RESUMO
Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical specimens has been extensively used as laboratory tool for the diagnosis for tuberculosis. Despite it's dramatic scientific value in practice, it is not as sensitive as expected for the detection of M. tuberculosis. The results of the study suggest that PCR using 123 bp fragment of DNA belonging to IS6110 is specific (95.6%) but only has a sensitivity of 30% to detect M. tuberculosis in clinical specimens.
Assuntos
Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Primers do DNA/genética , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Erros de Diagnóstico , Humanos , Reação em Cadeia da Polimerase/estatística & dados numéricos , Sensibilidade e Especificidade , Tuberculose/diagnósticoRESUMO
PURPOSE: Tuberculous etiology has been suggested in Eales' disease. Because epiretinal membrane (ERM) is formed on the inner surface of the retina in Eales' disease, it could be the most appropriate intraocular specimen for investigation. Therefore, a nested polymerase chain reaction (nPCR), which detects MPB64 gene of Mycobacterium tuberculosis on the archival specimens of ERM of well-documented Eales' and non-Eales' patients, was applied and the results compared. METHODS: nPCR technique was standardized, and the sensitivity and specificity of the primers were determined. nPCR technique was applied to tissue sections obtained from formalin-fixed and paraffin-embedded tissues of ERM from 23 patients with Eales' disease and 27 noninfective and non-Eales' disease patients as controls. RESULTS: nPCR technique was specific for M. tuberculosis genome and sensitive enough to detect 0.25 fg (corresponding to the presence of a single bacillus). Eleven (47.8%) ERM of 23 Eales' disease and 3 (11.1%) of 27 controls were positive for M. tuberculosis genome. The difference between the two groups was statistically significant (P = 0.001), indicating association of this bacterium with Eales' disease. CONCLUSIONS: The demonstration of the presence of M. tuberculosis DNA by nPCR technique in significant number of ERM of Eales' disease compared with the controls further emphasizes the probable role of this bacterium in the pathogenesis of this enigmatic clinical condition.
Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/genética , DNA Bacteriano/análise , Membrana Epirretiniana/microbiologia , Mycobacterium tuberculosis/genética , Flebite/microbiologia , Veia Retiniana , Tuberculose Ocular/microbiologia , Primers do DNA/química , Humanos , Reação em Cadeia da Polimerase/métodos , Hemorragia Retiniana/microbiologia , Sensibilidade e EspecificidadeRESUMO
Nucleic acid amplification using IS6110 primers to detect Mycobacterium tuberculosis in clinical specimens has been extensively used as laboratory tool for the diagnosis for tuberculosis. Despite it's dramatic scientific value in practice, it is not as sensitive as expected for the detection of Mycobacterium tuberculosis. The results of the study suggest that PCR using 123 bp fragment of DNA belonging to IS6110 is specific (95.6%) but only has a sensitivity of 30% to detect M. tuberculosis in clinical specimens.
