[STUDY OF DIRECT TB-LAMP USING NON-CENTRIFUGAL SPUTUMS ABOUT EFFICIENCY FOR RAPID DIAGNOSIS OF TUBERCULOSIS].

Objective: To evaluate the efficiency of the direct tuberculosis-loop-mediated isothermal amplification (TB-LAMP) assay by using non-centrifuged sputum samples. STUDY PERIOD AND METHODS: The study was conducted between June 2013 and February 2014. We collected 111 sputum samples from patients who had been radiographically diagnosed with tuberculosis and had not received any treatments for longer than 5 days. In the direct TB-LAMP assay, a loop-mediated isothermal amplification kit and 60-μL sputum samples were used. A direct smear microscopy test was used as the smear test. Then, the same sputum samples were processed with a CCE pretreatment reagent, and 100 μL of the solution samples were cultured by using the mycobacterial growth indicator tube (MGIT) culture method.

Results: Forty-six of the 111 samples were positive in the smear microscopy tests. All the smear-positive samples were positive in both the MGIT and direct TB-LAMP assay (100%). The mean positive detection time with the direct TB-LAMP assay was 13 minutes 55 seconds. Of 56 smear-negative and MGIT positive samples, 44 (78.6%) were judged to be positive using the direct TB-LAMP assay, with a mean positive detection time of 15 minutes 59 seconds.

Discussion: The direct TB-LAMP assay using non-centrifuged sputum samples was demonstrated to have a high detection rate and thus may be considered useful for rapid and effective tuberculosis diagnosis.