2019 Volume 68 Issue 2 Pages 296-301
The rapid identification of acid-fast bacteria for determining a treatment plan and preventing nosocomial infections is critical. The nucleic acid amplification test is used for the rapid identification of acid-fast bacteria. We evaluated the performances of TRCReady with EXTRAGEN (EX) and TRCR MB-Lysis Reagent (TRCR) to detect Mycobacterium tuberculosis complex (TB), Mycobacterium avium (MAV), and Mycobacterium intracellurare (MIN). For the detection of 71 clinical samples targeting TB, the positive and negative concordance rates between EX and TRCR were 33% (2/6) and 100% (65/65), respectively. For the detection of 76 clinical samples targeting MAV and MIN, the positive and negative concordance rates between EX and TRCR were 57% (8/14) and 100% (62/62), respectively. The 10 samples that confirmed a discrepancy between EX and TRCR showed EX-positive/TRCR-negative and smearing test negative. For measuring the dilution series of type strain (Mycobacterium bovis BCG, MAV, and MIN) with TRCReady and for measuring the number of colonies, the detection limits of EX for M. bovis BCG, MAV, and MIN were 30, 60, and 30 CFU/mL, respectively. On the other hand, the detection limits of TRCR for M. bovis BCG, MAV, and MIN were 3,000, 360, and 690 CFU/mL, respectively. Compared with TRCR, EX showed higher performance to detect TB, MAV, and MIN. EX is presumed to be useful for the detection of TB, MAV, and MIN from samples containing a small amount of bacteria.
