An altered Mycobacterium tuberculosis metabolome induced by katG mutations resulting in isoniazid resistance.

نویسنده

  • Du Toit Loots
چکیده

The most common form of drug resistance found in tuberculosis (TB)-positive clinical samples is monoresistance to isoniazid. Various genomics and proteomics studies to date have investigated this phenomenon; however, the exact mechanisms relating to how this occurs, as well as the implications of this on the TB-causing organisms function and structure, are only partly understood. Considering this, we followed a metabolomics research approach to identify potential new metabolic pathways and metabolite markers, which when interpreted in context would give a holistic explanation for many of the phenotypic characteristics associated with a katG mutation and the resulting isoniazid resistance in Mycobacterium tuberculosis. In order to achieve these objectives, gas chromatography-time of flight mass spectrometry (GCxGC-TOFMS)-generated metabolite profiles from two isoniazid-resistant strains were compared to a wild-type parent strain. Principal component analyses showed clear differentiation between the groups, and the metabolites best describing the separation between these groups were identified. It is clear from the data that due to a mutation in the katG gene encoding catalase, the isoniazid-resistant strains experience increased susceptibility to oxidative stress and have consequently adapted to this by upregulating the synthesis of a number of compounds involved in (i) increased uptake and use of alkanes and fatty acids as a source of carbon and energy and (ii) the synthesis of a number of compounds directly involved in reducing oxidative stress, including an ascorbic acid degradation pathway, which to date hasn't been proposed to exist in these organisms.

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منابع مشابه

Characterization of Mutations in the Rpob and Katg Gene of Mycobacterium Tuberculosis Isolates From Pasteur Institute of Tehran

Objective: The Rifampicin resistance and susceptibility of Mycobacterium tuberculosis are caused by mutations in the 81-base pair region of the rpoB gene encoding the b-subunit of RNA polymerase. Methods: Isoniazid resistance of M. tuberculosis is related to mutations in inha , oxyR and ahpC genes which 30 to 90 percent of Isoniazid resistance is occurred in 3015 codons of kat...

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Characterization of Mutations in the Rpob and Katg Gene of Mycobacterium Tuberculosis Isolates From Pasteur Institute of Tehran

Objective: The Rifampicin resistance and susceptibility of Mycobacterium tuberculosis are caused by mutations in the 81-base pair region of the rpoB gene encoding the b-subunit of RNA polymerase. Methods: Isoniazid resistance of M. tuberculosis is related to mutations in inha , oxyR and ahpC genes which 30 to 90 percent of Isoniazid resistance is occurred in 3015 codons of kat...

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Isoniazid 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...

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تشخیص موتاسیون در کدون 315 ژن katG، مارکر مقاومت به ایزونیازید در سوش‌های مایکوباکتریوم توبرکولوزیس‌ جدا شده از بیماران اصفهان و تهران با روش PCR-RFLP

Background and Objective: Drug resistance to tuberculosis is continuously increasing and is a significant threat to tuberculosis control programs because afew effective drugs are present against Mycobacterium tuberculosis. Although isoniazid (INH) is the most effective drug against tuberculosis, resistance to this drug also develops readily. Mutations in katG, specially the Ser315Thr substituti...

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Mutations in katG gene sequences in isoniazid-resistant clinical isolates of Mycobacterium tuberculosis are rare.

In this study, a battery of oligonucleotides was directed toward the katG gene and PCR-single-stranded conformation polymorphism (SSCP) analysis was used to search for katG gene deviations in clinical isolates of Mycobacterium tuberculosis from different geographical regions. Since a complete deletion of the katG gene was not found, it is suggested that deletion is not a major mechanism of ison...

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عنوان ژورنال:
  • Antimicrobial agents and chemotherapy

دوره 58 4  شماره 

صفحات  -

تاریخ انتشار 2014