Talk:Abnormal Development - Toxoplasmosis: Difference between revisions

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http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021132
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021132
==2003==
===Comparison of two DNA targets for the diagnosis of Toxoplasmosis by real-time PCR using fluorescence resonance energy transfer hybridisation probes===
BMC Infect Dis. 2003 May 2;3:7.
Reischl U, Bretagne S, Krüger D, Ernault P, Costa JM.
Source
Institute of Medical Microbiology and Hygiene, University Hospital Regensburg, Franz-Josef-Straubeta-Allee 11, D-93053 Regensburg, Germany. udo.reischl@klinik.uni-regensburg.de
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.
PMID: 12729464
http://www.ncbi.nlm.nih.gov/pubmed/12729464

Revision as of 17:41, 25 July 2011

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Cite this page: Hill, M.A. (2024, March 29) Embryology Abnormal Development - Toxoplasmosis. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Abnormal_Development_-_Toxoplasmosis

2011

Toxoplasmosis and horse meat, france

Emerg Infect Dis. 2011 Jul;17(7):1327-8.

Pomares C, Ajzenberg D, Bornard L, Bernardin G, Hasseine L, Darde ML, Marty P. Source Universite de Nice-Sophia Antipolis-Inserm U895, Nice, France. Abstract To the Editor: Toxoplasma gondii parasites are obligate intracellular apicomplexans that can infect virtually all warm-blooded animals; felids are definitive hosts. The most common sources of human infection are ingestion of tissue cysts in undercooked meat or of food or water contaminated with oocysts shed by felids and transplacental transmission. Acquired toxoplasmosis in immunocompetent humans is frequently asymptomatic but is associated with cervical or occipital lymphadenopathy in approximately 10% of patients. Severe or fatal outcomes for immunocompetent patients have been attributed to the virulence of specific T. gondii genotypes (1). We describe 3 cases of toxoplasmosis caused by atypical strains probably acquired by from ingestion of raw horse meat imported from Canada and Brazil.

PMID: 21762609


High level of soluble HLA-G in amniotic fluid is correlated with congenital transmission of Toxoplasma gondii

Clin Immunol. 2011 Feb;138(2):129-34. Epub 2010 Dec 24.

Robert-Gangneux F, Gangneux JP, Vu N, Jaillard S, Guiguen C, Amiot L. Source Laboratoire de Parasitologie, Faculté de Médecine et Centre Hospitalier Universitaire de Rennes, Rennes, France. florence.robert-gangneux@univ-rennes1.fr Abstract The expression of human leukocyte antigen (HLA)-G on cytotrophoblast cells contributes to maternal-fetal tolerance. Soluble forms of HLA-G (sHLA-G) can be detected in amniotic fluid (AF) and a decrease of sHLA-G is known to be correlated to fetal loss. In this work we investigated the role of sHLA-G in the transplacental passage of the protozoan parasite Toxoplasma gondii, responsible for congenital toxoplasmosis in about 30% of fetuses when primary infection (PI) occurs during pregnancy. We determined the sHLA-G concentration in 61 AF from women with PI and 24 controls. Our results showed higher sHLA-G levels in AF from PI than in controls (p<0.001). Moreover sHLA-G level from congenitally infected fetuses (n=12) was higher than in fetus in whom congenital infection was ruled out (n=49, p<0.05). These data suggest that sHLA-G could participate in immunomodulation necessary to avoid fetal loss due to Toxoplasma infection, but that over-expression could favor congenital transmission.

Copyright © 2010 Elsevier Inc. All rights reserved.

PMID: 21185786

Knowledge of Toxoplasmosis among Doctors and Nurses Who Provide Prenatal Care in an Endemic Region

Infect Dis Obstet Gynecol. 2011;2011:750484. Epub 2011 May 18.

da Silva LB, de Oliveira Rde V, da Silva MP, Bueno WF, Amendoeira MR, de Souza Neves E. Source Laboratório de Doenças Febris Agudas, Instituto de Pesquisa Clínica Evandro Chagas, Fiocruz, Avenida Brasil 4365, 21040-360 Rio de Janeiro, RJ, Brazil.

Abstract

Congenital toxoplasmosis is a potentially severe infection and its prevention is most often based on serological screening in pregnant women. Many cases could be prevented by simple precautions during pregnancy. Aiming to assess the knowledge about toxoplasmosis among professionals working in antenatal care in a high prevalent region, a questionnaire was administered to 118 obstetric nurses and physicians attending at primary care units and hospitals. The questionnaire was self-completed and included questions on diagnosis, clinical issues, and prevention. Only 44% of total answers were corrected. Lower scores were observed among those with over 10 years of graduation, working in primary care units, and nurses. Errors were mainly observed in questions of prevention and diagnosis. As congenital toxoplasmosis is a mother-to-child (MTC) transmitted disease, early diagnosis and treatment can prevent serious and irreversible fetal damage. Thus, doctors and nurses who provide prenatal care must be appropriately trained on prophylactic, diagnostic, and clinical aspects of toxoplasmosis. The authors suggest that measures should be taken for continuing education regarding toxoplasmosis in pregnancy.

PMID: 21747644

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3124125

Discovering disease associations by integrating electronic clinical data and medical literature

PLoS One. 2011;6(6):e21132. Epub 2011 Jun 23.

Holmes AB, Hawson A, Liu F, Friedman C, Khiabanian H, Rabadan R. Source Department of Biomedical Informatics, Columbia University College of Physicians and Surgeons, New York, New York, United States of America.

Abstract

Electronic health record (EHR) systems offer an exceptional opportunity for studying many diseases and their associated medical conditions within a population. The increasing number of clinical record entries that have become available electronically provides access to rich, large sets of patients' longitudinal medical information. By integrating and comparing relations found in the EHRs with those already reported in the literature, we are able to verify existing and to identify rare or novel associations. Of particular interest is the identification of rare disease co-morbidities, where the small numbers of diagnosed patients make robust statistical analysis difficult. Here, we introduce ADAMS, an Application for Discovering Disease Associations using Multiple Sources, which contains various statistical and language processing operations. We apply ADAMS to the New York-Presbyterian Hospital's EHR to combine the information from the relational diagnosis tables and textual discharge summaries with those from PubMed and Wikipedia in order to investigate the co-morbidities of the rare diseases Kaposi sarcoma, toxoplasmosis, and Kawasaki disease. In addition to finding well-known characteristics of diseases, ADAMS can identify rare or previously unreported associations. In particular, we report a statistically significant association between Kawasaki disease and diagnosis of autistic disorder.

PMID: 21731656 http://www.ncbi.nlm.nih.gov/pubmed/21731656

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0021132

2003

Comparison of two DNA targets for the diagnosis of Toxoplasmosis by real-time PCR using fluorescence resonance energy transfer hybridisation probes

BMC Infect Dis. 2003 May 2;3:7.

Reischl U, Bretagne S, Krüger D, Ernault P, Costa JM. Source Institute of Medical Microbiology and Hygiene, University Hospital Regensburg, Franz-Josef-Straubeta-Allee 11, D-93053 Regensburg, Germany. udo.reischl@klinik.uni-regensburg.de

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.

PMID: 12729464 http://www.ncbi.nlm.nih.gov/pubmed/12729464