1
|
Saki J, Arjmand R. Toxoplasma gondii genotyping in AIDS patients using high resolution melt analysis (HRM analysis) in Khuzestan province, southwest Iran. J Parasit Dis 2023; 47:630-634. [PMID: 37520196 PMCID: PMC10382417 DOI: 10.1007/s12639-023-01601-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 05/27/2023] [Indexed: 08/01/2023] Open
Abstract
Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma gondii, a common protozoan in the Apicomplexa phylum. Several studies in Iran have demonstrated the presence of the parasite in various hosts, but no data on T. gondii genotyping in HIV patients in Khuzestan, Southwest Iran, is available. One hundred of blood samples from AIDS patients were collected and tested by real-time PCR High Resolution Melting analyses for T.gondii detection and genotyping. T. gondii was discovered in 8 out of 100 (8%) AIDS patients with dominant Type I. This study suggest that HRM method demonstrated excellent discriminating ability for T. gondii, and AIDS patients should be tested for Toxoplasma detection and genotyping to prevent parasite pathogenicity.
Collapse
Affiliation(s)
- J. Saki
- Cellular and Molecular Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Reza Arjmand
- Faculty of Medicine, Department of Parasitology, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| |
Collapse
|
2
|
Manuel L, Santos-Gomes G, Noormahomed EV. Human toxoplasmosis in Mozambique: gaps in knowledge and research opportunities. Parasit Vectors 2020; 13:571. [PMID: 33176884 PMCID: PMC7659051 DOI: 10.1186/s13071-020-04441-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 10/30/2020] [Indexed: 01/01/2023] Open
Abstract
Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma gondii that afflicts humans worldwide and wild and domestic warm-blooded animals. In immunocompetent individuals, the acute phase of infection presents transient low or mild symptoms that remain unnoticed. In immunocompromised patients, T. gondii is a life-threatening opportunistic infection, which can result from the reactivation of latent infection or primary infection. Moreover, congenital toxoplasmosis, which results from the transplacental passage of tachyzoites into the fetus during a pregnant primary infection, can lead to miscarriage, stillbirth, or ocular and neurologic disease, and neurocognitive deficits in the newborns. Thus, the present review aims to address the current knowledge of T. gondii infection and toxoplasmosis in Africa and especially in Mozambique, stressing the importance of identifying risk factors and promote awareness among the health care providers and population, assessing the gaps in knowledge and define research priorities. In Mozambique, and in general in southern African countries, clinical disease and epidemiological data have not yet been entirely addressed in addition to the implications of T. gondii infection in immunocompetent individuals, in pregnant women, and its relation with neuropsychiatric disorders. The main gaps in knowledge in Mozambique include lack of awareness of the disease, lack of diagnostic methods in health facilities, lack of genetic data, and lack of control strategies.![]()
Collapse
Affiliation(s)
- Leonardo Manuel
- Faculty of Health Sciences, Universidade Lurio, Nampula, Mozambique
| | - Gabriela Santos-Gomes
- Global Health and Tropical Medicine (GHTM), Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal
| | - Emilia V Noormahomed
- Department of Microbiology, Faculty of Medicine, Universidade Eduardo Mondlane (UEM), Maputo, Mozambique. .,Department of Medicine, Infectious Disease Division, University of California, San Diego, USA. .,Mozambique Institute for Health Education and Research (MIHER), Maputo, Mozambique.
| |
Collapse
|
3
|
Smith JR, Ashander LM, Arruda SL, Cordeiro CA, Lie S, Rochet E, Belfort R, Furtado JM. Pathogenesis of ocular toxoplasmosis. Prog Retin Eye Res 2020; 81:100882. [PMID: 32717377 DOI: 10.1016/j.preteyeres.2020.100882] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 12/12/2022]
Abstract
Ocular toxoplasmosis is a retinitis -almost always accompanied by vitritis and choroiditis- caused by intraocular infection with Toxoplasma gondii. Depending on retinal location, this condition may cause substantial vision impairment. T. gondii is an obligate intracellular protozoan parasite, with both sexual and asexual life cycles, and infection is typically contracted orally by consuming encysted bradyzoites in undercooked meat, or oocysts on unwashed garden produce or in contaminated water. Presently available anti-parasitic drugs cannot eliminate T. gondii from the body. In vitro studies using T. gondii tachyzoites, and human retinal cells and tissue have provided important insights into the pathogenesis of ocular toxoplasmosis. T. gondii may cross the vascular endothelium to access human retina by at least three routes: in leukocyte taxis; as a transmigrating tachyzoite; and after infecting endothelial cells. The parasite is capable of navigating the human neuroretina, gaining access to a range of cell populations. Retinal Müller glial cells are preferred initial host cells. T. gondii infection of the retinal pigment epithelial cells alters the secretion of growth factors and induces proliferation of adjacent uninfected epithelial cells. This increases susceptibility of the cells to parasite infection, and may be the basis of the characteristic hyperpigmented toxoplasmic retinal lesion. Infected epithelial cells also generate a vigorous immunologic response, and influence the activity of leukocytes that infiltrate the retina. A range of T. gondii genotypes are associated with human ocular toxoplasmosis, and individual immunogenetics -including polymorphisms in genes encoding innate immune receptors, human leukocyte antigens and cytokines- impacts the clinical manifestations. Research into basic pathogenic mechanisms of ocular toxoplasmosis highlights the importance of prevention and suggests new biological drug targets for established disease.
Collapse
Affiliation(s)
- Justine R Smith
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA.
| | - Liam M Ashander
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
| | - Sigrid L Arruda
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Cynthia A Cordeiro
- Cordeiro et Costa Ophtalmologie, Campos dos Goytacazes, Brazil; Formerly of Department of Ophthalmology, Federal University of Minas Gerais School of Medicine, Belo Horizonte, Brazil
| | - Shervi Lie
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Elise Rochet
- Eye & Vision Health and Flinders Centre for Innovation in Cancer, Flinders University College of Medicine & Public Health, Adelaide, Australia
| | - Rubens Belfort
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - João M Furtado
- Department of Ophthalmology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil; Formerly of Casey Eye Institute, Oregon Health & Science University, USA
| |
Collapse
|
4
|
Arshadi M, Akhlaghi L, Meamar AR, Alizadeh Ghavidel L, Nasiri K, Mahami-Oskouei M, Mousavi F, Rampisheh Z, Khanmohammadi M, Razmjou E. Sero-molecular detection, multi-locus genotyping, and clinical manifestations of ocular toxoplasmosis in patients in northwest Iran. Trans R Soc Trop Med Hyg 2020; 113:195-202. [PMID: 30624725 DOI: 10.1093/trstmh/try137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/23/2018] [Accepted: 12/05/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Our goal was to use molecular techniques to verify and characterise clinical diagnoses of ocular toxoplasmosis. Clinical cases were evaluated against IgM and IgG Toxoplasma antibodies, and IgG avidity was tested. B1 gene was assessed for molecular detection, and multi-locus genotyping were conducted to type Toxoplasma infections. METHODS A cross-sectional study was conducted in 33 patients with suspected active ocular toxoplasmosis. Patients were examined by an ophthalmologist and clinical manifestations were recorded. Toxoplasma gondii IgG and IgM from serum samples were analysed by chemiluminescence immunoassay and ELISA. Acute vs chronic infection was evaluated by IgG avidity testing. Molecular diagnosis of T. gondii infection targeted the B1 gene, and the T. gondii genotype was determined by amplification of the GRA6, SAG2, SAG3, BTUB and APICO loci. The correlation of age, gender, occupation, education, contact with cats or soil, and the consumption of undercooked meat with the incidence of ocular toxoplasmosis was evaluated. RESULTS Twenty-eight patients (84.8%) were seropositive, two (6%) were both IgG and IgM positive, while one (3%) showed IgG avidity <40%. Molecular testing confirmed toxoplasmosis in 27 patients (81.8%). Chorioretinal scarring (p=0.014) and posterior uveitis (p=0.004) was significantly associated with ocular toxoplasmosis patients. Multi-locus genotyping showed genotype I. Ocular toxoplasmosis showed no significant correlation with gender, age, behaviours, occupation or education. CONCLUSION Clinical manifestations, serological and molecular detection of Toxoplasma were highly correlated in the diagnosis of ocular toxoplasmosis. Genotype I was predominant in ocular toxoplasmosis in northwest Iran. A larger comparative study should be conducted to provide a broader view of the molecular epidemiology of T. gondii genotypes and its role in toxoplasmosis.
Collapse
Affiliation(s)
- Mehdi Arshadi
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Lame Akhlaghi
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Meamar
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Leila Alizadeh Ghavidel
- Department of Ophthalmology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Kamal Nasiri
- Department of Ophthalmology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahmoud Mahami-Oskouei
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Farideh Mousavi
- Department of Ophthalmology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Zahra Rampisheh
- Preventive Medicine and Public Health Research Center, Iran University of Medical Sciences, Tehran, Iran.,Department of Community Medicine, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Khanmohammadi
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Elham Razmjou
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
5
|
Smith JR, Ashander LM, Ma Y, Rochet E, Furtado JM. Model Systems for Studying Mechanisms of Ocular Toxoplasmosis. Methods Mol Biol 2020; 2071:297-321. [PMID: 31758460 DOI: 10.1007/978-1-4939-9857-9_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The most common human disease caused by infection with Toxoplasma gondii is ocular toxoplasmosis, which typically is manifest as recurrent attacks of necrotizing retinal inflammation with subsequent scarring. The multilayered retina contains specialized cell populations, including endothelial cells, epithelial cells, neurons and supporting cells, all of which may be involved in this condition. In vitro investigations of basic mechanisms operating in human ocular toxoplasmosis use cellular and molecular methods that are common to the study of many pathological processes, and the novel aspect of this research is the use of human retinal cell subsets. Most in vivo research on ocular toxoplasmosis is conducted in the laboratory mouse. Experimental models involve local or systemic inoculation of parasites to induce acute disease, or sequential systemic and local parasite inoculations to trigger recurrent disease. We present methods for in vitro and in vivo studies of ocular toxoplasmosis, including dissection of the human eye, and culture and infection of differentiated cell populations from the retina, as well as induction of mouse ocular toxoplasmosis by intraocular, or sequential systemic and intraocular, inoculations, and imaging of toxoplasmic retinal lesions.
Collapse
Affiliation(s)
- Justine R Smith
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.
| | - Liam M Ashander
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Yuefang Ma
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - Elise Rochet
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia
| | - João M Furtado
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
6
|
Lie S, Rochet E, Segerdell E, Ma Y, Ashander LM, Shadforth AMA, Blenkinsop TA, Michael MZ, Appukuttan B, Wilmot B, Smith JR. Immunological Molecular Responses of Human Retinal Pigment Epithelial Cells to Infection With Toxoplasma gondii. Front Immunol 2019; 10:708. [PMID: 31118929 PMCID: PMC6506780 DOI: 10.3389/fimmu.2019.00708] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/15/2019] [Indexed: 11/13/2022] Open
Abstract
Ocular toxoplasmosis is the commonest clinical manifestation of infection with obligate intracellular parasite, Toxoplasma gondii. Active ocular toxoplasmosis is characterized by replication of T. gondii tachyzoites in the retina, with reactive inflammation. The multifunctional retinal pigment epithelium is a key target cell population for T. gondii. Since the global gene expression profile is germane to understanding molecular involvements of retinal pigment epithelial cells in ocular toxoplasmosis, we performed RNA-Sequencing (RNA-Seq) of human cells following infection with T. gondii tachyzoites. Primary cell isolates from eyes of cadaveric donors (n = 3), and the ARPE-19 human retinal pigment epithelial cell line, were infected for 24 h with GT-1 strain T. gondii tachyzoites (multiplicity of infection = 5) or incubated uninfected as control. Total and small RNA were extracted from cells and sequenced on the Illumina NextSeq 500 platform; results were aligned to the human hg19 reference sequence. Multidimensional scaling showed good separation between transcriptomes of infected and uninfected primary cell isolates, which were compared in edgeR software. This differential expression analysis revealed a sizeable response in the total RNA transcriptome-with significantly differentially expressed genes totaling 7,234 (28.9% of assigned transcripts)-but very limited changes in the small RNA transcriptome-totaling 30 (0.35% of assigned transcripts) and including 8 microRNA. Gene ontology and pathway enrichment analyses of differentially expressed total RNA in CAMERA software, identified a strong immunologic transcriptomic signature. We conducted RT-qPCR for 26 immune response-related protein-coding and long non-coding transcripts in epithelial cell isolates from different cadaveric donors (n = 3), extracted by a different isolation protocol but similarly infected with T. gondii, to confirm immunological activity of infected cells. For microRNA, increases in miR-146b and miR-212 were detected by RT-qPCR in 2 and 3 of these independent cell isolates. Biological network analysis in the InnateDB platform, including 735 annotated differentially expressed genes plus 2,046 first-order interactors, identified 10 contextural hubs and 5 subnetworks in the transcriptomic immune response of cells to T. gondii. Our observations provide a solid base for future studies of molecular and cellular interactions between T. gondii and the human retinal pigment epithelium to illuminate mechanisms of ocular toxoplasmosis.
Collapse
Affiliation(s)
- Shervi Lie
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Elise Rochet
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Erik Segerdell
- Department of Biostatistics, Oregon Health and Sciences University, Portland, OR, United States
| | - Yuefang Ma
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Liam M. Ashander
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Audra M. A. Shadforth
- Queensland Eye Institute, Brisbane, QLD, Australia
- School of Biomedical Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Timothy A. Blenkinsop
- Departments of Cell, Developmental and Regenerative Biology, and Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Michael Z. Michael
- Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Binoy Appukuttan
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
- Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| | - Beth Wilmot
- Department of Biostatistics, Oregon Health and Sciences University, Portland, OR, United States
| | - Justine R. Smith
- Eye and Vision Health, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
- Flinders Centre for Innovation in Cancer, Flinders University College of Medicine and Public Health, Adelaide, SA, Australia
| |
Collapse
|
7
|
Brydak-Godowska J, Moskal K, Borkowski PK, Przybyś M, Turczyńska M, Kęcik D. A Retrospective Observational Study of Uveitis in a Single Center in Poland with a Review of Findings in Europe. Med Sci Monit 2018; 24:8734-8749. [PMID: 30504763 PMCID: PMC6289025 DOI: 10.12659/msm.910749] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 07/17/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND This study aimed to review the causes, presentation, and clinicopathological associations of uveitis in a single department of ophthalmology in Poland, and to compare the findings with previously published studies from other European countries. MATERIAL AND METHODS Review of local patient records between 2005-2015 identified patients diagnosed with uveitis. Data obtained included age, gender, imaging findings, and laboratory diagnostic findings. A literature review identified 24 publications from 1976-2017 that reported observational data from patients with uveitis in Europe. Statistical analysis compared the findings. RESULTS Between 2005-2015, 279 patients were diagnosed with uveitis (mean age, 38.3±15.3 years) (61.6% women) including unilateral uveitis (60.5%), with posterior uveitis (48.4%), anterior uveitis (26.5%), and intermediate uveitis (12.9%). A general etiology was established in 76.3% and included ocular-specific syndromes (31.8%), infection (27.9%), and an association with systemic disease (16.8%), but 23.6% were unclassifiable. Specific causes of uveitis included toxoplasmosis (17.9%), Fuchs uveitis (12.2%), white dot syndromes (WDS) (10.4%), sarcoidosis (6.1%), toxocariasis (6.1%), HLA-B27-associated acute anterior uveitis (AAU) (5.7%), multiple sclerosis (4.7%), ankylosing spondylitis (3.6%) and herpesvirus infection (2.5%). Data from 26 published studies (24,126 patients with uveitis) from 12 European countries showed that idiopathic uveitis was most common (36.6%); the identified causes included toxoplasmosis (9.4%), WDS (7.2%), and Fuchs uveitis (6.1%). CONCLUSIONS In a single ophthalmic center in Poland, and throughout Europe, the causes of uveitis are varied. Genetic, geographic, social and environmental factors are likely to affect the cause of uveitis in different populations.
Collapse
Affiliation(s)
| | - Katarzyna Moskal
- Student Research Group (Ophthalmology), Medical University of Warsaw, Warsaw, Poland
| | - Piotr K. Borkowski
- Department of Infectious Tropical Diseases and Hepatology, Medical University of Warsaw, Warsaw, Poland
| | - Mariusz Przybyś
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Monika Turczyńska
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Dariusz Kęcik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
8
|
Human toxoplasmosis: a systematic review for genetic diversity of Toxoplasma gondii in clinical samples. Epidemiol Infect 2018; 147:e36. [PMID: 30394261 PMCID: PMC6518561 DOI: 10.1017/s0950268818002947] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Toxoplasma gondii (T. gondii) as an obligate intracellular protozoan with a worldwide distribution can infect virtually all warm-blooded animals and humans. This study aims to provide a summary of the available data on genotypes of T. gondii in human. Five databases including MEDLINE in PubMed, Scopus, Science Direct, Web of Science and Google Scholar were searched for the T. gondii genotyping in human during 1995-August 2017. Next, we screened all the articles based on the inclusion and exclusion criteria. Overall, 26 studies were eligible regarding genotyping T. gondii in human samples. In clonal genotyping, 167 out of 286 cases (58%) were infected with type II. Genetic characterisation of T. gondii isolates displayed that type II was the most predominant genotype in human with the prevalence of 64.3%, 62.1% and 41.7% in patients with AIDS, congenital and ocular toxoplasmosis, respectively. In ToxoDB genotyping, most individuals were infected with genotypes #9 and #65 (21.2%). Based on these results, genotype profile of T. gondii isolates is different throughout the world. The strains in Asian and African countries are characterised by low genetic diversity, while in North and South America a wide diversity of this parasite is found. In countries without any data (e.g. Australia, Western and Southern Africa and Western Asia), identification of T. gondii genotypes might discover higher genetic diversity.
Collapse
|
9
|
Belfort RN, Isenberg J, Fernandes BF, Di Cesare S, Belfort R, Burnier MN. Evaluating the presence of Toxoplasma gondii in peripheral blood of patients with diverse forms of uveitis. Int Ophthalmol 2016; 37:19-23. [PMID: 26975400 DOI: 10.1007/s10792-016-0221-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 03/07/2016] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to evaluate the presence of Toxoplasmosis gondii in samples of peripheral blood from patients with varying etiologies of uveitis. Whole blood from patients with different forms of uveitis was tested for the presence of T. gondii using real-time PCR targeting the well-characterized 529 bp fragment. Extracted DNA was both frozen. Thirty-one patients were included in the current study and grouped as follows: acute toxoplasmosis (n = 10); toxoplasmic retinal scars (n = 9); non-infectious etiologies of uveitis (n = 6); and IgG negative for toxoplasmosis (n = 6). In total, only two patients were shown to have circulating T. gondii in peripheral blood; both of these patients were IgG positive for toxoplasmosis, were receiving immunosuppressive therapy for autoimmune uveitis, and had no clinical features of toxoplasmosis. T. gondii was identified in peripheral blood of some immunosuppressed patients. No other patients, including those with acute toxoplasmosis, had circulating parasites in peripheral blood.
Collapse
Affiliation(s)
- Rubens N Belfort
- The Henry C. Witleson Ocular Pathology Laboratory, McGill University, 3375 University, Room 216, Montréal, QC, Canada
- Department of Ophthalmology and Visual Sciences, Vision Institute, Federal University of São Paulo, Rua Botucatu, 821, São Paulo, SP, Brazil
| | - Jordan Isenberg
- The Henry C. Witleson Ocular Pathology Laboratory, McGill University, 3375 University, Room 216, Montréal, QC, Canada.
| | - Bruno F Fernandes
- The Henry C. Witleson Ocular Pathology Laboratory, McGill University, 3375 University, Room 216, Montréal, QC, Canada
| | - Sebastian Di Cesare
- The Henry C. Witleson Ocular Pathology Laboratory, McGill University, 3375 University, Room 216, Montréal, QC, Canada
| | - Rubens Belfort
- Department of Ophthalmology and Visual Sciences, Vision Institute, Federal University of São Paulo, Rua Botucatu, 821, São Paulo, SP, Brazil
| | - Miguel N Burnier
- The Henry C. Witleson Ocular Pathology Laboratory, McGill University, 3375 University, Room 216, Montréal, QC, Canada
- Department of Ophthalmology and Visual Sciences, Vision Institute, Federal University of São Paulo, Rua Botucatu, 821, São Paulo, SP, Brazil
| |
Collapse
|
10
|
NOROUZI M, SEYYED TABAEI SJ, NIYYATI M, SABER V, BEHNIAFAR H. Genotyping of Toxoplasma gondii Strains Isolated from Patients with Ocular Toxoplasmosis in Iran. IRANIAN JOURNAL OF PARASITOLOGY 2016; 11:316-324. [PMID: 28127336 PMCID: PMC5256047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Toxoplasma gondii is an obligate, intracellular protozoon that develops its sexual stage in cat's intestinal epithelial cells as definitive host and develops its asexual stage in different tissues of a wide range hosts called intermediate host. The protozoon is a food-borne and worldwide parasite that can cause serious complications such as abortion in pregnant women, encephalitis, and ocular toxoplasmosis. The present study aimed to genotype T. gondii strains isolated from patients with toxoplasmic retinochoroiditis. METHODS Fifty-two blood samples were taken from patients with ocular toxoplasmosis, from July 2013 to July 2014. The specimens were collected from three ophthalmological hospitals of Tehran, Iran. After that, DNA extraction was performed using kit on separated buffy coats of serologically positive blood samples. Then PCR was done in GRA6 gene. For digestion of products, MseI endonuclease was used. Finally, some of the PCR products were sequenced. RESULTS All of 52 samples were found positive by serological and PCR-RFLP methods and all of isolated strains belong to type III genotype. Type III genotype has the highest prevalence in Iranian ocular toxoplasmic patients. CONCLUSION T. gondii, particularly its type III should not be neglected as a cause of retinochoroiditis.
Collapse
Affiliation(s)
- Maryam NOROUZI
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyyed Javad SEYYED TABAEI
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran,Correspondence
| | - Maryam NIYYATI
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Vafa SABER
- Dept. of Medical Parasitology and Mycology, School of Medicine, International Branch of Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed BEHNIAFAR
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| |
Collapse
|
11
|
Seroprevalence and genetic characterization of Toxoplasma gondii in cancer patients in Anhui Province, Eastern China. Parasit Vectors 2015; 8:162. [PMID: 25889184 PMCID: PMC4379604 DOI: 10.1186/s13071-015-0778-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/04/2015] [Indexed: 12/01/2022] Open
Abstract
Background Recent studies have indicated the predominance of Toxoplasma gondii genotype Chinese 1 in animals in China. However, little is known of the genetic features of the parasite in humans. This study aims to determine the prevalence of anti-T. gondii antibodies based on which the genetic character of the parasite was identified in cancer patients in China. Methods A total of 1014 serum samples with malignant neoplasms were collected from six tertiary-care hospitals (HAUCM, APH, HAMU, XAH, FHH and HBMC) from January, 2012 to August, 2013. Antibodies against T. gondii were examined by enzyme-linked immunosorbent assay (ELISA). Blood samples were subsequently used for PCR assay to detect T. gondii DNA (gra6). The DNA positive samples were subjected to genotyping using a multiplex multilocus nested PCR-RFLP at 10 loci, including sag1, sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1 and apico. Samples from the patients were anonymous and only data with regard to age and gender was available at sample collection. Results Overall, 8.38% (85/1014) of the examined patients showed positive antibodies against T. gondii. Among them, 61 (6.02%) were seropositive only for IgG, 16 (1.58%) were only for IgM, and 8 (0.79%) were found to be positive for both IgG and IgM. The seroprevalence of antibodies to Toxoplasma ranged from 5.8% to 11.0%, without regional difference (χ2 = 4.764, P = 0.445). No significant differences of the positive rates of T. gondii infection were noted in genders (male, 8.96%; female, 7.45%) (χ2 = 0.707, P = 0.400) and in ages (χ2 = 1.172, P = 0.947). Of 1014 DNA samples, 36 (3.55%) were positive for T. gondii by nested PCR at gra6 locus and nine gave rise to complete genotyping results. All samples with achieved PCR-RFLP genotyping showed a common genetic character of type Chinese 1 (ToxoDB#9). Conclusion Seroprevalence of toxoplasmosis in immunosuppressed individuals is rarely reported in China and we presented a positive rate of 8.38% in cancer patients. Toxoplasma genomic DNA genotyping demonstrated a common genetic character of Chinese 1, indicating a possible pathogenic origin of animals in human infection.
Collapse
|
12
|
Brydak-Godowska J, Moneta-Wielgoś J, Kęcik D, Borkowski PK. Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period and lactation: clinical observations. Med Sci Monit 2015; 21:598-603. [PMID: 25711713 PMCID: PMC4350878 DOI: 10.12659/msm.892219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background During pregnancy and labor, the immune response is physiologically impaired and women are more susceptible to infections. Since many drugs may have potentially adverse effects on the fetus and newborn, less aggressive treatment regimens should be considered in pregnant and lactating patients. The aim of our study was to present the management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, and lactation. Material/Methods A retrospective study was undertaken of the clinical records of 24 women during pregnancy, postpartum period, and lactation who were referred in the years 1994–2014 to the Department of Zoonoses and Tropical Diseases or the Department of Ophthalmology, Medical University of Warsaw for toxoplasmic retinochoroiditis. The diagnosis was based on the typical ophthalmoscopic picture, confirmed by serological testing using an ELISA method. Results A total of 28 attacks of toxoplasmic retinochoroiditis were observed in 24 patients during pregnancy, postpartum period, and lactation. The choice of treatment was guided by the character and location of the inflammatory lesion and the gestational age. Topical (steroidal/nonsteroidal eye drops) and systemic treatments with spiramycin or azithromycin, Fansidar (pyrimethamine 25 mg/sulfadoxine 500 mg), and prednisone were used. Conclusions Management of toxoplasmic retinochoroiditis during pregnancy, postpartum period, or lactation must be individualized and guided by the gestational age and location of the active lesion. Women of childbearing age with toxoplasma ocular lesions should be informed by their doctors about possible active recurrences during pregnancy and followed carefully by an ophthalmologist when pregnant.
Collapse
Affiliation(s)
| | | | - Dariusz Kęcik
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
| | - Piotr Karol Borkowski
- Department of Zoonoses and Tropical Diseases, Medical University of Warsaw, Warsaw, Poland
| |
Collapse
|
13
|
Toxoplasma gondii superinfection and virulence during secondary infection correlate with the exact ROP5/ROP18 allelic combination. mBio 2015; 6:e02280. [PMID: 25714710 PMCID: PMC4358003 DOI: 10.1128/mbio.02280-14] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii infects a wide variety of vertebrate species globally. Infection in most hosts causes a lifelong chronic infection and generates immunological memory responses that protect the host against new infections. In regions where the organism is endemic, multiple exposures to T. gondii likely occur with great frequency, yet little is known about the interaction between a chronically infected host and the parasite strains from these areas. A widely used model to explore secondary infection entails challenge of chronically infected or vaccinated mice with the highly virulent type I RH strain. Here, we show that although vaccinated or chronically infected C57BL/6 mice are protected against the type I RH strain, they are not protected against challenge with most strains prevalent in South America or another type I strain, GT1. Genetic and genomic analyses implicated the parasite-secreted rhoptry effectors ROP5 and ROP18, which antagonize the host’s gamma interferon-induced immunity-regulated GTPases (IRGs), as primary requirements for virulence during secondary infection. ROP5 and ROP18 promoted parasite superinfection in the brains of challenged survivors. We hypothesize that superinfection may be an important mechanism to generate T. gondii strain diversity, simply because two parasite strains would be present in a single meal consumed by the feline definitive host. Superinfection may drive the genetic diversity of Toxoplasma strains in South America, where most isolates are IRG resistant, compared to North America, where most strains are IRG susceptible and are derived from a few clonal lineages. In summary, ROP5 and ROP18 promote Toxoplasma virulence during reinfection. Toxoplasma gondii is a widespread parasite of warm-blooded animals and currently infects one-third of the human population. A long-standing assumption in the field is that prior exposure to this parasite protects the host from subsequent reexposure, due to the generation of protective immunological memory. However, this assumption is based on clinical data and mouse models that analyze infections with strains common to Europe and North America. In contrast, we found that the majority of strains sampled from around the world, in particular those from South America, were able to kill or reinfect the brains of hosts previously exposed to T. gondii. The T. gondii virulence factors ROP5 and ROP18, which inhibit key host effectors that mediate parasite killing, were required for these phenotypes. We speculate that these results underpin clinical observations that pregnant women previously exposed to Toxoplasma can develop congenital infection upon reexposure to South American strains.
Collapse
|
14
|
Tolba MM, El-Taweel HA, Khalil SS, Hazzah WA, Heshmat MG. Genotype analysis of T. gondii strains associated with human infection in Egypt. Parasitol Res 2014; 113:1563-9. [DOI: 10.1007/s00436-014-3801-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/28/2014] [Indexed: 11/29/2022]
|
15
|
New clinical and experimental insights into Old World and neotropical ocular toxoplasmosis. Int J Parasitol 2014; 44:99-107. [DOI: 10.1016/j.ijpara.2013.09.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/20/2013] [Accepted: 09/22/2013] [Indexed: 01/12/2023]
|
16
|
Costa JM, Alanio A, Moukoury S, Clairet V, Debruyne M, Poveda JD, Bretagne S. Direct genotyping of Toxoplasma gondii from amniotic fluids based on B1 gene polymorphism using minisequencing analysis. BMC Infect Dis 2013; 13:552. [PMID: 24252188 PMCID: PMC4225555 DOI: 10.1186/1471-2334-13-552] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 11/12/2013] [Indexed: 01/04/2023] Open
Abstract
Background Because some Toxoplasma gondii genotypes may be more virulent in pregnant women, discriminating between them appears valuable. Currently, the main genotyping method is based on single copy microsatellite markers, which limit direct genotyping from amniotic fluids (AFs) to samples with a high parasitic load. We investigated whether the multicopy gene B1 could type the parasite with a higher sensitivity. To estimate the amplifiable DNA present in AFs, we first compared three different PCR assays used for Toxoplasma infection diagnosis: the P30-PCR, targeting the single copy gene P30; the B1-PCR, targeting the repeated B1 gene; and RE-PCR, targeting the repeated element. Results Of the 1792 AFs analyzed between 2008 and 2011, 73 were RE-PCR positive. Of those, 49 (67.1%) were P30-PCR and B1-PCR positive, and 14 (19.2%) additional AFs were B1-PCR positive only. All 63 BI-positive AFs (France n = 49; overseas n = 14) could be genotyped based on an analysis of eight nucleotide polymorphisms (SNPs) located within the B1 gene. Following high-resolution melting (HRM) analysis, minisequencing was carried out for each of the eight SNPs. DNA from six reference strains was included in the study, and AFs were assigned to one of the three major lineages (Types I, II, and III). In total, 26 genotypes were observed, and the hierarchical clustering distinguished two clades in lineages II (IIa, n = 30 and IIb, n = 4) and III (IIIa n = 23 and IIIb n = 6). There was an overrepresentation of overseas isolates in Clade IIb (4/4, 100%) and Clade IIIa (8/22; 36.4%) (p <0.0001), whereas medical interruption and fetal death were overrepresented in Clade IIb (2/4, 50%) and Clade IIIa (4/23, 17.4%) (p = 0.049). Conclusions Although the current genotyping system cannot pretend to replace multilocus typing, we clearly show that targeting the multicopy B1 gene yields a genotyping capacity of AFs around 20% better than when single copy targets are used. The present genotyping method also allows clear identification of genotypes of potential higher virulence.
Collapse
|
17
|
Abstract
Although microbial culture remains the gold standard for diagnosis of many ocular infections, the technique is limited by low yield, inability to detect certain organisms, and potentially long delays to results. DNA-based molecular diagnostic techniques use detection of specific nucleic acid sequences as evidence for presence of suspected pathogens. The polymerase chain reaction (PCR) is a powerful molecular biology technique that allows for detection of fewer than 10 copies of pathogen genome. Recent technical advances in PCR have permitted quantitation of pathogen load using quantitative PCR (qPCR), and have permitted multiplexing of primer sets. Use of pan-bacterial and pan-fungal primers for ribosomal DNA sequences has allowed diagnosis of bacterial and fungal infections using molecular techniques. In this review, we highlight recent advances in the application of PCR to the diagnosis of anterior segment and posterior segment ocular infectious diseases.
Collapse
|
18
|
Molecular Genotyping of Toxoplasma gondii in Human Spontaneous Aborted Fetuses in Shiraz, Southern Iran. IRANIAN JOURNAL OF PUBLIC HEALTH 2013; 42:620-5. [PMID: 23967430 PMCID: PMC3744259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/18/2013] [Indexed: 12/03/2022]
Abstract
BACKGROUND Congenital toxoplasmosis is associated with variable complications including encephalitis, microcephaly, hydrocephaly, hepatitis, lymphadenopathy and even intrauterine death. Presence of Toxoplasma gondii in human placenta may induce congenital infection. The aim of this study was to determine the genotypes of Toxoplasma gondii infection in human spontaneous aborted fetuses in Shiraz, south of Iran. METHODS Five hundred and forty two paraffin-embedded blocks of aborted placenta were collected, from two university-affiliated hospitals in Shiraz. Occurrence of spontaneous abortion was confirmed by examine of the slides. After re-cutting of the blocks and dewaxing, semi-nested PCR assay was used to detect the fragments of T. gondii B1 gene in the samples. Also direct molecular genotyping was performed on positive samples with Restriction Fragment Length Polymorphism-PCR analysis on the SAG2 gene. RESULTS Among the 542 tissue samples, the B1 gene was amplified from 78 (14.4%) of cases with the semi nested PCR and typed by RFLP. The genotype of Toxoplasma strains of 65 (out of 78) PCR-positive samples were evaluated and 54 out of 65 (83.1%) were found to be type II and 11 out of 65 (16.9%) were type I. CONCLUSION Considering the high level of Toxoplasma infection in aborted fetuses in this study, Toxoplasma might largely contribute to spontaneous abortion in this area of Iran.
Collapse
|
19
|
Abstract
Toxoplasma gondii, an Apicomplexan, is a pathogic protozoan that can infect the central nervous system. Infection during pregnancy can result in a congenial infection with severe neurological sequelae. In immunocompromised individuals reactivation of latent neurological foci can result in encephalitis. Immunocompetent individuals infected with T. gondii are typically asymptomatic and maintain this infection for life. However, recent studies suggest that these asymptomatic infections may have effects on behavior and other physiological processes. Toxoplasma gondii infects approximately one-third of the world population, making it one of the most successful parasitic organisms. Cats and other felidae serve as the definite host producing oocysts, an environmentally resistant life cycle stage found in cat feces, which can transmit the infection when ingested orally. A wide variety of warm-blooded animals, including humans, can serve as the intermediate host in which tissue cysts (containing bradyzoites) develop. Transmission also occurs due to ingestion of the tissue cysts. There are three predominant clonal lineages, termed Types I, II and III, and an association with higher pathogenicity with the Type I strains in humans has emerged. This chapter presents a review of the biology of this infection including the life cycle, transmission, epidemiology, parasite strains, and the host immune response. The major clinical outcomes of congenital infection, chorioretinitis and encephalitis, and the possible association of infection of toxoplasmosis with neuropsychiatric disorders such as schizophrenia, are reviewed.
Collapse
Affiliation(s)
- Sandra K Halonen
- Department of Microbiology, Montana State University, Bozeman, MT, USA
| | | |
Collapse
|
20
|
Furtado JM, Winthrop KL, Butler NJ, Smith JR. Ocular toxoplasmosis I: parasitology, epidemiology and public health. Clin Exp Ophthalmol 2012; 41:82-94. [DOI: 10.1111/j.1442-9071.2012.02821.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
| | | | - Nicholas J Butler
- Division of Ocular Immunology, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Justine R Smith
- Casey Eye Institute
- Cell & Developmental Biology, Oregon Health & Science University, Portland, Oregon
| |
Collapse
|
21
|
Subauste CS, Ajzenberg D, Kijlstra A. Review of the series "Disease of the year 2011: toxoplasmosis" pathophysiology of toxoplasmosis. Ocul Immunol Inflamm 2012; 19:297-306. [PMID: 21970661 DOI: 10.3109/09273948.2010.605198] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxoplasma gondii is a major cause of chronic parasitic infection in the world. This protozoan can cause retino-choroiditis in newborns and in adults, both immunocompetent and immunodeficient. This disease tends to be recurrent and can lead to severe visual impairment. The authors review current knowledge on the role of parasite genetics in influencing susceptibility to ocular toxoplasmosis and on the immuno-pathogenesis of this disease.
Collapse
Affiliation(s)
- Carlos S Subauste
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.
| | | | | |
Collapse
|
22
|
Genotyping of the protozoan pathogen Toxoplasma gondii using high-resolution melting analysis of the repeated B1 gene. J Microbiol Methods 2011; 86:357-63. [PMID: 21741999 DOI: 10.1016/j.mimet.2011.06.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 06/20/2011] [Indexed: 12/27/2022]
Abstract
Genetic studies of the protozoan parasite Toxoplasma gondii have identified three main distinct types according to virulence in some hosts. Several methods have been developed to differentiate genotypes currently dominated by microsatellite markers targeting single-copy loci. We analyzed the possibility of using the 35-fold repetitive B1 gene via high-resolution melting (HRM) curve analysis. Sequencing of the B1 gene of 14 reference strains (four Type I, six Type II, and four Type III strains) identified 18 single nucleotide polymorphisms (SNP). Primers were designed to amplify eight of them for HRM analysis and for relative quantification of each nucleotide variation using SNaPshot mini-sequencing. Genotyping with five microsatellite markers was performed for comparison. Two to four HRM profiles were obtained depending on the SNP tested. The differences observed relied on the different ratios of nucleotides at the SNP locus as evidenced via SNaPshot mini-sequencing. The three main lineages could be distinguished by using several HRM profiles. Some HRM profiles proved more informative than the analysis based on five microsatellite markers, showing additional differences in Type I and Type II strains. Using HRM analysis, we obtained at least an equally good discrimination of the main lineages than that based on five microsatellite markers.
Collapse
|
23
|
Direct genotyping of Toxoplasma gondii in ocular fluid samples from 20 patients with ocular toxoplasmosis: predominance of type II in France. J Clin Microbiol 2011; 49:1513-7. [PMID: 21248092 DOI: 10.1128/jcm.02196-10] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
We report the direct genotyping analysis of Toxoplasma gondii in ocular samples collected from 20 patients, as well as associated clinical and epidemiological data. This work was aimed at better understanding the impact of genotypes of Toxoplasma gondii strains on toxoplasmic retinochoroiditis. For this purpose, we studied the aqueous humor (AH) or vitreous humor (VH) of 20 patients presenting with ocular toxoplasmosis (OT) in 2 hospitals in France. Genetic characterization was obtained with microsatellite markers in a multiplex PCR assay. In contrast to the results of previous studies, we found no association between atypical Toxoplasma gondii genotypes and the occurrence of OT. Considering the local epidemiological data, our OT patients seemed to be infected more frequently by ordinary type II strains found in the environment. In conclusion, direct genotyping of Toxoplasma gondii strains from aqueous or vitreous humor showed a predominance of the type II genotype in ocular toxoplasmosis; this may be due to a high exposure rate of this genotype in humans.
Collapse
|
24
|
Herrmann DC, Pantchev N, Vrhovec MG, Barutzki D, Wilking H, Fröhlich A, Lüder CGK, Conraths FJ, Schares G. Atypical Toxoplasma gondii genotypes identified in oocysts shed by cats in Germany. Int J Parasitol 2009; 40:285-92. [PMID: 19695254 DOI: 10.1016/j.ijpara.2009.08.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 08/07/2009] [Accepted: 08/10/2009] [Indexed: 11/17/2022]
Abstract
A total of 18,259 feline faecal samples from cats in Germany were collected and analysed for the presence of Toxoplasma gondii oocysts between June 2007 and December 2008. The proportion of T. gondii-positive samples collected between January and June was significantly lower than between July and December. The age of cats shedding T. gondii oocysts was not significantly different from the age of negative control cats. Forty-six T. gondii-positive samples were genetically characterised using nine PCR-restriction fragment length polymorphism (RFLP) markers which included newSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. In addition, 22 isolates that had already been partially characterised in a previous study were further typed using PCR-RFLP markers c22-8, c29-2, L358, PK1 and Apico. Genotyping of the 68 isolates revealed that the majority of T. gondii isolates (n=54) had Type II patterns at all loci but displayed a Type I pattern at the Apico locus. Three isolates displayed Type II patterns at all loci, including the Apico locus. In addition, we detected one isolate with clonal Type III patterns at all loci and three isolates with atypical and mixed genotypes. Seven isolates could not be fully genotyped. One of those isolates displayed alleles of both Types I and II at the Apico locus. To our knowledge this is the first description of the presence of T. gondii genotypes different from the clonal Types I, II and III in the faeces of naturally infected cats.
Collapse
Affiliation(s)
- D C Herrmann
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Epidemiology, Seestrasse 55, 16868 Wusterhausen, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Use of GRA6-derived synthetic polymorphic peptides in an immunoenzymatic assay to serotype Toxoplasma gondii in human serum samples collected from three continents. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:1380-6. [PMID: 18667636 DOI: 10.1128/cvi.00186-08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Serotyping is a simple typing method that consists of an immunoenzymatic assay (enzyme-linked immunosorbent assay [ELISA]) using synthetic polymorphic peptides derived from Toxoplasma gondii antigens. We developed a new ELISA based on GRA6 C-terminal polymorphic peptides. Serum samples from 41 human infections due to 23 archetypal (type I, II, or III) and 18 nonarchetypal strains were selected in order to validate this approach. For 20 out of the 23 archetypal infections, there was a clear correlation between microsatellite genotype and GRA6 serotyping. All infections due to nonarchetypal strains were misclassified as archetypal strain infections. The GRA6 C-terminal peptides from these strains were analyzed to explain this misclassification. A second group of 455 patients with acute and chronic toxoplasmosis due to unknown genotypes from different European, African, and Latin American countries were included in this study, and the strain type predicted by this method. The results suggest that serotyping is a promising method for typing strains, although limitations exist for African and South American strains as a consequence of higher peptide polymorphism. Other peptides from different markers must be studied in order to discriminate archetypal from nonarchetypal strains.
Collapse
|