Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples

Detalhes bibliográficos
Autor(a) principal: Okay, Thelma Suely
Data de Publicação: 2009
Outros Autores: Yamamoto, Lidia, Oliveira, Léa Campos, Manuli, Erika Regina, Andrade Junior, Heitor Franco de, Del Negro, Gilda Maria Barbaro
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Clinics
Texto Completo: https://www.revistas.usp.br/clinics/article/view/17989
Resumo: INTRODUCTION: Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics. PATIENTS: A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks). METHODS: One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed. RESULTS: Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%). DISCUSSION: The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil. CONCLUSION: The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23.
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spelling Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples Toxoplasma gondiiToxoplasmosisCongenital infectionPCRMolecular diagnosis INTRODUCTION: Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics. PATIENTS: A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks). METHODS: One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed. RESULTS: Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%). DISCUSSION: The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil. CONCLUSION: The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23. Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo2009-03-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://www.revistas.usp.br/clinics/article/view/1798910.1590/S1807-59322009000300004Clinics; Vol. 64 No. 3 (2009); 171-176 Clinics; v. 64 n. 3 (2009); 171-176 Clinics; Vol. 64 Núm. 3 (2009); 171-176 1980-53221807-5932reponame:Clinicsinstname:Universidade de São Paulo (USP)instacron:USPenghttps://www.revistas.usp.br/clinics/article/view/17989/20054Okay, Thelma SuelyYamamoto, LidiaOliveira, Léa CamposManuli, Erika ReginaAndrade Junior, Heitor Franco deDel Negro, Gilda Maria Barbaroinfo:eu-repo/semantics/openAccess2012-05-22T18:50:00Zoai:revistas.usp.br:article/17989Revistahttps://www.revistas.usp.br/clinicsPUBhttps://www.revistas.usp.br/clinics/oai||clinics@hc.fm.usp.br1980-53221807-5932opendoar:2012-05-22T18:50Clinics - Universidade de São Paulo (USP)false
dc.title.none.fl_str_mv Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
title Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
spellingShingle Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
Okay, Thelma Suely
Toxoplasma gondii
Toxoplasmosis
Congenital infection
PCR
Molecular diagnosis
title_short Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
title_full Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
title_fullStr Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
title_full_unstemmed Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
title_sort Significant performance variation among PCR systems in diagnosing congenital toxoplasmosis in São Paulo, Brazil: analysis of 467 amniotic fluid samples
author Okay, Thelma Suely
author_facet Okay, Thelma Suely
Yamamoto, Lidia
Oliveira, Léa Campos
Manuli, Erika Regina
Andrade Junior, Heitor Franco de
Del Negro, Gilda Maria Barbaro
author_role author
author2 Yamamoto, Lidia
Oliveira, Léa Campos
Manuli, Erika Regina
Andrade Junior, Heitor Franco de
Del Negro, Gilda Maria Barbaro
author2_role author
author
author
author
author
dc.contributor.author.fl_str_mv Okay, Thelma Suely
Yamamoto, Lidia
Oliveira, Léa Campos
Manuli, Erika Regina
Andrade Junior, Heitor Franco de
Del Negro, Gilda Maria Barbaro
dc.subject.por.fl_str_mv Toxoplasma gondii
Toxoplasmosis
Congenital infection
PCR
Molecular diagnosis
topic Toxoplasma gondii
Toxoplasmosis
Congenital infection
PCR
Molecular diagnosis
description INTRODUCTION: Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics. PATIENTS: A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks). METHODS: One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed. RESULTS: Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%). DISCUSSION: The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil. CONCLUSION: The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23.
publishDate 2009
dc.date.none.fl_str_mv 2009-03-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv https://www.revistas.usp.br/clinics/article/view/17989
10.1590/S1807-59322009000300004
url https://www.revistas.usp.br/clinics/article/view/17989
identifier_str_mv 10.1590/S1807-59322009000300004
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv https://www.revistas.usp.br/clinics/article/view/17989/20054
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo
publisher.none.fl_str_mv Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo
dc.source.none.fl_str_mv Clinics; Vol. 64 No. 3 (2009); 171-176
Clinics; v. 64 n. 3 (2009); 171-176
Clinics; Vol. 64 Núm. 3 (2009); 171-176
1980-5322
1807-5932
reponame:Clinics
instname:Universidade de São Paulo (USP)
instacron:USP
instname_str Universidade de São Paulo (USP)
instacron_str USP
institution USP
reponame_str Clinics
collection Clinics
repository.name.fl_str_mv Clinics - Universidade de São Paulo (USP)
repository.mail.fl_str_mv ||clinics@hc.fm.usp.br
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