Next-Gen Dual Transcriptomics for Adult Extrapulmonary Tuberculosis Biomarkers and Host-Pathogen Interplay in Human Cells: A Strategic Review.

Tuberculosis (TB) is a major public health concern that results in significant morbidity and mortality, particularly in middle- to low-income countries. Extra-pulmonary tuberculosis (EPTB) in adults is a form of TB that affects organs other than the lungs and is challenging to diagnose and treat due to a lack of accurate early diagnostic markers and inadequate knowledge of host immunity. Next-generation sequencing-based approaches have shown potential for identifying diagnostic biomarkers and host immune responses related to EPTB. This strategic review discusses on the significance using primary human cells and cell lines for in vitro transcriptomic studies on common forms of EPTB, such as lymph node TB, brain TB, bone TB, and endometrial TB to derive potential insights. While organoids have shown promise as a model system, primary cell lines still remain a valuable tool for studying host-pathogen interplay due to their conserved immune system, non-iPSC origin, and lack of heterogeneity in cell population. This review outlines a basic workflow for researchers interested in performing transcriptomics studies in EPTB, and also discusses the potential of cell-line based dual RNA-Seq technology for deciphering comprehensive transcriptomic signatures, host-pathogen interplay, and biomarkers from the host and Mycobacterium tuberculosis. Thus, emphasizing the implementation of this technique which can significantly contribute to the global anti-TB effort and advance our understanding of EPTB.

Consolidating the potency of matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) in viral diagnosis: Extrapolating its applicability for COVID diagnosis?

MALDI-TOF-MS has essentially delivered more than expected with respect to clinical pathogens. Viruses are the most versatile entities of clinical pathogens that have challenged well-established microbiological methodologies. This review evaluates the existing scenario with respect to MALDI TOF-MS analytical technique in the successful analysis of viral pathogens. The milestones achieved with respect to detection and identification of COVID-19 has been presented. The fact that only a handful of scattered applications for COVID-19 exist has been pointed out in the review. Further, the lapses in the utilization of the available state-of-the art MALDI-TOF-MS variants/benchmark sophistications for COVID-19 analysis, are highlighted. When the world is seeking for rapid solutions for early, sensitive, rapid COVID-19 diagnosis, maybe MALDI-TOF-MS, may be the actual 'gold standard'. Reverting to the title, this review emphasizes that there is a need for extrapolating MALDI-TOF-MS for COVID-19 analysis and this calls for urgent scientific attention.

Toll like receptor (2 and 4) expression and cytokine release by human neutrophils during tuberculosis treatment-A longitudinal study.

Host innate immune responses to tuberculosis are poorly explored. Recent findings emphasize the importance of innate cells in working against Mycobacterium tuberculosis, the etiologic agent of this deadly disease. In this study we have tried to learn the role of neutrophils in building up immunity against this pathogen during therapy. We isolated neutrophils from peripheral blood of healthy volunteers and pulmonary tuberculosis patients at different phases of their treatment and cultured them withtoll like receptor ligands overnight. Toll like receptor 2 and 4 expression on neutrophils was analyzed using flow cytometry. The supernatants were used to measure cytokines. We found that in tuberculosis patients, expression of TLR2, a proven receptor of Mycobacterium tuberculosis on neutrophils, was increased throughout the duration of therapy (measured at diagnosis, second month and sixth month of therapy). This demonstrates that TLR2 expression is altered as a result of treatment, but not TLR4. Also, the chemokines IL-8 and MIP1α showed a 'dip and raise' fashion as the therapy proceeded. Even though the increase in the pro-inflammatory cytokine secretion by neutrophils seen at the end of therapy is not as expected, it definitely increases our understanding on the function of these cells during TB disease and its resolution and opens new direction in neutrophil research.

The Role of N-Acetyl Transferases on Isoniazid Resistance from Mycobacterium tuberculosis and Human: An In Silico Approach / 결핵및호흡기질환

BACKGROUND: N-acetyl transferase (NAT) inactivates the pro-drug isoniazid (INH) to N-acetyl INH through a process of acetylation, and confers low-level resistance to INH in Mycobacterium tuberculosis (MTB). Similar to NAT of MTB, NAT2 in humans performs the same function of acetylation. Rapid acetylators, may not respond to INH treatment efficiently, and could be a potential risk factor, for the development of INH resistance in humans. METHODS: To understand the contribution of NAT of MTB and NAT2 of humans in developing INH resistance using in silico approaches, in this study, the wild type (WT) and mutant (MT)-NATs of MTB, and humans, were modeled and docked, with substrates and product (acetyl CoA, INH, and acetyl INH). The MT models were built, using templates 4BGF of MTB, and 2PFR of humans. RESULTS: On the basis of docking results of MTB-NAT, it can be suggested that in comparison to the WT, binding affinity of MT-G207R, was found to be lower with acetyl CoA, and higher with acetyl-INH and INH. In case of MT-NAT2 from humans, the pattern of score with respect to acetyl CoA and acetyl-INH, was similar to MT-NAT of MTB, but revealed a decrease in INH score. CONCLUSION: In MTB, MT-NAT revealed high affinity towards acetyl-INH, which can be interpreted as increased formation of acetyl-INH, and therefore, may lead to INH resistance through inactivation of INH. Similarly, in MT-NAT2 (rapid acetylators), acetylation occurs rapidly, serving as a possible risk factor for developing INH resistance in humans.

Impact of isoniazid resistance on virulence of global and south Indian clinical isolates of Mycobacterium tuberculosis.

Isoniazid (INH) is the only anti-tuberculous drug for which a relationship has been noticed between acquisition of resistance and lack of virulence. Mutation in katG gene is the chief cause for INH resistance in Mycobacterium tuberculosis (MTB). Classical studies have demonstrated that INH-resistant (INH(r)) mutants with a defective katG gene were catalase deficient and markedly attenuated in guinea pigs. Also, earlier studies on south Indian INH(r) isolates were shown to have lower virulence and higher susceptibility to H2O2. However, later studies including that of our's suggest that INH resistance is not always accompanied by compromised virulence and/or survival. Therefore, this review focuses on the influence of INH resistance on virulence of MTB from global and south Indian isolates.