Abstract: Objective To evaluate the value of BacT/Alert 3D system for isolation of mycobacteria from clinical specimens. Methods 416 specimens were collected from December 2004 to April 2005 and inoculated in BacT/Alert 3D system(0.5ml) and on two Lowenstein-Jensen(L-J) slants(0.1ml each),respectively.Smears were stained by auramine O. Results Of 416 clinical specimens,144(34.6%) were isolated Mycobacterium strains.Of these 144 strains,130 strains were isolated by BacT/Alert 3D system,and 126 were isolated by L-J medium.The mean time of detection for BacT/Alert 3D system and L-J medium was 19.9 and 26.4 days,respectively.The overall contamination rates of BacT/Alert 3D system and on L-J medium were 3.6% and 5.8%,respectively. Conclusion Combination of BacT/Alert 3D system and L-J medium might raise isolation of mycobacteria and lower the contamination rate.

Key words: BacT/Alert 3D system, Mycobacteria tuberculosis, Culture media