Isoniazid induces its own resistance in nonreplicating Mycobacterium tuberculosis.
نویسندگان
چکیده
Isoniazid (INH) resistance is most frequent among drug-resistant Mycobacterium tuberculosis clinical isolates. This study was conducted to investigate whether INH could induce its own resistance. During INH susceptibility testing in BACTEC 12B and MGIT 960 media, weekly subcultures were made from the drug-containing media into fresh medium without drug and susceptibility testing was performed. Rifampin (RIF) was used as a control drug. M. tuberculosis H37Rv and three clinical isolates were tested in this study. INH-resistant subcultures were analyzed for catalase activity, INH susceptibility, and mutations associated with INH resistance. With inoculum size (10(4) bacilli) smaller than a size that contains spontaneously INH-resistant mutants, INH was found to induce resistance to itself in INH-tolerant persisters but not to other drugs. The minimum time required for induction of INH resistance was 5 to 6 days. In contrast, RIF did not induce RIF resistance. Eight subcultures with INH-induced resistance were analyzed, and two had a MIC of 0.4 microg/ml INH and six had MICs of over 2 microg/ml INH. Four of the eight subcultures with INH-induced resistance had lost catalase activity, with three having katG mutations. Despite being a powerful frontline tuberculosis drug, INH has the potential drawback of inducing its own stable genetic resistance in INH-tolerant persisters. This finding helps to explain the higher frequency and prevalence of INH-resistant isolates than isolates with resistance to other drugs in patients.
منابع مشابه
Evaluating the effect of Dracocephalum kotschyi methanol extract on Mycobacterium tuberculosis
Background and objectives: Tuberculosis (TB) is the major public health problem in the world. Each year there are 2-3 million deaths worldwide caused by TB. The increasing incidence of Multi Drug Resistance tuberculosis (MDR-TB) worldwide highlights the urgent need to search for new anti-tuberculosis compounds. It has been reported that medicinal plant, Dracocephalum kotschyi, possesse...
متن کاملMinor Contribution of inhA-15 Mutations to the Rapid Detection of Isoniazid Resistance in Mycobacterium Tuberculosis Isolates
متن کامل
Examining the basis of isoniazid tolerance in nonreplicating Mycobacterium tuberculosis using transcriptional profiling.
BACKGROUND Understanding how growth state influences Mycobacterium tuberculosis responses to antibiotic exposure provides a window into drug action during patient chemotherapy. In this article, we describe the transcriptional programs mediated by isoniazid (INH) during the transition from log-phase to nonreplicating bacilli, from INH-sensitive to INH-tolerant bacilli respectively, using the Way...
متن کاملIsoniazid MIC and KatG Gene Mutations among Mycobacterium tuberculosis Isolates in Northwest of Iran
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 slo...
متن کاملDetection of Isoniazid and Rifampin Resistant Strain of Mycobacterium Tuberculosis Isolated from patients in Golestan province (North of Iran)
Abstract Background and objectives: With almost nine million new cases each year, tuberculosis is still one of the most Life-threatening diseases in the World. Distribution of drug resistant strains of M.tuberculosis has a lot of importance. This research was carried out to determine the frequency of drug resistance of M. tuberculosis in strains isolated in Golestan province. Material and...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Antimicrobial agents and chemotherapy
دوره 51 6 شماره
صفحات -
تاریخ انتشار 2007