Vol.52 No.7 July 2004
Evaluation of rapid automated susceptibility testing with liquid medium for Mycobacterium tuberculosis Comparison of test results by mycobacteria growth indicator tube to those by conventional method or NCCLS
1)Chemotherapy Division, Mitsubishi Kagaku Bio-Clinical Laboratories, Inc.,
3-30-1 Shimura, Itabashi-ku, Tokyo, Japan
2)Department of Laboratory Medicine, National Defense Medical College
Abstract
Susceptibility test results obtained by the Mycobacteria Growth Indicator Tube 960 SIRE susceptibility test (MGIT960 SIRE, Nippon Becton Dickinson Co., Ltd.), a kit for rapid automated susceptibility testing for Mycobacterium tuberculosis, for MGIT960 with liquid medium were compared to those by 1% Ogawa medium (conventional) and proportion method (NCCLS). The four drugs tested were streptomycin, isoniazid (INH), rifampicin (RFP), and ethambutol. Fifty-two strains of Mycobacterium tuberculosis isolated from patients with tuberculosis were used as test strains.
Susceptibility test results obtained by these three methods, all coincided in 92.3% to 96.2% of strains, which showed favorable coincidence although they depended on these drugs. Strains suspected of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) resistant to INH and RFP were three (5.8%) for MGIT960 SIRE and one (1.9%) for NCCLS but none were detected by the 1% Ogawa medium. The mean time required for the susceptibility test was 7.8 days for MGIT960 SIRE, 10.1 days for the 1% Ogawa medium, and 21.0 days for NCCLS method. Susceptibility test results were thus obtained most rapidly by MGIT960 SIRE.
MGIT960 SIRE is useful for determining the susceptibility of Mycobacterium tuberculosis to antibiotics since test results coincide well with those obtained by 1% Ogawa medium and NCCLS, which are used widely in Japan, and test results are rapidly obtained by MGIT960 SIRE. This makes it possible to detect MDR-TB rapidly, speeding up time to treatment.
Key word
automatic susceptibility test, liquid medium, Mycobacterium tuberculosis
Received
April 12, 2004
Accepted
May 25, 2004
Jpn. J. Chemother. 52 (7): 371-375, 2004
