S. FoongladdaD. RoengsanthiaW. ArjrattanakoolC. ChuchottawornA. ChaiprasertS. G. FranzblauMahidol UniversityCentral Chest Hospital ThailandUniversity of Illinois at Chicago2018-07-242018-07-242002-12-01International Journal of Tuberculosis and Lung Disease. Vol.6, No.12 (2002), 1118-1122102737192-s2.0-0036924086https://repository.li.mahidol.ac.th/handle/20.500.14594/20297The MTT method for rifampicin and isoniazid susceptibility testing of Mycobacterium tuberculosis was developed by using bacterial suspension prepared from colonies on solid media. The MTT tube assay in 1 ml Middlebrook 7H9 broth was completed within 4 days for rifampicin (RMP) and within 7 days for isoniazid (INH). When MTT assay results with 279 M. tuberculosis clinical isolates were compared with those of the conventional proportion method on Löwenstein-Jensen medium, high specificity and sensitivity values of 100% and 94.1%, respectively, for RMP susceptibility testing, and 99.5% and 89.2%, respectively, for INH susceptibility testing were obtained. The accuracy of the MTT method for RMP and INH was >0.97 concordance with the proportion method. The MTT method is simple, inexpensive and rapid. The high level of agreement with the conventional proportion method suggests a potential to rapidly detect drug-resistant M. tuberculosis in developing countries, as only basic microbiological equipment is need.Mahidol UniversityMedicineArticleSCOPUS