RESUMO
The diagnostic value of the DNA polymerase chain reaction for the detection of M. tuberculosis in tuberculous meningitis uas established by using cerebrospinal fluids obtained from 7 bacteriologically confirmed patients (Group IA), 17 clinically diagnosed patients (Group IB), 21 patients with other bacterial or viral meningitis (Group IIA) and two norrnal persons (Group IIB) The PCR was perforrned with P1 and P2 primer set which directed against the 123bp segment of IS5110. A repetitive sequence of M. tuberculosis chromosome. The sensitivity and specificity of the PCR for the detection of M. tuberculosis was evaluated by using DNAs purified from cultured M tuberculosis and M intracellulare . The detection limit by the PCR amplication with Pl and P2 primer was lfg of DNA for M. tuberculosis and lpg for M. intracellulare indicating that the PCR was very sensitive for M. tubererculosis DNA detection; although weakly cross-reactive with DNA of M. tuberculosis. Of the 7 cerebrospinnal fluids from bacterologically proven tuberculous meningitis patients (Group IA), 7 samples were all positive by PCR (10Q%). 15 sarnples of 17 the AFB smear-negative and culture-negative samples from tuberculous meningitis patients (Group IB) were positive by PCR (88.2%) and 2 of 2l sanples from other meningitis patients (Group IIA) showed positive reaction (9.5%). There were no sarnples whick showed positive reaction by PCR among 2 sarnples from normal persons (Group IIB). This results indicated that the PCR using P1 and P2 primer set was useful for the early diagosis of tuberculous meningitis.