background & objectives: although isoniazid is the most efficient in killing the tuberculosis bacilli, resistance to this drug also develops most readily. mutations in katg, inha and ahpc are responsible for isoniazid resistance in a large proportion of tuberculosis cases. the frequency of these mutations varies with population samples, however. this study provided the first molecular character...

The molecular basis for isoniazid resistance in Mycobacterium tuberculosis is complex. Putative isoniazid resistance mutations have been identified in katG, ahpC, inhA, kasA, and ndh. However, small sample sizes and related potential biases in sample selection have precluded the development of statistically valid and significant population genetic analyses of clinical isoniazid resistance. We p...

BACKGROUND Isoniazid has been the backbone of tuberculosis chemotherapy for 6 decades. Resistance to isoniazid threatens the efficacy of treatment of tuberculosis disease and infection. To inform policies around treatment of tuberculosis disease and infection in children, we sought to estimate both the proportion of child tuberculosis cases with isoniazid resistance and the number of incident i...

BACKGROUND Guidelines for latent tuberculosis infection do not consider drug-resistance patterns when recommending treatment for immigrant children. OBJECTIVES The purpose of this research was to decide at what rate of isoniazid resistance a different regimen other than isoniazid for 9 months should be considered. METHODS We constructed a decision tree by using published data. We studied 3 ...

Past genotypic studies of Mycobacterium tuberculosis may have incorrectly estimated the importance of specific drug resistance mutations due to a number of sampling biases including an overrepresentation of multidrug-resistant (MDR) isolates. An accurate assessment of resistance mutations is crucial for understanding basic resistance mechanisms and designing genotypic drug resistance assays. We...

OBJECTIVES The high prevalence of isoniazid-resistant Mycobacterium tuberculosis is often explained by a high mutation rate for this trait, although detailed information to support this theory is absent. We studied the development of isoniazid resistance in vitro, making use of a laboratory strain of M. tuberculosis. METHODS Spontaneous isoniazid-resistant mutants were characterized by molecu...

BACKGROUND & OBJECTIVE There is a need to understand the nature of drug resistance patterns and predictors of emergence of drug resistance in Mycobacterium tuberculosis. There could be common factors/mechanisms for resistance to the drugs, isoniazid and ethambutol, both acting on cell wall. The present study was conducted to analyze the antimycobacterial susceptibility patterns of M. tuberculos...

objective(s) isoniazid (inh) is one of the main first line drugs used in treatment of tuberculosis and development of resistance against this compound can result in serious problems in treatment procedures. resistance to inh is mediated mainly by mutation in katg gene that is coded for the catalase enzyme. the proportional method for detection of inh-resistance is time consuming due to the slow...

OBJECTIVES Molecular assays to detect drug resistance in Mycobacterium tuberculosis are more rapid than standard drug susceptibility testing. To evaluate the efficacy of such assays in this setting, the GenoType MTBDRplus assay (HAIN Lifescience) and multiplex allele-specific PCR assays were carried out. METHODS The GenoType MTBDRplus assay was evaluated for the detection of rifampicin and is...