Evaluation of the BDProbeTec ET system for direct detection of Mycobacterium tuberculosis complex in respiratory and extra-respiratory specimens

Abstract number: 902_p1491

Lecuona M.


To evaluate the usefulness of BDProbeTec ET system for direct detection of Mycobacterium tuberculosis complex (MTBC) by comparing results to those of conventional mycobacterial culture performed with BACTEC MGIT 960 and Lowestein–Jensen medium.


Four hundred and ninety two samples (382 respiratory and 110 extra-pulmonary) from patients with negative smear microscopy and a high probability of tuberculosis were assessed by BDProbeTec and by culture for mycobacteria. In all samples the internal amplification control (IAC) was successfully performed.


Of 492 specimens, 29 grew MTBC (and in five cultures grew nontuberculous mycobacteria). BDProbeTec ET detected 25 of the 29 MTBC culture-positive specimens and gave a positive result in 10 of the 463 negative cultures, resulting in initial overall sensitivity, specificity and positive and negative predictive values of 86.2%, 97.8%, 71.4% and 99.1%, respectively. BDProbeTec ET was positive in none of the nontuberculous mycobacteria. After analysing respiratory and extra-pulmonary samples separately, the sensitivity and specificity values of the BDProbeTec ET were 90%, 97.5% and 77.7%, 99% respectively.


These data suggest that the performance is good for negative smear samples and that sensitivity increases when analysing respiratory specimens. The BDProbetec ET system offers the advantage of including an IAC in the specimen well.


Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Location: Oxford, UK
Presentation type:
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