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Xia J, Fu Y, Huang W, Uddin T, Sibley LD. Constitutive upregulation of transcription factors underlies permissive bradyzoite differentiation in a natural isolate of Toxoplasma gondii. mBio 2024:e0064124. [PMID: 39150246 DOI: 10.1128/mbio.00641-24] [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: 02/29/2024] [Accepted: 06/28/2024] [Indexed: 08/17/2024] Open
Abstract
Toxoplasma gondii bradyzoites play a critical role in pathology due to their long-term persistence in intermediate hosts and their potential to reactivate, resulting in severe diseases in immunocompromised individuals. Currently, there is no effective treatment for eliminating bradyzoites. Hence, better in vitro models of T. gondii bradyzoite development would facilitate identification of therapeutic targets for bradyzoites. Herein, we characterized a natural isolate of T. gondii, called Tg68, which showed slower in vitro replication of tachyzoites, and permissive bradyzoite development under stress conditions in vitro. Transcriptional analysis revealed constitutive expression in Tg68 tachyzoites of the key regulators of bradyzoite development including BFD1, BFD2, and several AP2 factors. Consistent with this finding, Tg68 tachyzoites expressed high levels of bradyzoite-specific genes including BAG1, ENO1, and LDH2. Moreover, after stress-induced differentiation, Tg68 bradyzoites exhibited gene expression profiles of mature bradyzoites, even at early time points. These data suggest that Tg68 tachyzoites exist in a pre-bradyzoite stage primed to readily develop into mature bradyzoites under stress conditions in vitro. Tg68 presents a novel model for differentiation in vitro that will serve as a useful tool for the investigation of bradyzoite biology and the development of therapeutics. IMPORTANCE Toxoplasma gondii is a widespread protozoan that chronically infects ~30% of the world's population. T. gondii can differentiate between the fast-growing life stage that causes acute infection and the slow-growing stage that persists in the host for extended periods of time. The slow-growing stage cannot be eliminated by the host immune response or currently known antiparasitic drugs. Studies on the slow-growing stage have been limited due to the limitations of in vivo experiments and the challenges of in vitro manipulation. Here, we characterize a natural isolate of T. gondii, which constitutively expresses factors that drive development and that is permissive to convert to the slow-growing stage under stress conditions in vitro. The strain presents a novel in vitro model for studying the chronic phase of toxoplasmosis and identifying new therapeutic treatments for chronic infections.
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Affiliation(s)
- Jing Xia
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Wanyi Huang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Taher Uddin
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
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2
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Xia J, Fu Y, Huang W, Sibley LD. Constitutive upregulation of transcription factors underlies permissive bradyzoite differentiation in a natural isolate of Toxoplasma gondii. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582596. [PMID: 38464000 PMCID: PMC10925318 DOI: 10.1101/2024.02.28.582596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Toxoplasma gondii bradyzoites play a critical role in pathology due to their long-term persistence in intermediate hosts and their potential to reactivate, resulting in severe diseases in immunocompromised individuals. Currently there is no effective treatment for eliminating bradyzoites. Hence, better in vitro models of T. gondii cyst development would facilitate identification of therapeutic targets for bradyzoites. Herein we characterized a natural isolate of T. gondii, called Tg68, which showed slower in vitro replication of tachyzoites, and permissive bradyzoite development under stress conditions in vitro. Transcriptional analysis revealed constitutive expression in Tg68 tachyzoites of the key regulators of bradyzoite development including BFD1, BFD2, and several AP2 factors. Consistent with this finding, Tg68 tachyzoites expressed high levels of bradyzoite-specific genes including BAG1, ENO1, and LDH2. Moreover, after stress induced differentiation, Tg68 bradyzoites exhibited gene expression profiles of mature bradyzoites, even at early time points. These data suggest that Tg68 tachyzoites exist in a pre-bradyzoite stage primed to readily develop into mature bradyzoites under stress conditions in vitro. Tg68 presents a novel model for differentiation in vitro that will serve as a useful tool for investigation of bradyzoite biology and development of therapeutics.
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Affiliation(s)
- Jing Xia
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Yong Fu
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Wanyi Huang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - L David Sibley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63130, USA
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3
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Ifijen IH, Atoe B, Ekun RO, Ighodaro A, Odiachi IJ. Treatments of Mycobacterium tuberculosis and Toxoplasma gondii with Selenium Nanoparticles. BIONANOSCIENCE 2023; 13:249-277. [PMID: 36687337 PMCID: PMC9838309 DOI: 10.1007/s12668-023-01059-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2023] [Indexed: 01/13/2023]
Abstract
Toxoplasma gondii and Mycobacterium tuberculosis are pathogens that are harmful to humans. When these diseases interact in humans, the result is typically fatal to the public health. Several investigations on the relationship between M. tuberculosis and T. gondii infections have found that there is a strong correlation between them with each infection having a reciprocal effect on the other. TB may contribute to the reactivation of innate toxoplasmosis or enhance susceptibility to a new infection, and toxoplasma co-infection may worsen the severity of pulmonary tuberculosis. As a consequence, there is an earnest and urgent necessity to generate novel therapeutics that can subdue these challenges. Selenium nanostructures' compelling properties have been shown to be a successful treatment for Mycobacterium TB and Toxoplasma gondii. Despite the fact that selenium (Se) offers many health advantages for people, it also has a narrow therapeutic window; therefore, consuming too much of either inorganic or organic compounds based on selenium can be hazardous. Compared to both inorganic and organic Se, Se nanoparticles (SeNPs) are less hazardous. They are biocompatible and excellent in selectively targeting specific cells. As a consequence, this review conducted a summary of the efficacy of biogenic Se NPs in the treatment of tuberculosis (TB) and toxoplasmosis. Mycobacterium tuberculosis, Toxoplasma gondii, and their co-infection were all briefly described.
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Affiliation(s)
- Ikhazuagbe H. Ifijen
- Department of Research Outreach, Rubber Research Institute of Nigeria, Iyanomo, P.M.B, 1049, Benin City, Nigeria
| | - Best Atoe
- Department of Daily Need, Worldwide Healthcare, 100, Textile Mill Road, Benin City, Edo State Nigeria
| | - Raphael O. Ekun
- grid.440833.80000 0004 0642 9705Department of Electrical Electronics, Cyprus International University, Haspolat, Lefkosa, North Cyprus Mersin 10 Turkey
| | - Augustine Ighodaro
- Depatment of Aseptic Quality, Quantum Pharmaceuticals, Quantum House, Durham, UK
| | - Ifeanyi J. Odiachi
- grid.461933.a0000 0004 0446 5040Department of Science Laboratory Technology, Delta State Polytechnic Ogwashi-Uku, Ogwashi-Uku, Nigeria
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4
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Chen M, Zhou L, Li S, Wei H, Chen J, Yang P, Peng H. Toxoplasma gondii DNA methyltransferases regulate parasitic energy metabolism. Acta Trop 2022; 229:106329. [PMID: 35122712 DOI: 10.1016/j.actatropica.2022.106329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/10/2022] [Accepted: 01/23/2022] [Indexed: 11/29/2022]
Abstract
The intracellular protozoan Toxoplasma gondii results in serious diseases such as encephalitis, and retinochoroiditis in immunocompromised patients. The interconversion between tachyzoites and bradyzoites under the host's immune pressure results in the interchange of acute infection and chronic infection. We previously reported two functional DNA methyltransferases (DNMT) in Toxoplasma gondii named TgDNMTa and TgDNMTb. In this research, proteomics analysis for T. gondii tachyzoites of ME49 WT, dnmta knockout (ME49-∆Tgdnmta), and dnmtb knockout (ME49-∆Tgdnmtb) strains, revealed 362 significantly regulated proteins for ME49-∆Tgdnmta, and 219 for ME49-∆Tgdnmtb, compared with the proteins of ME49 WT. TgDNMTa down regulated three glycolytic enzymes, one gluconeogenic enzyme and four pyruvate metabolic enzymes. Furthermore, TgDNMTb up regulated two proteins in the tricarboxylic acid (TCA) cycle. Glucose metabolic flux detection showed that TgDNMTa inhibited the glycolysis pathway, while TgDNMTb promoted the tricarboxylic acid (TCA) cycle so as to promote parasite's proliferation. These findings demonstrated that the functions of Toxoplasma gondii DNA methyltransferases extended beyond DNA methylation to the regulation of parasitic energy metabolism.
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Affiliation(s)
- Min Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Lijuan Zhou
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Shengmin Li
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Hiaxia Wei
- Department of Pathogenic Biology, Guangzhou Medical University, Guangzhou 511436, China
| | - Jiating Chen
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Pei Yang
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Hongjuan Peng
- Department of Pathogen Biology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China.
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Zhang Y, Mi R, Xie J, Jia H, Ling H, Zhang X, Luo L, Gong H, Han X, Huang Y, Zeng Z, Chen Z. Seroprevalence and the Risk Factor of Toxoplasma gondii Infection to Slaughter Pigs in Chongqing, China. Vector Borne Zoonotic Dis 2022; 22:238-243. [DOI: 10.1089/vbz.2021.0101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yehua Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Rongsheng Mi
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jianhua Xie
- Chongqing Animal Disease Prevention and Control Center, Chongqing, China
| | - Haiyan Jia
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Hongquan Ling
- Chongqing Animal Disease Prevention and Control Center, Chongqing, China
| | - Xiaoli Zhang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Lu Luo
- Chongqing Animal Disease Prevention and Control Center, Chongqing, China
| | - Haiyan Gong
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiangan Han
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yan Huang
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zheng Zeng
- Chongqing Animal Disease Prevention and Control Center, Chongqing, China
| | - Zhaoguo Chen
- Key Laboratory of Animal Parasitology of Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Animal Products on Biohazards (Shanghai) of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
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6
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Kim HJ, Ahn HJ, Kang H, Park J, Oh SG, Choi S, Lee WK, Nam HW. Secretome Analysis of Host Cells Infected with Toxoplasma gondii after Treatment of Human Epidermal Growth Factor Receptor 2/4 Inhibitors. THE KOREAN JOURNAL OF PARASITOLOGY 2020; 58:249-255. [PMID: 32615738 PMCID: PMC7338902 DOI: 10.3347/kjp.2020.58.3.249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/21/2020] [Indexed: 11/28/2022]
Abstract
Toxoplasma gondii, a ubiquitous, intracellular parasite of the phylum Apicomplexa, infects an estimated one-third of the human population as well as a broad range of warm-blooded animals. We have observed that some tyrosine kinase inhibitors suppressed the growth of T. gondii within host ARPE-10 cells. Among them, afatinib, human epithermal growth factor receptor 2 and 4 (HER2/4) inhibitor, may be used as a therapeutic agent for inhibiting parasite growth with minimal adverse effects on host. In this report, we conducted a proteomic analysis to observe changes in host proteins that were altered via infection with T. gondii and the treatment of HER2/4 inhibitors. Secreting proteins were subjected to a procedure of micor basic reverse phase liquid chromatography, nano-liquid chromatography-mass spectrometry, and ingenuity pathway analysis serially. As a result, the expression level of heterogeneous nuclear ribonucleoprotein K, semaphorin 7A, a GPI membrane anchor, serine/threonine-protein phosphatase 2A, and calpain small subunit 1 proteins were significantly changed, and which were confirmed further by western blot analysis. Changes in various proteins, including these 4 proteins, can be used as a basis for explaining the effects of T. gondii infections and HER2/4 inhibitors.
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Affiliation(s)
- Hye-Jung Kim
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea
| | - Hye-Jin Ahn
- Deptartment of Parasitology, College of Medicine, Catholic University of Korea, Seoul 06591, Korea
| | - Hyeweon Kang
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea.,College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea
| | - Jaehui Park
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea.,College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea
| | - Seul Gi Oh
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea.,College of Pharmacy, Chungbuk National University, Cheongju 28160, Korea
| | - Saehae Choi
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea
| | - Won-Kyu Lee
- New Drug Development Center, OSONG Biomedical Innovation Foundation, Cheongju 28160, Korea
| | - Ho-Woo Nam
- Deptartment of Parasitology, College of Medicine, Catholic University of Korea, Seoul 06591, Korea
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7
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Gómez-Chávez F, Cañedo-Solares I, Ortiz-Alegría LB, Flores-García Y, Figueroa-Damián R, Luna-Pastén H, Gómez-Toscano V, López-Candiani C, Arce-Estrada GE, Bonilla-Ríos CA, Mora-González JC, García-Ruiz R, Correa D. A Proinflammatory Immune Response Might Determine Toxoplasma gondii Vertical Transmission and Severity of Clinical Features in Congenitally Infected Newborns. Front Immunol 2020; 11:390. [PMID: 32231666 PMCID: PMC7082359 DOI: 10.3389/fimmu.2020.00390] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 02/19/2020] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii is the etiological agent of toxoplasmosis. Mother-to-child transmission of this parasite can occur during pregnancy. Newborns with congenital toxoplasmosis may develop central nervous system impairment, with severity ranging from subclinical manifestations to death. A proinflammatory/regulated specific immune profile is crucial in the defense against the parasite; nevertheless, its role in the infected pregnant women and the congenitally infected offspring has been poorly explored, and there is still no consensus about its relation to parasite vertical transmission or to severity and dissemination in the congenitally infected newborns. This work aimed to characterize these relations by means of principal component and principal factor analyses. For this purpose, we determined the specific production of the four immunoglobulin G antibody subclasses, cytokines, and lymphocyte proliferation in the T. gondii–infected pregnant women−10 who transmitted the infection to their offspring and seven who did not—as well as in 11 newborns congenitally infected and grouped according to disease severity (five mild and six moderate/severe) and dissemination (four local and seven disseminated). We found that the immune response of nontransmitter women differed from that of the transmitters, the latter having a stronger proinflammatory response, supporting a previous report. We also found that newborns who developed moderate/severe disease presented higher levels of lymphocyte proliferation, particularly of CD8+ and CD19+ cells, a high proportion of tumor necrosis factor α producers, and reduced expression of the immune modulator transforming growth factor β, as opposed to children who developed mild clinical complications. Our results suggest that a distinctive, not regulated, proinflammatory immune response might favor T. gondii vertical transmission and the development of severe clinical manifestations in congenitally infected newborns.
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Affiliation(s)
- Fernando Gómez-Chávez
- Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City, Mexico.,Cátedras CONACyT-Instituto Nacional de Pediatría, Mexico City, Mexico.,Departamento de Formación Básica Disciplinaria, ENMyH-IPN, Mexico City, Mexico
| | | | | | | | | | - Héctor Luna-Pastén
- Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City, Mexico
| | | | | | | | | | | | - Ricardo García-Ruiz
- Laboratorio de Cannabinoides, Facultad de Medicina, UNAM, Mexico City, Mexico
| | - Dolores Correa
- Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City, Mexico
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8
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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: 150] [Impact Index Per Article: 30.0] [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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Corona CC, Zhang M, Wadhawan A, Daue ML, Groer MW, Dagdag A, Lowry CA, Hoisington AJ, Ryan KA, Stiller JW, Fuchs D, Mitchell BD, Postolache TT. Toxoplasma gondii IgG associations with sleep-wake problems, sleep duration and timing. Pteridines 2019; 30:1-9. [PMID: 30918422 PMCID: PMC6433149 DOI: 10.1515/pteridines-2019-0001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Evidence links Toxoplasmagondii (T. gondii), a neurotropic parasite, with schizophrenia, mood disorders and suicidal behavior, all of which are associated and exacerbated by disrupted sleep. Moreover, low-grade immune activation and dopaminergic overstimulation, which are consequences of T. gondii infection, could alter sleep patterns and duration. Methods: Sleep data on 833 Amish participants [mean age (SD) = 44.28 (16.99) years; 59.06% women] were obtained via self-reported questionnaires that assessed sleep problems, duration and timing. T. gondii IgG was measured with ELISA. Data were analyzed using multivariable logistic regressions and linear mixed models, with adjustment for age, sex and family structure. Results: T. gondii seropositives reported less sleep problems (p < 0.005) and less daytime problems due to poor sleep (p < 0.005). Higher T. gondii titers were associated with longer sleep duration (p < 0.05), earlier bedtime (p< 0.005) earlier mid-sleep time (p < 0.05). Conclusions: It seems unlikely that sleep mediates the previously reported associations between T. gondii and mental illness. Future longitudinal studies with objective measures are necessary to replicate our findings.
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Affiliation(s)
- Celine C Corona
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Man Zhang
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimers, MD 21201, USA
| | - Abhishek Wadhawan
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA, Saint Elizabeths Hospital, Psychiatry Residency Program, Washington, DC 20032, USA
| | - Melanie L Daue
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimers, MD 21201, USA, Program for Personalized and Genomic Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA, Geriatrics Research and Education Clinical Center, Veteran Affairs Medical Center, Baltimore, MD 21201, USA
| | - Maureen W Groer
- College of Nursing, University of South Florida College of Nursing, Tampa, FL 33612, USA
| | - Aline Dagdag
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA, Psychiatry Adult Inpatient & Behavioral Health, University of Maryland Medical Center, Baltimore, MD 21201, USA
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA; Department of Physical Medicine and Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO80045, USA, Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Military and Veteran. Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, CO80 045, USA
| | - Andrew J Hoisington
- Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Veterans Integrated Service Network (VISN) 19, Military and Veteran. Microbiome: Consortium for Research and Education (MVM-CoRE), Aurora, CO80 045, USA, Department of Systems Engineering and Management, Air Force Institute of Technology, Wright-Patterson AFB, OH 45433, USA
| | - Kathleen A Ryan
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimers, Md 21201, USA, Program for Personalized and Genomic Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - John W Stiller
- Mood and Anxiety Program, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD 21201, USA, Saint Elizabeths Hospital, Department of Neurology, Washington DC 20032, USA; Maryland State Athletic Commission, Baltimore, MD 21202, USA
| | - Dietmar Fuchs
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Braxton D Mitchell
- Division of Endocrinology, Diabetes and Nutrition, Department of Medicine, University of Maryland School of Medicine, Baltimers, MD 21201, USA, Program for Personalized and Genomic Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA, Geriatrics Research and Education Clinical Center, Veteran Affairs Medical Center, Baltimore, MD 21201, USA
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10
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Salman D, Pumidonming W, Oohashi E, Igarashi M. Prevalence of Toxoplasma gondii and other intestinal parasites in cats in Tokachi sub-prefecture, Japan. J Vet Med Sci 2018; 80:960-967. [PMID: 29731476 PMCID: PMC6021893 DOI: 10.1292/jvms.17-0713] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The present study investigated the prevalence of Toxoplasma gondii and
other intestinal parasites in cats in the Tokachi subprefecture in Japan. A total of 365
household cats were included in the study, and 353 serum and 351 fecal samples were
collected and analyzed. T. gondii IgG antibodies were detected in the
sera of 16.14% of cats based on Latex agglutination test and ELISA. For ELISA, T.
gondii RH strain tachyzoites lysate and T. gondii SAG2
recombinant protein were used as antigens. Low seropositivity was detected in cats younger
than one year and older than 11 years; outdoor and hunter cats showed significantly high
seropositivities. Neutering either in male or female cats, but not gender, had a
considerable effect on seroprevalence. Toxoplasma gondii oocysts were
detected in one fecal sample. The overall parasitic infestation in cats was 12.5%. Other
detected parasites included Toxocara species, which showed the highest
prevalence of 7.7%, followed by Isospora spp. (2%),
Taenia spp. (1.7%), and Ancylostoma spp. (0.9%).
Spirometra spp. was detected in only one sample. Outdoor cats comprised
50% of all 44 parasite-infested cats. Although T. gondii oocysts were
detected in only one sample, the relatively high seroprevalence of T.
gondii indicated that it can pose significant risks to the environment. Our
findings highlighted the potential of outdoor cats as a source of T.
gondii and other parasites.
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Affiliation(s)
- Doaa Salman
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.,Department of Animal Medicine, Faculty of Veterinary Medicine, Sohag University, Sohag 82524, Egypt
| | - Wilawan Pumidonming
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.,Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Phitsanulok 65000, Thailand
| | - Eiji Oohashi
- Akashiya Animal Hospital, Makubetsu, Hokkaido 089-0535, Japan
| | - Makoto Igarashi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
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11
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Affiliation(s)
- D Buxton
- Department of Pathology and Immunology, Moredun Research Institute, Edinburgh
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12
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Ching XT, Fong MY, Lau YL. Evaluation of the Protective Effect of Deoxyribonucleic Acid Vaccines Encoding Granule Antigen 2 and 5 Against Acute Toxoplasmosis in BALB/c Mice. Am J Trop Med Hyg 2017; 96:1441-1447. [PMID: 28719288 DOI: 10.4269/ajtmh.16-0548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
AbstractToxoplasma gondii infects a broad range of warm-blooded hosts, including humans. Important clinical manifestations include encephalitis in immunocompromised patients as well as miscarriage and fetal damage during early pregnancy. Toxoplasma gondii dense granule antigen 2 and 5 (GRA2 and GRA5) are essential for parasitophorous vacuole development of the parasite. To evaluate the potential of GRA2 and GRA5 as recombinant DNA vaccine candidates, these antigens were cloned into eukaryotic expression vector (pcDNA 3.1C) and evaluated in vaccination experiments. Recombinant DNA vaccines constructed with genes encoding GRAs were validated in Chinese hamster ovary cells before evaluation using lethal challenge of the virulent T. gondii RH strain in BALB/c mice. The DNA vaccines of pcGRA2 and pcGRA5 elicited cellular-mediated immune response with significantly higher levels of interferon-gamma, interleukin-2 (IL-2), IL-4, and IL-10 (P < 0.05) compared with controls. A mixed T-helper cell 1 (Th1)/Th2 response was associated with slightly prolonged survival. These findings provide evidence that DNA vaccination with GRA2 and GRA5 is associated with Th1-like cell-mediated immune responses. It will be worthwhile to construct recombinant multiantigen combining full-length GRA2 or/and GRA5 with various antigenic proteins such as the surface antigens and rhoptry antigens to improve vaccination efficacy.
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Affiliation(s)
- Xiao Teng Ching
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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Recombinase polymerase amplification (RPA) combined with lateral flow (LF) strip for detection of Toxoplasma gondii in the environment. Vet Parasitol 2017; 243:199-203. [PMID: 28807294 DOI: 10.1016/j.vetpar.2017.06.026] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 06/23/2017] [Accepted: 06/25/2017] [Indexed: 02/04/2023]
Abstract
Toxoplasma gondii infects all warm-blooded vertebrates, resulting in a great threat to human health and significant economic loss to the livestock industry. Ingestion of infectious oocysts of T. gondii from the environment is the major source of transmission. Detection of T. gondii oocysts by existing methods is laborious, time-consuming and expensive. The objective of the present study was to develop a recombinase polymerase amplification (RPA) method combined with a lateral flow (LF) strip for detection of T. gondii oocysts in the soil and water. The DNA of T. gondii oocysts was amplified by a pair of specific primers based on the T. gondii B1 gene over 15min at a constant temperature ranging from 30°C to 45°C using RPA. The amplification product was visualized by the lateral flow (LF) strip within 5min using the specific probe added to the RPA reaction system. The sensitivity of the established assay was 10 times higher than that of nested PCR with a lower detection limit of 0.1 oocyst per reaction, and there was no cross-reactivity with other closely related protozoan species. Fifty environmental samples were further assessed for the detection validity of the LF-RPA assay (B1-LF-RPA) and compared with nested PCR based on the B1 gene sequence. The B1-LF-RPA and nested PCR both showed that 5 out of the 50 environmental samples were positive. The B1-LF-RPA method was also proven to be sufficiently tolerant of existing inhibitors in the environment. In addition, the advantages of simple operation, speediness and cost-effectiveness make B1-LF-RPA a promising molecular detection tool for T. gondii.
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Ching XT, Fong MY, Lau YL. Evaluation of Immunoprotection Conferred by the Subunit Vaccines of GRA2 and GRA5 against Acute Toxoplasmosis in BALB/c Mice. Front Microbiol 2016; 7:609. [PMID: 27199938 PMCID: PMC4847622 DOI: 10.3389/fmicb.2016.00609] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 04/12/2016] [Indexed: 12/24/2022] Open
Abstract
Toxoplasmosis is a foodborne disease caused by Toxoplasma gondii, an obligate intracellular parasite. Severe symptoms occur in the immunocompromised patients and pregnant women leading to fatality and abortions respectively. Vaccination development is essential to control the disease. The T. gondii dense granule antigen 2 and 5 (GRA2 and GRA5) have been targeted in this study because these proteins are essential to the development of parasitophorous vacuole (PV), a specialized compartment formed within the infected host cell. PV is resistance to host cell endosomes and lysosomes thereby protecting the invaded parasite. Recombinant dense granular proteins, GRA2 (rGRA2) and GRA5 (rGRA5) were cloned, expressed, and purified in Escherichia coli, BL21 (DE3) pLysS. The potential of these purified antigens as subunit vaccine candidates against toxoplasmosis were evaluated through subcutaneous injection of BALB/c mice followed by immunological characterization (humoral- and cellular-mediated) and lethal challenge against virulent T. gondii RH strain in BALB/c mice. Results obtained demonstrated that rGRA2 and rGRA5 elicited humoral and cellular-mediated immunity in the mice. High level of IgG antibody was produced with the isotype IgG2a/IgG1 ratio of ≈0.87 (p < 0.001). Significant increase (p < 0.05) in the level of four cytokines (IFN-γ, IL-2, IL-4, and IL-10) was obtained. The antibody and cytokine results suggest that a mix mode of Th1/Th2-immunity was elicited with predominant Th1-immune response inducing partial protection against T. gondii acute infection in BALB/c mice. Our findings indicated that both GRA2 and GRA5 are potential candidates for vaccine development against T. gondii acute infection.
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Affiliation(s)
- Xiao T Ching
- Department of Parasitology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Mun Y Fong
- Department of Parasitology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
| | - Yee L Lau
- Department of Parasitology, Faculty of Medicine, University of Malaya Kuala Lumpur, Malaysia
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15
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Amina SD, Fatma B, Ismail G, Edmee G, Djamila BA, ohamed BE, Djamel G. Sero-epidemiological survey on toxoplasmosis in cattle, sheep and goats in Algeria. ACTA ACUST UNITED AC 2015. [DOI: 10.5897/ajar2015.9575] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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16
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Bustillo JL, Diaz JD, Pacheco IC, Gritz DC. Cuban Ocular Toxoplasmosis Epidemiology Study (COTES): incidence and prevalence of ocular toxoplasmosis in Central Cuba. Br J Ophthalmol 2014; 99:382-6. [PMID: 25253767 DOI: 10.1136/bjophthalmol-2014-305843] [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] [Indexed: 11/04/2022]
Abstract
BACKGROUND Serological studies indicate that rates of ocular toxoplasmosis (OT) vary geographically, with higher rates in tropical regions. Little is known about population-based rates of active OT. We aimed to describe the epidemiology of OT in Central Cuba. METHODS This large-population, cross-sectional cohort study used a prospective database at a large regional referral centre in Central Cuba. The patient database was searched for all patients who presented with OT during the 12-month study period from 1 April 2011 to 31 March 2012. Inclusion criteria were the clinical diagnosis of OT, characterised by focal retinochoroidal inflammation and a response to therapy as expected. Gender-stratified and age-stratified study population data from the 2012 Cuban Census were used to calculate incidence rates and prevalence ratios. RESULTS Among 279 identified patients with OT, 158 presented with active OT. Of these, 122 new-onset and 36 prior-onset cases were confirmed. Based on the total population in the Sancti Spiritus province (466,106 persons), the overall incidence of active OT was 26.2 per 100,000 person-years (95% CI 21.7 to 31.3) with an annual prevalence ratio of 33.9 per 100,000 persons (95% CI 28.8 to 39.6). The incidence of active OT was lowest in the oldest age group and highest in patients aged 25-44 years (4.5 and 42.1 per 100,000 person-years, respectively). CONCLUSIONS This first report describing population-based rates of OT in the Cuban population highlights the importance of patient age as a likely risk factor for OT. Disease rates were found to be highest in females and young to middle-aged adults.
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Affiliation(s)
- Jorge L Bustillo
- Instituto Superior de Ciencias Medicas de Sancti Spiritus, Sancti Spiritus, Cuba
| | - Jose D Diaz
- Albert Einstein College of Medicine, Bronx, New York, USA
| | - Idarmes C Pacheco
- Instituto Superior de Ciencias Medicas de Sancti Spiritus, Sancti Spiritus, Cuba
| | - David C Gritz
- Department of Ophthalmology, Montefiore Medical Center, Bronx, New York, USA
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17
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Tonkin ML, Crawford J, Lebrun ML, Boulanger MJ. Babesia divergens and Neospora caninum apical membrane antigen 1 structures reveal selectivity and plasticity in apicomplexan parasite host cell invasion. Protein Sci 2014; 22:114-27. [PMID: 23169033 DOI: 10.1002/pro.2193] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/02/2012] [Accepted: 10/05/2012] [Indexed: 11/09/2022]
Abstract
Host cell invasion by the obligate intracellular apicomplexan parasites, including Plasmodium (malaria) and Toxoplasma (toxoplasmosis), requires a step-wise mechanism unique among known host-pathogen interactions. A key step is the formation of the moving junction (MJ) complex, a circumferential constriction between the apical tip of the parasite and the host cell membrane that traverses in a posterior direction to enclose the parasite in a protective vacuole essential for intracellular survival. The leading model of MJ assembly proposes that Rhoptry Neck Protein 2 (RON2) is secreted into the host cell and integrated into the membrane where it serves as the receptor for apical membrane antigen 1 (AMA1) on the parasite surface. We have previously demonstrated that the AMA1-RON2 interaction is an effective target for inhibiting apicomplexan invasion. To better understand the AMA1-dependant molecular recognition events that promote invasion, including the significant AMA1-RON2 interaction, we present the structural characterization of AMA1 from the apicomplexan parasites Babesia divergens (BdAMA1) and Neospora caninum (NcAMA1) by X-ray crystallography. These studies offer intriguing structural insight into the RON2-binding surface groove in the AMA1 apical domain, which shows clear evidence for receptor-ligand co-evolution, and the hyper variability of the membrane proximal domain, which in Plasmodium is responsible for direct binding to erythrocytes. By incorporating the structural analysis of BdAMA1 and NcAMA1 with existing AMA1 structures and complexes we were able to define conserved pockets in the AMA1 apical groove that could be targeted for the design of broadly reactive therapeutics.
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Affiliation(s)
- Michelle L Tonkin
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
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18
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Lee WK, Ahn HJ, Yu YG, Nam HW. Rhoptry protein 6 from Toxoplasma gondii is an intrinsically disordered protein. Protein Expr Purif 2014; 101:146-51. [DOI: 10.1016/j.pep.2014.06.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/10/2014] [Accepted: 06/20/2014] [Indexed: 11/15/2022]
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Ahmed HA, Shafik SM, Ali MEM, Elghamry ST, Ahmed AA. Molecular detection of Toxoplasma gondii DNA in milk and risk factors analysis of seroprevalence in pregnant women at Sharkia, Egypt. Vet World 2014. [DOI: 10.14202/vetworld.2014.594-600] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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20
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Evaluation of the adjuvant effect of pidotimod on the immune protection induced by UV-attenuated Toxoplasma gondii in mouse models. Parasitol Res 2013; 112:3151-60. [DOI: 10.1007/s00436-013-3491-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 06/03/2013] [Indexed: 10/26/2022]
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Abstract
INTRODUCTION Toxoplasma gondii, the agent that causes toxoplasmosis, is an opportunistic parasite that infects many mammalian species. It is an obligate intracellular parasite that causes severe congenital neurological and ocular disease mostly in immunocompromised humans. The current regimen of therapy includes only a few medications that often lead to hypersensitivity and toxicity. In addition, there are no vaccines available to prevent the transmission of this agent. Therefore, safer and more effective medicines to treat toxoplasmosis are urgently needed. AREAS COVERED The author presents in silico and in vitro strategies that are currently used to screen for novel targets and unique chemotypes against T. gondii. Furthermore, this review highlights the screening technologies and characterization of some novel targets and new chemical entities that could be developed into highly efficacious treatments for toxoplasmosis. EXPERT OPINION A number of diverse methods are being used to design inhibitors against T. gondii. These include ligand-based methods, in which drugs that have been shown to be efficacious against other Apicomplexa parasites can be repurposed to identify lead molecules against T. gondii. In addition, structure-based methods use currently available repertoire of structural information in various databases to rationally design small-molecule inhibitors of T. gondii. Whereas the screening methods have their advantages and limitations, a combination of methods is ideally suited to design small-molecule inhibitors of complex parasites such as T. gondii.
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Affiliation(s)
- Sandhya Kortagere
- Drexel University College of Medicine, Institute for Molecular Medicine, Department of Microbiology and Immunology, 2900, Queen Lane, PA 19129, USA.
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22
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Braga MDSCDO, André MR, Jusi MMG, Freschi CR, Teixeira MCA, Machado RZ. Occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in cats with outdoor access in São Luís, Maranhão, Brazil. REVISTA BRASILEIRA DE PARASITOLOGIA VETERINARIA 2012; 21:107-11. [DOI: 10.1590/s1984-29612012000200007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 01/13/2012] [Indexed: 11/22/2022]
Abstract
The present study aimed to investigate the frequency of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in cats with outdoor access in São Luís, Maranhão, Brazil. The presence of IgG anti-T. gondii and anti-N. caninum antibodies was tested using the Indirect Immunofluorescent Antibody Test (IFAT). IgG anti-T. gondii and anti-N. caninum antibodies were detected in 101 (50.5%) and 54 (27%) sampled cats, respectively. The titers of anti-T. gondii antibodies ranged from 40 (cut-off) to 2560. On the other hand, the titers of anti-N. caninum antibodies ranged from 25 (cut-off) to 400. Twenty-seven cats (13.5%) were shown to be seropositive for both parasites. Seventy-four cats (34%) were seropositive only for T. gondii. Twenty-two cats (11%) were seropositive only for N. caninum. The present study showed that cats with outdoor access in São Luís, Maranhão, are exposed to T. gondii and N. caninum.
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Cenci-Goga BT, Rossitto PV, Sechi P, McCrindle CM, Cullor JS. Toxoplasma in Animals, Food, and Humans: An Old Parasite of New Concern. Foodborne Pathog Dis 2011; 8:751-62. [DOI: 10.1089/fpd.2010.0795] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Beniamino T. Cenci-Goga
- Sezione di Ispezione degli Alimenti di Origine Animale, Facoltà di Medicina Veterinaria, Università degli Studi di Perugia, Perugia, Italy
| | - Paul V. Rossitto
- Veterinary Medicine Teaching and Research Center, UC Davis School of Veterinary Medicine, Tulare, California
| | - Paola Sechi
- Sezione di Ispezione degli Alimenti di Origine Animale, Facoltà di Medicina Veterinaria, Università degli Studi di Perugia, Perugia, Italy
| | - Cheryl M.E. McCrindle
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - James S. Cullor
- Veterinary Medicine Teaching and Research Center, UC Davis School of Veterinary Medicine, Tulare, California
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Cong H, Mui EJ, Witola WH, Sidney J, Alexander J, Sette A, Maewal A, McLeod R. Towards an immunosense vaccine to prevent toxoplasmosis: protective Toxoplasma gondii epitopes restricted by HLA-A*0201. Vaccine 2010; 29:754-62. [PMID: 21095258 DOI: 10.1016/j.vaccine.2010.11.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 10/29/2010] [Accepted: 11/06/2010] [Indexed: 10/18/2022]
Abstract
The ideal vaccine to protect against toxoplasmosis in humans would include antigens that elicit a protective T helper cell type 1 immune response, and generate long-lived IFN-γ-producing CD8(+) T cells. Herein, we utilized a predictive algorithm to identify candidate HLA-A02 supertype epitopes from Toxoplasma gondii proteins. Thirteen peptides elicited production of IFN-γ from PBMC of HLA-A02 supertype persons seropositive for T. gondii infection but not from seronegative controls. These peptides displayed high-affinity binding to HLA-A02 proteins. Immunization of HLA-A*0201 transgenic mice with these pooled peptides, with a universal CD4(+) epitope peptide called PADRE, formulated with adjuvant GLA-SE, induced CD8(+) T cell IFN-γ production and protected against parasite challenge. Peptides identified in this study provide candidates for inclusion in immunosense epitope-based vaccines.
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Affiliation(s)
- Hua Cong
- Department of Surgery, The University of Chicago, 5841 S. Maryland Ave., MC 2114, Chicago, IL 60637, USA
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Hencken CP, Jones-Brando L, Bordón C, Stohler R, Mott BT, Yolken R, Posner GH, Woodard LE. Thiazole, oxadiazole, and carboxamide derivatives of artemisinin are highly selective and potent inhibitors of Toxoplasma gondii. J Med Chem 2010; 53:3594-601. [PMID: 20373807 DOI: 10.1021/jm901857d] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have prepared 23 new dehydroartemisinin (DART) trioxane derivatives (11 thiazoles, 2 oxadiazoles, and 10 carboxamides) and have screened them for in vitro activity in the Toxoplasma lytic cycle. Fifteen (65%) of the derivatives were noncytotoxic to host cells (TD(50) > or = 320 microM). Eight thiazole derivatives and two carboxamide derivatives displayed effective inhibition of Toxoplasma growth (IC(50) = 0.25-0.42 microM), comparable in potency to artemether (IC(50) = 0.31 microM) and >100 times more inhibitory than the currently employed front-line drug trimethoprim (IC(50) = 46 microM). The thiazoles as a group were more effective than the other derivatives at inhibiting growth of extracellular as well as intracellular parasites. Unexpectedly, two thiazole trioxanes (5 and 6) were parasiticidal; both inhibited parasite replication irreversibly after parasite exposure to 10 microM of drug for 24 h, whereas the standard trioxane drugs artemisinin and artemether were not parasiticidal. Some of the new derivatives of artemisinin described here represent effective anti-Toxoplasma trioxanes as well as molecular probes for elucidating the mechanism of action of the DART class of artemisinin derivatives.
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Affiliation(s)
- Christopher P Hencken
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
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Crawford J, Tonkin ML, Grujic O, Boulanger MJ. Structural characterization of apical membrane antigen 1 (AMA1) from Toxoplasma gondii. J Biol Chem 2010; 285:15644-15652. [PMID: 20304917 PMCID: PMC2865318 DOI: 10.1074/jbc.m109.092619] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 01/19/2010] [Indexed: 11/06/2022] Open
Abstract
Apical membrane antigen 1 (AMA1) is an essential component of the moving junction complex used by Apicomplexan parasites to invade host cells. We report the 2.0 A resolution x-ray crystal structure of the full ectodomain (domains I, II, and III) of AMA1 from the pervasive protozoan parasite Toxoplasma gondii. The structure of T. gondii AMA1 (TgAMA1) is the most complete of any AMA1 structure to date, with more than 97.5% of the ectodomain unambiguously modeled. Comparative sequence analysis reveals discrete segments of divergence in TgAMA1 that map to areas of established functional importance in AMA1 from Plasmodium vivax (PvAMA1) and Plasmodium falciparum (PfAMA1). Inspection of the TgAMA1 structure reveals a network of apical surface loops, reorganized in both size and chemistry relative to PvAMA1/PfAMA1, that appear to serve as structural filters restricting access to a central hydrophobic groove. The terminal portion of this groove is formed by an extended loop from DII that is 14 residues shorter in TgAMA1. A pair of tryptophan residues (Trp(353) and Trp(354)) anchor the DII loop in the hydrophobic groove and frame a conserved tyrosine (Tyr(230)), forming a contiguous surface that may be critical for moving junction assembly. The minimalist DIII structure folds into a cystine knot that probably stabilizes and orients the bulk of the ectodmain without providing excess surface area to which invasion-inhibitory antibodies can be generated. The detailed structural characterization of TgAMA1 provides valuable insight into the mechanism of host cell invasion by T. gondii.
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Affiliation(s)
- Joanna Crawford
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Michelle L Tonkin
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Ognjen Grujic
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Martin J Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
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Crawford J, Lamb E, Wasmuth J, Grujic O, Grigg ME, Boulanger MJ. Structural and functional characterization of SporoSAG: a SAG2-related surface antigen from Toxoplasma gondii. J Biol Chem 2010; 285:12063-70. [PMID: 20164173 DOI: 10.1074/jbc.m109.054866] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii, the etiological agent of toxoplasmosis, utilizes stage-specific expression of antigenically distinct glycosylphosphatidylinositol-tethered surface coat proteins to promote and establish chronic infection. Of the three infective stages of T. gondii, sporozoites are encapsulated in highly infectious oocysts that have been linked to large scale outbreaks of toxoplasmosis. SporoSAG (surface antigen glycoprotein) is the dominant surface coat protein expressed on the surface of sporozoites. Using a bioinformatic approach, we show that SporoSAG clusters with the SAG2 subfamily of the SAG1-related superfamily (SRS) and is non-polymorphic among the 11 haplogroups of T. gondii strains. In contrast to the immunodominant SAG1 protein expressed on tachyzoites, SporoSAG is non-immunogenic during natural infection. We report the 1.60 A resolution crystal structure of SporoSAG solved using cadmium single anomalous dispersion. SporoSAG crystallized as a monomer and displays unique features of the SRS beta-sandwich fold relative to SAG1 and BSR4. Intriguingly, the structural diversity is localized to the upper sheets of the beta-sandwich fold and may have important implications for multimerization and host cell ligand recognition. The structure of SporoSAG also reveals an unexpectedly acidic surface that contrasts with the previously determined SAG1 and BSR4 structures where a basic surface is predicted to play a role in binding negatively charged glycosaminoglycans. Our structural and functional characterization of SporoSAG provides a rationale for the evolutionary divergence of this key SRS family member.
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Affiliation(s)
- Joanna Crawford
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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Tenter AM. Toxoplasma gondii in animals used for human consumption. Mem Inst Oswaldo Cruz 2010; 104:364-9. [PMID: 19430665 DOI: 10.1590/s0074-02762009000200033] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 12/16/2008] [Indexed: 11/22/2022] Open
Abstract
Food-borne toxoplasmosis in humans may result from exposure to different stages of Toxoplasma gondii, in particular from the ingestion of tissue cysts or tachyzoites contained in meat, primary offal (viscera) or meat-derived products of many different animals, or the ingestion of sporulated oocysts that are contained in the environment and may contaminate food and water. Although the potential for transmission of the parasite to humans via food has been known for several decades, it is not known which routes are most important from a public health point of view. It is likely that transmission of the parasite to humans is influenced not only by the potential contamination of various food sources, but also by the individual behaviour of consumers in different ethnic groups and geographical regions. Most current methods for detection of T. gondii in meat-producing animals, in products of animal origin, or in the environment are insufficient because they do not allow quantification of infectious stages. Hence, most studies report only qualitative data from which it is difficult to assess the true risk of infection in individual cases. There is a need for quantitative data so that efficient strategies to reduce food-borne transmission of T. gondii to humans can be developed.
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Affiliation(s)
- Astrid M Tenter
- Institut für Parasitologie, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 17, 30559 Hannover, Germany.
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Abstract
Research on infectious agents as a possible cause of schizophrenia has become prominent in the past decade. Toxoplasma gondii has emerged as a prime candidate for a variety of reasons; (i) many studies have reported that individuals with schizophrenia, compared to controls, have a higher prevalence of antibodies to T. gondii, (ii) some individuals with adult toxoplasmosis develop psychotic symptoms similar to those of schizophrenia, (iii) epidemiologically, there are many similarities between toxoplasmosis and schizophrenia, (iv) antipsychotic drugs known to be effective in schizophrenia also inhibit some parasites, including T. gondii, (v) Toxoplasma has been shown to induce elevated levels of dopamine in experimentally infected animals (elevated dopamine is commonly seen in individuals with schizophrenia) and (vi) studies have shown that individuals with schizophrenia, compared to controls, have had greater exposure to cats in childhood. A number of questions remain concerning a role for Toxoplasma in the aetiology of schizophrenia, including the roles of strain variation, the timing and source of infection, and the role of host genes in determining disease susceptibility. The establishment of a firm association between Toxoplasma and the aetiology of schizophrenia and related disorders would represent a major breakthrough in the understanding of these disorders and would lead to novel methods for their treatment and prevention.
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Affiliation(s)
- R H Yolken
- Stanley Division of Developmental Neurovirology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-4933, USA.
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30
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Crawford J, Grujic O, Bruic E, Czjzek M, Grigg ME, Boulanger MJ. Structural characterization of the bradyzoite surface antigen (BSR4) from Toxoplasma gondii, a unique addition to the surface antigen glycoprotein 1-related superfamily. J Biol Chem 2009; 284:9192-8. [PMID: 19155215 PMCID: PMC2666571 DOI: 10.1074/jbc.m808714200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Revised: 12/17/2008] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that infects nearly one-third of the human population. The success of T. gondii is based on its complex life cycle; a lytic tachyzoite form disseminates infection, whereas an encysted bradyzoite form establishes a latent, chronic infection. Persistence and transmissibility is central to the survival of the parasite and is, in part, mediated by a family of antigenically distinct surface antigen glycoprotein (SAG)-related sequences (SRS) adhesins that play a dual role in host cell attachment and host immune evasion. More than 160 members of the SRS family have been identified with only the tachyzoite-expressed SAG1 structurally characterized. Here we report the first structural description of the bradyzoite adhesin BSR4 using x-ray crystallography and small angle x-ray scattering. The 1.90-A crystal structure of BSR4 reveals an architecture comprised of tandem beta sandwich domains organized in a head to tail fashion with the N-terminal domain responsible for dimer formation. A restructured topology in BSR4 results in a ligand-binding site that is significantly reorganized in both structure and chemistry relative to SAG1, consistent with BSR4 binding a distinct physiological ligand. The small angle x-ray scattering solution structure of BSR4 highlights a potentially important structural role for the interdomain polymorphic linker that imparts significant flexibility that may promote structural adaptation during ligand binding. This study reveals an unexpected level of structural diversity within the SRS superfamily and provides important insight into the role of these virulence factors.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/chemistry
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Antigens, Protozoan/metabolism
- Antigens, Surface/chemistry
- Antigens, Surface/genetics
- Antigens, Surface/immunology
- Antigens, Surface/metabolism
- Crystallography, X-Ray
- Ligands
- Models, Molecular
- Molecular Sequence Data
- Phylogeny
- Protein Folding
- Protein Multimerization
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Sequence Alignment
- Toxoplasma/chemistry
- Toxoplasma/genetics
- Toxoplasma/immunology
- Toxoplasma/metabolism
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Affiliation(s)
- Joanna Crawford
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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31
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Bonyadian M, Hematzade F, Manuchehri K. Seroprevalence of antibodies to Toxoplasma gondii in sheep in center of Iran. Pak J Biol Sci 2009; 10:3228-30. [PMID: 19090132 DOI: 10.3923/pjbs.2007.3228.3230] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To provide an epidemiologic investigation of the seroprevalence of antibodies to Toxoplasma gondii in sheep population in Chaharmhal and Bakhtiari province (Iran) this study was conducted, the province containing five townships, (Shahrekord, Borujen, Farsan, Ardal and Lordegan). One thousands serum samples (600 female and 400 male) were examined to detect antibodies to T. gondii by Indirect Fluorescent Antibody Test (IFAT). Serological results showed that the seroprevalence of antibodies to T. gondii was 29.1%. The seroprevalence in the townships were 38, 22.5, 32, 35 and 18%, respectively. The results of titration of positive samples showed the following titers: 11% with 1/20, 9.3% with 1/40, 15.1% with 1/80, 28.9% with 1/160 and 35.7% with/320 or more. There was no significant difference between the two sexes, while there was a significant difference between the townships located in east and west of the province.
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Affiliation(s)
- M Bonyadian
- Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord University
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32
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Straub KW, Cheng SJ, Sohn CS, Bradley PJ. Novel components of the Apicomplexan moving junction reveal conserved and coccidia-restricted elements. Cell Microbiol 2008; 11:590-603. [PMID: 19134112 DOI: 10.1111/j.1462-5822.2008.01276.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Apicomplexan parasites generally invade their host cells by anchoring the parasite to the host membrane through a structure called the moving junction (MJ). This MJ is also believed to sieve host proteins from the nascent parasitophorous vacuole membrane, which likely protects the pathogen from lysosomal destruction. Previously identified constituents of the Toxoplasma MJ have orthologues in Plasmodium, indicating a conserved structure throughout the Apicomplexa. We report here two novel MJ proteins, RON5 and RON8. While RON5 is conserved in Plasmodium, RON8 appears restricted to the coccidia. RON8, which is likely essential, co-immunoprecipitates RON5 and known MJ proteins from extracellular parasites, indicating that a preformed complex exists within the parasites. Upon secretion, we show that RON8 within the MJ localizes to the cytoplasmic face of the host plasma membrane. To examine interactions between RON8 and the host cell, we expressed RON8 in mammalian cells and show that it targets to its site of action at the periphery in a manner dependent on the C-terminal portion of the protein. The discovery of RON5 and RON8 provides new insight into conserved and unique elements of the MJ, furthering our understanding of how the MJ contributes to the intricate mechanism of Apicomplexan invasion.
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Affiliation(s)
- Kurtis W Straub
- Department of Microbiology, Immunology and Molecular Genetics, University of California-Los Angeles, Los Angeles, CA 90095-1489, USA
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33
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Tamer GS, Dundar D, Yalug I, Caliskan S, Yazar S, Aker A. The schizophrenia and Toxoplasma gondii connection: infectious, immune or both? Adv Ther 2008; 25:703-9. [PMID: 18563312 DOI: 10.1007/s12325-008-0063-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Recent research has suggested a possible link between toxoplasmic agents and schizophrenia. We aimed to assess this by measuring Toxoplasma gondii-associated antibodies in schizophrenia patients and controls METHODS We used a commercially available enzyme-linked immunosorbent assay (ELISA) kit to measure the level of immunoglobulin G (IgG) and IgM antibodies in serum samples from schizophrenia patients (n=40) and from a group of non-schizophrenic control subjects (n=37) RESULTS Among schizophrenic patients, 16 (40%) showed IgG seropositivity and two (5%) showed IgM seropositivity. Among the control group, five (13.5%) were found have IgG seropositivity and one (2.7%) showed IgM seropositivity. In our study we found that IgG T gondii antibodies were significantly higher in schizophrenia patients compared with controls CONCLUSIONS This study supports the theory that toxoplasmic agents may have a role in the aetiology of schizophrenia.
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Affiliation(s)
- Gulden Sonmez Tamer
- Kocaeli University, Medical Faculty, Department of Clinical Microbiology, Kocaeli, Turkey.
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Yolken RH, Torrey EF. Are some cases of psychosis caused by microbial agents? A review of the evidence. Mol Psychiatry 2008; 13:470-9. [PMID: 18268502 DOI: 10.1038/mp.2008.5] [Citation(s) in RCA: 225] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The infectious theory of psychosis, prominent early in the twentieth century, has recently received renewed scientific support. Evidence has accumulated that schizophrenia and bipolar disorder are complex diseases in which many predisposing genes interact with one or more environmental agents to cause symptoms. The protozoan Toxoplasma gondii and cytomegalovirus are discussed as examples of infectious agents that have been linked to schizophrenia and in which genes and infectious agents interact. Such infections may occur early in life and are thus consistent with neurodevelopmental as well as genetic theories of psychosis. The outstanding questions regarding infectious theories concern timing and causality. Attempts are underway to address the former by examining sera of individuals prior to the onset of illness and to address the latter by using antiinfective medications to treat individuals with psychosis. The identification of infectious agents associated with the etiopathogenesis of schizophrenia might lead to new methods for the diagnosis, treatment and prevention of this disorder.
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Affiliation(s)
- R H Yolken
- The Stanley Laboratory of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins University Medical Center, Baltimore, MD 21287-4933, USA.
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35
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Hornok S, Edelhofer R, Joachim A, Farkas R, Berta K, Répási A, Lakatos B. Seroprevalence of Toxoplasma gondii and Neospora caninum infection of cats in Hungary. Acta Vet Hung 2008; 56:81-8. [PMID: 18401958 DOI: 10.1556/avet.56.2008.1.8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Blood samples were collected from 330 cats in Hungary in order to evaluate their seroconversion to Toxoplasma gondii and Neospora caninum using the indirect fluorescent antibody test (IFAT). The overall prevalence of toxoplasmosis was 47.6%, the prevalence being 22.4% among urban, 50% among suburban and 61.3% among rural animals. Significantly more cats had high IFAT titres (1:640 to 1:5120) in the countryside. Female cats were more frequently infected with T. gondii than males (53.3% vs. 39.3%), and seropositivity increased with the age of animals. The prevalence (0.6%) and titre (1:40) of antibodies to N. caninum was low. Sixty-two cats were also screened for seroconversion to feline infectious peritonitis (FIP) virus. Higher titres to T. gondii were more frequently detected among FIP-positive cats, but this difference was non-significant due to the small number of cats with concurrent infection.
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Affiliation(s)
- Sándor Hornok
- 1 Szent István University Department of Parasitology and Zoology, Faculty of Veterinary Science H-1078 Budapest István u. 2 Hungary
| | - Renate Edelhofer
- 2 University of Veterinary Medicine Department of Pathobiology, Institute of Parasitology and Zoology Vienna Austria
| | - Anja Joachim
- 2 University of Veterinary Medicine Department of Pathobiology, Institute of Parasitology and Zoology Vienna Austria
| | - Róbert Farkas
- 1 Szent István University Department of Parasitology and Zoology, Faculty of Veterinary Science H-1078 Budapest István u. 2 Hungary
| | | | - Attila Répási
- 4 Szent István University Clinic for Large Animals, Faculty of Veterinary Science Üllő Hungary
| | - Béla Lakatos
- 5 Clinic and Laboratory for Feline Medicine Budapest Hungary
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36
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Seilacher A, Reif WE, Wenk P. The parasite connection in ecosystems and macroevolution. Naturwissenschaften 2006; 94:155-69. [PMID: 17111182 DOI: 10.1007/s00114-006-0164-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Revised: 07/18/2006] [Accepted: 08/22/2006] [Indexed: 11/25/2022]
Abstract
In addition to their obvious negative effects ("pathogens"), endoparasites of various kinds play an important role in shaping and maintaining modern animal communities. In the long-term, parasites including pathogens are indispensable entities of any ecosystem. To understand this, it is essential that one changes the viewpoint from the host's interests to that of the parasite. Together with geographic isolation, trophic arms race, symbiosis, and niche partitioning, all parasites (including balance strategists, i.e. seemingly non-pathogenic ones) modulate their hosts' population densities. In addition, heteroxenic parasites control the balance between predator and prey species, particularly if final and intermediate hosts are vertebrates. Thereby, such parasites enhance the bonds in ecosystems and help maintain the status quo. As the links between eukaryotic parasites and their hosts are less flexible than trophic connections, parasite networks probably contributed to the observed stasis and incumbency of ecosystems over geologic time, in spite of continuous Darwinian innovation. Because heteroxenic parasites target taxonomic levels above that of the species (e.g. families), these taxa may have also become units of selection in global catastrophies. Macroevolutionary extrapolations, however, are difficult to verify because endoparasites cannot fossilize.
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Affiliation(s)
- Adolf Seilacher
- Geology Department Yale University, POB 208109, New Heaven, CT 06520, USA.
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Haddadzadeh HR, Khazraiinia P, Aslani M, Rezaeian M, Jamshidi S, Taheri M, Bahonar A. Seroprevalence of Toxoplasma gondii infection in stray and household cats in Tehran. Vet Parasitol 2006; 138:211-6. [PMID: 16529863 DOI: 10.1016/j.vetpar.2006.02.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Revised: 02/01/2006] [Accepted: 02/14/2006] [Indexed: 11/28/2022]
Abstract
The prevalence of anti-Toxoplasma gondii specific IgG in stray and household cats in Tehran was determined by Indirect Fluorescent Antibody Test (IFAT) on serum samples from 100 cats (50 stray and 50 households). Overall infection rate was 63%. The infection rate in stray cats (90%) was significantly higher (p<0.001) than that of household cats (36%). Last serum positive dilutions varied from 1: 32 to 1: 512 titres in which the highest percentage (27%) was for 1:256 and the least (4.8%) was at 1:32. The rate of infection between male and female cats of both groups was not significantly different; 90.3% versus 89.5% for male and female in stray cats, respectively. Different sexes of household cats were seropositive at the same rate (36%). A high positive correlation (r(2)=0.97) between age and the rate of infection was observed. The prevalence of Toxoplasma gondii infection in cats in Tehran was high, especially in stray cats which are probably the main source of Toxoplasma infection in this area.
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Affiliation(s)
- H R Haddadzadeh
- Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453,Tehran, Iran.
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38
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Azevedo SS, Batista CSA, Vasconcellos SA, Aguiar DM, Ragozo AMA, Rodrigues AAR, Alves CJ, Gennari SM. Seroepidemiology of Toxoplasma gondii and Neospora caninum in dogs from the state of Paraíba, Northeast region of Brazil. Res Vet Sci 2004; 79:51-6. [PMID: 15894024 DOI: 10.1016/j.rvsc.2004.10.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 09/20/2004] [Accepted: 10/13/2004] [Indexed: 10/26/2022]
Abstract
A cross-sectional study was conducted to determine the seroprevalence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to investigate the risk factors related to antibodies against T. gondii and N. caninum in dogs of the city of Campina Grande, state of Paraiba, Northeast region of Brazil. For this purpose, 286 blood samples were collected from dogs during the rabies vaccination campaign, in September 2003, and on this occasion questionnaires addressing epidemiological aspects of the infections were given to each dog owner. The sera were analyzed for anti-T. gondii and anti-N. caninum antibodies by indirect fluorescent antibody tests. Of the total of 286 dogs, 129 were positive for T. gondii (titer16) with a prevalence value of 45.1% (95% CI=39.24-51.07%). For N. caninum, 24 dogs were positive (titer50), with a prevalence value of 8.4% (95% CI=5.45-12.23%). Antibodies to T. gondii and N. caninum were found simultaneously in 14 dogs (4.9%; 95% CI=2.7-8.08%). For T. gondii infection, the risk factors associated with seroprevalence was the age of the animals, with dogs older than one year presenting higher values of odds ratio, and co-habitation of cats in the household. For N. caninum infection, dogs that have street contact had higher odds of seropositivity than dogs that remained exclusively in a domestic environment.
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Affiliation(s)
- S S Azevedo
- Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, Brazil
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39
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Johnson M, Broady K, Angelici MC, Johnson A. The relationship between nucleoside triphosphate hydrolase (NTPase) isoform and Toxoplasma strain virulence in rat and human toxoplasmosis. Microbes Infect 2003; 5:797-806. [PMID: 12850206 DOI: 10.1016/s1286-4579(03)00148-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Avirulent strains of Toxoplasma gondii possess only the nucleoside triphosphate hydrolase II (NTPaseII) isoform, whilst virulent strains possess both NTPaseI and NTPaseII. To determine if it is possible to identify the infective strain type (virulent or avirulent) in T. gondii infections by serological methods, we developed isoform-specific peptide ELISAs from the NTPaseI and NTPaseII antigens of T. gondii. When rats were immunized with either recombinant NTPaseI or NTPaseII, the ELISA could differentially identify antibody reactivity to each NTPase isoform. This ELISA was then used to test six groups of rats that were infected with either one of three virulent (RH, P or Ent) or three avirulent (Me49, C or TPR) strains of T. gondii. No differential antibody reactivity was detected by either whole recNTPase ELISA or peptide ELISA in the sera of rats, whether infected by virulent or avirulent strains of T. gondii. We also studied a panel of human sera from patients infected with known laboratory strains of T. gondii or naturally infected patients where the parasite was isolated and its virulence determined in mice. Differential reactivity to whole recNTPase isoforms was detected in some human sera, but this reactivity was not detected by the isoform-specific peptide ELISAs. Although the NTPase peptides do exhibit differential antibody reactivity, this is not correlated with the virulence status of the infecting strain.
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Affiliation(s)
- Michael Johnson
- Institute of the Biotechnology of Infectious Diseases, University of Technology, Westbourne St, St Leonards, Sydney 2065, Australia.
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40
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Ali CN, Harris JA, Watkins JD, Adesiyun AA. Seroepidemiology of Toxoplasma gondii in dogs in Trinidad and Tobago. Vet Parasitol 2003; 113:179-87. [PMID: 12719132 DOI: 10.1016/s0304-4017(03)00075-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A cross-sectional study was conducted to determine the seroprevalence of Toxoplasma gondii agglutinins and to investigate the relationship between various risk factors and occurrence of toxoplasmosis in dogs in Trinidad. Of a total 250 dogs, comprising domestic, hunting and stray dogs, 80 (32.0%) were positive for T. gondii agglutinins at a titre of > or =1:32 using a latex agglutination test. Stray dogs (60.5%) had statistically significantly higher (P<0.001) seroprevalence for toxoplasmosis than hunting dogs (30.5%) and domestic dogs (25.5%). Amongst dogs whose ages were known, the prevalence of toxoplasmosis was significantly highest (P=0.037) in dogs in the >2-3 years age group compared with other age groups. Dogs that consumed home-cooked foods had a seroprevalence of 32.9% compared with those fed commercial dog foods (17.2%) and dogs fed both home-cooked and commercial foods (21.0%). However, the difference was not statistically significant (P>0.05; chi(2)). The rather high prevalence of toxoplasmosis in stray dogs is a good indication of the extent of the infection in the environment.
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Affiliation(s)
- C N Ali
- Faculty of Medical Sciences, School of Veterinary Medicine, The University of the West Indies, St. Augustine, Trinidad and Tobago.
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Mann T, Gaskins E, Beckers C. Proteolytic processing of TgIMC1 during maturation of the membrane skeleton of Toxoplasma gondii. J Biol Chem 2002; 277:41240-6. [PMID: 12177058 DOI: 10.1074/jbc.m205056200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Membrane skeletons play an important role in the maintenance of cell shape and integrity in many cell types. In the protozoan parasite Toxoplasma gondii this function is performed by the subpellicular network, a resilient structure composed of tightly interwoven 10-nm filaments. We report here that this network is assembled at an early stage in the development of daughter parasites. The networks of immature and mature parasites differ dramatically with respect to their stability. Although in immature parasites the network is completely solubilized by detergent, the network in mature parasites is entirely detergent-resistant. Conversion of the detergent-labile to the detergent-resistant network occurs late in daughter cell development and appears to be coupled to proteolytic processing of the carboxyl terminus of TgIMC1, the major subunit of the network filaments. A single cysteine residue in the TgIMC1 carboxyl terminus was found to be essential for this processing event. The dramatic change in resistance to detergent extraction probably reflects an overall change in structural stability of the subpellicular network that accompanies maturation of daughter parasites and allows a switch from an assembly-competent but loose structure to one that is rigid and offers mechanical strength to the mature parasite.
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Affiliation(s)
- Tara Mann
- Division of Geographic Medicine, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294-2170, USA
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Kristensson K, Mhlanga JDM, Bentivoglio M. Parasites and the brain: neuroinvasion, immunopathogenesis and neuronal dysfunctions. Curr Top Microbiol Immunol 2002; 265:227-57. [PMID: 12014192 DOI: 10.1007/978-3-662-09525-6_12] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- K Kristensson
- Department of Neuroscience, Retzius väg 8, Karolinska Institutet, 171 77 Stockholm, Sweden
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Dijkstra T, Eysker M, Schares G, Conraths FJ, Wouda W, Barkema HW. Dogs shed Neospora caninum oocysts after ingestion of naturally infected bovine placenta but not after ingestion of colostrum spiked with Neospora caninum tachyzoites. Int J Parasitol 2001; 31:747-52. [PMID: 11403764 DOI: 10.1016/s0020-7519(01)00230-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
An experiment was carried out to determine whether bovine colostrum or placenta could be a source of infection of Neospora caninum for dogs. For this purpose, two dogs were fed bovine colostrum to which culture-derived N. caninum tachyzoites were added and two other dogs were fed placental cotyledonary tissue from N. caninum seropositive cows. One dog served as a negative control during the start of the experiment but this control dog was fed cotyledonary tissue later on. None of the dogs did produce serum antibodies to N. caninum. All three dogs that were fed cotyledonary tissue did shed N. caninum oocysts, but no oocyst shedding was seen in the two dogs that were fed colostrum with N. caninum tachyzoites. Oocyst excretion did not resume in two dogs after repeated feeding of N. caninum infected placenta. The identity of the oocysts was confirmed by a bioassay in gerbils. It is concluded that ingestion of bovine placenta by dogs is an effective mode of transmission of N. caninum from cattle to dogs.
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Affiliation(s)
- T Dijkstra
- Animal Health Service, P.O. Box 361, 9200 AJ Drachten, The Netherlands.
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Abstract
Toxoplasmosis is one of the more common parasitic zoonoses world-wide. Its causative agent, Toxoplasma gondii, is a facultatively heteroxenous, polyxenous protozoon that has developed several potential routes of transmission within and between different host species. If first contracted during pregnancy, T. gondii may be transmitted vertically by tachyzoites that are passed to the foetus via the placenta. Horizontal transmission of T. gondii may involve three life-cycle stages, i.e. ingesting infectious oocysts from the environment or ingesting tissue cysts or tachyzoites which are contained in meat or primary offal (viscera) of many different animals. Transmission may also occur via tachyzoites contained in blood products, tissue transplants, or unpasteurised milk. However, it is not known which of these routes is more important epidemiologically. In the past, the consumption of raw or undercooked meat, in particular of pigs and sheep, has been regarded as a major route of transmission to humans. However, recent studies showed that the prevalence of T. gondii in meat-producing animals decreased considerably over the past 20 years in areas with intensive farm management. For example, in several countries of the European Union prevalences of T. gondii in fattening pigs are now <1%. Considering these data it is unlikely that pork is still a major source of infection for humans in these countries. However, it is likely that the major routes of transmission are different in human populations with differences in culture and eating habits. In the Americas, recent outbreaks of acute toxoplasmosis in humans have been associated with oocyst contamination of the environment. Therefore, future epidemiological studies on T. gondii infections should consider the role of oocysts as potential sources of infection for humans, and methods to monitor these are currently being developed. This review presents recent epidemiological data on T. gondii, hypotheses on the major routes of transmission to humans in different populations, and preventive measures that may reduce the risk of contracting a primary infection during pregnancy.
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Affiliation(s)
- A M Tenter
- Institut für Parasitologie, Tierärztliche Hochschule Hannover, Bünteweg 17, D-30559, Hannover, Germany.
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Abstract
OBJECTIVES This retrospective cohort study examined the association between resident characteristics and the development of wandering behavior. METHODS Subjects included a total of 8982 residents from the states of Mississippi, Texas, and Vermont who had baseline and 3-month follow-up Minimum Data Set assessments between 1 January 1996 and 31 December 1997. RESULTS Residents who had a short-term memory problem (Odds Ratio (OR) = 3.05), had pneumonia (OR = 3.15), asked repetitive questions (OR = 2.19), had a long-term memory problem (OR = 2.06), exhibited dementia (OR = 19.4), constipation (OR = 1.82), expressed sadness or pain (OR = 1.65), and used antipsychotic medication (OR = 1.70), were at an increased risk for developing wandering behavior compared to residents without these characteristics. Residents with functional impairment (OR = 0.28) and women (OR = 0.61) were less likely to develop wandering behavior. CONCLUSIONS Results of this study may be useful in constructing causal theories for the development of wandering behavior.
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Affiliation(s)
- D K Kiely
- Hebrew Rehabilitation Center for Aged, HRCA Research and Training Institute, Boston, MA 02131, USA.
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Fazaeli A, Carter PE, Pennington TH. Intergenic spacer (IGS) polymorphism: a new genetic marker for differentiation of Toxoplasma gondii strains and Neospora caninum. J Parasitol 2000; 86:716-23. [PMID: 10958446 DOI: 10.1645/0022-3395(2000)086[0716:isipan]2.0.co;2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The region between the 28S and 18S rRNA genes, including the intergenic spacer (IGS) region and the 5S rRNA gene, from 32 strains of Toxoplasma gondii and the NC1 strain of Neospora caninum was amplified and used for DNA sequencing and/or restriction fragment length polymorphism (RFLP) analysis. The 5S rDNA sequences from 20 strains of T. gondii were identical. The IGS region between the 5S and 18S rRNA genes (nontranscribed spacer 2 or NTS 2) showed 10 nucleotide variations. Six of the 10 variant positions correlated with the murine virulence of the strains. Intraspecific polymorphisms distinguished the virulent strains of zymodemes 5, 6, and 8 from other virulent strains (in zymodeme 1). RFLP methods (IGS-RFLP) were developed and used to characterize the virulent and avirulent patterns among 29 T. gondii strains. Sequence diversity of 19.8% was found between T. gondii and N. caninum when comparing a region of 919 bp at the 3' end of NTS 2. The sequence variation in ribosomal IGS could therefore be a useful marker for Toxoplasma strain identification and for distinguishing N. caninum from T. gondii.
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MESH Headings
- Animals
- Base Sequence
- DNA, Protozoan/chemistry
- DNA, Ribosomal/chemistry
- Genetic Markers
- Humans
- Molecular Sequence Data
- Neospora/classification
- Neospora/genetics
- Neospora/isolation & purification
- Neospora/pathogenicity
- Polymerase Chain Reaction
- Polymorphism, Restriction Fragment Length
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 28S/genetics
- RNA, Ribosomal, 5S/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Toxoplasma/classification
- Toxoplasma/genetics
- Toxoplasma/isolation & purification
- Toxoplasma/pathogenicity
- Virulence
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Affiliation(s)
- A Fazaeli
- Department of Medical Microbiology, University of Aberdeen, Medical School, Foresterhill, United Kingdom
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Bezirtzoglou E. Non-Bacterial Agents of Foodborne Illness. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2000. [DOI: 10.1080/089106000750060369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Eugenia Bezirtzoglou
- From the Dept of Microbiology, Medical School, University of Ioannina, 45110-Ioannina, Greece
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Sohn WM, Nam HW. Western blot analysis of stray cat sera against Toxoplasma gondii and the diagnostic availability of monoclonal antibodies in sandwich-ELISA. THE KOREAN JOURNAL OF PARASITOLOGY 1999; 37:249-56. [PMID: 10634041 PMCID: PMC2733202 DOI: 10.3347/kjp.1999.37.4.249] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A total of 198 sera from stray cats was assayed against Toxoplasma gondii antigen by western blot. Out of 198 sera assayed, 26 sera (13.1%) showed typical blot patterns against T. gondii. When spotted by ELISA absorbance and indirect latex agglutination test (ILAT) titer, all 26 cases were distributed over the cut-off value of ELISA whereas 24 cases (92.3%) were in the positive range of 1:32 or higher and 2 cases in negative range by ILAT. Among western blot negative 172 sera, 162 cases were negative in both ILAT and ELISA while 10 cases were reactive falsely such that three cases were ILAT positive with 1:32 titer and 9 cases were ELISA positive (2 cases overlapped). These 10 cases reacted peculiarly without typical binding pattern in Western blot. Sandwich-ELISA was performed with monoclonal antibodies (mAbs) of Tg563 (30 kDa, SAG1), Tg505 (22 kDa, SAG2), Tg605 (43 kDa, SAG3), Tg556 (28 kDa. GRA2), Tg737 (32 kDa, GRA6), Tg695 (66 kDa, ROP2), Tg786 (42 kDa, ROP6), and Tg621 (32 kDa, anonymous but cytosolic) clone, respectively. All western blot-positive cases were in the positive range and negative cases in the negative range clearly. Among the 10 false reactive cases, 3 cases were in the positive range with one or more mAbs. All mAbs used in this study were confirmed to be specific to T. gondii infection as a standardized sandwich-ELISA to differentiate it from other pathogens.
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Affiliation(s)
- W M Sohn
- Department of Parasitology, College of Medicine, Gyeongsang National University, Chinju, Korea
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Garcia JL, Navarro IT, Ogawa L, de Oliveira RC, de Faria Garcia SM, Leite J. [Seroepidemiology of toxoplasmosis and ocular evaluation by Amsler grid in patients from the rural area treated at the Jaguapitã county health center, Paraná State, Brazil]. Rev Soc Bras Med Trop 1999; 32:671-6. [PMID: 10881104 DOI: 10.1590/s0037-86821999000600009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In this study, we collected serum from 82 randomly selected patients from a rural area in Jaguapitã county, Paraná State. All sera were subjected to indirect immunofluorescence assay (IFA) to detect IgG antibodies against T. gondii. Serum titers >/=+ 16 were considered positive. Of the 82 evaluated sera, 68 (82.9%) were positive to toxoplasmosis and 14 (17.1%) were non-reactive. The most common titers found were 64 (23/33.8%) and 256 (16/23.5%), the highest titer being 4096 (8/11.8%). The 82 patients were also evaluated by the Amsler Grid test, with 22 (26.8%) patients presenting at least one alteration in this test. Masculinity was found to be a protection factor in the Amsler grid test (OR = 0.21 0.04 < OR < 0. 86 chi2 = 4,98 p = 0,02). There were no significant statistical differences related to the epidemiological investigation. We concluded that T. gondii has a wide distribution in the population studied.
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Affiliation(s)
- J L Garcia
- Departamento de Medicina Veterinária Preventiva e de Serviço Social, Universidade Estadual de Londrina, PR, Brasil
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