EVALUATION OF A NONRADIOMETRIC SYSTEM (BACTEC-9000 MB) FOR DETECTION OF MYCOBACTERIA IN HUMAN CLINICAL-SAMPLES

This study was carried out to evaluate the rare of recovery and time r equired for detection of mycobacteria from pulmonary and extrapulmonar y human clinical, samples, by using a fluorescence-quenching-based oxy gen sensor (BACTEC 9000 MB; Becton Dickinson Microbiology Systems, Spa rks, Md.). The results were compared with those obtained by microscopy , conventional culture in Lowenstein-Jensen (LJ) medium, and a BACTEC radiometric system (BACTEC 460 TB; Becton Dickinson). Of the 779 clini cal samples processed, 364 from pulmonary sites and 415 from extrapulm onary sites, 62 (7.9%) were positive for mycobacterial isolates; of th e positive samples, 59 (95.1%) were detected with the fluorescent BACT EC 9000 MB system, 57 (91.9%) were detected with the radiometric syste m (BACTEC 460 TB), and 43 (69.3%) were detected with LJ conventional c ulture. The mean rimes to detection of all mycobacteria with BACTEC 90 00 MB and BACTEC 460 TB were similar (10.3 and 10.0 days, respectively ). The results obtained indicate that the nonradiometric BACTEC (BACTE C 9000 MB) system is as efficient as Bactec 460 TB and significantly m ore efficient than LJ for the rapid recovery of mycobacteria from both pulmonary and extrapulmonary clinical specimens, Though alae BACTEC 9 000 MB system is recommended for respiratory specimens, ne demonstrate d that it can be successfully used also for recovery of mycobacteria f rom clinical specimens from various extrapulmonary sites.