[Application of FDA/EB staining for the detection of viable or non-viable mycobacteria in clinical specimens].

Two-hundred sputum specimens from tuberculosis patients were examined for viable or non-viable mycobacteria by a combination of fluorescein diacetate ethidium bromide (FDA/EB) staining, Ziehl-Neelsen staining, and the use of cultures in 3% Ogawa egg medium. The sputum specimens were treated with 3% NaOH for 10 min and washed in PBS. The bacteria was then harvested by centrifugation at 6,000 rpm for 5 min. Each sample was subjected to FDA/EB staining, Ziehl-Neelsen staining and cultures to compare the staining -method results and the results of colony formation. Ziehl-Neelsen staining method revealed acid-fast bacteria in the specimens, distributed from Gaffky 1 to Gaffky 8. The number of FDA-positive specimens and culture-positive specimens were identical in all Gaffky grades, suggesting that the FDA staining method well reflected the presence of viable mycobacteria in the specimens. We concluded that FDA staining is a valuable method to detect viable mycobacteria in sputum specimens on the first day of examination. It is therefore advantageous for doctors and patients to be immediately informed of culture results rather than waiting for several weeks.