Meta-Analysis of BACTEC MGIT 960 and BACTEC 460 TB, with or without Solid Media, for Detection of Mycobacteria

Abstract

In a meta-analysis of 10 studies, the BACTEC 960/MGIT and BACTEC 460 systems showed a sensitivity and specificity in detecting mycobacteria (1,381 strains from 14,745 clinical specimens) of 81.5 and 99.6% and 85.8 and 99.9%, respectively. Combined with solid media, the sensitivity of the two systems increased to 87.7 and 89.7%, respectively.Currently, a combination of conventional solid media with a broth-based method is the accepted reference standard for the diagnosis of mycobacterial infection (5, 26). Among the methods utilizing liquid media, the half-automated radiometric BACTEC 460 TB system (BACTEC 460) is widely accepted as the reference standard. This system, however, is also known for some well-established limitations, which include problems with the use of radioactive material, cumbersome manual loading and unloading, potential hazard of needle stick injury, risk of cross contamination, and lack of computerized data management.Recently, the BACTEC Mycobacteria Growth Indicator Tube System (BACTEC 960/MGIT), a newly developed nonradiometric, fully automated, continuously monitoring system, was introduced as an alternative to the radiometric BACTEC 460 for growth and detection of mycobacteria. The results of several comparative studies show that BACTEC 960/MGIT is a suitable tool for the detection of Mycobacterium tuberculosis and other mycobacterial species, though rather wide variations in diagnostic performance have been reported (1-3, 6, 10-14, 16-18, 21, 23-25, 27, 28, 30-35). To provide an evaluation of the quality of the available reports and an overall summary of the diagnostic accuracy of BACTEC 960/MGIT versus that of BACTEC 460, we performed a systematic review and metaanalysis.Literature search. The literature was searched for the period from January 1990 to June 2003 with the Medline, Embase, and Cochrane libraries. The studies were included for analysis if they compared the results of BACTEC 960/MGIT and BACTEC 460TB with and without solid media, they reported data on false-positive (sample flagged as positive without any microscopic or cultural evidence of acid-fast bacilli by subculture at the end of the incubation period), false-negative (negative test samples found positive on subculture), truepositive, and true-negative results separately; the results of the tests were compared against the reference standard, which was defined as a positive culture with at least one of the three systems used, and the comparison between tests was performed prospectively with the same series of patients from a relevant clinical population, defined as a group of individuals requiring routine microbiologic investigations for suspected pulmonary or extrapulmonary mycobacterial infections.Statistical analysis. To evaluate if variations between primary studies in test threshold had an influence on the accuracy of diagnostic procedures, we used receiver operator characteristic (ROC) curves (9,15,20,22).The common value of noncomparative binary outcomes, as sensitivity and specificity, were obtained by transf...

Comparison of the Recovery of Mycobacterium Bovis Isolates Using the BACTEC MGIT 960 System, BACTEC 460 System, and Middlebrook 7H10 and 7H11 Solid Media

“…1 Studies were recently performed comparing the MGIT 960 system with the BACTEC 460 TB system as well as different types of solid media for detecting mycobacteria, including M. tuberculosis. 3,5,6,10,13 The detection rates for the MGIT 960 system were comparable with the BACTEC 460 system in these studies. Mean time to detection and contamination rates of the MGIT 960 system were similar to those of the BACTEC 460 system.…”

Isolation frequency of Mycobacterium tuberculosis in tertiary reference hospital and their susceptibility patterns against four major anti-tuberculosis drugs

“…9 MGIT yönteminin izolasyon süresini kısaltması ve hemen hemen bütün önemli mikobakteri türlerinde doğru tanı koymayı sağlaması onu değerli hale getirmiştir. 16,17 Konya ilinde 1621 hasta örneğinde yapılan bir çalışmada MGIT besiyerinde üreme zamanının kısaldığı, bu durumun umut verici olduğu fakat doğru sonuç verebilmek için MGIT ve LJ kültür ortamlarının birlikte değerlendirilmesi gerektiği belirtilmiştir. 20 Tüberküloz tedavisinde kullanılan ilaç sayının kısıtlı olması ve tedavide kullanılmakta olan ilaçların bazılarına direnç gelişmesi önemli bir sorundur.…”

“…[9][10][11][12][13][14][15] MGIT yönte-minin izolasyon süresini kısaltması ve hemen hemen bütün önemli mikobakteri türlerinde doğru tanı koymayı sağlaması, onu değerli bir tanı yöntemi haline getirmiştir. 16,17 Çalışmamızda, hastalar ve semptomlu temaslı-lardan alınan örneklerde Mycobacterium tuberculosis'in iki farklı yöntemle saptanması ve iki farklı yön-temle dört majör anti-tüberküloz ilaca karşı direnç durumlarının belirlenmesi amaçlanmıştır.…”

La signature immunologique

“…En se basant sur ce paradigme, nous avons formulé l'hypothèse selon laquelle les réponses immunitaires spécifiques à Mtb pourraient différer fonctionnellement entre ITL et maladie active. Cette hypothèse a été testée en analysant la capacité des lymphocytes CD4 + spécifiques de • La culture microbiologique, considérée comme la méthode de référence, donne un résultat fiable lisible entre 10 jours et plusieurs semaines après ensemencement de milieux spécifiques par des échan-tillons de matériels biologiques [6].…”