Improved diagnosis of central nervous system tuberculosis by MPB64-Target PCR.

Brazilian Journal of Microbiology (Impact Factor: 0.45). 06/2008; 39(2):209-213. DOI: 10.1590/S1517-83822008000200002
Source: PubMed

ABSTRACT Central nervous system (CNS) tuberculosis is a serious clinical problem, the treatment of which is sometimes hampered by delayed diagnosis. Clearly, prompt laboratory diagnosis is of vital importance as the spectrum of disease is wide and abnormalities of the cerebrospinal fluid (CSF) are incredibly variable. Since delayed hypersensitivity is the underlying immune response, bacterial load is very low. The conventional bacteriological methods rarely detect Mycobacterium tuberculosis in CSF and are of limited use in diagnosis of tuberculous meningitis (TBM). This double blind study was, therefore, directed to the molecular analysis of CNS tuberculosis by an in-house-developed PCR targeted for amplification of a 240bp nucleotide sequence coding for MPB64 protein specific for Mycobacterium tuberculosis. Based on the clinical criteria, 47 patients with CNS tuberculosis and a control group of 10 patients having non-tubercular lesions of the CNS were included in the study. Analyses were done in three groups; one group consisting of 27 patients of TBM, a second group of 20 patients with intracranial tuberculomas and a third group of 10 patients having nontubercular lesions of the CNS acted as control. There were no false positive results by PCR and the specificity worked out to be 100%. In the three study groups, routine CSF analysis (cells and chemistry), CSF for AFB smear and culture were negative in all cases. PCR was positive for 21/27 patients (77.7% sensitivity) of the first group of TBM patients, 6/20 patients (30% sensitivity) of the second group with intracranial tuberculomas were positive by PCR and none was PCR-positive (100% specificity) in the third group. Thus, PCR was found to be more sensitive than any other conventional method in the diagnosis of clinically suspected tubercular meningitis.

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    ABSTRACT: Background Til date, none of the diagnostic techniques available for the detection of female genital tuberculosis (FGTB) are 100% accurate. We therefore, proposed to use the endometrial tissue biopsies (ETBs), ovarian tissue biopsies (OTBs) and pelvic aspirated fluids (PAFs) for the diagnosis of FGTB among infertile women by conventional versus molecular methods. Methodology/Principal Findings A total of 302 specimens were collected both from 202 infertile women highly suspected of having FGTB on laparoscopy examination and 100 control women of reproductive age. Out of 302 specimens, 150 (49.67%) were ETBs, 95 (31.46%) were OTBs and 57 (18.87%) were PAFs. All specimens were tested by conventional techniques, later compared with multi-gene PCR for the detection of Mycobacterium tuberculosis (MTB) and correlated with laparoscopic findings. The presence of MTB DNA was observed in 49.5% of ETBs, 33.17% of OTBs and 5.44% of PAF specimens collected from highly suspected FGTB patients. All women of control group were confirmed as negative for tuberculosis. The conventional methods showed 99% to 100% specificity with a low sensitivity, ranging from 21.78% to 42.08% while hematoxylin and eosin staining showed a sensitivity of 51.48%. Multi-gene PCR was found to have much higher sensitivity of 70.29% with MTB64 gene, 86.63% with 19 kDa antigen gene at species and TRC4 element at regional MTB complex and 88.12% with 32 kDa protein gene at genus level. The specificity of multi-gene PCR was 100%. Compared with culturing and Ziehl-Neelsen's staining, multi-gene PCR demonstrated improvement in the detection of FGTB (χ2 = 214.612, 1 df, McNemar's test value <0.0001). Conclusions Significance We suggest site specific sampling, irrespective of sample type and amplification of the 19 kDa antigen gene in combination with TRC4 element as a successful multi-gene PCR for the diagnosis of FGTB and differentiation of mycobacterial infection among endo-ovarian tissue biopsies and PAFs taken from infertile women.
    PLoS ONE 05/2014; 9(5):e98005. DOI:10.1371/journal.pone.0098005 · 3.53 Impact Factor
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    ABSTRACT: RESUMEN La tuberculosis con afección del sistema nervioso central representa 1% de todos los casos de tuberculosis. Se comunica el caso de una mujer inmunocompetente con daño del sistema nervioso central de tipo miliar y sin enfermedad pulmonar evidente. La tuberculosis puede afectar extensamente a sujetos inmunocompetentes. La sospecha clínica y el seguimiento de un protocolo específico para confirmar el diagnóstico, así como la instauración oportuna del tratamiento, son fundamentales para evitar secuelas neurológicas o, incluso, la muerte. Palabras clave: tuberculosis, miliar, sistema nervioso central.
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    ABSTRACT: BACKGROUND: An estimated 14 million people worldwide have active tuberculosis (TB). About 3% of these patients will have osteoarticular involvement and approximately 25% to 60% will have an infectious focus in the spine. Early diagnosis is essential as prompt treatment is associated with improved outcome and reduced mortality. This is particularly true within a high HIV-1 seroprevalence setting. MATERIALS AND METHODS: All patients admitted to Kalafong District Hospital from January 2008 to December 2010 with a clinico-radiological diagnosis of spinal TB were included in this study. In all cases Ziehl-Nielsson (ZN) microscopy, TB culture, TB polymerase chain reaction (PCR), and histology with ZN stains were collected, and the turnaround times for these assays recorded. HIV testing was performed on patients who gave consent for the procedure. RESULTS: In total, 29 patients were included in this study. Seventeen patients consented to HIV testing of which 11 were confirmed to be positive. It was determined that sensitivity for culture and PCR were comparable at 77% and 72% respectively. Furthermore, when looking at the subgroup of HIV-1 positive patients specifically, both assays performed better, with sensitivities of 88% and 82% respectively. The TAT for assays was highly variable, with PCR and histology having comparable times. CONCLUSIONS: PCR testing for spinal TB shows promising results especially within the HIV-1-positive population. Although this type of testing theoretically offers a shorter turnaround time, results were available in similar time frames as for histology. Therefore, on-site testing should be offered in hospitals with high case loads of TB, and combination testing should be used rather than opting for a single testing modality.
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