Evaluation of a nonradiometric system (BACTEC 9000 MB) for detection of mycobacteria in human clinical samples

Abstract

This study was carried out to evaluate the rate of recovery and time required for detection of mycobacteria from pulmonary and extrapulmonary human clinical samples, by using a fluorescence-quenching-based oxygen sensor (BACTEC 9000 MB; Becton Dickinson Microbiology Systems, Sparks, 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 clinical samples processed, 364 from pulmonary sites and 415 from extrapulmonary sites, 62 (7.9%) were positive for mycobacterial isolates; of the positive samples, 59 (95.1%) were detected with the fluorescent BACTEC 9000 MB system, 57 (91.9%) were detected with the radiometric system (BACTEC 460 TB), and 43 (69.3%) were detected with LJ conventional culture. The mean times to detection of all mycobacteria with BACTEC 9000 MB and BACTEC 460 TB were similar (10.3 and 10.0 days, respectively). The results obtained indicate that the nonradiometric BACTEC (BACTEC 9000 MB) system is as efficient as Bactec 460 TB and significantly more efficient than LJ for the rapid recovery of mycobacteria from both pulmonary and extrapulmonary clinical specimens. Though the BACTEC 9000 MB system is recommended for respiratory specimens, we demonstrated that it can be successfully used also for recovery of mycobacteria from clinical specimens from various extrapulmonary sites.

Routine Use of PCR–Reverse Cross-Blot Hybridization Assay for Rapid Identification of Mycobacterium Species Growing in Liquid Media

“…An important development for the rapid isolation of mycobacteria from clinical samples was the introduction of liquid medium for primary cultures, which increased the rates of isolation of mycobacteria (19,33). In addition, methods based on lipid composition analysis by gas-liquid chromatography (28) and high-performance liquid chromatography (HPLC) (5) and on the use of species-specific DNA or RNA probes (12,23) have been developed for the identification of mycobacteria to the species level.…”

“…A total of 5,466 clinical specimens (including sputum, urine, stool, bronchoalveolar lavage, gastric and cerebrospinal fluid, blood, and tissue biopsy specimens) were submitted for cultures for mycobacteria. These specimens were processed and cultured by well-known protocols (8,17,33).…”

Isolation of Blood-Borne Mycobacterium avium by Using the Nonradioactive BACTEC 9000 MB System and Comparison with a Solid-Culture System

“…The necessity of evaluating the performance of any automated system for detection of MAC in blood has recently been stressed (7). Previous evaluations of the BACTEC 9000 MB included all species of mycobacteria in various clinical specimens including respiratory samples; pleural, abdominal, and cerebrospinal fluids; and urine specimens, but experience with blood culture was limited (10,13,17). To date, no study has been specifically devoted to the isolation of blood-borne mycobacteria.…”

Diagnosis and treatment of pulmonary tuberculosis

“…Auramine-rhodamine staining appears to be more sensitive than classic Z-N stains [1]. Middlebrook plate media, Septic-Check acid-fast bacillus system and BACTEC methods are also better than conventional L-J media [2][3][4]. A combination of solid plus liquid media is the current gold standard for accurate detection of mycobacteria in culture [5].…”