Direct Detection of Mycobacterium sp in Respiratory Specimen with rpoB-PCR and Comparison with Concentration Flurochrome Staining

The purpose of the present study was to evaluate the usefulness of rpoB-PCR assay and concentration flurochrome (CF) staining against culture for direct detection of mycobacteria sp in respiratory specimen amongsymptomatic patients. Of the 900 specimens 52 were culture positive with Löwenstein-Jensen Medium (LJM). Of the 52 culture positive samples, 48 were positive by rpoB-PCR (sensitivity 92.3%) and 46 of culture positive specimens were positive by CF staining (sensitivity 88.4%). On the other hand, of the 848 culture negative samples, 5 were positive by rpoB-PCR (specificity99.5%) and 3 were positive by CF staining (specificity99.6%). Both of tests are highly sensitiveand specificfor direct detection of mycobacteria sp from respiratory specimen within hours and CF staining should be recommended for routine use in the clinical microbiology laboratory in developing countries, where limited resources for usage of molecular techniques for rapid detection of tuberculosis.