, as well as among animals infected by T. gondii and N. caninum. Infections caused by N. caninum and N. hughesi are almost indistinguishable by serology. Neospora caninum, B. besnoiti and Sarcocystis spp. infections in cattle show some degree of serologic cross-reactivity. Antibody cross-reactivity between Neospora spp. and H. heydorni-infected animals is suspected, but not proven to occur. We review serologic cross-reactivity among animals and/or humans infected with T. gondii, Neospora spp., Sarcocystis spp., Hammondia spp. and B. besnoiti. Emphasis is laid upon antigens and serological methods for N. caninum diagnosis which were tested for cross-reactivity with related protozoa. Species-specific antigens, as well as stage-specific proteins have been identified in some of these parasites and have promising use for diagnosis and epidemiological surveys.
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Marino ND, Boothroyd JC. Toxoplasma growth in vitro is dependent on exogenous tyrosine and is independent of AAH2 even in tyrosine-limiting conditions. Exp Parasitol 2017; 176:52-58. [PMID: 28257757 PMCID: PMC5423395 DOI: 10.1016/j.exppara.2017.02.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 02/25/2017] [Indexed: 02/05/2023]
Abstract
Toxoplasma gondii is an obligate intracellular parasite capable of infecting virtually all nucleated cell types in almost all warm-blooded animals. Interestingly, Toxoplasma has a relatively full repertoire of amino acid biosynthetic machinery, perhaps reflecting its broad host range and, consequently, its need to adapt to a wide array of amino acid resources. Although Toxoplasma has been shown to be auxotrophic for tryptophan and arginine, it has not previously been determined if Toxoplasma is also auxotrophic for tyrosine. Toxoplasma tachyzoites and bradyzoites were recently found to express an amino acid hydroxylase (AAH2) that is capable of synthesizing tyrosine and dihydroxyphenylalanine (DOPA) from phenylalanine; however, the role of AAH2 in tachyzoite and bradyzoite infection has not yet been identified. To determine if Toxoplasma requires exogenous tyrosine for growth, we performed growth assays on tachyzoites and bradyzoites in nutrient-rich media titrated with varying amounts of tyrosine. We found that Toxoplasma tachyzoites form significantly smaller plaques in tyrosine-limiting media in a dose-dependent manner and that this phenotype is not affected by deletion of TgAAH2. To determine if bradyzoites require exogenous tyrosine for growth, we induced differentiation from tachyzoites in vitro in tyrosine-limiting media and found that replication and vacuole number are all decreased in tyrosine-deficient media. Importantly, culture of confluent human fibroblasts in tyrosine-deficient media does not affect their viability, indicating that, at least in vitro, the need for tyrosine is at the level of Toxoplasma, not the host cell supporting its growth.
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Affiliation(s)
- Nicole D Marino
- Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305, USA
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, CA 94305, USA.
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Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalisation. Sci Rep 2016; 6:33654. [PMID: 27641141 PMCID: PMC5027544 DOI: 10.1038/srep33654] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/30/2016] [Indexed: 01/23/2023] Open
Abstract
Toxoplasma gondii is a common parasite of humans and animals, which is transmitted via oocysts in cat faeces or tissue cysts in contaminated meat. The robust oocyst and sporocyst walls protect the infective sporozoites from deleterious external attacks including disinfectants. Upon oocyst acquisition, these walls lose their integrity to let the sporozoites excyst and invade host cells following a process that remains poorly understood. Given the resistance of the oocyst wall to digestive enzymes and the ability of oocysts to cause parenteral infections, the present study investigated the possible contribution of macrophages in supporting sporozoite excystation following oocyst internalisation. By using single cell micromanipulations, real-time and time-point imaging techniques, we demonstrated that RAW macrophages could interact rapidly with oocysts and engulfed them by remodelling of their actin cytoskeleton. Internalised oocysts were associated to macrophage acidic compartments and showed evidences of wall disruption. Sporozoites were observed in macrophages containing oocyst remnants or in new macrophages, giving rise to dividing tachyzoites. All together, these results highlight an unexpected role of phagocytic cells in processing T. gondii oocysts, in line with non-classical routes of infection, and open new perspectives to identify chemical factors that lead to oocyst wall disruption under physiological conditions.
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Gondim LFP, Wolf A, Vrhovec MG, Pantchev N, Bauer C, Langenmayer MC, Bohne W, Teifke JP, Dubey JP, Conraths FJ, Schares G. Characterization of an IgG monoclonal antibody targeted to both tissue cyst and sporocyst walls of Toxoplasma gondii. Exp Parasitol 2016; 163:46-56. [PMID: 26836446 DOI: 10.1016/j.exppara.2016.01.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 11/17/2022]
Abstract
Toxoplasma gondii infects animals habiting terrestrial and aquatic environments. Its oocysts and tissue cysts are important for the horizontal transmission of this parasite. The oocyst and tissue cyst walls are crucial for the ability of the parasite to persist in the environment or in animal tissues, respectively. However, the composition of these walls is not well understood. We report the generation of monoclonal antibodies directed against wall components using mice immunized with oocyst antigens of T. gondii. One monoclonal antibody (mAb) G1/19 reacted solely with T. gondii sporozoites. The respective antigen had a relative molecular weight (Mr) of 30 kDa. MAb G1/19 failed to react with sporozoites of any other coccidian parasite species tested (Hammondia hammondi, Hammondia heydorni, Cystoisospora felis, Eimeria bovis, Sarcocystis sp.). Another mAb, designated K8/15-15, recognized antigens in sporocyst walls of the parasite and in the walls of in vivo or in vitro produced tissue cysts, as demonstrated by immunofluorescence and immunoblot assays. Antigens of 80 to a high molecular weight protein of about 350 kDa Mr were recognized by this antibody using antigen extracts from sporocysts, and from in vitro or in vivo generated tissue cysts of the parasite. Tissue cyst and sporocyst walls of H. hammondi and H. heydorni, and tissue cysts of Neospora caninum were also recognized by mAb K8/15-15. Sporocyst walls of C. felis also reacted to this mAb. The cyst walls of Sarcocystis sp. and Besnoitia besnoiti were not recognized by mAb K8/15-15. Reactivity by a single mAb against T. gondii antigens in tissue cysts and sporocysts had not been reported previously. MAb K8/15-15 may be a practical tool for the identification of both cysts and sporocysts of the parasite, and may also be potentially employed in proteomic studies on the identification of new components of the cyst and sporocyst walls of T. gondii.
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Affiliation(s)
- Luís F P Gondim
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493, Greifswald-Insel Riems, Germany; Universidade Federal da Bahia, Escola de Medicina Veterinária e Zootecnia, Departamento de Anatomia, Patologia e Clínicas, Av. Adhemar de Barros 500, 40170-110, Salvador, Bahia, Brazil.
| | - Alexander Wolf
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | | | | | - Christian Bauer
- Institute of Parasitology, Justus Liebig University Giessen, Giessen, Germany
| | - Martin C Langenmayer
- Institute of Veterinary Pathology, Ludwig Maximilians University Munich, Munich, Germany; Institute for Infectious Diseases and Zoonoses, Ludwig Maximilians University Munich, Munich, Germany
| | - Wolfgang Bohne
- Department of Microbiology, University of Gottingen, Kreuzbergring 57, D-37075 Göttingen, Germany
| | - Jens P Teifke
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Department of Experimental Animal Facilities and Biorisk Management, 17493, Greifswald-Insel Riems, Germany
| | - Jitender P Dubey
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, Beltsville, MD 20705, USA
| | - Franz J Conraths
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Gereon Schares
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Südufer 10, 17493, Greifswald-Insel Riems, Germany
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Santana SS, Gebrim LC, Carvalho FR, Barros HS, Barros PC, Pajuaba ACAM, Messina V, Possenti A, Cherchi S, Reiche EMV, Navarro IT, Garcia JL, Pozio E, Mineo TWP, Spano F, Mineo JR. CCp5A Protein from Toxoplasma gondii as a Serological Marker of Oocyst-driven Infections in Humans and Domestic Animals. Front Microbiol 2015; 6:1305. [PMID: 26635770 PMCID: PMC4656833 DOI: 10.3389/fmicb.2015.01305] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 11/09/2015] [Indexed: 11/14/2022] Open
Abstract
Considering that the current immunoassays are not able to distinguish the infective forms that cause Toxoplasma gondii infection, the present study was carried out to evaluate the reactivity of two recombinant proteins (CCp5A and OWP1) from oocyst/sporozoite, in order to differentiate infections occurring by ingestion of oocysts or tissue cysts. The reactivity of the recombinant proteins was assessed against panels of serum samples from animals (chickens, pigs, and mice) that were naturally or experimentally infected by different infective stages of the parasite. Also, we tested sera from humans who have been infected by oocysts during a well-characterized toxoplasmosis outbreak, as well as sera from pregnant women tested IgM+/IgG+ for T. gondii, which source of infection was unknown. Only the sporozoite-specific CCp5A protein was able to differentiate the parasite stage that infected chickens, pigs and mice, with specific reactivity for oocyst-infected animals. Furthermore, the CCp5A showed preferential reactivity for recent infection by oocyst/sporozoite in pigs and mice. In humans, CCp5A showed higher reactivity with serum samples from the outbreak, compared with serum from pregnant women. Altogether, these findings demonstrate the usefulness of the CCp5A protein as a new tool to identify the parasite stage of T. gondii infection, allowing its application for diagnosis and epidemiological investigations in animals and humans. The identification of parasite infective stage can help to design effective strategies to minimize severe complications in immunocompromised people and, particularly, in pregnant women to prevent congenital infection.
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Affiliation(s)
- Silas S Santana
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Luiz C Gebrim
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Fernando R Carvalho
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Heber S Barros
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Patrício C Barros
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Ana C A M Pajuaba
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Valeria Messina
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità Rome, Italy
| | - Alessia Possenti
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità Rome, Italy
| | - Simona Cherchi
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità Rome, Italy
| | - Edna M V Reiche
- Department of Clinical Medicine, State University of Londrina - University Hospital Londrina, Brazil
| | - Italmar T Navarro
- Department of Preventive Veterinary Medicine, State University of Londrina Londrina, Brazil
| | - João L Garcia
- Department of Preventive Veterinary Medicine, State University of Londrina Londrina, Brazil
| | - Edoardo Pozio
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità Rome, Italy
| | - Tiago W P Mineo
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
| | - Furio Spano
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità Rome, Italy
| | - José R Mineo
- Laboratory of Immunoparasitology, Institute of Biomedical Sciences, Federal University of Uberlândia Uberlândia, Brazil
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Jonscher E, Erdbeer A, Günther M, Kurth M. Two COWP-like cysteine rich proteins from Eimeria nieschulzi (coccidia, apicomplexa) are expressed during sporulation and involved in the sporocyst wall formation. Parasit Vectors 2015. [PMID: 26209229 PMCID: PMC4514997 DOI: 10.1186/s13071-015-0982-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background The family of cysteine rich proteins of the oocyst wall (COWPs) originally described in Cryptosporidium can also be found in Toxoplasma gondii (TgOWPs) localised to the oocyst wall as well. Genome sequence analysis of Eimeria suggests that these proteins may also exist in this genus and led us to the assumption that these proteins may also play a role in oocyst wall formation. Methods In this study, COWP-like encoding sequences had been identified in Eimeria nieschulzi. The predicted gene sequences were subsequently utilized in reporter gene assays to observe time of expression and localisation of the reporter protein in vivo. Results Both investigated proteins, EnOWP2 and EnOWP6, were expressed during sporulation. The EnOWP2-promoter driven mCherry was found in the cytoplasm and the EnOWP2, respectively EnOWP6, fused to mCherry was initially observed in the extracytoplasmatic space between sporoblast and oocyst wall. This, so far unnamed compartment was designated as circumplasm. Later, the mCherry reporter co-localised with the sporocyst wall of the sporulated oocysts. This observation had been confirmed by confocal microscopy, excystation experiments and IFA. Transcript analysis revealed the intron-exon structure of these genes and confirmed the expression of EnOWP2 and EnOWP6 during sporogony. Conclusions Our results allow us to assume a role, of both investigated EnOWP proteins, in the sporocyst wall formation of E. nieschulzi. Data mining and sequence comparisons to T. gondii and other Eimeria species allow us to hypothesise a conserved process within the coccidia. A role in oocyst wall formation had not been observed in E. nieschulzi. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-0982-3) contains supplementary material, which is available to authorized users.
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Krusor C, Smith WA, Tinker MT, Silver M, Conrad PA, Shapiro K. Concentration and retention ofToxoplasma gondiioocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems. Environ Microbiol 2015; 17:4527-37. [DOI: 10.1111/1462-2920.12927] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/05/2015] [Accepted: 05/26/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Colin Krusor
- Pathology, Microbiology, and Immunology; School of Veterinary Medicine; University of California; Davis CA USA
| | | | - M. Tim Tinker
- Western Ecological Research Center; United States Geological Survey; Santa Cruz CA USA
- Ecology and Evolutionary Biology; University of California; Santa Cruz CA USA
| | - Mary Silver
- Ocean Sciences; University of California; Santa Cruz CA USA
| | - Patricia A. Conrad
- Pathology, Microbiology, and Immunology; School of Veterinary Medicine; University of California; Davis CA USA
- One Health Institute; University of California; Davis CA USA
| | - Karen Shapiro
- Pathology, Microbiology, and Immunology; School of Veterinary Medicine; University of California; Davis CA USA
- One Health Institute; University of California; Davis CA USA
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Alternative splicing mechanisms orchestrating post-transcriptional gene expression: intron retention and the intron-rich genome of apicomplexan parasites. Curr Genet 2015; 62:31-8. [PMID: 26194054 DOI: 10.1007/s00294-015-0506-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 07/09/2015] [Accepted: 07/09/2015] [Indexed: 12/13/2022]
Abstract
Apicomplexan parasites including Toxoplasma gondii and Plasmodium species have complex life cycles that include multiple hosts and differentiation through several morphologically distinct stages requiring marked changes in gene expression. This review highlights emerging evidence implicating regulation of mRNA splicing as a mechanism to prime these parasites for rapid gene expression upon differentiation. We summarize the most important insights in alternative splicing including its role in regulating gene expression by decreasing mRNA abundance via 'Regulated Unproductive Splicing and Translation'. As a related but less well-understood mechanism, we discuss also our recent work suggesting a role for intron retention for precluding translation of stage specific isoforms of T. gondii glycolytic enzymes. We additionally provide new evidence that intron retention might be a widespread mechanism during parasite differentiation. Supporting this notion, recent genome-wide analysis of Toxoplasma and Plasmodium suggests intron retention is more pervasive than heretofore thought. These findings parallel recent emergence of intron retention being more prevalent in mammals than previously believed, thereby adding to the established roles in plants, fungi and unicellular eukaryotes. Deeper mechanistic studies of intron retention will provide important insight into its role in regulating gene expression in apicomplexan parasites and more general in eukaryotic organisms.
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Walker RA, Sharman PA, Miller CM, Lippuner C, Okoniewski M, Eichenberger RM, Ramakrishnan C, Brossier F, Deplazes P, Hehl AB, Smith NC. RNA Seq analysis of the Eimeria tenella gametocyte transcriptome reveals clues about the molecular basis for sexual reproduction and oocyst biogenesis. BMC Genomics 2015; 16:94. [PMID: 25765081 PMCID: PMC4345034 DOI: 10.1186/s12864-015-1298-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/29/2015] [Indexed: 01/12/2023] Open
Abstract
Background The protozoan Eimeria tenella is a common parasite of chickens, causing avian coccidiosis, a disease of on-going concern to agricultural industries. The high prevalence of E. tenella can be attributed to the resilient oocyst stage, which is transmitted between hosts in the environment. As in related Coccidia, development of the eimerian oocyst appears to be dependent on completion of the parasite’s sexual cycle. RNA Seq transcriptome profiling offers insights into the mechanisms governing the biology of E. tenella sexual stages (gametocytes) and the potential to identify targets for blocking parasite transmission. Results Comparisons between the sequenced transcriptomes of E. tenella gametocytes and two asexual developmental stages, merozoites and sporozoites, revealed upregulated gametocyte transcription of 863 genes. Many of these genes code for proteins involved in coccidian sexual biology, such as oocyst wall biosynthesis and fertilisation, and some of these were characterised in more depth. Thus, macrogametocyte-specific expression and localisation was confirmed for two proteins destined for incorporation into the oocyst wall, as well as for a subtilisin protease and an oxidoreductase. Homologues of an oocyst wall protein and oxidoreductase were found in the related coccidian, Toxoplasma gondii, and shown to be macrogametocyte-specific. In addition, a microgametocyte gamete fusion protein, EtHAP2, was discovered. Conclusions The need for novel vaccine candidates capable of controlling coccidiosis is rising and this panel of gametocyte targets represents an invaluable resource for development of future strategies to interrupt parasite transmission, not just in Eimeria but in other Coccidia, including Toxoplasma, where transmission blocking is a relatively unexplored strategy. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1298-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Robert A Walker
- Queensland Tropical Health Alliance Research Laboratory, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns Campus, McGregor Road, Smithfield, QLD, 4878, Australia. .,Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland.
| | - Philippa A Sharman
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns Campus, McGregor Road, Smithfield, QLD, 4878, Australia.
| | - Catherine M Miller
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns Campus, McGregor Road, Smithfield, QLD, 4878, Australia.
| | - Christoph Lippuner
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland. .,Department of Farm Animal, University of Zurich, Winterthurerstrasse, CH-8057, Zürich, Switzerland.
| | - Michal Okoniewski
- Functional Genomics Center Zurich, Winterthurerstrasse, CH-8057, Zürich, Switzerland.
| | - Ramon M Eichenberger
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland.
| | - Chandra Ramakrishnan
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland.
| | - Fabien Brossier
- Apicomplexes et Immunité Mucosale, INRA, UMR1282, Infectiologie et Santé Publique, F-37380, Nouzilly, France. .,Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, F-37000, Tours, France.
| | - Peter Deplazes
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland.
| | - Adrian B Hehl
- Institute of Parasitology, University of Zurich, Winterthurerstrasse 266a, CH-8057, Zürich, Switzerland.
| | - Nicholas C Smith
- Queensland Tropical Health Alliance Research Laboratory, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns Campus, McGregor Road, Smithfield, QLD, 4878, Australia.
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Dresely I, Daugschies A, Lendner M. Establishment of a germ carrier assay to assess disinfectant efficacy against oocysts of coccidian parasites. Parasitol Res 2014; 114:273-81. [PMID: 25339515 DOI: 10.1007/s00436-014-4189-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 10/14/2014] [Indexed: 11/24/2022]
Abstract
Parasites are a common threat to human and animal health. One option to combat parasites that produce infective environmental stages is to inactivate them by chemical disinfection. Standardised laboratory assays that enable proper evaluation of products suspected to be efficient are highly desirable to allow prudent selection and use of such potentially hazardous agents. Here, we present a newly developed in vitro germ carrier assay to evaluate inactivation of oocysts of the model organism Cryptosporidium parvum by chemical disinfectants. Stainless steel discs were used as carrier to mimic surface contamination by C. parvum oocysts. The germ carriers were incubated with approved chemical disinfectant for the specified time (2 h) and rinsed thereafter to remove the disinfectant and recover the exposed oocysts. Recovered oocysts were transferred to HCT-8 monolayers, and 48 h later, genomic DNA was extracted and quantified by real-time PCR targeting the hsp70 gene to estimate parasite reproduction. A panel of commercially available and approved disinfectants were examined and data compared with those of suspension assays and historical data obtained from efficacy assays based on infection of chicken with oocysts of Eimeria tenella. Altogether, data achieved by these divergent assays allowed similar conclusions although the sensitivity of the in vitro assay was higher. Consequently, a threshold of 99.5% inactivation is proposed to evaluate disinfectants in vitro using C. parvum as model organism as compared to the E. tenella animal infection assay (95%).
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Affiliation(s)
- Ira Dresely
- Institute of Parasitology, An den Tierkliniken 35, 04103, Leipzig, Germany
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Chapman HD, Barta JR, Blake D, Gruber A, Jenkins M, Smith NC, Suo X, Tomley FM. A selective review of advances in coccidiosis research. ADVANCES IN PARASITOLOGY 2014; 83:93-171. [PMID: 23876872 DOI: 10.1016/b978-0-12-407705-8.00002-1] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coccidiosis is a widespread and economically significant disease of livestock caused by protozoan parasites of the genus Eimeria. This disease is worldwide in occurrence and costs the animal agricultural industry many millions of dollars to control. In recent years, the modern tools of molecular biology, biochemistry, cell biology and immunology have been used to expand greatly our knowledge of these parasites and the disease they cause. Such studies are essential if we are to develop new means for the control of coccidiosis. In this chapter, selective aspects of the biology of these organisms, with emphasis on recent research in poultry, are reviewed. Topics considered include taxonomy, systematics, genetics, genomics, transcriptomics, proteomics, transfection, oocyst biogenesis, host cell invasion, immunobiology, diagnostics and control.
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Affiliation(s)
- H David Chapman
- Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA.
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Mazzillo FFM, Shapiro K, Silver MW. A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii. PLoS One 2013; 8:e82477. [PMID: 24386100 PMCID: PMC3867372 DOI: 10.1371/journal.pone.0082477] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Accepted: 10/23/2013] [Indexed: 11/19/2022] Open
Abstract
Toxoplasma gondii is a land-derived parasite that infects humans and marine mammals. Infections are a significant cause of mortality for endangered southern sea otters (Enhydra lutris nereis), but the transmission mechanism is poorly understood. Otter exposure to T. gondii has been linked to the consumption of marine turban snails in kelp (Macrocystis pyrifera) forests. It is unknown how turban snails acquire oocysts, as snails scrape food particles attached to surfaces, whereas T. gondii oocysts enter kelp beds as suspended particles via runoff. We hypothesized that waterborne T. gondii oocysts attach to kelp surfaces when encountering exopolymer substances (EPS) forming the sticky matrix of biofilms on kelp, and thus become available to snails. Results of a dietary composition analysis of field-collected snails and of kelp biofilm indicate that snails graze the dense kelp-biofilm assemblage composed of pennate diatoms and bacteria inserted within the EPS gel-like matrix. To test whether oocysts attach to kelp blades via EPS, we designed a laboratory experiment simulating the kelp forest canopy in tanks spiked with T. gondii surrogate microspheres and controlled for EPS and transparent exopolymer particles (TEP - the particulate form of EPS). On average, 19% and 31% of surrogates were detected attached to kelp surfaces covered with EPS in unfiltered and filtered seawater treatments, respectively. The presence of TEP in the seawater did not increase surrogate attachment. These findings support a novel transport mechanism of T. gondii oocysts: as oocysts enter the kelp forest canopy, a portion adheres to the sticky kelp biofilms. Snails grazing this biofilm encounter oocysts as 'bycatch' and thereby deliver the parasite to sea otters that prey upon snails. This novel mechanism can have health implications beyond T. gondii and otters, as a similar route of pathogen transmission may be implicated with other waterborne pathogens to marine wildlife and humans consuming biofilm-feeding invertebrates.
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Affiliation(s)
- Fernanda F. M. Mazzillo
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Karen Shapiro
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Mary W. Silver
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, United States of America
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Strategies to discover the structural components of cyst and oocyst walls. EUKARYOTIC CELL 2013; 12:1578-87. [PMID: 24096907 DOI: 10.1128/ec.00213-13] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cysts of Giardia lamblia and Entamoeba histolytica and oocysts of Toxoplasma gondii and Cryptosporidium parvum are the infectious and sometimes diagnostic forms of these parasites. To discover the structural components of cyst and oocyst walls, we have developed strategies based upon a few simple assumptions. Briefly, the most abundant wall proteins are identified by monoclonal antibodies or mass spectrometry. Structural components include a sugar polysaccharide (chitin for Entamoeba, β-1,3-linked glucose for Toxoplasma, and β-1,3-linked GalNAc for Giardia) and/or acid-fast lipids (Toxoplasma and Cryptosporidium). Because Entamoeba cysts and Toxoplasma oocysts are difficult to obtain, studies of walls of nonhuman pathogens (E. invadens and Eimeria, respectively) accelerate discovery. Biochemical methods to dissect fungal walls work well for cyst and oocyst walls, although the results are often unexpected. For example, echinocandins, which inhibit glucan synthases and kill fungi, arrest the development of oocyst walls and block their release into the intestinal lumen. Candida walls are coated with mannans, while Entamoeba cysts are coated in a dextran-like glucose polymer. Models for cyst and oocyst walls derive from their structural components and organization within the wall. Cyst walls are composed of chitin fibrils and lectins that bind chitin (Entamoeba) or fibrils of the β-1,3-GalNAc polymer and lectins that bind the polymer (Giardia). Oocyst walls of Toxoplasma have two distinct layers that resemble those of fungi (β-1,3-glucan in the inner layer) or mycobacteria (acid-fast lipids in the outer layer). Oocyst walls of Cryptosporidium have a rigid bilayer of acid-fast lipids and inner layer of oocyst wall proteins.
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Evidence for a structural role for acid-fast lipids in oocyst walls of Cryptosporidium, Toxoplasma, and Eimeria. mBio 2013; 4:e00387-13. [PMID: 24003177 PMCID: PMC3760245 DOI: 10.1128/mbio.00387-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Coccidia are protozoan parasites that cause significant human disease and are of major agricultural importance. Cryptosporidium spp. cause diarrhea in humans and animals, while Toxoplasma causes disseminated infections in fetuses and untreated AIDS patients. Eimeria is a major pathogen of commercial chickens. Oocysts, which are the infectious form of Cryptosporidium and Eimeria and one of two infectious forms of Toxoplasma (the other is tissue cysts in undercooked meat), have a multilayered wall. Recently we showed that the inner layer of the oocyst walls of Toxoplasma and Eimeria is a porous scaffold of fibers of β-1,3-glucan, which are also present in fungal walls but are absent from Cryptosporidium oocyst walls. Here we present evidence for a structural role for lipids in the oocyst walls of Cryptosporidium, Toxoplasma, and Eimeria. Briefly, oocyst walls of each organism label with acid-fast stains that bind to lipids in the walls of mycobacteria. Polyketide synthases similar to those that make mycobacterial wall lipids are abundant in oocysts of Toxoplasma and Eimeria and are predicted in Cryptosporidium. The outer layer of oocyst wall of Eimeria and the entire oocyst wall of Cryptosporidium are dissolved by organic solvents. Oocyst wall lipids are complex mixtures of triglycerides, some of which contain polyhydroxy fatty acyl chains like those present in plant cutin or elongated fatty acyl chains like mycolic acids. We propose a two-layered model of the oocyst wall (glucan and acid-fast lipids) that resembles the two-layered walls of mycobacteria (peptidoglycan and acid-fast lipids) and plants (cellulose and cutin). Oocysts, which are essential for the fecal-oral spread of coccidia, have a wall that is thought responsible for their survival in the environment and for their transit through the stomach and small intestine. While oocyst walls of Toxoplasma and Eimeria are strengthened by a porous scaffold of fibrils of β-1,3-glucan and by proteins cross-linked by dityrosines, both are absent from walls of Cryptosporidium. We show here that all oocyst walls are acid fast, have a rigid bilayer, dissolve in organic solvents, and contain a complex set of triglycerides rich in polyhydroxy and long fatty acyl chains that might be synthesized by an abundant polyketide synthase. These results suggest the possibility that coccidia build a waxy coat of acid-fast lipids in the oocyst wall that makes them resistant to environmental stress.
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Abstract
SUMMARYEimeriais a common genus of apicomplexan parasites that infect diverse vertebrates, most notably poultry, causing serious disease and economic loss. Like all apicomplexans, eimerians have a complex life cycle characterized by asexual divisions that amplify the parasite population in preparation for sexual reproduction. This can be divided into three events: gametocytogenesis, producing gametocytes from merozoites; gametogenesis, producing microgametes and macrogametes from gametocytes; and fertilization of macrogametes by microgametes, producing diploid zygotes with ensuing meiosis completing the sexual phase. Sexual development inEimeriadepends on the differential expression of stage-specific genes, rather than presence or absence of sex chromosomes. Thus, it involves the generation of specific structures and, implicitly, storage of proteins and regulation of protein expression in macrogametes, in preparation for fertilization. InEimeria, the formation of a unique, resilient structure, the oocyst wall, is essential for completion of the sexual phase and parasite transmission. In this review, we piece together the molecular events that underpin sexual reproduction inEimeriaand use additional details from analogous events inPlasmodiumto fill current knowledge gaps. The mechanisms governing sexual stage formation and subsequent fertilization may represent targets for counteracting parasite transmission.
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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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Zhao G, Zhou A, Lu G, Meng M, Sun M, Bai Y, Han Y, Wang L, Zhou H, Cong H, Zhao Q, Zhu XQ, He S. Identification and characterization of Toxoplasma gondii aspartic protease 1 as a novel vaccine candidate against toxoplasmosis. Parasit Vectors 2013; 6:175. [PMID: 23768047 PMCID: PMC3691725 DOI: 10.1186/1756-3305-6-175] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Accepted: 06/09/2013] [Indexed: 11/26/2022] Open
Abstract
Background Toxoplasma gondii is an obligate intracellular parasite that can pose a serious threat to human health by causing toxoplasmosis. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance. Aspartic proteases play essential roles in the T. gondii lifecycle. The parasite has four aspartic protease encoding genes, which are called toxomepsin 1, 2, 3 and 5 (TgASP1, 2, 3 and 5, respectively). Methods Bioinformatics approaches have enabled us to identify several promising linear-B cell epitopes and potential Th-cell epitopes on TgASP1, thus supporting its potential as a DNA vaccine against toxoplasmosis. We expressed TgASP1 in Escherichia coli and used the purified protein to immunize BALB/c mice. The antibodies obtained were used to determine where TgASP1 was localized in the parasite. We also made a TgASP1 DNA vaccine construct and evaluated it for the level of protection conferred to mice against infection with the virulent RH strain of T. gondii. Results TgASP1 appears to be a membrane protein located primarily at the tip of the T. gondii tachyzoite. Investigation of its potential as a DNA vaccine showed that it elicited strong humoral and cellular immune responses in mice, and that these responses were mediated by Th-1 cells. Mice immunized with the vaccine had greater levels of protection against mortality following challenge with T. gondii RH tachyzoites than did those immunized with PBS or the empty vector control. Conclusions TgASP1 is a novel candidate DNA vaccine that merits further investigation.
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Affiliation(s)
- Guanghui Zhao
- Department of Parasitology, Shandong University School of Medicine, Jinan, Shandong Province, People's Republic of China
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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: 4.5] [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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