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Steinberg HE, Ramachandran PS, Diestra A, Pinchi L, Ferradas C, Kirwan DE, Diaz MM, Sciaudone M, Wapniarski A, Zorn KC, Calderón M, Cabrera L, Pinedo-Cancino V, Wilson MR, Asayag CR, Gilman RH, Bowman NM. Clinical and Metagenomic Characterization of Neurological Infections of People With Human Immunodeficiency Virus in the Peruvian Amazon. Open Forum Infect Dis 2023; 10:ofad515. [PMID: 37965640 PMCID: PMC10642733 DOI: 10.1093/ofid/ofad515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 10/26/2023] [Indexed: 11/16/2023] Open
Abstract
Background Neurological opportunistic infections cause significant morbidity and mortality in people with human immunodeficiency virus (HIV) but are difficult to diagnose. Methods One hundred forty people with HIV with acute neurological symptoms from Iquitos, Peru, were evaluated for cerebral toxoplasmosis with quantitative polymerase chain reaction (qPCR) of cerebrospinal fluid (CSF) and for cryptococcal meningitis with cryptococcal antigen test (CrAg) in serum or CSF. Differences between groups were assessed with standard statistical methods. A subset of samples was evaluated by metagenomic next-generation sequencing (mNGS) of CSF to compare standard diagnostics and identify additional diagnoses. Results Twenty-seven participants were diagnosed with cerebral toxoplasmosis by qPCR and 13 with cryptococcal meningitis by CrAg. Compared to participants without cerebral toxoplasmosis, abnormal Glasgow Coma Scale score (P = .05), unilateral focal motor signs (P = .01), positive Babinski reflex (P = .01), and multiple lesions on head computed tomography (CT) (P = .002) were associated with cerebral toxoplasmosis. Photophobia (P = .03) and absence of lesions on head CT (P = .02) were associated with cryptococcal meningitis. mNGS of 42 samples identified 8 cases of cerebral toxoplasmosis, 7 cases of cryptococcal meningitis, 5 possible cases of tuberculous meningitis, and incidental detections of hepatitis B virus (n = 1) and pegivirus (n = 1). mNGS had a positive percentage agreement of 71% and a negative percentage agreement of 91% with qPCR for T gondii. mNGS had a sensitivity of 78% and specificity of 100% for Cryptococcus diagnosis. Conclusions An infection was diagnosed by any method in only 34% of participants, demonstrating the challenges of diagnosing neurological opportunistic infections in this population and highlighting the need for broader, more sensitive diagnostic tests for central nervous system infections.
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Affiliation(s)
- Hannah E Steinberg
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
| | - Prashanth S Ramachandran
- Department of Infectious Diseases, The Peter Doherty Institute for Immunity and Infection, University of Melbourne, Melbourne, Australia
- Department of Neurology, The Royal Melbourne Hospital, University of Melbourne, Melbourne, Australia
- Department of Neurology, St. Vincent’s Hospital, University of Melbourne, Melbourne, Australia
- Weill Institute for Neurosciences, Department of Neurology, University of California, SanFrancisco, San Francisco, California, USA
| | - Andrea Diestra
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Cusi Ferradas
- Emerging Diseases and Climate Change Research Unit, School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Daniela E Kirwan
- Institute for Infection and Immunity, St George's, University of London, London, United Kingdom
| | - Monica M Diaz
- Department of Neurology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Michael Sciaudone
- Division of Infectious Diseases, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - Annie Wapniarski
- Weill Institute for Neurosciences, Department of Neurology, University of California, SanFrancisco, San Francisco, California, USA
| | - Kelsey C Zorn
- Weill Institute for Neurosciences, Department of Neurology, University of California, SanFrancisco, San Francisco, California, USA
| | - Maritza Calderón
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Viviana Pinedo-Cancino
- Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonía, Centro de Investigación de Recursos Naturales, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
- Faculty of Human Medicine, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
| | - Michael R Wilson
- Weill Institute for Neurosciences, Department of Neurology, University of California, SanFrancisco, San Francisco, California, USA
| | - Cesar Ramal Asayag
- Department of Clinical Sciences, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
- Department of Infectious and Tropical Diseases, Hospital Regional de Loreto, Iquitos, Peru
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Natalie M Bowman
- Division of Infectious Diseases, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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Robert MG, Brenier-Pinchart MP, Garnaud C, Fricker-Hidalgo H, Pelloux H. Molecular diagnosis of toxoplasmosis: recent advances and a look to the future. Expert Rev Anti Infect Ther 2021; 19:1529-1542. [PMID: 34112045 DOI: 10.1080/14787210.2021.1941867] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Toxoplasmosis is a globally distributed parasitic infection that can be particularly severe when opportunistic or congenital. Its diagnosis requires accurate and rapid techniques that rely mainly on serology and molecular methods. AREAS COVERED The aim of this review was to discuss the positioning of the molecular diagnosis of toxoplasmosis according to the different clinical situations possibly resulting from infection with T. gondii, and to detail recent developments in this technique. The English and French literature were searched with the following keywords: 'Toxoplasmosis', "Molecular diagnosis" and 'PCR'. EXPERT OPINION Molecular techniques have revolutionized the diagnosis of toxoplasmosis, and practices have considerably evolved over the past decades. However, there is still a high degree of inter-laboratory heterogeneity which impairs comparisons between results and studies. Efforts to standardize practices are underway.
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Affiliation(s)
- Marie Gladys Robert
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France
| | - Marie-Pierre Brenier-Pinchart
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France.,Centre National de Référence Toxoplasmose - Pôle Biologie Moléculaire, France
| | - Cécile Garnaud
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, CNRS, CHU Grenoble Alpes, Grenoble INP, TIMC-IMAG, Grenoble, France
| | | | - Hervé Pelloux
- Service de Parasitologie-Mycologie, CHU Grenoble Alpes, Grenoble, France.,Université Grenoble Alpes, Institut pour l'Avancée des Biosciences (IAB), Grenoble, France.,Centre National de Référence Toxoplasmose - Pôle Biologie Moléculaire, France
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Steinberg HE, Bowman NM, Diestra A, Ferradas C, Russo P, Clark DE, Zhu D, Magni R, Malaga E, Diaz M, Pinedo-Cancino V, Ramal Asayag C, Calderón M, Carruthers VB, Liotta LA, Gilman RH, Luchini A. Detection of toxoplasmic encephalitis in HIV positive patients in urine with hydrogel nanoparticles. PLoS Negl Trop Dis 2021; 15:e0009199. [PMID: 33651824 PMCID: PMC7954332 DOI: 10.1371/journal.pntd.0009199] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/12/2021] [Accepted: 02/02/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Diagnosis of toxoplasmic encephalitis (TE) is challenging under the best clinical circumstances. The poor clinical sensitivity of quantitative polymerase chain reaction (qPCR) for Toxoplasma in blood and CSF and the limited availability of molecular diagnostics and imaging technology leaves clinicians in resource-limited settings with few options other than empiric treatment. METHOLOGY/PRINCIPLE FINDINGS Here we describe proof of concept for a novel urine diagnostics for TE using Poly-N-Isopropylacrylamide nanoparticles dyed with Reactive Blue-221 to concentrate antigens, substantially increasing the limit of detection. After nanoparticle-concentration, a standard western blotting technique with a monoclonal antibody was used for antigen detection. Limit of detection was 7.8pg/ml and 31.3pg/ml of T. gondii antigens GRA1 and SAG1, respectively. To characterize this diagnostic approach, 164 hospitalized HIV-infected patients with neurological symptoms compatible with TE were tested for 1) T. gondii serology (121/147, positive samples/total samples tested), 2) qPCR in cerebrospinal fluid (11/41), 3) qPCR in blood (10/112), and 4) urinary GRA1 (30/164) and SAG1 (12/164). GRA1 appears to be superior to SAG1 for detection of TE antigens in urine. Fifty-one HIV-infected, T. gondii seropositive but asymptomatic persons all tested negative by nanoparticle western blot and blood qPCR, suggesting the test has good specificity for TE for both GRA1 and SAG1. In a subgroup of 44 patients, urine samples were assayed with mass spectrometry parallel-reaction-monitoring (PRM) for the presence of T. gondii antigens. PRM identified antigens in 8 samples, 6 of which were concordant with the urine diagnostic. CONCLUSION/SIGNIFICANCES Our results demonstrate nanoparticle technology's potential for a noninvasive diagnostic test for TE. Moving forward, GRA1 is a promising target for antigen based diagnostics for TE.
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Affiliation(s)
- Hannah E. Steinberg
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, United States of America
| | - Natalie M. Bowman
- Division of Infectious Disease, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Andrea Diestra
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cusi Ferradas
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Paul Russo
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Virginia, United States of America
| | - Daniel E. Clark
- Vanderbilt University Medical Center, Division of Cardiovascular Medicine, Nashville, Tennessee, United States of America
| | - Deanna Zhu
- Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Ruben Magni
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Virginia, United States of America
| | - Edith Malaga
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Monica Diaz
- Department of Neurology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Viviana Pinedo-Cancino
- Laboratorio de Investigación de Productos Naturales Antiparasitarios de la Amazonía, Facultad de Medicina Humana, Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
| | - Cesar Ramal Asayag
- Universidad Nacional de la Amazonía Peruana, Iquitos, Peru
- Department of Infectious Diseases, Hospital Regional de Loreto, Iquitos, Peru
| | - Maritza Calderón
- Laboratorio de Investigación en Enfermedades Infecciosas, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Lance A. Liotta
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Virginia, United States of America
| | - Robert H. Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Alessandra Luchini
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Virginia, United States of America
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Opsteegh M, Dam-deisz C, de Boer P, Decraeye S, Faré A, Hengeveld P, Luiten R, Schares G, van Solt-smits C, Verhaegen B, Verkleij T, van der Giessen J, Wisselink HJ. Methods to assess the effect of meat processing on viability of Toxoplasma gondii: towards replacement of mouse bioassay by in vitro testing. Int J Parasitol 2020; 50:357-69. [DOI: 10.1016/j.ijpara.2020.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 04/13/2020] [Accepted: 04/17/2020] [Indexed: 12/11/2022]
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Gutierrez-Loli R, Ferradas C, Diestra A, Traianou A, Bowman N, Bok J, Reimer-McAtee M, Ramal C, Ticona E, Steinberg H, Mayta H, Calderon M, Calla-Choque JS, Sterling C, Gilman RH, For The Toxoplasmosis Working Group In Peru And Bolivia. Development of a Novel Protocol Based on Blood Clot to Improve the Sensitivity of qPCR Detection of Toxoplasma gondii in Peripheral Blood Specimens. Am J Trop Med Hyg 2019; 100:83-89. [PMID: 30457102 DOI: 10.4269/ajtmh.17-0920] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Quantitative polymerase chain reaction (qPCR) for Toxoplasma gondii multicopy genes has emerged as a promising strategy for sensitive detection of parasite DNA. qPCR can be performed from blood samples, which are minimally invasive to collect. However, there is no consensus about what type of blood specimen yields the best sensitivity. The development of a novel protocol for qPCR detection of T. gondii using blood clot, involving an appropriate DNA extraction method and the use of an internal amplification control to monitor the reaction is presented in the current study. Assays directed to the B1 and REP529 genes were performed in spiked specimens of whole blood, guanidine-ethylenediaminetetraacetic acid blood, and clot. The clot-based qPCR was shown to be more sensitive when compared with other types of specimens, detecting five and 0.05 T. gondii genomes, using B1 and REP529 targets, respectively. Finally, a comparative analysis with samples from HIV patients with clinical suspicion of toxoplasmosis was performed, demonstrating the detection of four positive suspected cases with clots compared with only one using guanidine-ethylenediaminetetraacetic acid blood. The high analytical sensitivity and the cost-effective advantages offered by clot supports this methodology as a good laboratory tool to monitor parasite burden.
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Affiliation(s)
- Renzo Gutierrez-Loli
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Cusi Ferradas
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Andrea Diestra
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Aliki Traianou
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Natalie Bowman
- Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jeroen Bok
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | | | - Cesar Ramal
- Hospital Regional de Loreto "Felipe Santiago Arriola Iglesias," Iquitos, Peru
| | - Eduardo Ticona
- Infectious Diseases and Tropical Medicine Unit, Hospital Nacional Dos de Mayo, Lima, Peru
| | - Hannah Steinberg
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Holger Mayta
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Maritza Calderon
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jaeson S Calla-Choque
- Laboratorio de Investigación en Enfermedades Infecciosas, Laboratorios de Investigación y Desarrollo, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Charles Sterling
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Robert H Gilman
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
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Vidal JE. HIV-Related Cerebral Toxoplasmosis Revisited: Current Concepts and Controversies of an Old Disease. J Int Assoc Provid AIDS Care 2019; 18:2325958219867315. [PMID: 31429353 PMCID: PMC6900575 DOI: 10.1177/2325958219867315] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/14/2019] [Accepted: 06/28/2019] [Indexed: 01/06/2023] Open
Abstract
Cerebral toxoplasmosis is the most common cause of expansive brain lesions in people living with HIV/AIDS (PLWHA) and continues to cause high morbidity and mortality. The most frequent characteristics are focal subacute neurological deficits and ring-enhancing brain lesions in the basal ganglia, but the spectrum of clinical and neuroradiological manifestations is broad. Early initiation of antitoxoplasma therapy is an important feature of the diagnostic approach of expansive brain lesions in PLWHA. Pyrimethamine-based regimens and trimethoprim-sulfamethoxazole (TMP-SMX) seem to present similar efficacy, but TMP-SMX shows potential practical advantages. The immune reconstitution inflammatory syndrome is uncommon in cerebral toxoplasmosis, and we now have more effective, safe, and friendly combined antiretroviral therapy (cART) options. As a consequence of these 2 variables, the initiation of cART can be performed within 2 weeks after initiation of antitoxoplasma therapy. Herein, we will review historical and current concepts of epidemiology, diagnosis, and treatment of HIV-related cerebral toxoplasmosis.
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Affiliation(s)
- José Ernesto Vidal
- Departamento de Neurologia, Instituto de Infectologia Emílio Ribas, São
Paulo, Brazil
- Departamento de Moléstias Infecciosas e Parasitárias, Hospital das Clínicas
HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
- Laboratório de Investigação Médica em Protozoologia, Bacteriologia e
Resistência Antimicrobiana (LIM 49), Instituto de Medicina Tropical, Universidade de São
Paulo, São Paulo, Brazil
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Abstract
PURPOSE OF REVIEW Toxoplasmosis in immunocompromised patients is associated with a high mortality rate. Molecular techniques are important tools to diagnose acute disease in immunocompromised patients, but there are various methods with variable efficiency. Some of them have been validated for the diagnosis of congenital toxoplasmosis, but the impact of their use has not been evaluated in immunocompromised patients. RECENT FINDINGS Toxoplasmosis is of increasing importance in non-HIV immunocompromised patients. In addition, the picture of disease shows greater severity in South America, both in immunocompetent study participants and in congenitally infected infants. These epidemiological differences could influence the sensitivity of diagnostic methods. This review analyzes recent data on molecular diagnosis and compares them with older ones, in light of progress gained in molecular techniques and of recent epidemiological findings. Most recent studies were conducted in South America and used PCR targeting the B1 gene. PCR on blood could allow diagnosing a significant proportion of patients with ocular toxoplasmosis in Brazil. SUMMARY Quantitative PCR methods with specific probes should be used to improve sensitivity and warrant specificity. Performance of quantitative PCR targeting the repeated 529 bp sequence for the diagnosis of toxoplasmosis in immunocompromised patients needs evaluation in field studies in South America and in western countries.
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Feng X, Norose K, Li K, Hikosaka K. Utility of the cytochrome c oxidase subunit I gene for the diagnosis of toxoplasmosis using PCR. J Microbiol Methods 2017; 141:82-86. [PMID: 28803790 DOI: 10.1016/j.mimet.2017.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/23/2017] [Accepted: 08/06/2017] [Indexed: 11/26/2022]
Abstract
Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii, which belongs to the phylum Apicomplexa. Since this parasite causes severe clinical symptoms in immunocompromised patients, early diagnosis of toxoplasmosis is essential. PCR is currently used for early diagnosis, but there is no consensus regarding the most effective method for amplifying Toxoplasma DNA. In this study, we considered the utility of the cytochrome c subunit I (cox1) gene, which is encoded in the mitochondrial DNA of this parasite, as a novel target of PCR for the diagnosis of toxoplasmosis. To do this, we compared its copy number per haploid nuclear genome and the detection sensitivity of cox1-PCR with the previously reported target genes B1 and 18S rRNA and the AF146527 repeat element. We found that the copy number of cox1 was high and that the PCR using cox1 primers was more efficient at amplifying Toxoplasma DNA than the other PCR targets examined. In addition, PCR using clinical samples indicated that the cox1 gene would be useful for the diagnosis of toxoplasmosis. These findings suggest that use of cox1-PCR would facilitate the diagnosis of toxoplasmosis in clinical laboratories.
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Affiliation(s)
- Xue Feng
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Kazumi Norose
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Kexin Li
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
| | - Kenji Hikosaka
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
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Ajzenberg D, Lamaury I, Demar M, Vautrin C, Cabié A, Simon S, Nicolas M, Desbois-Nogard N, Boukhari R, Riahi H, Dardé ML, Massip P, Dupon M, Preux PM, Labrunie A, Boncoeur MP. Performance Testing of PCR Assay in Blood Samples for the Diagnosis of Toxoplasmic Encephalitis in AIDS Patients from the French Departments of America and Genetic Diversity of Toxoplasma gondii: A Prospective and Multicentric Study. PLoS Negl Trop Dis 2016; 10:e0004790. [PMID: 27355620 DOI: 10.1371/journal.pntd.0004790] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/30/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Toxoplasmic encephalitis in patients with AIDS is a life-threatening disease mostly due to reactivation of Toxoplasma gondii cysts in the brain. The main objective of this study was to evaluate the performance of real-time PCR assay in peripheral blood samples for the diagnosis of toxoplasmic encephalitis in AIDS patients in the French West Indies and Guiana. METHODOLOGY/PRINCIPAL FINDINGS Adult patients with HIV and suspicion of toxoplasmic encephalitis with start of specific antitoxoplasmic therapy were included in this study during 40 months. The real-time PCR assay targeting the 529 bp repeat region of T. gondii was performed in two different centers for all blood samples. A Neighbor-Joining tree was reconstructed from microsatellite data to examine the relationships between strains from human cases of toxoplasmosis in South America and the Caribbean. A total of 44 cases were validated by a committee of experts, including 36 cases with toxoplasmic encephalitis. The specificity of the PCR assay in blood samples was 100% but the sensitivity was only 25% with moderate agreement between the two centers. Altered level of consciousness and being born in the French West Indies and Guiana were the only two variables that were associated with significantly decreased risk of false negative results with the PCR assay. CONCLUSION/SIGNIFICANCE Our results showed that PCR sensitivity in blood samples increased with severity of toxoplasmic encephalitis in AIDS patients. Geographic origin of patients was likely to influence PCR sensitivity but there was little evidence that it was caused by differences in T. gondii strains. TRIAL REGISTRATION ClinicalTrials.gov NCT00803621.
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Rostami A, Keshavarz H, Shojaee S, Mohebali M, Meamar AR. Frequency of Toxoplasma gondii in HIV Positive Patients from West of Iran by ELISA and PCR. Iran J Parasitol 2014; 9:474-81. [PMID: 25759728 PMCID: PMC4345086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 10/10/2014] [Indexed: 11/16/2022]
Abstract
BACKGROUND Toxoplasma gondii, the obligate intracellular parasite is life threatening in AIDS patients. Diagnosis of toxoplasmosis is based on serological methods especially increasing of IgM and IgG titers, but finding of parasite or its components (antigenemia) may be beneficial method in order to detection of acute toxoplasmosis in immunocompromised patients. METHODS Ninety-four serum samples from HIV positive patients were collected from Sanandaj, Kordistan west of Iran. These patients were lived in Sanandaj of whom 26 were prisoners infected with HIV virus in prison. Toxoplasma gondii antibodies were determined by IgG ELISA. T. gondii antigen was identified by capture-ELISA. PCR was performed on samples with T. gondii antigenemia. CD4+ T cells counts had been determined by flowcytometry and were obtained from records of each patient. RESULTS Among the examined HIV seropositive individuals, 19.1% (18/94) and 5.3% (5/94) were positive for Toxoplasma-IgG and antigenemia, respectively. Besides, one of the samples was positively detected by PCR method. Mean age of participants was 37.9 ± 9.5 year. Prevalence of IgG antibody and antgenemia was higher in age group of 40-50 years old. The Mean of CD4+ T cells counts of participants (total of HIV+ patients, IgG positive patients and patients with antigenemia) was 699.2 ± 345.2, 655.1 ± 237.9 and 620.2 ± 215.1 respectively. CONCLUSION Capture-ELISA and PCR could confirm the T. gondii acute infection in HIV positive patients. For precise diagnosis of acute toxoplasmosis in HIV positive patient, performance of more studies based on more sensitive types of PCR is suggested.
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Affiliation(s)
- Ali Rostami
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossien Keshavarz
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Saeedeh Shojaee
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Mohebali
- School of Public Health, Tehran University of Medical Sciences, Tehran, Iran ; Center for Research of Endemic Parasites of Iran (CREPI), Tehran University of Medical Sciences, Tehran, Iran
| | - Ahmad Reza Meamar
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Abdel Aal AA, Attia SS, Hanafy NA, Al-Antably AS, Hassan MA, El-Sherbiny W, Nasr AS. Molecular Diagnosis of Toxoplasmosis in Non Immune Pregnant Females. Open Access Maced J Med Sci 2014. [DOI: 10.3889/oamjms.2014.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND AND AIM: Infection with the protozoan parasite Toxoplasma gondii has a worldwide distribution. Congenital infection is the most important part of the disease burden due to Toxoplasma infection in humans. Early diagnosis of maternal infection helps to prevent severe complications of toxoplasmosis. In the present study, three PCR assays (conventional, nested & quantitative) were evaluated for diagnosis of recent toxoplasmosis based on detection of Toxoplasma B1 gene.MATERIAL AND METHODS: The present study was carried out on 150 pregnant females who were serologically negative for anti-Toxoplasma IgG and IgM antibodies.RESULTS: The results revealed that out of 12 true positive cases (by 2 out of the 3 PCR protocols), 8 cases were positive by cPCR, 11 cases were positive by nPCR and 12 cases were positive by qPCR. Accurate estimation of genomic Toxoplasma DNA in positive samples was achieved by qPCR. In general, PCR assays offer a sensitive alternative of serological methods for diagnosis of recent maternal toxoplasmosis. In addition, qPCR decreases the risk of contamination of PCR products being a closed tube method and helps in estimation of infection load.CONCLUSIONS: We recommend screening of high-risk pregnant women by qPCR for early diagnosis of toxoplasmosis and proper management.
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Siddiqi OK, Ghebremichael M, Dang X, Atadzhanov M, Kaonga P, Khoury MN, Koralnik IJ. Molecular diagnosis of central nervous system opportunistic infections in HIV-infected Zambian adults. Clin Infect Dis 2014; 58:1771-7. [PMID: 24668125 PMCID: PMC4036687 DOI: 10.1093/cid/ciu191] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/16/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Knowledge of central nervous system (CNS) opportunistic infections (OIs) among people living with human immunodeficiency virus (HIV) in sub-Saharan Africa is limited. METHODS We analyzed 1 cerebrospinal fluid (CSF) sample from each of 331 HIV-infected adults with symptoms suggestive of CNS OI at a tertiary care center in Zambia. We used pathogen-specific primers to detect DNA from JC virus (JCV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) types 1 and 2, Mycobacterium tuberculosis, and Toxoplasma gondii via real-time polymerase chain reaction (PCR). RESULTS The patients' median CD4(+) T-cell count was 89 cells/µL (interquartile range, 38-191 cells/µL). Of 331 CSF samples, 189 (57.1%) had at least 1 pathogen. PCR detected DNA from EBV in 91 (27.5%) patients, M. tuberculosis in 48 (14.5%), JCV in 20 (6.0%), CMV in 20 (6.0%), VZV in 13 (3.9%), HSV-1 in 5 (1.5%), and HSV-2 and T. gondii in none. Fungal and bacteriological studies showed Cryptococcus in 64 (19.5%) patients, pneumococcus in 8 (2.4%), and meningococcus in 2 (0.6%). Multiple pathogens were found in 68 of 189 (36.0%) samples. One hundred seventeen of 331 (35.3%) inpatients died during their hospitalization. Men were older than women (median, 37 vs 34 years; P = .01), more recently diagnosed with HIV (median, 30 vs 63 days; P = .03), and tended to have a higher mortality rate (40.2% vs 30.2%; P = .07). CONCLUSIONS CNS OIs are frequent, potentially treatable complications of AIDS in Zambia. Multiple pathogens often coexist in CSF. EBV is the most prevalent CNS organism in isolation and in coinfection. Whether it is associated with CNS disease or a marker of inflammation requires further investigation. More comprehensive testing for CNS pathogens could improve treatment and patient outcomes in Zambia.
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Affiliation(s)
- Omar K. Siddiqi
- Division of Neuro-Virology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka
| | - Musie Ghebremichael
- Harvard Medical School and Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology, and Harvard University, Boston
| | - Xin Dang
- Division of Neuro-Virology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Masharip Atadzhanov
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka
| | - Patrick Kaonga
- Department of Internal Medicine, University of Zambia School of Medicine, Lusaka
| | - Michael N. Khoury
- Division of Neuro-Virology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Igor J. Koralnik
- Division of Neuro-Virology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
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Ibebuike K, Mantanga L, Emereole O, Ndolo P, Kajee A, Gopal R, Pather S. Cerebellar toxoplasmosis in HIV/AIDS infant: case report and review of the literature. Neurol Sci 2012; 33:1423-8. [PMID: 22286317 DOI: 10.1007/s10072-012-0960-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 01/19/2012] [Indexed: 10/14/2022]
Abstract
Cerebellar mass lesion is an uncommon presentation of toxoplasmosis. The authors report one rare case in an 11-month-old HIV/AIDS female infant who presented with deterioration in her developmental milestones. CT scan revealed a ring-enhancing mass lesion in the right cerebellar hemisphere with secondary obstructive hydrocephalus. A ventriculoperitoneal shunt was inserted prior to posterior fossa decompression and biopsy of the lesion. The specimens obtained were divided into two. One specimen was sent for histological diagnosis immediately after surgery while the second specimen was preserved until the release of the histology report. The initial histopathology report indicated a neoplastic process. Immunohistochemical stains were attempted but interpreted with difficulty due to severe tissue necrosis. After waiting for close to 6 weeks without a definite histological diagnosis, the preserved second specimen was sent for histological analysis as a fresh specimen, and reported a diagnosis of toxoplasmosis. This case presented diagnostic challenges to the authors whose radiological impressions of either a neoplastic lesion or a tuberculoma (based on our local neuroepidemiology) were reinforced by intraoperative findings highly suggestive of tuberculoma but which contrasted with the histological report, first as a neoplastic lesion and later toxoplasmosis. Although cerebellar toxoplasmosis is a rare complication of HIV/AIDS, this case report shows that toxoplasmosis should not be overlooked as a differential diagnosis of ring-enhancing cerebellar masses in HIV/AIDS patients irrespective of the patient's age and the absence of constitutional symptoms of toxoplasmosis.
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Yansouni CP, Bottieau E, Lutumba P, Winkler AS, Lynen L, Büscher P, Jacobs J, Gillet P, Lejon V, Alirol E, Polman K, Utzinger J, Miles MA, Peeling RW, Muyembe JJ, Chappuis F, Boelaert M. Rapid diagnostic tests for neurological infections in central Africa. Lancet Infect Dis 2013; 13:546-58. [PMID: 23623369 DOI: 10.1016/s1473-3099(13)70004-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Infections are a leading cause of life-threatening neuropathology worldwide. In central African countries affected by endemic diseases such as human African trypanosomiasis, tuberculosis, HIV/AIDS, and schistosomiasis, delayed diagnosis and treatment often lead to avoidable death or severe sequelae. Confirmatory microbiological and parasitological tests are essential because clinical features of most neurological infections are not specific, brain imaging is seldom feasible, and treatment regimens are often prolonged or toxic. Recognition of this diagnostic bottleneck has yielded major investment in application of advances in biotechnology to clinical microbiology in the past decade. We review the neurological pathogens for which rapid diagnostic tests are most urgently needed in central Africa, detail the state of development of putative rapid diagnostic tests for each, and describe key technical and operational challenges to their development and implementation. Promising field-suitable rapid diagnostic tests exist for the diagnosis of human African trypanosomiasis and cryptococcal meningoencephalitis. For other infections-eg, syphilis and schistosomiasis-highly accurate field-validated rapid diagnostic tests are available, but their role in diagnosis of disease with neurological involvement is still unclear. For others-eg, tuberculosis-advances in research have not yet yielded validated tests for diagnosis of neurological disease.
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Affiliation(s)
- Cedric P Yansouni
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium.
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Waap H, Cardoso R, Leitão A, Nunes T, Vilares A, Gargaté MJ, Meireles J, Cortes H, Ângelo H. In vitro isolation and seroprevalence of Toxoplasma gondii in stray cats and pigeons in Lisbon, Portugal. Vet Parasitol 2012; 187:542-7. [DOI: 10.1016/j.vetpar.2012.01.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 01/13/2012] [Accepted: 01/17/2012] [Indexed: 11/24/2022]
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Adurthi S, Mahadevan A, Bantwal R, Satishchandra P, Ramprasad S, Sridhar H, Shankar SK, Nath A, Jayshree RS. Utility of molecular and serodiagnostic tools in cerebral toxoplasmosis with and without tuberculous meningitis in AIDS patients: A study from South India. Ann Indian Acad Neurol 2011; 13:263-70. [PMID: 21264134 PMCID: PMC3021929 DOI: 10.4103/0972-2327.74197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Revised: 05/04/2010] [Accepted: 07/20/2010] [Indexed: 01/10/2023] Open
Abstract
Background: Antemortem diagnosis of cerebral toxoplasmosis, the second most common opportunistic infection (OI) in HIV-infected individuals in developing countries is a challenge. Materials and Methods: Toxoplasma gondii (T.gondii) -specific serology and nested polymerase chain reaction (nPCR) were evaluated in sera and ventricular/lumbar cerebrospinal fluid (CSF) of 22 autopsy confirmed cases of cerebral toxoplasmosis with HIV and 17 controls. Frequency of concomitant T.gondii infection was investigated in 17 cases of HIV-associated tuberculous meningitis (TBM). Results: The sensitivity, specificity, and positive and negative predictive values of T. gondii IgG on CSF (ventricular and lumbar) and sera was 100% in histology proven cerebral toxoplasmosis (concentrations: 258 ± 50, 231 ± 36, and 646 ± 243 IU/mL, respectively); majority (94%) being high avidity type, suggesting reactivation/reinfection. The sensitivity of B1 nPCR was 100% on ventricular CSF, whereas it was only 77% on lumbar CSF. Based on histology, nPCR, and IgG serology, T. gondii co-infection with TBM was observed in 65% (11/17) of cases. Discussion and Conclusion: CSF IgG serology and nPCR are tests with high sensitivity and specificity for the diagnosis of cerebral toxoplasmosis. TBM and cerebral toxoplasmosis can coexist and should be considered in the background of HIV infection in developing countries.
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Affiliation(s)
- Sreenivas Adurthi
- Department of Microbiology, Kidwai Memorial Institute of Oncology, Bangalore, India
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Lau YL, Meganathan P, Sonaimuthu P, Thiruvengadam G, Nissapatorn V, Chen Y. Specific, sensitive, and rapid diagnosis of active toxoplasmosis by a loop-mediated isothermal amplification method using blood samples from patients. J Clin Microbiol 2010; 48:3698-702. [PMID: 20660217 DOI: 10.1128/JCM.00462-10] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Loop-mediated isothermal amplification (LAMP), a rapid nucleic acid amplification method, was developed for the clinical diagnosis of toxoplasmosis. Three LAMP assays based on the SAG1, SAG2, and B1 genes of Toxoplasma gondii were developed. The sensitivities and specificities of the LAMP assays were evaluated by comparison with the results of conventional nested PCR. The LAMP assays were highly sensitive and had a detection limit of 0.1 tachyzoite, and no cross-reactivity with the DNA of other parasites was observed. Blood was collected from 105 individuals to test the LAMP assays: 40 patients with active toxoplasmosis, 40 negative controls, and 25 patients with other parasitic infections. The SAG2-based LAMP (SAG2-LAMP) had a greater sensitivity (87.5%) than the SAG1-LAMP (80%), B1-LAMP (80%), and nested PCR (62.5%). All the LAMP assays and nested PCR were 100% specific. This is the first report of a study which applied the LAMP method to diagnose toxoplasmosis from human blood samples. Due to its simplicity, sensitivity, and specificity, LAMP is suggested as an appropriate method for routine diagnosis of active toxoplasmosis in humans.
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Filisetti D, Cocquerelle V, Pfaff A, Villard O, Candolfi E. Placental testing for Toxoplasma gondii is not useful to diagnose congenital toxoplasmosis. Pediatr Infect Dis J 2010; 29:665-7. [PMID: 20305580 DOI: 10.1097/inf.0b013e3181d7a725] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We examined 785 placentas, including 51 from documented cases of congenital toxoplasmosis. Toxoplasma was detected in 16 placentas, including 1 in which congenital toxoplasmosis was ruled out. Placental screening had poor sensitivity (25%) but good specificity (99%), positive predictive value (93%), and negative predictive value (95%).
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Herold MA, Kühne R, Vosberg M, Ostheeren-Michaelis S, Vogt P, Karrer U. Disseminated toxoplasmosis in a patient with non-Hodgkin lymphoma. Infection 2009; 37:551-4. [PMID: 19499181 DOI: 10.1007/s15010-009-9007-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 03/02/2009] [Indexed: 10/20/2022]
Abstract
Toxoplasmosis is a well-recognized opportunistic disease in HIV-infected individuals that is caused by the reactivation of a previous infection, primarily in the central nervous system, during profound immunodeficiency. Toxoplasmosis has been described more rarely in patients with cancer and chemotherapy. We report a case of a patient with a history of chemotherapy for non-Hodgkin lymphoma who developed pain and progressive paresthesia of the right arm 6 weeks after remission. Relapsing lymphoma was suspected, and steroid and radiation treatment were initiated, but the patient died 5 days later due to multiple organ failure. Autopsy revealed disseminated toxoplasmosis. This case illustrates that toxoplasmosis should be suspected in patients with neoplastic disease, especially lymphomas, who present with unexplained neurologic, pulmonary, or febrile symptoms during or after chemotherapy.
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Abstract
Cerebral toxoplasmosis is a major cause of morbidity and mortality among HIV-infected patients, particularly from developing countries. This article summarizes current literature on cerebral toxoplasmosis. It focuses on: Toxoplasma gondii genetic diversity and its possible relationship with disease presentation; host responses to the parasite antigens; host immunosupression in HIV and cerebral toxoplasmosis as well as different diagnostic methods; clinical and radiological features; treatment; and the direction that studies on cerebral toxoplasmosis will likely take in the future.
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Affiliation(s)
- Vera Lucia Pereira-Chioccola
- Laboratório de Parasitologia, Instituto Adolfo Lutz, Av. Dr Arnaldo, 351, 8 andar, CEP 01246-902, São Paulo, SP, Brazil
| | - José Ernesto Vidal
- Departamento de Neurologia, Instituto de Infectologia Emílio Ribas, Av. Dr Arnaldo, 165 CEP 05411-000, Sao Paulo, SP, BrazilandServiço de Extensão ao atendimento de Pacientes HIV/AIDS, Divisão de Moléstias Infecciosas e Parasitárias, Hospital das Clínicas da Faculdade de Medicina da Universidade de Sao Paulo, Rua Frei Caneca 557, Sao Paulo, SP, Brazil
| | - Chunlei Su
- Department of Microbiology F409, Walters Life Sciences Building, The University of Tennessee, 1414 W. Cumberland Ave., Knoxville, TN 37996-0845, USA
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Correia CC, Melo HRL, Costa VMA. Influence of neurotoxoplasmosis characteristics on real-time PCR sensitivity among AIDS patients in Brazil. Trans R Soc Trop Med Hyg 2009; 104:24-8. [PMID: 19709704 DOI: 10.1016/j.trstmh.2009.06.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 06/03/2009] [Accepted: 06/03/2009] [Indexed: 12/12/2022] Open
Abstract
Cerebral toxoplasmosis among individuals with AIDS may be difficult to diagnose and needs to be differentiated from other neurological diseases. A validation study was performed on real-time PCR for detecting the B1 gene of Toxoplasma gondii in the blood and cerebrospinal fluid (CSF) of AIDS patients with cerebral toxoplasmosis. The study included 135 AIDS patients divided into two groups: Group I comprised 85 patients with neurotoxoplasmosis; and Group II comprised 50 patients with non-toxoplasmic neurological diseases. Real-time PCR on blood showed a sensitivity of 1.5%, specificity of 100.0%, positive predictive value (PPV) of 100.0% and negative predictive value (NPV) of 36.5%. CSF testing produced better results, with a sensitivity of 35.3%, specificity of 100.0%, PPV of 100.0% and NPV of 44.7%. The group presenting with pleocytosis and four or more encephalic lesions was associated with greater CSF positivity on PCR. In conclusion, real-time PCR on blood was not useful for diagnosis. CSF testing showed low sensitivity but high specificity. Greater numbers of lesions and greater CSF cellularity may improve the sensitivity of the method.
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Affiliation(s)
- Carolina C Correia
- Departamento de Medicina Tropical, Universidade Federal de Pernambuco, Recife, PE, Brazil.
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Alfonso Y, Fraga J, Jiménez N, Fonseca C, Dorta-Contreras AJ, Cox R, Capó V, Bandera F, Pomier O, Ginorio D. Detection of Toxoplasma gondii in cerebrospinal fluid from AIDS patients by nested PCR and rapid identification of type I allele at B1 gene by RFLP analysis. Exp Parasitol 2009; 122:203-7. [DOI: 10.1016/j.exppara.2009.03.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 03/02/2009] [Accepted: 03/16/2009] [Indexed: 10/21/2022]
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Alfonso Y, Fraga J, Fonseca C, Jiménez N, Pinillos T, Dorta-Contreras AJ, Cox R, Capó V, Pomier O, Bandera F, Ginorio D. Molecular diagnosis of Toxoplasma gondii infection in cerebrospinal fluid from AIDS patients. Cerebrospinal Fluid Res 2009; 6:2. [PMID: 19267913 PMCID: PMC2657107 DOI: 10.1186/1743-8454-6-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 03/06/2009] [Indexed: 12/02/2022] Open
Abstract
Background Toxoplasmic encephalitis (TE) is one of the most common opportunistic infections in immunocompromised patients. In Cuba, despite the highly active antiretroviral therapy, TE is still the most important cause of cerebral mass lesions in patients infected with the human immunodeficiency virus (HIV). The detection of Toxoplasma gondii by PCR may facilitate the diagnosis and follow-up of TE in acquired immunodeficiency syndrome (AIDS) patients by direct identification of parasite DNA in clinical samples. The aim of the present study was to evaluate a rapid PCR method using the B1 gene to detect T. gondii in cerebrospinal fluid (CSF) samples from patients with suspected TE. Methods CSF samples from AIDS and HIV-negative patients were analyzed. Patients were divided into two groups according to the Centre for Disease Control and Prevention (CDC) criteria for AIDS-related TE: AIDS patients with suspected neurotoxoplasmosis and AIDS and HIV-negative patients with other confirmed neurological diseases but no suspicions of TE. Predictive values, diagnostic accuracy, sensitivity and specificity of the PCR B1 method were calculated. Results The results obtained from 190 patients showed that this assay has a good sensitivity and specificity (83.3% and 95.7%, respectively) for the diagnosis of TE in AIDS patients. Conclusion PCR using the B1 gene and B22/B23 set of primers is a single, rapid and reliable method that may be valuable for discrimination between toxoplasmosis and other central nervous system (CNS) diseases.
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Affiliation(s)
- Yenisey Alfonso
- Parasitology Department, Institute of Tropical Medicine 'Pedro Kourí', PO Box 601, Marianao 13, Ciudad de La Habana, Cuba.
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Mahalakshmi B, Therese KL, Madhavan HN, Biswas J. Diagnostic value of specific local antibody production and nucleic acid amplification technique-nested polymerase chain reaction (nPCR) in clinically suspected ocular toxoplasmosis. Ocul Immunol Inflamm 2006; 14:105-12. [PMID: 16597540 DOI: 10.1080/09273940500545692] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The study was to evaluate the diagnostic efficacy of nested polymerase chain reaction (nPCR) using primers targeting B1 gene of Toxoplasma gondii (T. gondii) with Witmer Desmonts coefficient (WDC) technique in intraocular fluids of clinically suspected toxoplasma retino choroiditis (TRC) patients. MATERIALS AND METHODS Two hundred and seventy eight specimens from 189 patients (25 TRC patients and 164 controls) consisting of 189 serum samples and 89 intraocular fluids were included in the study. The clinical specimens were categorized into TRC patients (typical TRC lesion-group I & atypical TRC lesion-group II) and controls (voluntary blood donors-group III, patients undergoing uncomplicated cataract surgery-group IV, ocular inflammation of non-toxoplasma origin-group V). Detection of anti T. gondii IgG and IgM antibodies in serum samples and intraocular fluids were performed and WDC was calculated by the standard method. The standardized nPCR was applied on the 89 intraocular fluids. RESULTS Clinical diagnosis of TRC based on fundus examination was considered to be the "gold standard." Anti T. gondii IgG/IgM antibodies were detected in serum by ELISA in 95.6% of 25 clinically suspected TRC patients (gp I and II), 28% of gp III, 40.4% of gp IV, and in 58.3% of gpV. Witmer Desmont's coefficient was positive in 72.7% (16/22) and nPCR in 59.1% (13/22) of TRC patients (gp I and II). Both WDC and nPCR were negative in all the controls. The difference in sensitivity of WDC and nPCR was not statistically significant (p=0.5247). CONCLUSIONS Though both WDC and nPCR were reliable diagnostic techniques for ocular toxoplasmosis, nPCR is more acceptable because of the amount of specimen(s) required, rapidity, cost effectiveness, and direct evidence of T. gondii DNA in the intraocular fluids.
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Affiliation(s)
- B Mahalakshmi
- L&T Microbiology Research Centre, Vision Research Foundation, Sankara Nethralaya, Chennai, India
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Colombo FA, Vidal JE, Penalva de Oliveira AC, Hernandez AV, Bonasser-Filho F, Nogueira RS, Focaccia R, Pereira-Chioccola VL. Diagnosis of cerebral toxoplasmosis in AIDS patients in Brazil: importance of molecular and immunological methods using peripheral blood samples. J Clin Microbiol 2005; 43:5044-7. [PMID: 16207959 PMCID: PMC1248484 DOI: 10.1128/jcm.43.10.5044-5047.2005] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cerebral toxoplasmosis is the most common cerebral focal lesion in AIDS and still accounts for high morbidity and mortality in Brazil. Its occurrence is more frequent in patients with low CD4(+) T-cell counts. It is directly related to the prevalence of anti-Toxoplasma gondii antibodies in the population. Therefore, it is important to evaluate sensitive, less invasive, and rapid diagnostic tests. We evaluated the value of PCR using peripheral blood samples on the diagnosis of cerebral toxoplasmosis and whether its association with immunological assays can contribute to a timely diagnosis. We prospectively analyzed blood samples from 192 AIDS patients divided into two groups. The first group was composed of samples from 64 patients with cerebral toxoplasmosis diagnosed by clinical and radiological features. The second group was composed of samples from 128 patients with other opportunistic diseases. Blood collection from patients with cerebral toxoplasmosis was done before or on the third day of anti-toxoplasma therapy. PCR for T. gondii, indirect immunofluorescence, enzyme-linked immunosorbent assay, and an avidity test for toxoplasmosis were performed on all samples. The PCR sensitivity and specificity for diagnosis of cerebral toxoplasmosis in blood were 80% and 98%, respectively. Patients with cerebral toxoplasmosis (89%) presented higher titers of anti-T. gondii IgG antibodies than patients with other diseases (57%) (P<0.001). These findings suggest the clinical value of the use of both PCR and high titers of anti-T. gondii IgG antibodies for the diagnosis of cerebral toxoplasmosis. This strategy may prevent more invasive approaches.
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Affiliation(s)
- Fabio A Colombo
- Department of Parasitology, Instituto Adolfo Lutz, São Paulo, SP, Brazil
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Abstract
For detection of Toxoplasma gondii we compared the sensitivity of two different DNA extraction methods and three different PCR assays. Sensitivities of DNA extraction by QIAamp DNA mini Kit or MagNa pure followed by PCR, nested PCR and oligochromatography or Light Cycler PCR using either SYBR green chemistry or TaqMan probe were compared. No significant difference between extraction methods was found using pure T. gondii tachyzoites. Spiked blood samples, 10(4) to 10 parasites per sample, generated no difference in sensitivity between the two DNA extraction methods when analysed by nested PCR detected by oligochromatography or analysed by Light Cycler PCR TaqMan. In spiked blood samples Light Cycler PCR SYBR green was unable to detect the parasite and a reduction in sensitivity was observed with the TaqMan assay. Conventional PCR was more sensitive when DNA was extracted from the spiked samples using the QIAamp DNA mini Kit. Conventional and nested PCR were found to be more sensitive than Light Cycler PCR TaqMan using the QIAamp DNA mini Kit. It was not possible to use Light Cycler PCR SYBR green in blood samples. Conventional PCR was more sensitive for detection of T. gondii in spiked blood samples using QIAamp DNA mini Kit DNA extraction, suggesting that the choice of DNA extraction method may affect PCR assays differently.
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Affiliation(s)
- Benjamin Edvinsson
- Department Laboratory Medicine, F82, Karolinska Institute, Huddinge University hospital, Stockholm, Sweden.
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Goto M, Takahashi T, Kanda T, Iwamoto A. Detection of Toxoplasma gondii by Polymerase Chain Reaction in Cerebrospinal Fluid from Human Immunodeficiency Virus-1-infected Japanese Patients with Focal Neurological Signs. J Int Med Res 2004; 32:665-70. [PMID: 15587761 DOI: 10.1177/147323000403200612] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We aimed to determine the effectiveness of using the polymerase chain reaction (PCR) to detect Toxoplasma gondii in cerebrospinal fluid (CSF) specimens from Japanese patients infected with human immunodeficiency virus (HIV)-1. Twenty-six HIV-positive individuals presenting with focal neurological signs and a possible diagnosis of T. gondii encephalitis (TE) were enrolled in the study between April 1997 and March 2003. Eight patients were diagnosed as having TE using the accepted diagnostic criteria; PCR amplified the T. gondii B1 gene in CSF samples from five of these eight patients. CSF samples from the 18 patients without TE were negative for T. gondii DNA. The sensitivity, specificity and positive and negative predictive values for detecting T. gondii in CSF using PCR were 62.5%, 100%, 100% and 85.7%, respectively. These results suggest that PCR might be a clinically useful technique for detecting T. gondii DNA in patients infected with HIV showing focal neurological signs. Improvements in sensitivity are needed, however.
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Affiliation(s)
- M Goto
- Division of Infectious Diseases, Advanced Clinical Research Centre, Institute of Medical Science, University of Tokyo, Tokyo, Japan
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Vidal JE, Colombo FA, de Oliveira ACP, Focaccia R, Pereira-Chioccola VL. PCR assay using cerebrospinal fluid for diagnosis of cerebral toxoplasmosis in Brazilian AIDS patients. J Clin Microbiol 2004; 42:4765-8. [PMID: 15472338 PMCID: PMC522299 DOI: 10.1128/jcm.42.10.4765-4768.2004] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 04/12/2004] [Accepted: 06/29/2004] [Indexed: 11/20/2022] Open
Abstract
Highly active antiretroviral therapy has decreased the incidence of opportunistic infections in the central nervous system in AIDS patients. However, neurological abnormalities still remain important causes of mortality and morbidity in developing countries. In Brazil, cerebral toxoplasmosis is the most common cerebral mass lesion in AIDS patients. For these reasons, early, inexpensive, and sensitive diagnostic tests must be evaluated. The aim of this study was to evaluate PCR, using cerebrospinal fluid (CSF) samples to detect Toxoplasma gondii DNA, and to determine if the association of PCR with immunological assays can contribute to a timely diagnosis. We studied two sample groups. First, we analyzed stored CSF samples from 29 newborns and from 39 adults with AIDS without a definitive diagnosis of toxoplasmosis. The goal of this step was to standardize the methodology with a simple and economical procedure to recover the T. gondii DNA. Next, we prospectively evaluated CSF samples from 12 AIDS patients with a first episode of cerebral toxoplasmosis and 18 AIDS patients with other neurological opportunistic diseases and without previous cerebral toxoplasmosis. In all PCR samples, an indirect immunofluorescent assay and an enzyme-linked immunosorbent assay were performed. Samples from all patients with cerebral toxoplasmosis presented positive PCR results (sensitivity, 100%), and a sample from one of the 18 AIDS patients with other neurological diseases also presented positive PCR results (specificity, 94.4%). These findings suggest the clinical utility of PCR in the diagnosis of cerebral toxoplasmosis in developing countries.
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Affiliation(s)
- José E Vidal
- Department of Infectious Disease, Instituto de Infectologia Emílio Ribas, Sao Paulo, Brazil
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Filisetti D, Gorcii M, Pernot-Marino E, Villard O, Candolfi E. Diagnosis of congenital toxoplasmosis: comparison of targets for detection of Toxoplasma gondii by PCR. J Clin Microbiol 2004; 41:4826-8. [PMID: 14532233 PMCID: PMC254317 DOI: 10.1128/jcm.41.10.4826-4828.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three PCR targets (18S ribosomal DNA, B1, and AF146527) and mouse inoculation were compared for 83 samples in the context of congenital toxoplasmosis. These four techniques are not statistically different in terms of sensitivity and specificity. However, further analysis highlighted problems sometimes encountered with PCR diagnosis of congenital toxoplasmosis.
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Affiliation(s)
- Denis Filisetti
- Institut de Parasitologie et de Pathologie Tropicale, Strasbourg, France.
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Schatzberg SJ, Haley NJ, Barr SC, deLahunta A, Olby N, Munana K, Sharp NJH. Use of a multiplex polymerase chain reaction assay in the antemortem diagnosis of toxoplasmosis and neosporosis in the central nervous system of cats and dogs. Am J Vet Res 2004; 64:1507-13. [PMID: 14672429 DOI: 10.2460/ajvr.2003.64.1507] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop a multiplex polymerase chain reaction (PCR) assay for the detection of Toxoplasma gondii and Neospora caninum DNA in canine and feline biological samples. SAMPLE POPULATION; Biological samples from 7 cats with systemic (n = 4) or CNS (3) toxoplasmosis, 6 dogs with neospora- or toxoplasma-associated encephalitis, and 11 animals with nonprotozoal disease. PROCEDURE Primers for T gondii, N caninum, and the canine ferritin gene (dogs) or feline histone 3.3 gene (cats) were combined in a single PCR assay. The DNA was extracted from paraffin-embedded brain tissue, CSF, or skeletal muscle. The PCR products with positive results were cloned, and sequence identity was confirmed. RESULTS Of 7 cats and 4 dogs with immunohistochemical or serologic evidence of toxoplasmosis, PCR results were positive for all cats and 3 dogs for T gondii, and positive for T gondii and N caninum for 1 dog. Another dog had negative PCR results for both parasites. Of 2 dogs with immunohistochemical or serologic evidence of neosporosis, PCR results were positive for 1 for N caninum and positive for the other for T gondii. All negative-control samples yielded negative results for T gondii and N caninum on the PCR assay. CONCLUSIONS AND CLINICAL RELEVANCE Standard tests for toxoplasmosis or neosporosis associated with the CNS rely on serologic, histologic, or immunohistochemical analysis and can be difficult to interpret. The multiplex PCR assay with built-in control reactions could be a complementary clinical tool for the antemortem diagnosis of toxoplasmosis or neosporosis associated with the CNS.
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Affiliation(s)
- Scott J Schatzberg
- Department of Medicine, The Bobst Hospital, Animal Medical Center, New York, NY 10021, USA
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Reischl U, Bretagne S, Krüger D, Ernault P, Costa JM. Comparison of two DNA targets for the diagnosis of Toxoplasmosis by real-time PCR using fluorescence resonance energy transfer hybridization probes. BMC Infect Dis 2003; 3:7. [PMID: 12729464 PMCID: PMC156600 DOI: 10.1186/1471-2334-3-7] [Citation(s) in RCA: 239] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2002] [Accepted: 05/02/2003] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Toxoplasmosis is an infectious disease caused by the parasitic protozoan Toxoplasma gondii. It is endemic worldwide and, depending on the geographic location, 15 to 85% of the human population are asymptomatically infected. Routine diagnosis is based on serology. The parasite has emerged as a major opportunistic pathogen for immunocompromised patients, in whom it can cause life-threatening disease. Moreover, when a pregnant woman develops a primary Toxoplasma gondii infection, the parasite may be transmitted to the fetus and cause serious damage. For these two subpopulations, a rapid and accurate diagnosis is required to initiate treatment. Serological diagnosis of active infection is unreliable because reactivation is not always accompanied by changes in antibody levels, and the presence of IgM does not necessarily indicate recent infection. Application of quantitative PCR has evolved as a sensitive, specific, and rapid method for the detection of Toxoplasma gondii DNA in amniotic fluid, blood, tissue samples, and cerebrospinal fluid. METHODS Two separate, real-time fluorescence PCR assays were designed and evaluated with clinical samples. The first, targeting the 35-fold repeated B1 gene, and a second, targeting a newly described multicopy genomic fragment of Toxoplasma gondii. Amplicons of different intragenic copies were analyzed for sequence heterogeneity. RESULTS Comparative LightCycler experiments were conducted with a dilution series of Toxoplasma gondii genomic DNA, 5 reference strains, and 51 Toxoplasma gondii-positive amniotic fluid samples revealing a 10 to 100-fold higher sensitivity for the PCR assay targeting the newly described 529-bp repeat element of Toxoplasma gondii. CONCLUSION We have developed a quantitative LightCycler PCR protocol which offer rapid cycling with real-time, sequence-specific detection of amplicons. Results of quantitative PCR demonstrate that the 529-bp repeat element is repeated more than 300-fold in the genome of Toxoplasma gondii. Since individual intragenic copies of the target are conserved on sequence level, the high copy number leads to an ultimate level of analytical sensitivity in routine practice. This newly described 529-bp repeat element should be preferred to less repeated or more divergent target sequences in order to improve the sensitivity of PCR tests for the diagnosis of toxoplasmosis.
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Affiliation(s)
- Udo Reischl
- Institute of Medical Microbiology and Hygiene, University Hospital Regensburg, Franz-Josef-Strauβ-Allee 11, D-93053 Regensburg, Germany
| | - Stéphane Bretagne
- Laboratoire de Parasitiologie, Hôpital H. Mondor-APHP and UMR BIPAR 946, F-94010 Créteil, France
| | - Dominique Krüger
- Institute for Parasitology and Mycology, Robert-Koch Institut, Nordufer 20, D-13353 Berlin, Germany
| | - Pauline Ernault
- Laboratoire de Biologie Moléculaire M Dassault, Hôpital américain de Paris, 63 Bd V. Hugo, BP 109, F-92202 Neuilly, France
| | - Jean-Marc Costa
- Laboratoire de Biologie Moléculaire M Dassault, Hôpital américain de Paris, 63 Bd V. Hugo, BP 109, F-92202 Neuilly, France
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Joseph P, Calderón MM, Gilman RH, Quispe ML, Cok J, Ticona E, Chavez V, Jimenez JA, Chang MC, Lopez MJ, Evans CA. Optimization and evaluation of a PCR assay for detecting toxoplasmic encephalitis in patients with AIDS. J Clin Microbiol 2002; 40:4499-503. [PMID: 12454142 PMCID: PMC154600 DOI: 10.1128/jcm.40.12.4499-4503.2002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is a common life-threatening opportunistic infection. We used experimental murine T. gondii infection to optimize the PCR for diagnostic use, define its sensitivity, and characterize the time course and tissue distribution of experimental toxoplasmosis. PCR conditions were adjusted until the assay reliably detected quantities of DNA derived from less than a single parasite. Forty-two mice were inoculated intraperitoneally with T. gondii tachyzoites and sacrificed from 6 to 72 h later. Examination of tissues with PCR and histology revealed progression of infection from blood to lung, heart, liver, and brain, with PCR consistently detecting parasites earlier than microscopy and with no false-positive results. We then evaluated the diagnostic value of this PCR assay in human patients. We studied cerebrospinal fluid and serum samples from 12 patients with AIDS and confirmed toxoplasmic encephalitis (defined as positive mouse inoculation and/or all of the Centers for Disease Control clinical diagnostic criteria), 12 human immunodeficiency virus-infected patients with suspected cerebral toxoplasmosis who had neither CDC diagnostic criteria nor positive mouse inoculation, 26 human immunodeficiency virus-infected patients with other opportunistic infections and no signs of cerebral toxoplasmosis, and 18 immunocompetent patients with neurocysticercosis. Eleven of the 12 patients with confirmed toxoplasmosis had positive PCR results in either blood or cerebrospinal fluid samples (6 of 9 blood samples and 8 of 12 cerebrospinal fluid samples). All samples from control patients were negative. This study demonstrates the high sensitivity, specificity, and clinical utility of PCR in the diagnosis of toxoplasmic encephalitis in a resource-poor setting.
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Affiliation(s)
- Priya Joseph
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Maritza M. Calderón
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Robert H. Gilman
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
- Corresponding author. Mailing address: Asociacion Benéfica PRISMA (Proyectos en Informatica, Salud, Medicina y Agricultura), Carlos Gonzales 251 Urb, Maranga, San Miguel, Lima, Perú. Phone: 51 1 424 0221. Fax: 51 1 464 0781. E-mail:
| | - Monica L. Quispe
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Jaime Cok
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Eduardo Ticona
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Victor Chavez
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Juan A. Jimenez
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Maria C. Chang
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Martín J. Lopez
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
| | - Carlton A. Evans
- Northwestern University Medical School, Chicago, Illinois, Departments of Pathology & Microbiology, Universidad Peruana Cayetano Heredia, Asociacion Benefica Proyectos en Informatica, Salud, Medicina y Agricultura, Hospital Dos de Mayo, Department of Physiological Sciences and Tropical Medicine, Institute “Alexander Von Humboldt,” Universidad Peruana Cayetano Heredia, Lima, Peru, Wellcome Center for Clinical Tropical Medicine, Imperial College, London, United Kingdom
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Abstract
Toxoplasmosis is an anthropozoonotic disease endemic world-wide, caused by the apicomplexan Toxoplasma gondii. Although the course of infection is generally benign, it can cause significant morbidity and mortality in the developing fetus and in immunocompromised individuals. Biological diagnosis classically relies upon serology and direct detection of the parasite by inoculation to laboratory animals. In the past decade, the use of the polymerase chain reaction (PCR) has made a significant improvement in both the prenatal diagnosis of congenital toxoplasmosis and the detection of acute disease in the immunocompromised patient. Nevertheless, like many 'in-house' PCR assays, the PCR-Toxoplasma suffers from lack of standardization and variable performance according to the laboratory. A wide variety of primers has been used in different assays, but few comparative tests have been performed. Moreover, in contrast to other parasitic diseases, PCR-Toxoplasma has not yet attained a sufficient level of sensitivity, regardless of the clinical condition considered. These drawbacks are discussed, together with the undoubted gain that PCR has brought to this difficult diagnosis.
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Affiliation(s)
- Patrick Bastien
- CNRS UMR 5093 Gènome des Protozoaires Parasites, Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Faculté de Médecine, 163 Rue A. Broussonet, 34090 Montpellier, France.
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Jauregui LH, Higgins J, Zarlenga D, Dubey JP, Lunney JK. Development of a real-time PCR assay for detection of Toxoplasma gondii in pig and mouse tissues. J Clin Microbiol 2001; 39:2065-71. [PMID: 11376036 PMCID: PMC88090 DOI: 10.1128/jcm.39.6.2065-2071.2001] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A highly sensitive and specific method has been developed to reproducibly detect and quantitate Toxoplasma gondii burden in animal tissue samples using T. gondii ITS1-derived primers and a fluorogenic probe via real-time PCR. Assay specificity was confirmed against a panel of DNA samples from T. gondii and other common protozoa as well as host animal tissue. This Toxo TaqMan assay was able to detect as little as 0.1 pg of T. gondii genomic DNA, which is equivalent to 1 T. gondii bradyzoite, and has a dynamic range of detection of from 100 ng to 100 fg of T. gondii DNA. Tissues from experimentally infected mice and pigs as well as bradyzoite-spiked pig muscle samples were used to test and standardize this technique. Positive signals were obtained with T. gondii parasite concentrations ranging from 4 to 3.7 x 10(5) parasites per g of spiked pig tissue, with excellent linearity (R(2) = 0.9776). All T. gondii-infected animals were correctly identified by this technique. Results indicate that this assay is applicable to swine carcasses and commercial pig products, is compatible with automation technology for potential slaughterhouse use, and will enable scientists to diagnose and quantitate T. gondii in animal tissues.
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Affiliation(s)
- L H Jauregui
- Immunology and Disease Resistance Laboratory, Epidemiology and Systematics Laboratory, ANRI, ARS, U.S. Department of Agriculture, Beltsville, Maryland 20705, USA
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Miller D, Davis J, Rosa R, Diaz M, Perez E. Utility of tissue culture for detection of Toxoplasma gondii in vitreous humor of patients diagnosed with toxoplasmic retinochoroiditis. J Clin Microbiol 2000; 38:3840-2. [PMID: 11015415 PMCID: PMC87488 DOI: 10.1128/jcm.38.10.3840-3842.2000] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/1999] [Accepted: 05/08/2000] [Indexed: 11/20/2022] Open
Abstract
Laboratory recovery and confirmation of the etiologic agent in necrotizing retinochoroiditis are problematic. Tissue culture and intraocular antibody titers were compared as adjuncts to clinical diagnosis for toxoplasmic retinochoroiditis: the correlations were 91 and 67%, respectively. Isolation of Toxoplasma gondii may establish a definitive diagnosis in patients with toxoplasmic retinochoroiditis.
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Affiliation(s)
- D Miller
- Ocular Microbiology Department, Bascom Palmer Eye Institute, Anne Bates Leach Eye Hospital, University of Miami School of Medicine, Miami, Florida 33136, USA.
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38
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Abstract
In patients with HIV, Toxoplasma gondii is the most frequent infectious cause of focal brain lesions. Particularly in advanced HIV disease, it can cause significant morbidity and mortality. Current clinical practice involves empiric therapy with pyrimethamine and sulfadiazine, upon a presumptive diagnosis of toxoplasmic encephalitis, based on serologic, clinical, and radiological features. This approach continues to evolve, as new diagnostic strategies, such as the use of immunoglobulin G antibody titers and polymerase chain reaction, prophylaxis against opportunistic infections, and highly active antiretroviral therapy--HAART--come into play. Primary and secondary prophylaxis are the mainstay of treatment. There remains a continuing need for development of new anti-Toxoplasma therapy.
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Martins TB, Hillyard DR, Litwin CM, Taggart EW, Jaskowski TD, Hill HR. Evaluation of a PCR probe capture assay for the detection of Toxoplasma gondii. Incorporation of uracil N-glycosylase for contamination control. Am J Clin Pathol 2000; 113:714-21. [PMID: 10800405 DOI: 10.1309/2mwt-x9ph-v43m-v3mq] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Toxoplasma gondii is a cyst-forming parasite of clinical relevance in humans primarily because of the neurologic abnormalities it can cause. In some clinical circumstances, it is desirable to detect the pathogen directly. We modified a commercially available Toxoplasma polymerase chain reaction (PCR) probe capture assay by incorporating uracil N-glycosylase (UNG) to prevent carryover amplicon contamination. In addition, UNG inactivation and DNA denaturation were accomplished chemically to simplify the DNA hybridization to the capture probe. The incorporation of UNG effectively eliminated carryover contamination; the probe capture assay showed a log increase in detection sensitivity compared with standard agarose gel electrophoresis. To assess sensitivity and possible inhibition of amplification, different sample types were spiked with Toxoplasma organisms. After DNA extraction and PCR amplification, a sensitivity of 2 tachyzoites for the assay was determined in buffered saline, cerebrospinal fluid (CSF), serum, and amniotic fluid; 20 tachyzoites for whole blood; and 200 tachyzoites for brain tissue. An additional 20 human serum and CSF samples submitted for Toxoplasma serologic testing were run by the PCR method. Of these, only an IgM-positive CSF sample was PCR positive. The Toxoplasma PCR probe capture assay showed good sensitivity and was not substantially inhibited by several different clinically relevant samples.
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Affiliation(s)
- T B Martins
- ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT 84108, USA
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40
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Bou G, Figueroa MS, Martí-Belda P, Navas E, Guerrero A. Value of PCR for detection of Toxoplasma gondii in aqueous humor and blood samples from immunocompetent patients with ocular toxoplasmosis. J Clin Microbiol 1999; 37:3465-8. [PMID: 10523535 PMCID: PMC85668 DOI: 10.1128/jcm.37.11.3465-3468.1999] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii infection is an important cause of chorioretinitis in the United States and Europe. Most cases of Toxoplasma chorioretinitis result from congenital infection. Patients are often asymptomatic during life, with a peak incidence of symptomatic illness in the second and third decades of life. Diagnosis is mainly supported by ophthalmological examination and a good response to installed therapy. However, establishment of a diagnosis by ophthalmological examination alone can be difficult in some cases. To determine the diagnostic value of PCR for the detection of T. gondii, 56 blood and 56 aqueous humor samples from 56 immunocompetent patients were examined. Fifteen patients with a diagnosis of ocular toxoplasmosis had increased serum anti-T. gondii immunoglobulin G levels but were negative for anti-T. gondii immunoglobulin M (group 1), and 41 patients were used as controls (group 2). Samples were taken before antiparasitic therapy was initiated, and only one blood sample and one aqueous humor sample were obtained for each patient. Single nested PCRs and Southern blot hybridization were performed with DNA extracted from these samples. The results obtained showed sensitivity and specificity values of 53. 3 and 83%, respectively. Interestingly, among all patients with ocular toxoplasmosis, a positive PCR result with the aqueous humor sample was accompanied by a positive PCR result with the blood sample. This result suggests that ocular toxoplasmosis should not be considered a local event, as PCR testing of blood samples from patients with ocular toxoplasmosis yielded the same result as PCR testing of aqueous humor samples. PCR testing may be useful for discriminating between ocular toxoplasmosis and other ocular diseases, and also can avoid the problems associated with ocular puncture.
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Affiliation(s)
- G Bou
- Servicio de Microbiología, Hospital Ramón y Cajal, 28034 Madrid, Spain.
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41
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Lorenz H, Jäger C, Willems H, Baljer G. PCR detection of Coxiella burnetii from different clinical specimens, especially bovine milk, on the basis of DNA preparation with a silica matrix. Appl Environ Microbiol 1998; 64:4234-7. [PMID: 9797270 PMCID: PMC106632 DOI: 10.1128/aem.64.11.4234-4237.1998] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For PCR detection of Coxiella burnetii in various clinical specimens we developed a sample preparation method in which silica binding of DNA was used. This method was found to be fast, easily performed with large numbers of samples, and equally sensitive for all of the specimens tested (livers, spleens, placentas, heart valves, milk, blood). The DNA preparation method described here can also be used as an initial step in any PCR-based examination of specimens. The procedure was tested with more than 600 milk samples, which were taken from 21 cows that were seropositive for C. burnetii and reportedly had fertility problems (and therefore were suspected of shedding the agent through milk intermittently or continuously). Of the 21 cows tested, 6 were shedding C. burnetii through milk. Altogether, C. burnetii DNA was detected in 6% of the samples. There was no correlation between the shedding pattern and the serological results.
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Affiliation(s)
- H Lorenz
- Institute for Hygiene and Infectious Diseases of Animals, Justus-Liebig University, Giessen, Germany
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Cinque P, Giudici B, Bossolasco S. The application of the polymerase chain reaction of cerebrospinal fluid in the clinical management of AIDS-related CNS disorders. AIDS Patient Care STDS 1998; 12:287-94. [PMID: 11361955 DOI: 10.1089/apc.1998.12.287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In AIDS patients central nervous system (CNS) illness may be caused by HIV disease itself or by opportunistic agents, resulting in serious morbidity such as behavioral and motor disturbances, meningitis or encephalitis, among other disorders. Early diagnosis can allow specific treatment (e.g., antimicrobial treatment) that may prevent, ameliorate, or slow the catastrophic sequelae of infection, as well as reduce the need for expensive diagnostic procedures. Conventional microbiology techniques have proven inadequate for the diagnosis of most AIDS-related CNS diseases. However, the development in the past decade of the application of polymerase chain reaction (PCR) to clinical specimens has facilitated the early diagnosis of a number of infectious diseases in these patients. The technique permits the amplification of target nucleic acids such that common laboratory methods may then be used for diagnosis. The application of PCR to cerebrospinal fluid for early diagnosis of AIDS-related neurologic complications has been an impressive example of the application of PCR and may form the basis of new algorithms for diagnosis and possibly the evaluation of treatment protocols.
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Affiliation(s)
- P Cinque
- Division of Infectious Diseases, San Raffaele Hospital, Milan, Italy
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Pelloux H, Dupouy-Camet J, Derouin F, Aboulker JP, Raffi F. A multicentre prospective study for the polymerase chain reaction detection of Toxoplasma gondii DNA in blood samples from 186 AIDS patients with suspected toxoplasmic encephalitis. Bio-Toxo Study Group. AIDS 1997; 11:1888-90. [PMID: 9412712 DOI: 10.1097/00002030-199715000-00018] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Franzen C, Altfeld M, Hegener P, Hartmann P, Arendt G, Jablonowski H, Rockstroh J, Diehl V, Salzberger B, Fätkenheuer G. Limited value of PCR for detection of Toxoplasma gondii in blood from human immunodeficiency virus-infected patients. J Clin Microbiol 1997; 35:2639-41. [PMID: 9316922 PMCID: PMC230025 DOI: 10.1128/jcm.35.10.2639-2641.1997] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cerebral toxoplasmosis is a common, opportunistic, and often life-threatening disease in HIV-infected patients. Diagnosis is supported mainly by clinical evidence and computerized tomography or magnetic resonance imaging scans, but brain images may share features with other brain diseases occurring in HIV-infected patients. To determine the diagnostic value of PCR for the detection of Toxoplasma gondii in blood from HIV-infected patients, we examined 89 blood samples from 59 HIV-infected patients. PCR and Southern blot hybridization were done with DNA extracted from blood samples from 20 patients with confirmed cerebral toxoplasmosis and from 10 patients with suspected but not confirmed cerebral toxoplasmosis. The samples were taken before and 7 to 10 days after the beginning of antiparasitic therapy. For 9 patients who suffered from cerebral toxoplasmosis more than 6 months prior to the study and for 20 patients without any evidence for toxoplasmosis only one blood sample per patient was examined. PCR gave positive results with 5 of the 20 blood samples from patients who suffered from cerebral toxoplasmosis. After 7 to 10 days of therapy PCR results became negative in all these five cases. No amplification was seen with DNA from blood samples from the other 54 patients as the target. The results presented here show that PCR testing of blood samples from HIV-infected patients is of limited value for the diagnosis of cerebral toxoplasmosis. The sensitivity was only 25%, but the specificity was very high (100%), so this technique may be useful for discriminating between cerebral toxoplasmosis and other brain diseases which may be mistaken for toxoplasmosis.
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Affiliation(s)
- C Franzen
- Department of Internal Medicine I, University of Cologne, Germany.
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Pashley TV, Volpe F, Pudney M, Hyde JE, Sims PF, Delves CJ. Isolation and molecular characterization of the bifunctional hydroxymethyldihydropterin pyrophosphokinase-dihydropteroate synthase gene from Toxoplasma gondii1Note: Nucleotide sequence data reported in this paper are available in the EMBL, GenBank and DDJB databases under the accession number U81497.1. Mol Biochem Parasitol 1997; 86:37-47. [DOI: 10.1016/s0166-6851(97)02845-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Angel SO, Matrajt M, Margarit J, Nigro M, Illescas E, Pszenny V, Amendoeira MR, Guarnera E, Garberi JC. Screening for active toxoplasmosis in patients by DNA hybridization with the ABGTg7 probe in blood samples. J Clin Microbiol 1997; 35:591-5. [PMID: 9041395 PMCID: PMC229633 DOI: 10.1128/jcm.35.3.591-595.1997] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We report the potential use of a specific Toxoplasma gondii DNA probe (ABGTg7). We applied a dot blot hybridization assay to blood samples for the diagnosis of cerebral toxoplasmosis (CT), acute toxoplasmic lymphadenopathy (ATL), and disseminated toxoplasmosis in transplant recipients (TRs). We studied a total of 84 individuals: 38 patients and 46 controls. We found positive hybridization signals for 12 (66.7%) of 18 patients with confirmed CT, 9 (52.9%) of 17 patients with ATL, and 2 (66.7%) of 3 TRs. PCR assays were performed in parallel for patients with ATL, resulting in T. gondii DNA detection for 10 patients (58.8%). A comparative study between dot blot and PCR assays performed with the blood of mice that had been experimentally infected with tachyzoites gave similar results: 60 and 70% positive results, respectively. Finally, the sum of positive values obtained by both DNA tests (dot blot assay plus PCR) increased the rate of positivity for ATL patients to 76.4%. These results demonstrate that the T. gondii ABGTg7 repetitive DNA element is an additional useful resource for diagnosing Toxoplasma parasitemia in patients with CT and ATL and in TRs. Thus, our ABGTg7-based dot blot test may lead to an improvement in T. gondii detection methods in patients with acute toxoplasmosis.
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Affiliation(s)
- S O Angel
- Departamento Parasitología, Instituto Nacional de Microbiología Dr. Carlos G. Malbrán, CP 1281, Buenos Aires, Argentina
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Cinque P, Scarpellini P, Vago L, Linde A, Lazzarin A. Diagnosis of central nervous system complications in HIV-infected patients: cerebrospinal fluid analysis by the polymerase chain reaction. AIDS 1997; 11:1-17. [PMID: 9110070 DOI: 10.1097/00002030-199701000-00003] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Abstract
The diagnosis of toxoplasmosis in congenitally infected infants can be difficult; serology is unreliable, and diagnosis must be based on the combination of symptomatology and direct demonstration of the parasite. Four infants suspected of having Toxoplasma gondii infection were studied by serological analysis, tissue culture, and PCR determination. T. gondii was isolated from the urine of one patient. The parasite was detected by PCR in the blood and cerebrospinal fluid of three infants and in the urine in all patients. Because nested PCR proved to be a sensitive, relatively rapid, and specific method and because it can be applied to a variety of different clinical samples, PCR can be a valuable technique for the identification of T. gondii infections in children. The present study indicates that PCR examination of urine, a fluid never before used for diagnosis in this age group, may be valuable in diagnosing cases of congenital toxoplasmosis.
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Affiliation(s)
- I Fuentes
- Servicio de Parasitología, Instituto de Salud Carlos III, Madrid, Spain
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Cingolani A, De Luca A, Ammassari A, Murri R, Linzalone A, Grillo R, Giancola ML, Antinori A. Detection of T.gondii-DNA by PCR in AIDS-related toxoplasmic encephalitis. J Eukaryot Microbiol 1996; 43:118S-119S. [PMID: 8822900 DOI: 10.1111/j.1550-7408.1996.tb05035.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- A Cingolani
- Department of Infectious Diseases, Catholic University, Rome, Italy
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Ammassari A, Murri R, Cingolani A, De Luca A, Antinori A. AIDS-associated cerebral toxoplasmosis: an update on diagnosis and treatment. Curr Top Microbiol Immunol 1996; 219:209-22. [PMID: 8791702 DOI: 10.1007/978-3-642-51014-4_19] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- A Ammassari
- Department of Infectious Diseases, Catholic University, Rome, Italy
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