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Journal of Medicinal Chemistry Jul 2024(Mtb), the infectious agent of tuberculosis (TB), causes over 1.5 million deaths globally every year. Host-directed therapies (HDT) for TB are desirable for their...
(Mtb), the infectious agent of tuberculosis (TB), causes over 1.5 million deaths globally every year. Host-directed therapies (HDT) for TB are desirable for their potential to shorten treatment and reduce the development of antibiotic resistance. Previously, we described a modular biomimetic strategy to identify , targeting PPM1A (IC = 1.19 μM), a metal-dependent phosphatase exploited by Mtb to survive intracellularly. restricted the survival of Mtb in macrophages and lungs of infected mice. Herein, we redesigned to create , which is a more potent inhibitor for PPM1A (IC = 180 nM). efficiently increased the level of phosphorylation of S403-p62 and the expression of LC3B-II to activate autophagy, resulting in the dose-dependent clearance of Mtb in infected macrophages. possesses a good pharmacokinetic profile and oral bioavailability ( = 74%). In vivo, is well tolerated up to 50 mg/kg and significantly reduces the bacteria burden in the spleens of infected mice.
PubMed: 38958057
DOI: 10.1021/acs.jmedchem.4c00513 -
Frontiers in Cellular and Infection... 2024Tuberculosis (TB) persists as a global health challenge, with its treatment hampered by the side effects of long-term combination drug therapies and the growing issue of...
BACKGROUND
Tuberculosis (TB) persists as a global health challenge, with its treatment hampered by the side effects of long-term combination drug therapies and the growing issue of drug resistance. Therefore, the development of novel therapeutic strategies is critical. This study focuses on the role of immune checkpoint molecules (ICs) and functions of CD8+ T cells in the search for new potential targets against TB.
METHODS
We conducted differential expression genes analysis and CD8+ T cell functional gene analysis on 92 TB samples and 61 healthy individual (HI) samples from TB database GSE83456, which contains data on 34,603 genes. The GSE54992 dataset was used to validated the findings. Additionally, a cluster analysis on single-cell data from primates infected with mycobacterium tuberculosis and those vaccinated with BCG was performed.
RESULTS
The overexpression of LAG-3 gene was found as a potentially important characteristic of both pulmonary TB (PTB) and extrapulmonary TB (EPTB). Further correlation analysis showed that LAG-3 gene was correlated with GZMB, perforin, IL-2 and IL-12. A significant temporal and spatial variation in LAG-3 expression was observed in T cells and macrophages during TB infection and after BCG vaccination.
CONCLUSION
LAG-3 was overexpressed in TB samples. Targeting LAG-3 may represent a potential therapeutic target for tuberculosis.
Topics: Lymphocyte Activation Gene 3 Protein; Humans; Mycobacterium tuberculosis; CD8-Positive T-Lymphocytes; Tuberculosis; Animals; Antigens, CD; BCG Vaccine; Macrophages; Interleukin-2; Gene Expression Profiling; Tuberculosis, Pulmonary; Interleukin-12; Perforin; Male
PubMed: 38957797
DOI: 10.3389/fcimb.2024.1410015 -
Open Forum Infectious Diseases Jul 2024Direct whole genome sequencing (WGS) of () can be used as a tool to study drug resistance, mixed infections, and within-host diversity. However, WGS is challenging to...
BACKGROUND
Direct whole genome sequencing (WGS) of () can be used as a tool to study drug resistance, mixed infections, and within-host diversity. However, WGS is challenging to obtain from clinical samples due to low number of bacilli against a high background.
METHODS
We prospectively collected 34 samples (sputum, n = 17; bronchoalveolar lavage, n = 13; and pus, n = 4) from patients with active tuberculosis (TB). Prior to DNA extraction, we used a ligand-mediated magnetic bead method to enrich from clinical samples and performed WGS on Illumina platform.
RESULTS
was definitively identified based on WGS from 88.2% (30/34) of the samples, of which 35.3% (12/34) were smear negative. The overall median genome coverage was 15.2% (interquartile range [IQR], 7.7%-28.2%). There was a positive correlation between load of bacilli on smears and genome coverage ( < .001). We detected 58 genes listed in the World Health Organization mutation catalogue in each positive sample (median coverage, 85% [IQR, 61%-94%]), enabling the identification of mutations missed by routine diagnostics. Mutations causing resistance to rifampicin, isoniazid, streptomycin, and ethambutol were detected in 5 of 34 (14.7%) samples, including the S441A mutation that confers resistance to rifampicin, which is not covered by Xpert MTB/RIF.
CONCLUSIONS
We demonstrate the feasibility of magnetic bead-based enrichment for culture-free WGS of from clinical specimens, including smear-negative samples. This approach can also be integrated with low-cost sequencing workflows such as targeted sequencing for rapid detection of and drug resistance.
PubMed: 38957687
DOI: 10.1093/ofid/ofae320 -
Public Health Action Jun 2024The occurrence of transient culture positivity for (MTB), known as , poses significant challenges in understanding its spectrum and implications. Here, we report a case...
The occurrence of transient culture positivity for (MTB), known as , poses significant challenges in understanding its spectrum and implications. Here, we report a case of transient culture positivity, oscillating between detectable and non-detectable MTB cultures with minimal radiological features and review the literature on this phenomenon. The scarcity of scientific literature on this subject stems from the inherent impossibility of systematically studying mirage de tuberculose. Ethical and public health concerns prevent withholding treatment to monitor spontaneous reversion to negative cultures. Based on the literature, we estimate that mirage de tuberculose occurs in approximately one-third of individuals infected with MTB who exhibit no symptoms. Despite the inherently limited nature of these findings, they suggest that the significance of mirage de tuberculose may be greater than currently perceived. Managing cases of mirage de tuberculose presents formidable challenges from a public health perspective. Striking a balance between prompt treatment initiation to prevent transmission and the risk of unnecessary treatment requires careful consideration. In conclusion, mirage de tuberculose remains a poorly understood clinical entity with very limited literature available. Advancing research and interdisciplinary collaborations are essential to unravel the intricacies of this phenomenon and develop effective strategies to address its public health challenges.
PubMed: 38957505
DOI: 10.5588/pha.24.0056 -
MicroLife 2024Type VII secretion systems (T7SS) are found in bacteria across the Bacillota and Actinomycetota phyla and have been well described in , and pathogenic mycobacteria. The...
Type VII secretion systems (T7SS) are found in bacteria across the Bacillota and Actinomycetota phyla and have been well described in , and pathogenic mycobacteria. The T7SS from Actinomycetota and Bacillota share two common components, a membrane-bound EccC/EssC ATPase and EsxA, a small helical hairpin protein of the WXG100 family. However, they also have additional phylum-specific components, and as a result they are termed the T7SSa (Actinomycetota) and T7SSb (Bacillota), respectively. Here, we identify additional organizations of the T7SS across these two phyla and describe eight additional T7SS subtypes, which we have named T7SSc-T7SSj. T7SSd is found exclusively in Actinomycetota including the and genus, whereas the other seven are found only in Bacillota. All of the novel subtypes contain the canonical ATPase (TsxC) and the WXG100-family protein (TsxA). Most of them also contain a small ubiquitin-related protein, TsxB, related to the T7SSb EsaB/YukD component. Protein kinases, phosphatases, and forkhead-associated (FHA) proteins are often encoded in the novel T7SS gene clusters. Candidate substrates of these novel T7SS subtypes include LXG-domain and RHS proteins. Predicted substrates are frequently encoded alongside genes for additional small WXG100-related proteins that we speculate serve as cosecretion partners. Collectively our findings reveal unexpected diversity in the T7SS in Gram-positive bacteria.
PubMed: 38957458
DOI: 10.1093/femsml/uqae013 -
Cureus Jun 2024Background The diagnosis of complex lung disease (MAC-LD) requires two or more positive sputum cultures. Few reports have examined the usefulness of adding liquid...
Background The diagnosis of complex lung disease (MAC-LD) requires two or more positive sputum cultures. Few reports have examined the usefulness of adding liquid culture to conventional solid culture for diagnosing MAC-LD. Methods A retrospective, cohort study of patients examined at Kurashiki Central Hospital in Japan with a confirmed diagnosis of MAC-LD between January 1, 2002, and June 20, 2021, was conducted. The primary endpoint was the culture positivity rate, which was compared between the liquid and Ogawa culture media in patients who underwent sputum culture using both methods. Secondary endpoints were the culture positivity rate in smear-positive specimens and the positivity rate by radiological type. Results The study, which involved 351 patients and 702 specimens, showed a higher positivity rate for liquid culture (n=690, 98.3%) than Ogawa culture (n=315, 44.9%). Overall, 265 patients (75.5%) would have had delayed MAC-LD diagnosis without liquid medium being used. Of the 95 smear-positive specimens, 71 (74.7%) were positive on both cultures, whereas 24 (25.3%) were positive only on liquid culture. The positivity rate of Ogawa culture varied by radiological type. Conclusions Liquid culture is more valuable for the early diagnosis of MAC-LD than Ogawa culture.
PubMed: 38957255
DOI: 10.7759/cureus.61542 -
BMC Infectious Diseases Jul 2024Tuberculosis is a global health problem that causes 1. 4 million deaths every year. It has been estimated that sputum smear-negative diagnosis but culture-positive... (Comparative Study)
Comparative Study
Comparison of microscopic and xpert MTB diagnoses of presumptive mycobacteria tuberculosis infection: retrospective analysis of routine diagnosis at Cape Coast Teaching Hospital.
INTRODUCTION
Tuberculosis is a global health problem that causes 1. 4 million deaths every year. It has been estimated that sputum smear-negative diagnosis but culture-positive pulmonary TB diagnosis contribute to 12.6% of pulmonary TB transmission. TB diagnosis by smear microscopy smear has a minimum detection limit (LOD) of 5,000 to 10,000 bacilli per milliliter (CFU/ml) of sputum result in missed cases and false positives. However, GeneXpert technology, with a LOD of 131-250 CFU/ml in sputum samples and its implementation is believe to facilitate early detection TB and drug-resistant TB case. Since 2013, Ghana health Service (GHS) introduce GeneXpert MTB/RIF diagnostic in all regional hospitals in Ghana, however no assessment of performance between microscopy and GeneXpert TB diagnosis cross the health facilities has been reported. The study compared the results of routine diagnoses of TB by microscopy and Xpert MTB from 2016 to 2020 at the Cape Coast Teaching Hospital (CCTH).
METHODS
The study compared routine microscopic and GeneXpert TB diagnosis results at the Cape Coast Teaching Hospital (CCTH) from 2016 to 2020 retrospectively. Briefly, sputum specimens were collected into 20 mL sterile screw-capped containers for each case of suspected TB infection and processed within 24 h. The samples were decontaminated using the NALC-NaOH method with the final NaOH concentration of 1%. The supernatants were discarded after the centrifuge and the remaining pellets dissolved in 1-1.5 ml of phosphate buffer saline (PBS) and used for diagnosis. A fixed smears were Ziehl-Neelsen acid-fast stain and observed under microscope and the remainings were used for GeneXpert MTB/RIF diagnosis. The data were analyze using GraphPad Prism.
RESULTS
50.11% (48.48-51.38%) were females with an odd ratio (95% CI) of 1.004 (0.944-1.069) more likely to report to the TB clinic for suspected TB diagnosis. The smear-positive cases for the first sputum were 6.6% (5.98-7.25%), and the second sputum was 6.07% (5.45-6.73%). The Xpert MTB-RIF diagnosis detected 2.93% (10/341) (1.42-5.33%) in the first and 5.44% (16/294) (3.14-8.69%) in the second smear-negative TB samples. The prevalence of Xpert MTB-RIF across smear positive showed that males had 56.87% (178/313) and 56.15% (137/244) and females had 43.13% (135/313) and 43.85% (107/244) for the first and second sputum. Also, false negative smears were 0.18% (10/5607) for smear 1 and 0.31% (16/5126) for smear 2.
CONCLUSION
In conclusion, the study highlights the higher sensitivity of the GeneXpert assay compared to traditional smear microscopy for detecting MTB. The GeneXpert assay identified 10 and 16 positive MTB from smear 1 and smear 2 samples which were microscopic negative.
Topics: Humans; Mycobacterium tuberculosis; Retrospective Studies; Sputum; Ghana; Female; Hospitals, Teaching; Adult; Male; Microscopy; Middle Aged; Tuberculosis, Pulmonary; Young Adult; Adolescent; Sensitivity and Specificity; Aged; Molecular Diagnostic Techniques; Child; Child, Preschool
PubMed: 38956504
DOI: 10.1186/s12879-024-09566-9 -
BMC Infectious Diseases Jul 2024Multi-drug or rifamycin-resistant tuberculosis (MDR/RR-TB) is an important public health concern, including in settings with high HIV prevalence. TB drug resistance can... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Multi-drug or rifamycin-resistant tuberculosis (MDR/RR-TB) is an important public health concern, including in settings with high HIV prevalence. TB drug resistance can be directly transmitted or arise through resistance acquisition during first-line TB treatment. Limited evidence suggests that people living with HIV (PLHIV) might have an increased risk of acquired rifamycin-resistance (ARR).
METHODS
To assess HIV as a risk factor for ARR during first-line TB treatment, a systematic review and meta-analysis was conducted. ARR was defined as rifamycin-susceptibility at treatment start with rifamycin-resistance diagnosed during or at the end of treatment, or at recurrence. PubMed/MEDLINE, CINAHL, Cochrane Library, and Google Scholar databases were searched from inception to 23 May 2024 for articles in English; conference abstracts were also searched from 2004 to 2021. The Mantel-Haenszel random-effects model was used to estimate the pooled odds ratio of any association between HIV and ARR among individuals receiving first-line TB treatment.
RESULTS
Ten studies that included data collected between 1990 and 2014 were identified: five from the United States, two from South Africa and one each from Uganda, India and Moldova. A total of 97,564 individuals were included across all studies, with 13,359 (13.7%) PLHIV. Overall, 312 (0.32%) acquired rifamycin-resistance, among whom 115 (36.9%) were PLHIV. The weighted odds of ARR were 4.57 (95% CI, 2.01-10.42) times higher among PLHIV compared to HIV-negative individuals receiving first-line TB treatment.
CONCLUSION
The available data, suggest that PLHIV have an increased ARR risk during first-line TB treatment. Further research is needed to clarify specific risk factors, including advanced HIV disease and TB disease severity. Given the introduction of shorter, 4-month rifamycin-based regimens, there is an urgent need for additional data on ARR, particularly for PLHIV.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO CRD42022327337.
Topics: Humans; HIV Infections; Rifamycins; Antitubercular Agents; Tuberculosis, Multidrug-Resistant; Risk Factors; Mycobacterium tuberculosis; South Africa
PubMed: 38956461
DOI: 10.1186/s12879-024-09514-7 -
Cell Proliferation Jul 2024Tuberculosis (TB) is a chronic disease caused by Mycobacterium tuberculosis (M.tb) and responsible for millions of deaths worldwide each year. It has a complex... (Review)
Review
Tuberculosis (TB) is a chronic disease caused by Mycobacterium tuberculosis (M.tb) and responsible for millions of deaths worldwide each year. It has a complex pathogenesis that primarily affects the lungs but can also impact systemic organs. In recent years, single-cell sequencing technology has been utilized to characterize the composition and proportion of immune cell subpopulations associated with the pathogenesis of TB disease since it has a high resolution that surpasses conventional techniques. This paper reviews the current use of single-cell sequencing technologies in TB research and their application in analysing specimens from various sources of TB, primarily peripheral blood and lung specimens. The focus is on how these technologies can reveal dynamic changes in immune cell subpopulations, genes and proteins during disease progression after M.tb infection. Based on the current findings, single-cell sequencing has significant potential clinical value in the field of TB research. Next, we will focus on the real-world applications of the potential targets identified through single-cell sequencing for diagnostics, therapeutics and the development of effective vaccines.
PubMed: 38956399
DOI: 10.1111/cpr.13698 -
NPJ Vaccines Jul 2024The Mycobacterial growth inhibition assay (MGIA) is an ex-vivo assay used to measure the overall functional immune response elicited by infection or vaccination. In...
The Mycobacterial growth inhibition assay (MGIA) is an ex-vivo assay used to measure the overall functional immune response elicited by infection or vaccination. In tuberculosis (TB) vaccine development, MGIA is a potentially important tool for preclinical evaluation of early-stage vaccine candidates to complement existing assays, and to potentially reduce the need for lengthy and costly pathogenic Mycobacterium tuberculosis (Mtb) animal challenge experiments. The conventional method of MGIA in mice entails directly infecting mixed cell cultures, most commonly splenocytes, from immunised mice with mycobacteria. However, this direct infection of mixed cell populations may yield unreliable results and lacks sufficient sensitivity to discriminate well between different vaccines due to the low number of mycobacteria-permissive cells. Here, we modified the assay by inclusion of mycobacteria-infected congenic murine macrophage cell lines as the target cells, and by measuring the total number of killed cells rather than the relative reduction between different groups. Thus, using splenocytes from Mycobacterium bovis BCG immunised mice, and J774 and MH-S (BALB/c background) or BL/6-M (C57Bl/6 background) macrophage cell lines, we demonstrated that the modified assay resulted in at least 26-fold greater mycobacterial killing per set quantity of splenocytes as compared to the conventional method. This increased sensitivity of measuring mycobacterial killing was confirmed using both the standard culture forming unit (CFU) assay and luminescence readings of luciferase-tagged virulent and avirulent mycobacteria. We propose that the modified MGIA can be used as a highly calibrated tool for quantitating the killing capacity of immune cells in preclinical evaluation of vaccine candidates for TB.
PubMed: 38956057
DOI: 10.1038/s41541-024-00906-z