Multidrug resistance (MDR), defined as resistance to at least isoniazid (INH) and rifampin (RMP) which have the most effective bactericidal activity to M. tuberculosis, is now common throughout the world, with average rates of resistance of 15% in high-burden countries. Exposure of bacterial cells to low doses of ionizing radiation induces mutations that lead to genetic and subsequent phenotypi...

An examination of the pattern of lipid biosynthetic responses to isoniazid (INH) treatment of Mycobacterium tuberculosis and Mycobacterium smegmatis suggests that the mode of action of activated INH differs between these 2 organisms. Transformation of M. smegmatis with inhA on a plasmid construct conferred high-level resistance to INH, while the same construct failed to confer resistance upon M...

We evaluated thin-layer agar (TLA) for the detection of resistance of Mycobacterium tuberculosis to rifampicin (RMP) and isoniazid (INH) as a direct method in patients at risk of multidrug-resistant tuberculosis (MDR-TB). Quadrant TLA plates contain 7H10 Middlebrook growth control, para-nitrobenzoic acid, INH and RMP. Detection of RMP and INH resistance by TLA was compared to that in indirect c...

BACKGROUND The optimal management strategy for patients with isoniazid (INH) monoresistant forms of tuberculosis (TB) has been widely debated. The current daily 9-month regimen of rifampin, pyrazinamide and ethambutol was established based largely on trials in settings with low TB rates and low rates of drug resistance. OBJECTIVE To explore the outcomes of patients with INH-monoresistant TB ...

Isoniazid (INH) and rifampicin (RIF) are the two most effective drugs in tuberculosis therapy. Understanding the molecular mechanisms of resistance to these two drugs is essential to quickly diagnose multidrug-resistant (MDR) tuberculosis and extensive drug-resistant tuberculosis. Nine clinical Mycobacterium tuberculosis isolates resistant to only INH and RIF and 10 clinical pan-sensitive isola...

It is unknown whether MIRU-VNTR (Mycobacterial Interspersed Repetitive Unit-Variable Number of Tandem Repeat) is associated with drug resistance of Mycobacterium tuberculosis. The purpose of this study was to explore the ability of 24 MIRU loci to predict the drug resistance of Isoniazid (INH), Rifampicin (RFP), Streptomycin (SM), Ethambutol (EMB) and Pyrazinamide (PZA). We collected the drug r...

Multidrug-resistant (MDR) isolates of Mycobacterium tuberculosis complex (MTBC) are defined by resistance to at least rifampin (RMP) and isoniazid (INH). Rapid and accurate detection of multidrug resistance is essential for effective treatment and interruption of disease transmission of tuberculosis (TB). Overdiagnosis of MDR TB may result in treatment with second-line drugs that are more costl...

Isoniazid (INH) is a central component of drug regimens used worldwide to treat tuberculosis. Previous studies have identified resistance-associated mutations in katG, inhA, kasA, ndh, and the oxyR-ahpC intergenic region. DNA microarray-based experiments have shown that INH induces several genes in Mycobacterium tuberculosis that encode proteins physiologically relevant to the drug's mode of ac...

In this study, twenty-five strains of Mycobacterium tuberculosis resistant to isoniazid (INH) were isolated from patients with tuberculosis (TB). Nine strains (36%) were found to be virulent in guinea-pigs [root index virulence (RIV» 1 ]. The remaining sixteen strains (64%) were non-virulent (RIV <1). Of the nine strains resistant to INH as well as virulent to guinea-pigs, eight of them wer...

Molecular characterization of the drug resistance of Mycobacterium tuberculosis strains with different origins can generate information that is useful for developing molecular methods. These methods are widely applicable for rapid detection of drug resistance. A total of 166 rifampin (RIF)- and/or isoniazid (INH)-resistant strains of M. tuberculosis have been isolated from different parts of Vi...