Tuberculosis最新文献

Tuberculosis (TB) remains a highly lethal infectious disease. The primary preventive measure is Bacille Calmette-Guérin (BCG), a live attenuated vaccine. However, the current intradermal vaccination method with 10-dose vials faces challenges such as inadequate infant injection, inaccurate dispensing, and unstable storage. Researchers have explored Microneedle (MN) technology to address these concerns as a transdermal vaccine delivery approach. MNs offer painless administration, convenience, improved immunogenicity, and vaccine stability. This study aimed to develop a coated MN system using a micro-dispensing technique at a low temperature (4 °C) and specific excipients for precise dosing and vaccine viability enhancement. Long-term storage stability revealed enhanced storage stability of the BCG-coated MN (BCG-MN) vaccine, maintaining a survival rate of over 60 % for 8 weeks at -20 °C. In vivo, vaccination tests using BCG-MN patches on guinea pigs exhibited no adverse reactions. Moreover, the BCG-MN vaccine patches demonstrated superior immune response compared to injections, suggesting that this BCG vaccine-coated MN platform has the potential as a single-dose TB vaccination technology, offering precise dosing control and enhanced immune effectiveness with high storage stability.

The limitations of existing mouse models of lung infection with Mycobacteroides abscessus impede drug discovery and development. In contrast to current animal models that introduce NTM intravenously or by intranasal/intra-tracheal instillation or via bronchoscopy-guided insufflation, we developed a dry powder inhalation (DPI) of M. abscessus ATCC 19977 that generated paucibacillary lung infection and histopathology in immunocompetent mice. Swiss outbred mice receiving ∼1000 (3-log) colony forming units (CFU) of M. abscessus/gram lung tissue via the DPI administered by nose-only inhalation for 90 s showed peak bacterial burden of ∼3.35-log CFU/g in the lungs after 28 days. This was maintained at ∼2-log/g from Day 35 through 56 in the lungs, but not in the spleen. Histopathology indicated increasing severity of inflammation, fibrosis and lung consolidation. Bacteria were rarely recovered from spleen, and histopathological examination indicated partial resolution in the spleen between Days 49-56. The DPI, prepared by freeze-drying log-phase liquid culture with cryoprotectants was formulated to possess aerosol characteristics suitable for alveolar deposition. Aerosol exposure to inoculum mimics natural airborne infection. Non-invasive aerosol infection is convenient, inexpensive, does not require special equipment or extensive training and mitigates stress to animals, but biosafety level 3 containment is recommended to mitigate risk to experimenters.

Background: Immune imbalance is crucial in tuberculosis pathogenesis and may be modulated by mesenchymal stem cells (MSCs). However, how MSCs regulate the host's response to Mycobacterium tuberculosis (Mtb) is unclear.

Methods: Human umbilical cord-derived MSCs were co-cultured with Mtb-infected THP-1 macrophages. The intracellular release of ROS in macrophages was measured by DCFH-DA. Cytokine expression was measured by RT-qPCR, apoptosis by Annexin V/PI assay, and pyroptosis markers by Western blotting. Differentially expressed genes (DEGs) in Mtb-infected THP-1 co-cultured with or without MSCs were identified by RNA-seq and potential signaling pathways were analyzed through bioinformatics.

Results: The fibroblastic morphology of MSCs exhibited 95 % positivity for CD73, CD90, and CD105, while the positivity rate for negative marker HLA-DR was less than 2 %. In Mtb-infected THP-1 macrophages, co-culturing with MSCs increased ROS release, cytokines expression (IL-1β, IL-6, TNF-α), apoptosis, and pyroptosis markers (NLRP3, Caspase-1, and GSDMD). Comparative transcriptome analysis identified 347 up-regulated and 291 down-regulated DEGs, primarily associated with receptor-ligand interactions and enriched in cytokine signaling pathways including JAK-STAT, TNF, ferroptosis, and autophagy.

Conclusion: MSCs could enhance the macrophages' immune response to Mtb by activating immune receptors and inflammatory signaling pathways.

Tetracycline analogs from the minocycline family have recently shown promise for the treatment of non-tuberculous mycobacterial infections. However, current tetracycline and minocycline therapeutics can be limited by tolerability, stability, or inactivation by TetX. In this study, a series of novel 9-heteroaryl substituted minocycline analogs were designed and synthesized, which resulted in analogs with good in vitro activity against Mycobacterium tuberculosis and Mycobacterium abscessus, stability in water for more than 7 days, avoidance of TetX inactivation in M. abscessus, and a lack of cytotoxicity in HepG2 mammalian cells. In vivo efficacy was confirmed for the tetracycline analogs in an acute model of GM-CSF KO mice infected with M. abscessus, displaying superior efficacy to standard-of-care antibiotic clarithromycin. Molecular modeling and potentiation assays demonstrate avoidance of MabTetX, and the structure-activity relationships of the series are discussed herein for M. tuberculosis and M. abscessus.

We surveyed 15 persons with a medical qualification, 133 graduate students doing biomedical research and 56 students or working people with a college education in any discipline. Questions were designed to gauge awareness about inhaled therapies for tuberculosis (TB), non-tubercular mycobacterial lung disease (NTM-LD) and idiopathic pulmonary fibrosis (IPF). Respondents from six cities in North India, aged between 21 and 57 years answered 20 questions. All physicians, 99.25 % of graduate students and 85.71 % of the rest were aware and positive about inhalations for asthma, but these proportions fell to 69.92 and 66.07 in respect of other diseases. All respondents in the first two categories agreed that it was easy to train patients in the use of inhalation devices, while the third group was unanimous that there would be no aversion to using inhalation devices. A question asking whether the respondent would prescribe or opt for inhaled therapies for own use elicited an affirmative answer only from 40.00 % of physicians, 43.61 % of researchers and 23.21 % of college-educated persons (overall: 37.56 %). We concluded that inhaled therapies for diseases other than asthma are not well known and find limited acceptance among the populations sampled.

Extracellular vesicles (EVs) have recently emerged as a source of microbe-specific biomarkers for disease diagnosis. In the present study, we evaluated the utility of pleural fluid-derived extracellular vesicles (pEVs) as a source of Mycobacterium tuberculosis (M. tb.) antigens for pleural TB (pTB) diagnosis. EVs were isolated from pleural fluid (PF) samples and were characterized by scanning electron microscopy, and immunoblotting by targeting CD63 and LAMP2 markers. Antigen-detection ELISAs were developed for 2 M.tb.-specific antigens, MPT51 and MPT64 in pEVs (pEV-ELISA) and direct PF samples (PF-ELISA), and were evaluated on n = 86 samples in a blinded manner. Cut-off values were calculated by ROC-curve analysis to achieve 90 % (95%CI:73.47-97.89) and 86.67 % (95%CI:69.28-96.24) specificity for MPT51 and MPT64 pEV-ELISA respectively. The sensitivity of pEV-ELISA was 71.43 % (95%CI; 29.04-96.33) for MPT51 antigen and 57.14 % (95%CI; 18.41-90.1) for MPT64 antigen in the 'Definite' pTB group, while in the 'Definite and Probable' pTB group, the sensitivity was 62.86 % (95%CI:44.92-78.53) for MPT51 and 65.71 % (95%CI:47.79-80.87) for MPT64. The performance of PF-ELISA was sub-optimal, with 28.57 % (95%CI:3.67-70.96) and 14.29 % (95%CI:0.36-57.87) sensitivity for MPT51 and MPT64 in 'Definite' pTB group respectively. We conclude that M. tb.-antigens are concentrated in the EV-fraction of PF samples and EVs can be utilized for antigen-detection assays for pTB diagnosis.

Multi-drug-resistant Mycobacterium tuberculosis is an escalating global health problem, and a strong pipeline of novel compounds is needed to combat rising antimicrobial resistance. Ecumicin is a novel analogue of the natural antimycobacterial cyclic peptide ecumicin, with selective activity against Mycobacterium species. The activity of ecumicin∗ was compared to that of frontline tuberculosis therapies under in vitro conditions representative of niches where M. tuberculosis resides in the human lung. M. tuberculosis expressing luciferase was cultured in defined 7H9-based media containing glucose, butyrate, valerate, acidified glucose, low or high cholesterol concentrations, or intracellularly in human THP-1 and mouse RAW264.7 macrophages. Ecumicin∗ effectively killed M. tuberculosis under all assay conditions. The IC₉₀ of ecumicin∗ was increased in acidified 7H9 media, and both IC₉₀ and AUC₉₀ values were increased in valerate, cholesterol, high cholesterol culture media. In time-kill assays, anti-M. tuberculosis activity of ecumicin∗ was sustained for 28 days. By comparison, IC₅₀ and IC₉₀ of isoniazid were decreased in butyrate and cholesterols medias, and mycobacterial regrowth occurred in glucose and cholesterol culture medias within 14 days at high isoniazid concentrations. Ecumicin∗ inhibited M. tuberculosis growth in THP-1 macrophages, and at higher IC₉₀ in mouse RAW264.7 macrophages. Drug testing under disease-relevant conditions is important prior to in vivo examination, and ecumicin∗ has proven effective in multiple in vitro conditions typical of the lung environment of tuberculosis patients.

Background: Interferon-γ release assays (IGRAs) for tuberculosis infection (TBI) cannot distinguish different stages of the TBI spectrum (including spontaneously cleared infection). We investigated patterns of Mtb-specific blood mediators in people with and without TBI during tuberculosis preventive therapy (TPT).

Methods: Individuals with likelihood of recent Mtb exposure, aged 15-25 years, with valid IGRA results, in whom tuberculosis (TB) had been excluded, were included. Persons with TBI were sampled prior to TPT (IGRA + pre-treatment, n = 15) or after completion of TPT (IGRA + post-treatment, n = 15). Five persons without TBI were included as controls (IGRA-). Levels of 40 mediators related to TB immune control in blood incubated with Mtb antigens in the QuantiFERON-TB Plus® kit were assessed with electrochemiluminescence assay and compared between participant categories.

Results: The concentration of 10 mediators (GM-CSF, interferon-γ, IL-2, I-TAC, IL-12, IP-10, I-309, MCP-2, MIG, and VEGF) significantly differed between IGRA + pre-treatment and IGRA-. A non-significant trend in levels of these markers was observed between IGRA + pre-treatment, IGRA + post-treatment and IGRA-. Based on these mediators two clusters were identified: A (n = 16), including 5 IGRA-, 4 IGRA + pre-treatment, 7 IGRA + post-treatment and B (n = 19), including 11 IGRA + pre-treatment and 8 IGRA + post-treatment.

Conclusion: Plasma levels of several Mtb-triggered mediators differed with regard to TBI status among persons recently exposed to TB, suggesting the potential for alternative markers to assess TBI status. Longitudinal analysis of these mediators during TPT is warranted to explore whether these markers can be used to assess likelihood of persistence of viable bacilli in Mtb-exposed individuals.

Clinicaltrials: govID:NCT05621343.

Purpose: Tuberculosis (TB) remains a significant public health concern globally. Bacille Calmette-Guérin (BCG) vaccination is widely used, but scar formation post-vaccination is not universal, which raises concerns about its efficacy. The Mantoux test is used to assess the immune response following BCG vaccination. This study aims to evaluate the prevalence of BCG scar formation among vaccinated children and its correlation with Mantoux test reactions.

Methods: This quantitative, cross-sectional descriptive study was conducted among children aged 3 months to 9 years at the vaccination office in Omdawanban, Sudan, from September to October 2021. Data were collected using structured surveys and the Mantoux skin test.

Results: Out of 350 vaccinated children, 285 (81.4 %) exhibited a visible BCG scar, while 65 (18.6 %) did not. Mantoux test positivity was observed in 132 children (37.7 %). A significant association was found between the presence of a BCG scar and a positive Mantoux test result (p < 0.05), with 39.3 % of children with a visible scar showing positive Mantoux results compared to 30.8 % of children without a scar. The likelihood of a positive Mantoux test was 3.2 times higher in children with a visible BCG scar (OR = 3.2, 95 % CI [1.8-5.8]). Mantoux positivity also varied by age, with the highest rate (41.2 %) observed among children aged 5-9 years (p = 0.03).

Conclusions: There is a significant association between BCG scar formation and Mantoux test positivity. Improved training for healthcare workers and better education for mothers about vaccination are recommended.