title: Utility of the polymerase chain reaction in the diagnosis of tuberculous meningitis.
abstract: Due to inconsistent clinical presentations and the lack of a rapid, sensitive and specific test, tuberculous meningitis (TBM) is particularly difficult to diagnose. The present study was carried out to determine the utility of the polymerase chain reaction (PCR) using INS primers in the diagnosis of TBM and to compare the efficacy of two different DNA extraction protocols. Fifty-seven cerebrospinal fluid (CSF) samples from suspected cases of meningitis -- 30 definitive/possible TBM and 27 non-TBM -- were processed for microscopy, culture and PCR. Results of computer tomographic (CT) scan findings were noted. The results of smear, culture and PCR were compared using culture and/or clinical response to treatment as the gold standard. The sensitivity of microscopy, culture, CT scan and PCR was 3.3%, 26.7%, 60.0% and 66.7%, respectively. PCR following QIAmp DNA extraction had a sensitivity of 66.7% compared to PCR following a DNA extraction protocol based on the use of cetyl trimethyl ammonium bromide (CTAB) (50%). PCR was positive in all culture-positive CSF samples using either extraction method. PCR is a rapid and sensitive technique; above all, it can diagnose tuberculous meningitis at a very early stage.
authors.affiliation: Department of Microbiology, Seth GS Medical College and KEM Hospital, Mumbai, India.
authors.forename: Dhyanesh
authors.initials: D
authors.lastname: Desai
authors.forename: Gita
authors.initials: G
authors.lastname: Nataraj
authors.forename: Savita
authors.initials: S
authors.lastname: Kulkarni
authors.forename: Lata
authors.initials: L
authors.lastname: Bichile
authors.forename: Preeti
authors.initials: P
authors.lastname: Mehta
authors.forename: Sujata
authors.initials: S
authors.lastname: Baveja
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Rajan
authors.forename: Abhijit
authors.initials: A
authors.lastname: Raut
authors.forename: Asha
authors.initials: A
authors.lastname: Shenoy
mesh_terms: D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014390:Tuberculosis, Meningeal / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000382:microbiology