Rapid diagnosis of tuberculosis and multidrug resistance using a MGIT 960 system.
BACKGROUND
The purpose of this study was to compare the turnaround time for liquid culturing and primary anti-tuberculous drug susceptibility testing (DST) performed using the mycobacteria growth indicator tube (MGIT) 960 system (Becton Dickinson, USA) with that for conventional culturing and DST (by the absolute concentration method) performed using solid culture medium and to determine the concordance rates of DST results obtained using these 2 methods.


METHODS
In this retrospective study, we compared the turnaround times from receiving the request for mycobacterial culture to reporting the DST results before and after the introduction of the MGIT 960 system. Further, we determined the concordance between DST results for isoniazid and rifampin for Mycobacterium tuberculosis isolates obtained using the MGIT 960 system and the absolute concentration method, which was conducted at the Korean Institute of Tuberculosis.


RESULTS
The overall turnaround time for mycobacterial culturing and DST was 27 days for liquid culturing and DST using the MGIT 960 system versus approximately 70 days for culturing on solid medium and DST with the absolute concentration method (P<0.001). There was a good concordance between findings of DST obtained with the 2 methods (97.2%, kappa coefficient=0.855 for rifampin; and 95.6%, kappa coefficient=0.864 for isoniazid), for 1,083 clinical isolates.


CONCLUSIONS
The automated MGIT 960 system for culturing and DST of M. tuberculosis was successfully introduced in a hospital laboratory setting in Korea with significant shortening of the turnaround time.
Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Won-Jung
WJ
Koh
Yousang
Y
Ko
Chang-Ki
CK
Kim
Kyung Sun
KS
Park
Nam Yong
NY
Lee
D000995:Antitubercular Agents / Q000494:pharmacology*; D001331:Automation; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D012189:Retrospective Studies; D012293:Rifampin / Q000494:pharmacology; D013997:Time Factors; D014376:Tuberculosis / Q000175:diagnosis*
D000995:Antitubercular Agents; D007538:Isoniazid; D012293:Rifampin