OBJECTIVES Enzymatic acetylation of the antitubercular isoniazid (INH) by N-acetyltransferase represents a major metabolic pathway for INH in human beings. Acetylation greatly reduces the therapeutic activity of the drug, resulting in underdosing, decreased bioavailability and acquired INH resistance. Chemical modification of INH with a functional group that blocks acetylation, while maintainin...

INTRODUCTION A major role in the development of resistance of Mycobacterium tuberculosis to isoniazid (INH) is attributed to mutations in the katG gene coding for the catalase/peroxidase, an enzyme required for obtaining a pharmacologically active form of the drug. Analysis of mutations in the katG gene in M. tuberculosis strains may contribute to the development of reliable and rapid tests for...

Intravesical Mycobacterium bovis BCG instillation therapy is commonly used to prevent recurrences of carcinoma in situ (CIS) and/or Ta/T1 papillary tumors of the urinary bladder (8). A rare and serious complication associated with BCG treatment of bladder cancer is the development of disseminated BCG disease (1, 6). Current recommendations for bladder cancer patients (being treated with BCG) wh...

Resistance to isoniazid (INH) is the most common form of drug resistance in pulmonary tuberculosis (TB). Although fluoroquinolones (FQs) are recommended to strengthen treatment regimens for INH-resistant pulmonary TB, few studies have evaluated the clinical efficacy of FQ-containing regimens in patients with INH-resistant pulmonary TB. A retrospective cohort study of 140 patients with INH-resis...

s of "Tuberculosis Research" Vol. 9, 1958. Study on the Hemagglutination Reaction with Special Reference to the Influence of Heating on the Antigens Katsuo ONO and Yoshio TAKAHASHI Proteinic fractions were isolated from Sauton culture filtrates of human tubercle bacilli (H 37 Rv), by precipitation with trichloroacetic acid. Polysaccharine fractions were isolated from the deproteinized filtrates...

A novel method for detecting drug resistance in Mycobacterium tuberculosis using mycobacteriophage Φ (2) GFP10 was evaluated with clinical isolates. The phage facilitates microscopic fluorescence detection due to the high expression of green fluorescence protein which also simplifies the operative protocol as well. A total of 128 clinical isolates were tested by the phage assay for isoniazid (I...

The emergence of multidrug-resistant strains of Mycobacterium tuberculosis has increased the need for rapid drug susceptibility tests, which are needed for adequate patient treatment. The objective of the present study was to evaluate the mycobacteria growth indicator tube (MGIT) system to detect multidrug-resistant M. tuberculosis strains. The MGIT system was compared with two standard methods...

We thank Wang et al. for clarifying the role of the dihydrofolate reductase DfrA (Rv2763c) in isoniazid (INH) resistance (16). Concerning potential candidates for the unknown INH resistance mechanism(s), we would like to point out that the aldC (Rv2858c) T21A mutation is also present in Mycobacterium tuberculosis strains C (GenBank accession no. AAKR00000000) and CDC1551 (7), both of which belo...

Infections with multidrug-resistant (resistant at least to rifampicin, RIF and isoniazid, INH) strains of Mycobacterium tuberculosis (MDR-TB) are associated with high case fatality rates. Rapid identification' of MDR-TB strains is important for early institution of appropriate therapy. Two DNA line probe assays, GenoType MTBDR (GT-MTBDR) and INNO-LiPA Rif. TB (INNO-LiPA) were compared for their...

There is urgent need for rapid, point-of-care diagnostic tools for tuberculosis (TB) and drug sensitivity. Current methods based on in vitro growth take weeks, while DNA amplification can neither differentiate live from dead organisms nor determine phenotypic drug resistance. Here we show the development and evaluation of a rapid breath test for isoniazid (INH)-sensitive TB based on detection o...