Linked Life Data

17385062

Source:http://linkedlifedata.com/resource/pubmed/id/17385062

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-7-20
pubmed:abstractText
In this paper, we examined the diagnostic value of a real-time polymerase chain reaction (PCR) using fluorescence resonance energy transfer (TaqMan assay) with a new set of primers and probe targeting the B1 gene to reproducibly detect and quantify Toxoplasma gondii in human blood. A total of 183 buffy coat samples from patients serologically classified as recent toxoplasmosis (immunoglobulin M (IgM)+, n = 35) or chronic infection (IgM- and immunoglobulin G (IgG)+, n = 110), and seronegative individuals (n = 38) was investigated. Of the IgM seropositive patients, 17:35 (48.6%) presented parasitaemia, whereas 3.6% positivity was achieved in those individuals that theoretically corresponded to chronic infection (4:110). In the seronegative group, the assay provided 7.9% (3/38) of positive results. Interestingly, one of them was confirmed as positive in a conventional PCR targeting the Toxoplasma B1 gene after hybridization with an internal probe. Real-time PCR was able to accurately quantify the parasite load when concentrations of T. gondii DNA are low, revealing a parasite burden ranged from 9.92 x 10(-3) to 8.73 x 10(-1) tachyzoites genome per milliliter of blood. The chance of an IgM+ patient to present parasitemia detected by the TaqMan procedure was 19.02 times greater than in IgM- individuals (P < 0.05). It was observed a positive association between the optical density values of the IgM serological tests and the number of circulating parasites in the acute patients (P < 0.0001). The specificity of the molecular test was 95.3% when calculated using IgM+ patients as disease group and IgM- as nondisease group. The low sensitivity observed in the IgM seropositive group (48.6%) could be due to the use of buffy coat as clinical material for DNA extraction. An amplification control based on the human beta-actin gene was used in parallel to monitor PCR inhibition and to control for DNA integrity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0932-0113
pubmed:author
pubmed:issnType
Print
pubmed:volume
101
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
619-25
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Evaluation of a real-time PCR assay based on the repetitive B1 gene for the detection of Toxoplasma gondii in human peripheral blood.
pubmed:affiliation
Laboratório de Epidemiologia Molecular de Doenças Infecciosas, Departamento de Medicina Tropical, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Evaluation Studies