Multicenter evaluation of mycobacteria growth indicator tube (MGIT) compared with the BACTEC radiometric method, BBL biphasic growth medium and Löwenstein—Jensen medium

Abstract

OBJECTIVE: To evaluate the new BBL mycobacteria growth indicator tube (MGIT) in comparison with other media. METHODS: MGIT was evaluated in 10 Italian centers on 433 clinical samples, mainly of respiratory origin and mainly smear positive, in comparison with Löwenstein---Jensen and with one or more other methods represented, according to participating centers, by the BACTEC radiometric method or by the biphasic BBL Septi-Chek AFB system. While MGIT and Löwenstein---Jensen were used for all the samples, 285 of them were also inoculated in BACTEC vials and 274 in biphasic bottles. Of these samples, 132 were investigated with all the four methods. RESULTS: Although less rapid and sensitive than the radiometric method, the results of MGIT were equal when compared with the other two media with respect to overall isolation yield; furthermore, it allowed the detection of growth in significantly shorter times. CONCLUSIONS: The results of this study indicate the value of MGIT for the detection of mycobacteria and, thanks to its extreme simplicity of use, its suitability for small and large laboratories. Its combined use with a solid medium can substantially improve the diagnosis of mycobacterial infection.

Comparison of MB/BacT ALERT 3D System with Radiometric BACTEC System and Löwenstein-Jensen Medium for Recovery and Identification of Mycobacteria from Clinical Specimens: a Multicenter Study

“…Culture on solid media is labor-intensive and it may take several weeks for colonies to become detectable; even then, the process may require further subculture for definitive identification. Manual liquid medium methods are faster and sensitive, but handling of culture vials for visual inspection or reading is cumbersome and time-consuming (11,13,14,22). Limitations of the radiometric system are well known and include manual loading, potential risk of cross contamination related to the invasive reading, lack of computerized data management, and overall the accumulation of radioactive waste (6,7).…”

Evaluation of the performance of two liquid-phase culture media for the diagnosis of pulmonary tuberculosis in a national hospital in Lima, Peru

“…The mycobacteria growth indicator tube (MGIT; Becton Dickinson Microbiology Systems), developed relatively recently, is a liquid culture medium that develops an orange fluorescence in the presence of growing mycobacteria. [6][7][8][9][10][11] It appears to have a sensitivity equal to or better than that of solid media (especially in smear-negative cases of tuberculosis), requires less time for growth, and has lower costs than radiometric methods. [12][13][14][15][16][17][18] Middlebrook 7H9 is cheaper than MGIT, and has previously been successfully tested.…”

Multicenter Evaluation of the Mycobacteria Growth Indicator Tube for Testing Susceptibility of Mycobacterium tuberculosis to First-Line Drugs

“…The Mycobacteria Growth Indicator Tube (MGIT) is, at present, a manual system and has been reported as a sensitive and rapid method for the growth and detection of mycobacteria from clinical specimens (2,4,5,10,12,13,15). The MGIT contains a modified Middlebrook 7H9 broth in conjunction with a fluorescence quenching-based oxygen sensor (silicon rubber impregnated with ruthenium pentahydrate).…”