Mycobacterium tuberculosis enoyl-acyl-ACP reductase (InhA) has been demonstrated to be the primary target of isoniazid (INH). Recently, it was postulated that M. tuberculosis dihydrofolate reductase (DHFR) is also a target of INH, based on the findings that a 4R-INH-NADP adduct synthesized from INH by a nonenzymatic approach showed strong inhibition of DHFR in vitro, and overexpression of M. tu...

Ethionamide (ETH) is a structural analog of the antituberculosis drug isoniazid (INH). Both of these drugs target InhA, an enzyme involved in mycolic acid biosynthesis. INH requires catalase-peroxidase (KatG) activation, and mutations in katG are a major INH resistance mechanism. Recently an enzyme (EthA) capable of activating ETH has been identified. We sequenced the entire ethA structural gen...

In this study we aimed to learn about the nature and frequency of katG, inhA, and rpoB gene mutations underlying isoniazid (INH) and rifampin (RMP) resistance in clinical Mycobacterium tuberculosis complex isolates. The Silver Sequence DNA sequencing method was used to detect the resistance condition of 22 INH, 6 RMP, and 13 INH and RMP in previously determined drug-resistant clinical M. tuberc...

BACKGROUND Although resistance to isoniazid (INH) is the most common form of drug resistance seen among Mycobacterium tuberculosis isolates, there have been few studies on the efficacy and optimal duration of treatment for patients with INH-resistant tuberculosis (TB). METHODS We evaluated retrospectively the treatment outcomes of 39 patients who were treated for INH-resistant pulmonary TB. T...

The objective of the present study was to evaluate the potential development of DNA microarray chips to detect rifampicin (RFP) and isoniazid (INH) resistance in Mycobacterium tuberculosis (MTB), using samples from clinical tuberculosis (TB) patients in Soochow City, China. The sputum samples of 42 patients with TB in the Affiliated Hospital of Infectious Diseases of Soochow University (Soochow...

Early detection of drug resistance in Mycobacterium tuberculosis isolates allows for earlier and more effective treatment of patients. The aim of this study was to investigate the performance of the malachite green decolourisation assay (MGDA) in detecting isoniazid (INH) and rifampicin (RIF) resistance in M. tuberculosis clinical isolates. Fifty M. tuberculosis isolates, including 19 multidrug...

that RZ would be the most effective and the least expensive option for immigrants from Vietnam, Haiti, and the Philippines. 2 This issue may be even more cogent in Europe, given the massive migratory flows from low-income countries and considering that, unlike the United States, HIV-positive legal immigrants , who are at higher risk for active tuberculosis, are not expelled. The European framew...

We investigated mutations in the genes katG, inhA (regulatory and structural regions), and kasA and the oxyR-ahpC intergenic region of 97 isoniazid (INH)-resistant and 60 INH-susceptible Mycobacterium tuberculosis isolates obtained in two states in Brazil: São Paulo and Paraná. PCR-single-strand conformational polymorphism (PCR-SSCP) was evaluated for screening mutations in regions of prevalenc...

BACKGROUND Tetrandrine is a natural chemical product purified from fourstamen stephania root which recently has been shown to act similarly as synthesized drug efflux pump inhibitor verapamil. The aim of the study is to examine whether tetrandrine could potentiate anti-tubercular drugs to which Mycobacterium tuberculosis (MTB) has turned resistant via efflux mechanisms. METHODS We screened 20...

The history of tuberculosis treatment has observed sequential development of resistance to anti-tuberculosis drugs over the decades. Para amino salicylic acid (PAS) and isoniazid (INH) were introduced to reduce the development of streptomycin (SM) resistance, which heralded the era of combination treatment for tuberculosis [1]. Within 20 years, resistance to both INH and SM was already a challe...