COMPARISON OF THE SEPTI-CHEK AFB AND BACTEC SYSTEMS AND CONVENTIONAL CULTURE FOR RECOVERY OF MYCOBACTERIA

The performance of the Septi-Chek AFB system was compared with that of the BACTEC radiometric system and that of Lowenstein-jensen agar slan ts (LJ) for detection of mycobacteria in clinical specimens. A total o f 642 specimens were cultured; 61 (9.5%) yielded mycobacteria. Mycobac terium tuberculosis (34 isolates) and Mycobacterium avium complex (25 isolates) were the predominant species isolated. Of the 61 culture-pos itive specimens, 30 were smear positive and 31 were smear negative. Ov erall, 95% of the positive specimens were detected by Septi-Chek and B ACTEC (100% of M. tuberculosis isolates) and 75% by LJ (82% of M. tube rculosis isolates). The mean times to detection were 15 days for BACTE C, 23 days for Septi-Chek, and 27 days for LJ. Of the 30 smear-positiv e specimens, 100% were recovered by Septi-Chek and BACTEC and 90% were recovered by LJ. Of the 31 smear-negative specimens, 90% were detecte d by Septi-Chek and BACTEC and 61% were detected by LJ. The Septi-Chek and BACTEC systems are superior to the conventional (LJ) mycobacteria l culture method. Although Septi-Chek requires more time for the detec tion of mycobacteria than BACTEC, it is comparable in terms of overall recovery.