Detection of Mycobacterium tuberculosis in clinical specimens other than sputum by a specific DNA probe with amplification of the ribosomal RNA.

OBJECTIVE

To evaluate the Gen-Probe Amplified Mycobacterium tuberculosis Direst Test (MTD) for detection of Mycobacterium tuberculosis in clinical specimens other than sputum, especially cerebrospinal fluid (CSF) and pleural fluid (PF) specimens.

DESIGN

Six CSF, 17 PF and 23 bronchoalveolar lavage fluid (BALF) specimens that were submitted to our clinical laboratory for detection of mycobacteria were subjected to MTD and conventional smear and culture examinations.

RESULTS

Of 6 smear-negative CSF specimens, two were positive in MTD and culture examination. In PF specimens, two of 15 smear- and culture-negative specimens were positive in MTD, while one smear-negative but culture-positive specimen was MTD negative. Three of 20 smear- and culture-negative BALF specimens were positive in MTD. Three BALF specimens in which mycobacteria other than the M. tuberculosis complex detected by culture were negative in MTD.

CONCLUSION

MTD is very useful for rapid detection of M. tuberculosis in clinical specimens other than sputum as well as sputum, and should be especially valuable for rapid diagnosis of tuberculous meningitis which requires prompt initiation of appropriate anti-tuberculosis drug treatment.