1
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Joeres M, Cardron G, Passebosc-Faure K, Plault N, Fernández-Escobar M, Hamilton CM, O'Brien-Anderson L, Calero-Bernal R, Galal L, Luttermann C, Maksimov P, Conraths FJ, Dardé ML, Ortega-Mora LM, Jokelainen P, Mercier A, Schares G. A ring trial to harmonize Toxoplasma gondii microsatellite typing: comparative analysis of results and recommendations for optimization. Eur J Clin Microbiol Infect Dis 2023:10.1007/s10096-023-04597-7. [PMID: 37093325 DOI: 10.1007/s10096-023-04597-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 04/10/2023] [Indexed: 04/25/2023]
Abstract
A ring trial among five European laboratories was organized to reach consistency in microsatellite (MS) typing of the zoonotic parasite Toxoplasma gondii. Three sample sets were circulated and analyzed by each laboratory following a previously published method that is based on fragment length polymorphism of 15 MS markers. The first sample set compared typing results in general and focused on effects of DNA concentration; the second sample set focused on the polymorphic fingerprinting markers that can differentiate T. gondii strains within the same archetypal lineage; and the third set focused on non-archetypal genotypes. Methodological variations between laboratories, including the software programs used to determine MS fragment length, were collated using a questionnaire. Overall, lineage-level typing results reached a high level of agreement, especially in samples with the highest DNA concentrations. However, laboratory-specific differences were observed for particular markers. Major median differences in fragment length, of up to 6 base pairs, were related to the fluorophore used to label fragment-specific primers. In addition, primer pairs with identical sequences obtained from different suppliers resulted in fragments of differing length. Furthermore, differences in the way the sequencing profiles were assessed and interpreted may have led to deviating results in fragment length determination. Harmonization of MS typing, for example, by using the same fluorophores or by numerical adjustments applied to the fragment-lengths determined, could improve the uniformity of the results across laboratories. This is the first interlaboratory comparison, providing guidelines (added as a supplement) for the optimization of this technique.
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Affiliation(s)
- M Joeres
- Institute of Epidemiology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - G Cardron
- Institute of Epidemiology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - K Passebosc-Faure
- Centre National de Référence (CNR) Toxoplasmose Centre Hospitalier-Universitaire Dupuytren, Limoges, France
| | - N Plault
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, OmegaHealth, Limoges, France
| | - M Fernández-Escobar
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - C M Hamilton
- The Moredun Research Institute, Penicuik, Midlothian, UK
| | - L O'Brien-Anderson
- Infectious Disease Preparedness, Statens Serum Institut, Copenhagen, Denmark
| | - R Calero-Bernal
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - L Galal
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, OmegaHealth, Limoges, France
| | - C Luttermann
- Institute of Immunology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, -Insel Riems, Greifswald, Germany
| | - P Maksimov
- Institute of Epidemiology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - F J Conraths
- Institute of Epidemiology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany
| | - M L Dardé
- Centre National de Référence (CNR) Toxoplasmose Centre Hospitalier-Universitaire Dupuytren, Limoges, France
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, OmegaHealth, Limoges, France
| | - L M Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - P Jokelainen
- Infectious Disease Preparedness, Statens Serum Institut, Copenhagen, Denmark
| | - A Mercier
- Centre National de Référence (CNR) Toxoplasmose Centre Hospitalier-Universitaire Dupuytren, Limoges, France
- Inserm U1094, IRD U270, Univ. Limoges, CHU Limoges, EpiMaCT - Epidemiology of Chronic Diseases in Tropical Zone, Institute of Epidemiology and Tropical Neurology, OmegaHealth, Limoges, France
| | - G Schares
- Institute of Epidemiology, Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Südufer 10, 17493, Greifswald-Insel Riems, Germany.
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2
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Singh S, Murillo-León M, Endres NS, Arenas Soto AF, Gómez-Marín JE, Melbert F, Kanneganti TD, Yamamoto M, Campos C, Howard JC, Taylor GA, Steinfeldt T. ROP39 is an Irgb10-specific parasite effector that modulates acute Toxoplasma gondii virulence. PLoS Pathog 2023; 19:e1011003. [PMID: 36603017 PMCID: PMC9848475 DOI: 10.1371/journal.ppat.1011003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 01/18/2023] [Accepted: 11/14/2022] [Indexed: 01/06/2023] Open
Abstract
Toxoplasma gondii (T. gondii) is a zoonotic apicomplexan parasite that is an important cause of clinical disability in humans. On a global scale, one third of the human population is infected with T. gondii. Mice and other small rodents are believed to be responsible for transmission of T. gondii to the domestic cat, its definitive host. Interferon-inducible Immunity-Related GTPases (IRG proteins) are important for control of murine T. gondii infections. Virulence differences between T. gondii strains are linked to polymorphic rhoptry proteins (ROPs) that cooperate to inactivate individual IRG family members. In particular, the pseudokinase ROP5 isoform B is critically important in laboratory strains of mice. We identified T. gondii ROP39 in complex with ROP5B and demonstrate its contribution to acute T. gondii virulence. ROP39 directly targets Irgb10 and inhibits homodimer formation of the GTPase leading to an overall reduction of IRG protein loading onto the parasitophorous vacuolar membrane (PVM). Maintenance of PVM integrity rescues the parasite from IRG protein-mediated clearance in vitro and in vivo. This study identifies a novel T. gondii effector that is important for specific inactivation of the IRG resistance system. Our data reveal that yet unknown T. gondii effectors can emerge from identification of direct interaction partners of ROP5B.
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Affiliation(s)
- Shishir Singh
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Mateo Murillo-León
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Niklas Sebastian Endres
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ailan Farid Arenas Soto
- Grupo GEPAMOL, Centro de Investigaciones Biomedicas, Universidad del Quindio, Armenia, Quindio, Colombia
| | - Jorge Enrique Gómez-Marín
- Grupo GEPAMOL, Centro de Investigaciones Biomedicas, Universidad del Quindio, Armenia, Quindio, Colombia
| | - Florence Melbert
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Thirumala-Devi Kanneganti
- Department of Immunology, St. Jude Children´s Research Hospital, Memphis, Tenessee, United States of America
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
- Laboratory of Immunoparasitology, World Premier International Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan
| | - Claudia Campos
- Fundacao Calouste Gulbekian, Instituto Gulbekian de Ciencia, Oeiras, Portugal
| | | | - Gregory Alan Taylor
- Departments of Medicine; Molecular Genetics and Microbiology; and Immunology; and Center for the Study of Aging and Human Development, Duke University Medical Center, Durham, North Carolina, United States of America
- Geriatric Research, Education, and Clinical Center, Durham VA Health Care System, Durham, North Carolina, United States of America
| | - Tobias Steinfeldt
- Institute of Virology, Medical Center University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- * E-mail:
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3
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A unique Toxoplasma gondii haplotype accompanied the global expansion of cats. Nat Commun 2022; 13:5778. [PMID: 36182919 PMCID: PMC9526699 DOI: 10.1038/s41467-022-33556-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 09/22/2022] [Indexed: 11/08/2022] Open
Abstract
Toxoplasma gondii is a cyst-forming apicomplexan parasite of virtually all warm-blooded species, with all true cats (Felidae) as definitive hosts. It is the etiologic agent of toxoplasmosis, a disease causing substantial public health burden worldwide. Few intercontinental clonal lineages represent the large majority of isolates worldwide. Little is known about the evolutionary forces driving the success of these lineages, the timing and the mechanisms of their global dispersal. In this study, we analyse a set of 156 genomes and we provide estimates of T. gondii mutation rate and generation time. We elucidate how the evolution of T. gondii populations is intimately linked to the major events that have punctuated the recent history of cats. We show that a unique haplotype, whose length represents only 0.16% of the whole T. gondii genome, is common to all intercontinental lineages and hybrid populations derived from these lineages. This haplotype has accompanied wildcats (Felis silvestris) during their emergence from the wild to domestic settlements, their dispersal in the Old World, and their expansion in the last five centuries to the Americas. The selection of this haplotype is most parsimoniously explained by its role in sexual reproduction of T. gondii in domestic cats.
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4
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Bolais PF, Galal L, Cronemberger C, Pereira FDA, Barbosa ADS, Dib LV, Amendoeira MRR, Dardé ML, Mercier A. Toxoplasma gondii in the faeces of wild felids from the Atlantic Forest, Brazil. Mem Inst Oswaldo Cruz 2022; 117:e210302. [PMID: 35766781 PMCID: PMC9241165 DOI: 10.1590/0074-02760210302] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 03/28/2022] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Toxoplasma gondii is a apicomplexan parasite of virtually all warm-blooded species. All true cats (Felidae) can act as definitive hosts for this parasite by shedding resistant oocysts into the environment. However, the patterns of oocysts shedding are only partially understood in domestic cats and largely unknown in wild felids. OBJECTIVES We carried out molecular analysis of 82 faecal samples from wild felids collected in the Serra dos Órgãos National Park (Parnaso), Rio de Janeiro, Brazil. METHODS We screened samples for T. gondii DNA using a quantitative polymerase chain reaction (qPCR) targeting the 529bp DNA fragment. Polymerase chain reaction (PCR)-positive samples were genotyped using 15 microsatellite markers. RESULTS Only one faecal sample from a Puma yagouaroundi was PCR-positive [cycle threshold (Ct) = 26.88]. This sample was contaminated by a T. gondii strain of BrIII lineage, a common lineage in domestic animals from Brazil. MAIN CONCLUSIONS This first report of T. gondii in faeces of wild South American felids in their natural environment indicates infrequent oocyst shedding and suggests a role of acquired immunity in limiting re-excretion as in domestic cats. The presence of a domestic strain of T. gondii in a faecal sample from a wild felid at very low concentrations (not detected by microscopy) is consistent with the hypothesis of host-parasite co-adaptations limiting the circulation of T. gondii strains between domestic and wild environments.
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Affiliation(s)
- Paula F Bolais
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France
| | - Lokman Galal
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France
| | - Cecília Cronemberger
- Instituto Chico Mendes de Conservação da Biodiversidade, Parque Nacional da Serra dos Órgãos, Teresópolis, RJ, Brasil
| | - Fabiane de Aguiar Pereira
- Instituto Chico Mendes de Conservação da Biodiversidade, Parque Nacional da Serra dos Órgãos, Teresópolis, RJ, Brasil
| | - Alynne da Silva Barbosa
- Universidade Federal Fluminense, Instituto Biomédico, Departamento de Microbiologia e Parasitologia, Niterói, RJ, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Laís Verdan Dib
- Universidade Federal Fluminense, Instituto Biomédico, Departamento de Microbiologia e Parasitologia, Niterói, RJ, Brasil.,Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Maria Regina Reis Amendoeira
- Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Toxoplasmose e Outras Protozooses, Rio de Janeiro, RJ, Brasil
| | - Marie-Laure Dardé
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France.,Centre Hospitalier-Universitaire Dupuytren, Centre National de Référence, Toxoplasmose/Toxoplasma Biological Centre, Limoges, France
| | - Aurélien Mercier
- University of Limoges, Institute of Epidemiology and Tropical Neurology, Epidemiology of Chronic Diseases in Tropical Zone, OmegaHealth, Limoges, France.,Centre Hospitalier-Universitaire Dupuytren, Centre National de Référence, Toxoplasmose/Toxoplasma Biological Centre, Limoges, France
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5
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Calero-Bernal R, Fernández-Escobar M, Katzer F, Su C, Ortega-Mora LM. Unifying Virulence Evaluation in Toxoplasma gondii: A Timely Task. Front Cell Infect Microbiol 2022; 12:868727. [PMID: 35573788 PMCID: PMC9097680 DOI: 10.3389/fcimb.2022.868727] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 03/28/2022] [Indexed: 01/25/2023] Open
Abstract
Toxoplasma gondii, a major zoonotic pathogen, possess a significant genetic and phenotypic diversity that have been proposed to be responsible for the variation in clinical outcomes, mainly related to reproductive failure and ocular and neurological signs. Different T. gondii haplogroups showed strong phenotypic differences in laboratory mouse infections, which provide a suitable model for mimicking acute and chronic infections. In addition, it has been observed that degrees of virulence might be related to the physiological status of the host and its genetic background. Currently, mortality rate (lethality) in outbred laboratory mice is the most significant phenotypic marker, which has been well defined for the three archetypal clonal types (I, II and III) of T. gondii; nevertheless, such a trait seems to be insufficient to discriminate between different degrees of virulence of field isolates. Many other non-lethal parameters, observed both in in vivo and in vitro experimental models, have been suggested as highly informative, yielding promising discriminatory power. Although intra-genotype variations have been observed in phenotypic characteristics, there is no clear picture of the phenotypes circulating worldwide; therefore, a global overview of T. gondii strain mortality in mice is presented here. Molecular characterization has been normalized to some extent, but this is not the case for the phenotypic characterization and definition of virulence. The present paper proposes a baseline (minimum required information) for the phenotypic characterization of T. gondii virulence and intends to highlight the needs for consistent methods when a panel of T. gondii isolates is evaluated for virulence.
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Affiliation(s)
- Rafael Calero-Bernal
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
- *Correspondence: Rafael Calero-Bernal, ; Luis Miguel Ortega-Mora,
| | - Mercedes Fernández-Escobar
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
| | - Frank Katzer
- Disease Control Department, Moredun Research Institute, Edinburgh, United Kingdom
| | - Chunlei Su
- Department of Microbiology, University of Tennessee, Knoxville, TN, United States
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Madrid, Spain
- *Correspondence: Rafael Calero-Bernal, ; Luis Miguel Ortega-Mora,
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6
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Fabiani S, Caroselli C, Menchini M, Gabbriellini G, Falcone M, Bruschi F. Ocular toxoplasmosis, an overview focusing on clinical aspects. Acta Trop 2022; 225:106180. [PMID: 34699742 DOI: 10.1016/j.actatropica.2021.106180] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/25/2021] [Indexed: 12/15/2022]
Abstract
Toxoplasma gondii is a widespread protozoan parasite infecting approximately one third of the world population. After proliferation of tachyzoites during the acute stage, the parasite forms tissue cysts in various anatomical sites and establishes chronic infection. Nowadays the nature of the interplay between the protozoan and its human host remains elusive. This is clearly evident in ocular toxoplasmosis, in which the parasite establishes an ambivalent relationship with the eye, manipulating the immune response and inducing variable initial lesions and further relapses. This review will focus on epidemiology and environmental, parasite and host related risk factors, clinical manifestations and laboratory findings, treatment and prophylaxis approaches in ocular toxoplasmosis. An image collection of patients referred to the Unit of Ophthalmology of Pisa's Hospital will be presented, too.
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7
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Wilson AG, Wilson S, Alavi N, Lapen DR. Human density is associated with the increased prevalence of a generalist zoonotic parasite in mammalian wildlife. Proc Biol Sci 2021; 288:20211724. [PMID: 34666519 PMCID: PMC8527198 DOI: 10.1098/rspb.2021.1724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/23/2021] [Indexed: 01/24/2023] Open
Abstract
Macroecological approaches can provide valuable insight into the epidemiology of globally distributed, multi-host pathogens. Toxoplasma gondii is a zoonotic protozoan that infects any warm-blooded animal, including humans, in almost every ecosystem worldwide. There is substantial geographical variation in T. gondii prevalence in wildlife populations and the mechanisms driving this variation are poorly understood. We implemented Bayesian phylogenetic mixed models to determine the association between species' ecology, phylogeny and climatic and anthropogenic factors on T. gondii prevalence. Toxoplasma gondii prevalence data were compiled for free-ranging wild mammal species from 202 published studies, encompassing 45 079 individuals from 54 taxonomic families and 238 species. We found that T. gondii prevalence was positively associated with human population density and warmer temperatures at the sampling location. Terrestrial species had a lower overall prevalence, but there were no consistent patterns between trophic level and prevalence. The relationship between human density and T. gondii prevalence is probably mediated by higher domestic cat abundance and landscape degradation leading to increased environmental oocyst contamination. Landscape restoration and limiting free-roaming in domestic cats could synergistically increase the resiliency of wildlife populations and reduce wildlife and human infection risks from one of the world's most common parasitic infections.
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Affiliation(s)
- Amy G. Wilson
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Canadian Wildlife Health Cooperative, Abbotsford, British Columbia, Canada V3G 2M3
| | - Scott Wilson
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
- Environment and Climate Change Canada, Delta, British Columbia, Canada V4 K 3N2 0H3
| | - Niloofar Alavi
- Environment and Climate Change Canada, Ottawa, Ontario, Canada K1S 5B6
| | - David R. Lapen
- Ottawa Research Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada K1A 0C6
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8
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Zahedi M, Asgari Q, Badakhshan F, Sakhteman A, Ranjbar S, Khoshneviszadeh M. Anti- Toxoplasma gondii activity of 5-oxo-hexahydroquinoline derivatives: synthesis, in vitro and in vivo evaluations, and molecular docking analysis. Res Pharm Sci 2020; 15:367-380. [PMID: 33312215 PMCID: PMC7714012 DOI: 10.4103/1735-5362.293515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/28/2020] [Accepted: 08/20/2020] [Indexed: 11/04/2022] Open
Abstract
Background and purpose The aim of this study was to evaluate the in vitro and in vivo anti-Toxoplasma gondii (T. gondii) effect of 5-oxo-hexahydroquinoline compounds. Moreover, molecular docking study of the compounds into the active site of enoyl-acyl carrier protein reductase (ENR) as a necessary enzyme for the vitality of apicoplast was carried out. Experimental approach A number of 5-oxo-hexahydoquinoline derivatives (Z1-Z4) were synthesized. The T. gondii tachyzoites of RH strain were treated by different concentrations (1-64 μg/mL) of the compounds. The viability of the encountered parasites with compounds was assessed using flow cytometry and propidium iodide (PI) staining. Due to the high mortality effect of Z3 and Z4 in vitro, their chemotherapy effect was assessed by inoculation of tachyzoites to four BALB/c mice groups (n = 5), followed by the gavage of various concentrations of the compounds to the mice. Molecular docking was done to study the binding affinity of the synthesized 5-oxo-hexahydroquinolines into ENR enzyme active site byusing AutoDock Vina® software. Docking was performed by a Lamarckian Genetic Algorithm with 100 runs. Findings / Results Flow cytometry assay results indicated compounds Z3 and Z4 had relevant mortality effect on parasite tachyzoites. Besides, in vivo experiments were also performed and a partial increase of mice longevity between control and experiment groups was recorded. Molecular docking of Z3 and Z4 in the binding site of ENR enzyme indicated that the compounds were well accommodated within the binding site. Therefore, it could be suggested that these compounds may exert their anti-T. gondii activity through the inhibition of the ENR enzyme. Conclusion and implications Compounds Z3 and Z4 are good leads in order to develop better anti-T. gondii agents as they demonstrated both in vitro and in vivo inhibitory effects on tachyzoites viability and infection. Further studies on altering the route of administration along with additional pharmacokinetics evaluations are needed to improve the anti-T. gondii impacts of 5-oxo-hexahydroquinoline compounds.
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Affiliation(s)
- Mohammadsaeid Zahedi
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Qasem Asgari
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Fatemeh Badakhshan
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Amirhossein Sakhteman
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Sara Ranjbar
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Mehdi Khoshneviszadeh
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran.,Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
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9
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Serotyping, host genes and cytokines response in human ocular toxoplasmosis. Microb Pathog 2020; 148:104465. [DOI: 10.1016/j.micpath.2020.104465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 11/22/2022]
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10
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Janetka JW, Hopper AT, Yang Z, Barks J, Dhason MS, Wang Q, Sibley LD. Optimizing Pyrazolopyrimidine Inhibitors of Calcium Dependent Protein Kinase 1 for Treatment of Acute and Chronic Toxoplasmosis. J Med Chem 2020; 63:6144-6163. [PMID: 32420739 PMCID: PMC7325724 DOI: 10.1021/acs.jmedchem.0c00419] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Calcium dependent protein kinase 1 (CDPK1) is an essential Ser/Thr kinase that controls invasion and egress by the protozoan parasite Toxoplasma gondii. The Gly gatekeeper of CDPK1 makes it exquisitely sensitive to inhibition by small molecule 1H-pyrazolo[3,4-d]pyrimidine-4-amine (PP) compounds that are bulky ATP mimetics. Here we rationally designed, synthesized, and tested a series of novel PP analogs that were evaluated for inhibition of CDPK1 enzyme activity in vitro and parasite growth in cell culture. Optimal substitution on the PP scaffold included 2-pyridyl ethers directed into the hydrophobic pocket and small carbocyclic rings accessing the ribose-binding pocket. Further optimization of the series led to identification of the lead compound 3a that displayed excellent potency, selectivity, safety profile, and efficacy in vivo. The results of these studies provide a foundation for further work to optimize CDPK1 inhibitors for the treatment of acute and chronic toxoplasmosis.
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Affiliation(s)
- James W. Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis. MO 63110
| | | | - Ziping Yang
- Vyera Pharmaceuticals, 600 Third Avenue, New York, NY 10016
| | - Jennifer Barks
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Mary Savari Dhason
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
| | - L. David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis. MO 63110
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11
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Abstract
Toxoplasma is a widespread parasite of animals including many rodents that are a natural part of the transmission cycle between cats, which serve as the definitive host. Although wild rodents, including house mice, are relatively resistant, laboratory mice are highly susceptible to infection. As such, laboratory mice have been used to compare pathogenesis of natural variants and to evaluate the contributions of both host and parasite genes to infection. Protocols are provided here for evaluating acute and chronic infection with different parasite strains in laboratory mice. These protocols should provide uniform standards for evaluating natural variants and attenuated mutants and for comparing outcomes across different studies and between different laboratories.
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Affiliation(s)
- Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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12
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Simon S, de Thoisy B, Mercier A, Nacher M, Demar M. Virulence of atypical Toxoplasma gondii strains isolated in French Guiana in a murine model. ACTA ACUST UNITED AC 2019; 26:60. [PMID: 31549631 PMCID: PMC6757855 DOI: 10.1051/parasite/2019048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 07/25/2019] [Indexed: 11/18/2022]
Abstract
Background. Toxoplasma gondii is an obligate intracellular protozoan parasite of warm-blooded vertebrates. Most infections in immunocompetent patients are asymptomatic. However, since 2000s, strains with particular genetic profiles that differ from the known clonal type (type I, II, III), have been described. In French Guiana, these strains are highly pathogenic in immunocompetent patients. They have defined a new clinical entity called Amazonian Toxoplasmosis. The present study aims to further improve our knowledge on the pathogenicity of these Amazonian T. gondii strains in comparison with three reference strains using Swiss strain mice. With these data, we tried to establish a predictive virulence score to classify these strains, but also to correlate this virulence with the severity of the disease in infected patients. Results. All the virulence indicators revealed that the Amazonian strains isolated in French Guiana presented a high virulence profile, but lower than the highly virulent type I reference RH strain. The findings reveal differences in virulence between human and animal strains, but also between anthropized and wild strains. Conclusion. In addition to being a clinically relevant animal model of Amazonian Toxoplasmosis, this model could also provide a solid experimental basis for future studies aiming to investigate the underlying mechanisms of Amazonian Toxoplasmosis disease.
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Affiliation(s)
- Stéphane Simon
- Equipe EA3593 - Ecosystèmes Amazoniens et Pathologie Tropicale, Université de la Guyane, 97300 Cayenne, French Guiana - Laboratoire de Parasitologie - Mycologie, Cayenne General Hospital, 97300 Cayenne, French Guiana
| | - Benoit de Thoisy
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, 97300 Cayenne, French Guiana
| | - Aurélien Mercier
- INSERM UMR_S 1094, Neuroépidémiologie Tropicale, Laboratoire de Parasitologie-Mycologie, Faculté de Médecine, Université de Limoges, Limoges 87025, France - Centre National de Référence Toxoplasmose/Toxoplasma Biological Ressource Center, CHU Limoges, 87042 Limoges, France
| | - Mathieu Nacher
- Equipe EA3593 - Ecosystèmes Amazoniens et Pathologie Tropicale, Université de la Guyane, 97300 Cayenne, French Guiana - Centre d'Investigation Clinique Epidémiologie Clinique Antilles Guyane CIC CIE 1424, Cayenne General Hospital, 97300 Cayenne, French Guiana
| | - Magalie Demar
- Equipe EA3593 - Ecosystèmes Amazoniens et Pathologie Tropicale, Université de la Guyane, 97300 Cayenne, French Guiana - Laboratoire de Parasitologie - Mycologie, Cayenne General Hospital, 97300 Cayenne, French Guiana
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13
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Shapiro K, VanWormer E, Packham A, Dodd E, Conrad PA, Miller M. Type X strains of Toxoplasma gondii are virulent for southern sea otters (Enhydra lutris nereis) and present in felids from nearby watersheds. Proc Biol Sci 2019; 286:20191334. [PMID: 31431162 PMCID: PMC6732395 DOI: 10.1098/rspb.2019.1334] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Why some Toxoplasma gondii-infected southern sea otters (Enhydra lutris nereis) develop fatal toxoplasmosis while others have incidental or mild chronic infections has long puzzled the scientific community. We assessed robust datasets on T. gondii molecular characterization in relation to detailed necropsy and histopathology results to evaluate whether parasite genotype influences pathological outcomes in sea otters that stranded along the central California coast. Genotypes isolated from sea otters were also compared with T. gondii strains circulating in felids from nearby coastal regions to assess land-to-sea parasite transmission. The predominant T. gondii genotypes isolated from 135 necropsied sea otters were atypical Type X and Type X variants (79%), with the remainder (21%) belonging to Type II or Type II/X recombinants. All sea otters that died due to T. gondii as a primary cause of death were infected with Type X or X-variant T. gondii strains. The same atypical T. gondii strains were detected in sea otters with fatal toxoplasmosis and terrestrial felids from watersheds bordering the sea otter range. Our results confirm a land–sea connection for virulent T. gondii genotypes and highlight how faecal contamination can deliver lethal pathogens to coastal waters, leading to detrimental impacts on marine wildlife.
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Affiliation(s)
- Karen Shapiro
- Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA.,One Health Institute, University of California Davis, Davis, CA 95616, USA
| | - Elizabeth VanWormer
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE 68583, USA.,School of Natural Resources, University of Nebraska, Lincoln, NE 68583, USA
| | - Andrea Packham
- Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Erin Dodd
- California Department of Fish and Wildlife, Marine Wildlife Veterinary Care and Research Center, Santa Cruz, CA 95060, USA
| | - Patricia A Conrad
- Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA.,One Health Institute, University of California Davis, Davis, CA 95616, USA
| | - Melissa Miller
- One Health Institute, University of California Davis, Davis, CA 95616, USA.,California Department of Fish and Wildlife, Marine Wildlife Veterinary Care and Research Center, Santa Cruz, CA 95060, USA
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14
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Loeuillet C, Mondon A, Kamche S, Curri V, Boutonnat J, Cavaillès P, Cesbron-Delauw MF. Toxoplasma Hypervirulence in the Rat Model Parallels Human Infection and Is Modulated by the Toxo1 Locus. Front Cell Infect Microbiol 2019; 9:134. [PMID: 31119105 PMCID: PMC6504788 DOI: 10.3389/fcimb.2019.00134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/15/2019] [Indexed: 11/17/2022] Open
Abstract
Toxoplasmosis is considered as an opportunistic parasitic disease. If post-natally acquired in children or adults, it may pass unnoticed, at least with strains of European origin. However, in the wild biotopes especially in South America, Toxoplasma gondii strains display a greater genetic diversity, which correlates to higher virulence for humans, particularly along the Amazon River and its tributaries. In French Guiana, several atypical strains have been associated with severe clinical forms: ocular toxoplasmosis and acute respiratory distress syndrome both of which can result in death. Among these, the GUY008-ABE strain was responsible for an epidemic of severe disseminated toxoplasmosis in Suriname, which led to the death of one immunocompetent individual. To better understand the mechanism underlying the hypervirulence of the GUY008-ABE strain, we have tested the rat model which compared to the mouse, better reflects the immune resistance of humans to Toxoplasma infection. Here we compare the outcome of toxoplasmosis in F344 rats infected either by the GUY008-ABE strain or the type II Prugniaud strain. We show that the GUY008-ABE strain displays a higher virulence phenotype leading to the death of all infected rats observed in this study. GUY008-ABE infection was characterized by an increase of the parasite load in several organs, especially the heart and lung, and was mainly associated with severe histological changes in lungs. Moreover, correlating with its hypervirulence trait, the GUY008-ABE strain was able to form cysts in the LEW rat model otherwise known to be refractory to infection by other Toxoplasma strains. Together, these results show that the rat is a discriminating experimental model to study Toxoplasma virulence factors relevant to the pathogenesis of human infection and that the degree of virulence is linked to the Toxo1 locus.
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Affiliation(s)
- Corinne Loeuillet
- BNI Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Anais Mondon
- BNI Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Salima Kamche
- BNI Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Véronique Curri
- Therex Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Jean Boutonnat
- Therex Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France.,Unit of Anatomopathology, Institute of Biology and Pathology, Grenoble Alpes Hospital, Grenoble, France
| | - Pierre Cavaillès
- BNI Team, Grenoble Alpes, CNRS, Grenoble INP, TIMC-IMAG, Grenoble, France
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15
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Galal L, Hamidović A, Dardé ML, Mercier M. Diversity of Toxoplasma gondii strains at the global level and its determinants. Food Waterborne Parasitol 2019; 15:e00052. [PMID: 32095622 PMCID: PMC7033991 DOI: 10.1016/j.fawpar.2019.e00052] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 11/30/2022] Open
Abstract
The population structure of Toxoplasma gondii is characterized by contrasting geographic patterns of strain diversity at different spatial scales: global, regional and even local scales in some regions. The determinants of this diversity pattern and its possible evolutionary mechanisms are still largely unexplored. This review will focus on three main dichotomies observed in the population structure of the parasite: (1) domestic versus wild, (2) South America versus the rest of the world and (3) intercontinental clonal lineages versus regional or local clonal lineages. Here, the impact in terms of public health of this remarkably contrasting geographic diversity of T. gondii populations is discussed, with emphasis on the role of globalization of exchanges that could lead to rapid evolution of T. gondii population spatial structure and new challenges in a One Health context. Recombination events drive the evolution of population structure of Toxoplasma gondii. The population structure of Toxoplasma is different in wild and domestic environments. Virulence of Toxoplasma strains in reservoir hosts influences selection of local strains. Globalization of exchanges will impact the population structure of the parasite. Clinicians should be aware of more pathogenic strains imported from the wild environment or from South America.
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Affiliation(s)
- L Galal
- INSERM, Univ. Limoges, CHU Limoges, UMR 1094, Institut d'Epidémiologie et de Neurologie Tropicale, GEIST, 87000 Limoges, France
| | - A Hamidović
- INSERM, Univ. Limoges, CHU Limoges, UMR 1094, Institut d'Epidémiologie et de Neurologie Tropicale, GEIST, 87000 Limoges, France
| | - M L Dardé
- INSERM, Univ. Limoges, CHU Limoges, UMR 1094, Institut d'Epidémiologie et de Neurologie Tropicale, GEIST, 87000 Limoges, France.,Centre National de Référence Toxoplasmose/Toxoplasma Biological Resource Center, CHU Limoges, 87042 Limoges, France
| | - M Mercier
- INSERM, Univ. Limoges, CHU Limoges, UMR 1094, Institut d'Epidémiologie et de Neurologie Tropicale, GEIST, 87000 Limoges, France.,Centre National de Référence Toxoplasmose/Toxoplasma Biological Resource Center, CHU Limoges, 87042 Limoges, France
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16
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Hassan MA, Olijnik AA, Frickel EM, Saeij JP. Clonal and atypical Toxoplasma strain differences in virulence vary with mouse sub-species. Int J Parasitol 2019; 49:63-70. [PMID: 30471286 PMCID: PMC6344230 DOI: 10.1016/j.ijpara.2018.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 08/29/2018] [Accepted: 08/31/2018] [Indexed: 11/29/2022]
Abstract
The severe virulence of Toxoplasma gondii in classical laboratory inbred mouse strains contradicts the hypothesis that house mice (Mus musculus) are the most important intermediate hosts for its transmission and evolution because death of the mouse before parasite transmission equals death of the parasite. However, the classical laboratory inbred mouse strains (Mus musculus domesticus), commonly used to test Toxoplasma strain differences in virulence, do not capture the genetic diversity within Mus musculus. Thus, it is possible that Toxoplasma strains that are severely virulent in laboratory inbred mice are avirulent in some other mouse sub-species. Here, we present insight into the responses of individual mouse strains, representing strains of the genetically divergent Mus musculus musculus, Mus musculus castaneus and Mus musculus domesticus, to infection with individual clonal and atypical Toxoplasma strains. We observed that, unlike M. m. domesticus, M. m. musculus and M. m. castaneus are resistant to the clonal Toxoplasma strains. For M. m. musculus, we show that this is due to a locus on chromosome 11 that includes the genes that encode the interferon gamma (IFNG)-inducible immunity-related GTPases (Irgs) that can kill the parasite by localising and subsequently vesiculating the parasitophorous vacuole membrane. However, despite the localization of known effector Irgs to the Toxoplasma parasitophorous vacuole membrane, we observed that some atypical Toxoplasma strains are virulent in all the mouse strains tested. The virulence of these atypical strains in M. m. musculus could not be attributed to individual rhoptry protein 5 (ROP5) alleles, a secreted parasite pseudokinase that antagonises the canonical effector Irgs and is indispensable for parasite virulence in laboratory inbred mice (M. m. domesticus). We conclude that murine resistance to Toxoplasma is modulated by complex interactions between host and parasite genotypes and may be independent of known effector Irgs on murine chromosome 11.
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Affiliation(s)
- Musa A Hassan
- Division of Infection and Immunity, The Roslin Institute, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, UK; Centre for Tropical Livestock Health and Genetics, The University of Edinburgh, Edinburgh, UK.
| | - Aude-Anais Olijnik
- Division of Infection and Immunity, The Roslin Institute, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, UK; Centre for Tropical Livestock Health and Genetics, The University of Edinburgh, Edinburgh, UK
| | - Eva-Maria Frickel
- Host-Toxoplasma Interaction Laboratory, The Francis Crick Institute, London, UK
| | - Jeroen P Saeij
- Department of Pathology, Microbiology and Immunology, University of California, Davis, Davis, CA 95616, USA
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17
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Cubas-Atienzar AI, Hide G, Jiménez-Coello M, Ortega-Pacheco A, Smith JE. Genotyping of Toxoplasma gondii from pigs in Yucatan, Mexico. VETERINARY PARASITOLOGY- REGIONAL STUDIES AND REPORTS 2018; 14:191-199. [PMID: 31014729 DOI: 10.1016/j.vprsr.2018.10.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/13/2018] [Accepted: 10/26/2018] [Indexed: 01/19/2023]
Abstract
Toxoplasmosis is a zoonotic disease of worldwide distribution. The parasite exhibits strong geographical patterns of strain variation with contrasting high levels of diversity across South America and restricted variation across North America. Little is known about the diversity of strains in the transitional area between the two continents. Here we present data on the prevalance and diversity of Toxoplasma gondii in the Yucatan peninsula of Mexico, through a study in commercially reared pigs. A survey of 12 farms found evidence of circulating T. gondii DNA in 125 of 632 blood samples (19.8%, CI: 16.7%-23%). In addition, 46 tongue samples were collected from culled animals and 16 of these were positive for T. gondii DNA and 3 were positive in mouse bioassay. PCR-sequencing was used to generate genotyping data from blood and tissue samples. Four loci (SAG1, 2, 3 and GRA6) were reliably amplified and revealed a high diversity among Yucatan strains with evidence of recombination and novel alleles. Sequencing data from the four loci was achieved in eight samples each of which had a different genotype. The predominant allelic type was atypical, in relation to the dominant strain types (I, II, III), the number of allelic variants being 27 (I, II-III, u-1-25), 20 (I, III, u1-18), 6 (I, III, u1-4) and 11 (I, II, u1-9) for the SAG1, SAG2, SAG3 and GRA6 loci respectively. Phylogenetic analysis showed that T. gondii strains from Yucatan shared alleles with strains originating from both North and South America. Our findings are consistent with data from other regions of Central America and suggest the genetic population structure of the parasite, with significant levels of allelic variation and recombination, constitutes a reservoir from which new strains may emerge. Positive bioassay results (7.5%) indicate that consumption of undercooked pork could be a potential T. gondii infection risk to humans.
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Affiliation(s)
- Ana I Cubas-Atienzar
- Ecosystems and Environment Research Centre, School of Environment and Life Sciences, University of Salford, Salford, M5 4WT Manchester, UK.
| | - Geoff Hide
- Ecosystems and Environment Research Centre, School of Environment and Life Sciences, University of Salford, Salford, M5 4WT Manchester, UK
| | - Matilde Jiménez-Coello
- Campus de Ciencias Biológicas y Agropecuarias, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán, Mexico
| | - Antonio Ortega-Pacheco
- Campus de Ciencias Biológicas y Agropecuarias, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Yucatán, Km 15.5 Carretera Mérida-Xmatkuil, Mérida, Yucatán, Mexico
| | - Judith E Smith
- Ecosystems and Environment Research Centre, School of Environment and Life Sciences, University of Salford, Salford, M5 4WT Manchester, UK
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18
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Human impact on the diversity and virulence of the ubiquitous zoonotic parasite Toxoplasma gondii. Proc Natl Acad Sci U S A 2018; 115:E6956-E6963. [PMID: 29967142 PMCID: PMC6055184 DOI: 10.1073/pnas.1722202115] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A majority of emerging infectious diseases in humans are zoonoses. Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control. Toxoplasma gondii is one of the most widespread zoonotic pathogens known today. Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America. Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere. However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain. Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading. These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.
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19
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Jiang T, Shwab EK, Martin RM, Gerhold RW, Rosenthal BM, Dubey JP, Su C. A partition of Toxoplasma gondii genotypes across spatial gradients and among host species, and decreased parasite diversity towards areas of human settlement in North America. Int J Parasitol 2018; 48:611-619. [PMID: 29577892 DOI: 10.1016/j.ijpara.2018.01.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 12/24/2017] [Accepted: 01/01/2018] [Indexed: 10/17/2022]
Abstract
Toxoplasma gondii counts among the most consequential food-borne parasites, and although the parasite occurs in a wide range of wild and domesticated animals, farms may constitute a specific and important locus of transmission. If so, parasites in animals that inhabit agricultural habitats might be suspected of harbouring genetically distinct parasite types. To better understand habitat effects pertinent to this parasite's transmission, we compiled and analysed existing genotypic data of 623 samples from animals across a proximity gradient from areas of human settlement to the wilderness in North America. To facilitate such analysis, T. gondii isolates were divided into three groups: (i) from farm-bound animals (with the most limited home ranges on farms); (ii) from free-roaming animals (with wider home ranges on or near farms); and (iii) from wildlife. In addition, parasite genotype distribution in different animal species was analysed. We observed no absolute limitation of any of five major genotypes to any one habitat; however, the frequency of four genotypes decreased across the gradient from the farm-bound group, to the free-roaming group, then the wildlife, whereas a fifth genotype increased along that gradient. Genetic diversity was greater in free-roaming than in farm-bound animals. The genotypic composition of parasites in wildlife differed from those in farm-bound and free-roaming animals. Furthermore, parasite genotypes differed among host species. We conclude that T. gondii genotype distributions are influenced by the spatial habitat and host species composition, and parasite diversity decreases towards areas of human settlement, elucidating facts which may influence transmission dynamics and zoonotic potential in this ubiquitous but regionally variable parasite.
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Affiliation(s)
- Tiantian Jiang
- Department of Microbiology, The University of Tennessee, Knoxville, TN 37996, USA
| | - E Keats Shwab
- Department of Microbiology, The University of Tennessee, Knoxville, TN 37996, USA
| | - Robbie M Martin
- Department of Microbiology, The University of Tennessee, Knoxville, TN 37996, USA
| | - Richard W Gerhold
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN 37996, USA; Center for Wildlife Health, Department of Forestry, Wildlife, and Fisheries, the University of Tennessee, Knoxville, TN 37996, USA
| | - Benjamin M Rosenthal
- Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Jitender P Dubey
- Animal Parasitic Diseases Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, MD 20705, USA
| | - Chunlei Su
- Department of Microbiology, The University of Tennessee, Knoxville, TN 37996, USA.
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20
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Abstract
Early electron microscopy studies revealed the elaborate cellular features that define the unique adaptations of apicomplexan parasites. Among these were bulbous rhoptry (ROP) organelles and small, dense granules (GRAs), both of which are secreted during invasion of host cells. These early morphological studies were followed by the exploration of the cellular contents of these secretory organelles, revealing them to be comprised of highly divergent protein families with few conserved domains or predicted functions. In parallel, studies on host-pathogen interactions identified many host signaling pathways that were mysteriously altered by infection. It was only with the advent of forward and reverse genetic strategies that the connections between individual parasite effectors and the specific host pathways that they targeted finally became clear. The current repertoire of parasite effectors includes ROP kinases and pseudokinases that are secreted during invasion and that block host immune pathways. Similarly, many secretory GRA proteins alter host gene expression by activating host transcription factors, through modification of chromatin, or by inducing small noncoding RNAs. These effectors highlight novel mechanisms by which T. gondii has learned to harness host signaling to favor intracellular survival and will guide future studies designed to uncover the additional complexity of this intricate host-pathogen interaction.
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21
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22
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Alday PH, Doggett JS. Drugs in development for toxoplasmosis: advances, challenges, and current status. DRUG DESIGN DEVELOPMENT AND THERAPY 2017; 11:273-293. [PMID: 28182168 PMCID: PMC5279849 DOI: 10.2147/dddt.s60973] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Toxoplasma gondii causes fatal and debilitating brain and eye diseases. Medicines that are currently used to treat toxoplasmosis commonly have toxic side effects and require prolonged courses that range from weeks to more than a year. The need for long treatment durations and the risk of relapsing disease are in part due to the lack of efficacy against T. gondii tissue cysts. The challenges for developing a more effective treatment for toxoplasmosis include decreasing toxicity, achieving therapeutic concentrations in the brain and eye, shortening duration, eliminating tissue cysts from the host, safety in pregnancy, and creating a formulation that is inexpensive and practical for use in resource-poor areas of the world. Over the last decade, significant progress has been made in identifying and developing new compounds for the treatment of toxoplasmosis. Unlike clinically used medicines that were repurposed for toxoplasmosis, these compounds have been optimized for efficacy against toxoplasmosis during preclinical development. Medicines with enhanced efficacy as well as features that address the unique aspects of toxoplasmosis have the potential to greatly improve toxoplasmosis therapy. This review discusses the facets of toxoplasmosis that are pertinent to drug design and the advances, challenges, and current status of preclinical drug research for toxoplasmosis.
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Affiliation(s)
- P Holland Alday
- Division of Infectious Diseases, Oregon Health & Science University
| | - Joseph Stone Doggett
- Division of Infectious Diseases, Oregon Health & Science University; Portland Veterans Affairs Medical Center, Portland, OR, USA
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23
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Toxoplasma gondii: One Organism, Multiple Models. Trends Parasitol 2016; 33:113-127. [PMID: 27988095 DOI: 10.1016/j.pt.2016.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/15/2016] [Accepted: 11/18/2016] [Indexed: 12/13/2022]
Abstract
Toxoplasma gondii is an intensely studied protozoan parasite. It is also used as a model organism to research additional clinically relevant human and veterinary parasites due to ease of in vitro culture and genetic manipulation. Recently, it has been developed as a model of inflammatory bowel disease, due to their similar pathologies. However, researchers vary widely in how they use T. gondii, which makes study comparisons and interpretation difficult. The aim of this review is to provide researchers with a tool to: (i) determine the appropriateness of the different T. gondii models to their research, (ii) interpret results from the wide range of study conditions, and (iii) consider new advances in technology which could improve or refine their experimental setup.
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24
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Jones NG, Wang Q, Sibley LD. Secreted protein kinases regulate cyst burden during chronic toxoplasmosis. Cell Microbiol 2016; 19. [PMID: 27450947 DOI: 10.1111/cmi.12651] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/12/2016] [Accepted: 07/15/2016] [Indexed: 12/29/2022]
Abstract
Toxoplasma gondii is an apicomplexan parasite that secretes a large number of protein kinases and pseudokinases from its rhoptry organelles. Although some rhoptry kinases (ROPKs) act as virulence factors, many remain uncharacterized. In this study, predicted ROPKs were assessed for bradyzoite expression then prioritized for a reverse genetic analysis in the type II strain Pru that is amenable to targeted disruption. Using CRISPR/Cas9, we engineered C-terminally epitope tagged ROP21 and ROP27 and demonstrated their localization to the parasitophorous vacuole and cyst matrix. ROP21 and ROP27 were not secreted from microneme, rhoptry, or dense granule organelles, but rather were located in small vesicles consistent with a constitutive pathway. Using CRISPR/Cas9, the genes for ROP21, ROP27, ROP28, and ROP30 were deleted individually and in combination, and the mutant parasites were assessed for growth and their ability to form tissue cysts in mice. All knockouts lines were normal for in vitro growth and bradyzoite differentiation, but a combined ∆rop21/∆rop17 knockout led to a 50% reduction in cyst burden in vivo. Our findings question the existing annotation of ROPKs based solely on bioinformatic techniques and yet highlight the importance of secreted kinases in determining the severity of chronic toxoplasmosis.
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Affiliation(s)
- Nathaniel G Jones
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Qiuling Wang
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
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Performance Testing of PCR Assay in Blood Samples for the Diagnosis of Toxoplasmic Encephalitis in AIDS Patients from the French Departments of America and Genetic Diversity of Toxoplasma gondii: A Prospective and Multicentric Study. PLoS Negl Trop Dis 2016; 10:e0004790. [PMID: 27355620 PMCID: PMC4927177 DOI: 10.1371/journal.pntd.0004790] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/30/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana. METHODOLOGY/PRINCIPAL FINDINGS Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay. CONCLUSION/SIGNIFICANCE Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains. TRIAL REGISTRATION ClinicalTrials.gov NCT00803621.
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Abstract
Toxoplasma gondii is a widespread parasite of warm-blooded vertebrates that also causes opportunistic infections in humans. Rodents are a natural host for asexually replicating forms, whereas cats serve as the definitive host for sexual development. The laboratory mouse provides a model to study pathogenesis. Strains of T. gondii are globally diverse, with more than 16 distinct haplogroups clustered into 6 major clades. Forward genetic analysis of genetic crosses between different lineages has been used to define the molecular basis of acute virulence in the mouse. These studies have identified a family of secretory serine/threonine rhoptry kinases that target innate immune pathways to protect intracellular parasites from destruction. Rhoptry kinases target immunity-related GTPases, a family of immune effectors that is expanded in rodents. Similar forward genetic studies may be useful to define the basis of pathogenesis in other hosts, including humans, where infections of different strains present with variable clinical severity.
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Affiliation(s)
- Michael S Behnke
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803
| | - J P Dubey
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, US Department of Agriculture, Beltsville, Maryland 20705
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110;
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Analysis of Noncanonical Calcium-Dependent Protein Kinases in Toxoplasma gondii by Targeted Gene Deletion Using CRISPR/Cas9. Infect Immun 2016; 84:1262-1273. [PMID: 26755159 DOI: 10.1128/iai.01173-15] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Calcium-dependent protein kinases (CDPKs) are expanded in apicomplexan parasites, especially in Toxoplasma gondii where 14 separate genes encoding these enzymes are found. Although previous studies have shown that several CDPKs play a role in controlling invasion, egress, and cell division in T. gondii, the roles of most of these genes are unexplored. Here we developed a more efficient method for gene disruption using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) that was modified to completely delete large, multiexonic genes from the genome and to allow serial replacement by recycling of the selectable marker using Cre-loxP. Using this system, we generated a total of 24 mutants in type 1 and 2 genetic backgrounds to ascertain the functions of noncanonical CDPKs. Remarkably, although we were able to confirm the essentiality of CDPK1 and CDPK7, the majority of CDPKs had no discernible phenotype for growth in vitro or infection in the mouse model. The exception to this was CDPK6, loss of which leads to reduced plaquing, fitness defect in a competition assay, and reduced tissue cyst formation in chronically infected mice. Our findings highlight the utility of CRISPR/Cas9 for rapid serial gene deletion and also suggest that additional models are needed to reveal the functions of many genes in T. gondii.
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Local admixture of amplified and diversified secreted pathogenesis determinants shapes mosaic Toxoplasma gondii genomes. Nat Commun 2016; 7:10147. [PMID: 26738725 PMCID: PMC4729833 DOI: 10.1038/ncomms10147] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 11/09/2015] [Indexed: 01/22/2023] Open
Abstract
Toxoplasma gondii is among the most prevalent parasites worldwide, infecting many wild and domestic animals and causing zoonotic infections in humans. T. gondii differs substantially in its broad distribution from closely related parasites that typically have narrow, specialized host ranges. To elucidate the genetic basis for these differences, we compared the genomes of 62 globally distributed T. gondii isolates to several closely related coccidian parasites. Our findings reveal that tandem amplification and diversification of secretory pathogenesis determinants is the primary feature that distinguishes the closely related genomes of these biologically diverse parasites. We further show that the unusual population structure of T. gondii is characterized by clade-specific inheritance of large conserved haploblocks that are significantly enriched in tandemly clustered secretory pathogenesis determinants. The shared inheritance of these conserved haploblocks, which show a different ancestry than the genome as a whole, may thus influence transmission, host range and pathogenicity.
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Rhoptry Proteins ROP5 and ROP18 Are Major Murine Virulence Factors in Genetically Divergent South American Strains of Toxoplasma gondii. PLoS Genet 2015; 11:e1005434. [PMID: 26291965 PMCID: PMC4546408 DOI: 10.1371/journal.pgen.1005434] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/08/2015] [Indexed: 11/19/2022] Open
Abstract
Toxoplasma gondii has evolved a number of strategies to evade immune responses in its many hosts. Previous genetic mapping of crosses between clonal type 1, 2, and 3 strains of T. gondii, which are prevalent in Europe and North America, identified two rhoptry proteins, ROP5 and ROP18, that function together to block innate immune mechanisms activated by interferon gamma (IFNg) in murine hosts. However, the contribution of these and other virulence factors in more genetically divergent South American strains is unknown. Here we utilized a cross between the intermediately virulent North American type 2 ME49 strain and the highly virulent South American type 10 VAND strain to map the genetic basis for differences in virulence in the mouse. Quantitative trait locus (QTL) analysis of this new cross identified one peak that spanned the ROP5 locus on chromosome XII. CRISPR-Cas9 mediated deletion of all copies of ROP5 in the VAND strain rendered it avirulent and complementation confirmed that ROP5 is the major virulence factor accounting for differences between type 2 and type 10 strains. To extend these observations to other virulent South American strains representing distinct genetic populations, we knocked out ROP5 in type 8 TgCtBr5 and type 4 TgCtBr18 strains, resulting in complete loss of virulence in both backgrounds. Consistent with this, polymorphisms that show strong signatures of positive selection in ROP5 were shown to correspond to regions known to interface with host immunity factors. Because ROP5 and ROP18 function together to resist innate immune mechanisms, and a significant interaction between them was identified in a two-locus scan, we also assessed the role of ROP18 in the virulence of South American strains. Deletion of ROP18 in South American type 4, 8, and 10 strains resulted in complete attenuation in contrast to a partial loss of virulence seen for ROP18 knockouts in previously described type 1 parasites. These data show that ROP5 and ROP18 are conserved virulence factors in genetically diverse strains from North and South America, suggesting they evolved to resist innate immune defenses in ancestral T. gondii strains, and they have subsequently diversified under positive selection. Parasites and the hosts they infect are in constant struggle with each other for survival. On the one hand, the host needs to control parasite growth, while the parasite needs to evade the host response long enough to allow for efficient transmission. The parasite Toxoplasma gondii has evolved virulence factors ROP5 and ROP18 to evade innate immune mechanisms of its natural intermediate host, small rodents. These genes were initially identified in clonal parasite types isolated from Europe and North America, but the factors that contribute to virulence in genetically divergent South American strains have not been tested. Here we used forward and reverse genetic analyses to show that ROP5 and ROP18 are also major virulence factors in genetically distinct virulent South American strains. Given that ROP5 and ROP18 function as virulence factors in strains from North America, Europe, and South America they likely acquired their functions before Toxoplasma gondii radiated into its present global population structure.
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Khan A, Shaik JS, Behnke M, Wang Q, Dubey JP, Lorenzi HA, Ajioka JW, Rosenthal BM, Sibley LD. NextGen sequencing reveals short double crossovers contribute disproportionately to genetic diversity in Toxoplasma gondii. BMC Genomics 2014; 15:1168. [PMID: 25532601 PMCID: PMC4326188 DOI: 10.1186/1471-2164-15-1168] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 12/16/2014] [Indexed: 11/30/2022] Open
Abstract
Background Toxoplasma gondii is a widespread protozoan parasite of animals that causes zoonotic disease in humans. Three clonal variants predominate in North America and Europe, while South American strains are genetically diverse, and undergo more frequent recombination. All three northern clonal variants share a monomorphic version of chromosome Ia (ChrIa), which is also found in unrelated, but successful southern lineages. Although this pattern could reflect a selective advantage, it might also arise from non-Mendelian segregation during meiosis. To understand the inheritance of ChrIa, we performed a genetic cross between the northern clonal type 2 ME49 strain and a divergent southern type 10 strain called VAND, which harbors a divergent ChrIa. Results NextGen sequencing of haploid F1 progeny was used to generate a genetic map revealing a low level of conventional recombination, with an unexpectedly high frequency of short, double crossovers. Notably, both the monomorphic and divergent versions of ChrIa were isolated with equal frequency. As well, ChrIa showed no evidence of being a sex chromosome, of harboring an inversion, or distorting patterns of segregation. Although VAND was unable to self fertilize in the cat, it underwent successful out-crossing with ME49 and hybrid survival was strongly associated with inheritance of ChrIII from ME49 and ChrIb from VAND. Conclusions Our findings suggest that the successful spread of the monomorphic ChrIa in the wild has not been driven by meiotic drive or related processes, but rather is due to a fitness advantage. As well, the high frequency of short double crossovers is expected to greatly increase genetic diversity among progeny from genetic crosses, thereby providing an unexpected and likely important source of diversity. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1168) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | | | | | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, Campus Box 8230, 660S, Euclid Ave,, St, Louis, Mo 63110, USA.
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