Journal of Microbiology

Research Support, N.I.H., Extramural

Sulfolipid Accumulation in Mycobacterium tuberculosis Disrupted in the mce2 Operon: Olivera Marjanovic , Anthony T. Iavarone , Lee W. Riley; J. Microbiol. 2011;49(3):441-447. Published online June 30, 2011; DOI: https://doi.org/10.1007/s12275-011-0435-4

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Abstract: Mycobacterium tuberculosis, the causative agent of tuberculosis, has a lipid-rich cell wall that serves as an effective barrier against drugs and toxic host cell products, which may contribute to the organism’s persistence in a host. M. tuberculosis contains four homologous operons called mce (mce1-4) that encode putative ABC transporters involved in lipid importation across the cell wall. Here, we analyzed the lipid composition of M. tuberculosis disrupted in the mce2 operon. High resolution mass spectrometric and thin layer chromatographic analyses of the mutant’s cell wall lipid extracts showed accumulation of SL-1 and SL1278 molecules. Radiographic quantitative analysis and densitometry revealed 2.9, 3.9 and 9.8-fold greater amount of [35S] SL-1 in the mce2 operon mutant compared to the wild type M. tuberculosis during the early/mid logarithmic, late logarithmic and stationary phase of growth in liquid broth, respectively. The amount of [35S] SL1278 in the mutant also increased progressively over the same growth phases. The expression of the mce2 operon genes in the wild type strain progressively increased from the logarithmic to the stationary phase of bacterial growth in vitro, which inversely correlated with the proportion of radiolabel incorporation into SL-1 and SL1278 at these phases. Since the mce2 operon is regulated in wild type M. tuberculosis, its cell wall may undergo changes in SL-1 and SL1278 contents during a natural course of infection and this may serve as an important adaptive strategy for M. tuberculosis to maintain persistence in a host.

Journal Article

Genotypic and Phenotypic Characteristics of Tunisian Isoniazid-Resistant Mycobacterium tuberculosis Strains: Alya Soudani , Meriem Zribi , Feriel Messaadi , Taieb Messaoud , Afef Masmoudi , Mohamed Zribi , Chedlia Fendri; J. Microbiol. 2011;49(3):413-417. Published online June 30, 2011; DOI: https://doi.org/10.1007/s12275-011-0268-1

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Forty three isoniazid (INH)-resistant Mycobacterium tuberculosis isolates were characterized on the basis of the most common INH associated mutations, katG315 and mabA -15C→T, and phenotypic properties (i.e. MIC of INH, resistance associated pattern, and catalase activity). Typing for resistance mutations was performed by Multiplex Allele-Specific PCR and sequencing reaction. Mutations at either codon were detected in 67.5% of isolates: katG315 in 37.2, mabA -15C→T in 27.9 and both of them in 2.4%, respectively. katG sequencing showed a G insertion at codon 325 detected in 2 strains and leading to amino acid change T326D which has not been previously reported. Distribution of each mutation, among the investigated strains, showed that katG S315T was associated with multiple-drug profile, high-level INH resistance and loss or decreased catalase activity; whereas the mabA -15C→T was more prevalent in mono-INH resistant isolates, but it was not only associated with a low-level INH resistance. It seems that determination of catalase activity aids in the detection of isolates for which MICs are high and could, in conjunction with molecular methods, provide rapid detection of most clinical INH-resistant strains.

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Mutations in rpoB and katG genes and the inhA operon in multidrug-resistant Mycobacterium tuberculosis isolates from Zambia
Eddie S. Solo, Chie Nakajima, Trevor Kaile, Precious Bwalya, Grace Mbulo, Yukari Fukushima, Sylvia Chila, Nanthan Kapata, Yogendra Shah, Yasuhiko Suzuki
Journal of Global Antimicrobial Resistance.2020; 22: 302. CrossRef
Mutations of rpoB, katG, inhA and ahp genes in rifampicin and isoniazid-resistant Mycobacterium tuberculosis in Kyrgyz Republic
Jainagul Isakova, Nurmira Sovkhozova, Denis Vinnikov, Zoy Goncharova, Elnura Talaibekova, Nazira Aldasheva, Almaz Aldashev
BMC Microbiology.2018;[Epub] CrossRef
Genotyping and molecular detection of multidrug-resistant Mycobacterium tuberculosis among tuberculosis lymphadenitis cases in Addis Ababa, Ethiopia
O. Zewdie, A. Mihret, T. Abebe, A. Kebede, K. Desta, A. Worku, G. Ameni
New Microbes and New Infections.2018; 21: 36. CrossRef
Evaluation of the GenoType MTBDRplus assay for detection of rifampicin- and isoniazid-resistant Mycobacterium tuberculosis isolates in central Ethiopia
Zufan Bedewi Omer, Yalemtsehay Mekonnen, Adane Worku, Aboma Zewde, Girmay Medhin, Temesgen Mohammed, Rembert Pieper, Gobena Ameni
International Journal of Mycobacteriology.2016; 5(4): 475. CrossRef
Resistance to Isoniazid and Ethionamide in Mycobacterium tuberculosis : Genes, Mutations, and Causalities
Catherine Vilchèze, William R. Jacobs JR., Graham F. Hatfull, William R. Jacobs Jr.
Microbiology Spectrum.2014;[Epub] CrossRef

Research Support, Non-U.S. Gov't

Altered Protein Expression Patterns of Mycobacterium tuberculosis Induced by ATB107: Hongbo Shen , Enzhuo Yang , Feifei Wang , Ruiliang Jin , Shengfeng Xu , Qiang Huang , Honghai Wang; J. Microbiol. 2010;48(3):337-346. Published online June 23, 2010; DOI: https://doi.org/10.1007/s12275-010-9315-6

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Abstract: ATB107 is a potent inhibitor of indole-3-glycerol phosphate synthase (IGPS). It can effectively inhibit the growth of clinical isolates of drug-resistant Mycobacterium tuberculosis strains as well as M. tuberculosis H37Rv. To investigate the mechanism of ATB107 action in M. tuberculosis, two-dimensional gel electrophoresis coupled with MALDI-TOF-MS analysis (2-DE-MS) was performed to illustrate alterations in the protein expression profile in response to ATB107. Results show that ATB107 affected tryptophan biosynthesis by decreasing the expression of protein encoded by Rv3246c, the transcriptional regulatory protein of MtrA belonging to the MtrA-MtrB two-component regulatory system, in both drug-sensitive and drug-resistant virulent strains. ATB107 might present a stress condition similar to isoniazid (INH) or ethionamide for M. tuberculosis since the altered expression in response to ATB107 of some genes, such as Rv3140, Rv2243, and Rv2428, is consistent with INH or ethionamide treatment. After incubation with ATB107, the expression of 2 proteins encoded by Rv0685 and Rv2624c was down-regulated while that of protein encoded by Rv3140 was up-regulated in all M. tuberculosis strains used in this study. This may be the common response to tryptophan absence; however, relations to ATB107 are unknown and further evaluation is warranted.

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