TY - JOUR
T1 - Evaluation of a modified antimycobacterial susceptibility test using Middlebrook 7H10 agar containing 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride
AU - Lee, S.
AU - Kong, D. H.
AU - Yun, S. H.
AU - Lee, K. R.
AU - Lee, K. P.
AU - Franzblau, S. G.
AU - Lee, E. Y.
AU - Chang, C. L.
N1 - Funding Information:
This study was supported by a grant from the Korea Health 21 R&D Project, Ministry of Health and Welfare, Republic of Korea (03-PJ1-PG3-20600-0001).
PY - 2006/9
Y1 - 2006/9
N2 - A rapid and accurate antimycobacterial susceptibility test is essential for effective treatment of tuberculosis. The aim of this study was to evaluate a modified method applying 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC) to the Clinical and Laboratory Standards Institute (CLSI) guideline for susceptibility testing of Mycobacterium tuberculosis. A total of 132 clinical isolates of M. tuberculosis, forty-eight isolates showing resistance to one or more of the first-line antituberculosis drugs, and eighty-four fully susceptible isolates were collected from hospitals of a nationwide distribution from June to September 2004. The modified procedure was conducted basically according to the agar-proportion method described in the CLSI Guideline both with STC 50 μg/mL. The amount of growth in each well was recorded and graded at 2nd and 3rd weeks after inoculation. After 3 weeks of incubation, the diagnostic sensitivity and specificity for the detection of drug-resistant strains of STC-containing agar proportion methods were 100%, except ethambutol-low level resistance, of which the diagnostic sensitivity was 93.4%. After two weeks of incubation in STC-containing agar proportion methods, one hundred of the 107 strain-drug combinations have shown drug resistance, indicating the sensitivity of 93.5%. Especially, all 41 isoniazid-resistant strains and 19 of 21 rifampin-resistant strains (90.5%) could be detected after two weeks of incubation. A modification of the agar proportion method using STC resulted in a reliable and more easily interpretable data, and detected most of resistant strains a week earlier than conventional method.
AB - A rapid and accurate antimycobacterial susceptibility test is essential for effective treatment of tuberculosis. The aim of this study was to evaluate a modified method applying 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC) to the Clinical and Laboratory Standards Institute (CLSI) guideline for susceptibility testing of Mycobacterium tuberculosis. A total of 132 clinical isolates of M. tuberculosis, forty-eight isolates showing resistance to one or more of the first-line antituberculosis drugs, and eighty-four fully susceptible isolates were collected from hospitals of a nationwide distribution from June to September 2004. The modified procedure was conducted basically according to the agar-proportion method described in the CLSI Guideline both with STC 50 μg/mL. The amount of growth in each well was recorded and graded at 2nd and 3rd weeks after inoculation. After 3 weeks of incubation, the diagnostic sensitivity and specificity for the detection of drug-resistant strains of STC-containing agar proportion methods were 100%, except ethambutol-low level resistance, of which the diagnostic sensitivity was 93.4%. After two weeks of incubation in STC-containing agar proportion methods, one hundred of the 107 strain-drug combinations have shown drug resistance, indicating the sensitivity of 93.5%. Especially, all 41 isoniazid-resistant strains and 19 of 21 rifampin-resistant strains (90.5%) could be detected after two weeks of incubation. A modification of the agar proportion method using STC resulted in a reliable and more easily interpretable data, and detected most of resistant strains a week earlier than conventional method.
KW - Agar proportion method
KW - Colorimetry
KW - Drug resistance
KW - Mycobacterium tuberculosis
KW - Susceptibility test
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U2 - 10.1016/j.mimet.2006.02.004
DO - 10.1016/j.mimet.2006.02.004
M3 - Article
C2 - 16563534
AN - SCOPUS:33745952344
VL - 66
SP - 548
EP - 551
JO - Journal of Microbiological Methods
JF - Journal of Microbiological Methods
SN - 0167-7012
IS - 3
ER -