Phyo, Zayar. The Study of stress- and ManLAM-related gene expression patterns in clinical isolated mycobacterium tuberculosis under a multi-stress model combined with isoniazid. Master's Degree(Medical Technology). Chiang Mai University. Library. : Chiang Mai University, 2024.
The Study of stress- and ManLAM-related gene expression patterns in clinical isolated mycobacterium tuberculosis under a multi-stress model combined with isoniazid
Abstract:
Isoniazid stands as a frontline antibiotic utilized in the treatment of tuberculosis (TB), predominantly impacting the mycolic acid component within the cell wall of Mycobacterium tuberculosis (Mtb). It also affects the formation of lipoarabinomannan (LAM), an essential glycolipid in the cell envelope of Mtb. Despite the effectiveness of antibiotics for TB treatment, drug tolerance development in mycobacteria frequently stems from their adaptation to the hostile environment within the host, leading to treatment failure. Herein, we investigated mycobacterial adaptation to the isoniazid exposure in the host-mimicked conditions by focusing on the stress response genes (virS, icl1, whiB3, tgs1) and LAM-related genes (lprG, p55, lmeA, mptA, embC). Mtb H37Rv and mono-isoniazid resistant (INH-R) were cultivated in the host-mimicked multi-stress condition (MS) with or without isoniazid and the relative expressions of these gene candidates were measured using real-time PCR. In INH-R strain, treatment with isoniazid in multi-stress conditions caused the significant upregulation of tgs1, and LAM precursor-lipomannan (LM) synthesis and its transport genes (lprG, p55, lmeA, embC). In the case of H37Rv, all LAM-related genes and tgs1 were downregulated whereas other stress response genes were upregulated, remarkably in icl1 and whiB3. It was shown the critical role of stress response genes especially tgs1 in LAM regulation, potentially contributing to cross tolerance to other drugs in INH-R strain. The findings of this study propose a link between diverse gene expression patterns in different Mtb phenotypes and their distinct tendencies for developing drug resistance. These insights could contribute to the advancement of new strategies for treating and eliminating TB.