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1.
Infect Immun ; 89(12): e0031521, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1575412

ABSTRACT

Mycobacterium tuberculosis is a chronic infectious disease pathogen. To date, tuberculosis is a major infectious disease that endangers human health. To better prevent and treat tuberculosis, it is important to study the pathogenesis of M. tuberculosis. Based on early-stage laboratory research results, in this study, we verified the upregulation of sod2 in Bacillus Calmette-Guérin (BCG) and H37Rv infection. By detecting BCG/H37Rv intracellular survival in sod2-silenced and sod2-overexpressing macrophages, sod2 was found to promote the intracellular survival of BCG/H37Rv. miR-495 then was determined to be downregulated by BCG/H37Rv. BCG/H37Rv can upregulate sod2 expression by miR-495 to promote the intracellular survival of BCG/H37Rv through a decline in ROS levels. This study provides a theoretical basis for developing new drug targets and treating tuberculosis.


Subject(s)
Macrophages/microbiology , Macrophages/physiology , MicroRNAs/genetics , Mycobacterium tuberculosis/physiology , Reactive Oxygen Species/metabolism , Superoxide Dismutase/genetics , Tuberculosis/etiology , Tuberculosis/metabolism , Disease Susceptibility , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Mycobacterium bovis , Superoxide Dismutase/metabolism , Tuberculosis/pathology
2.
PLoS One ; 16(9): e0257647, 2021.
Article in English | MEDLINE | ID: covidwho-1430547

ABSTRACT

INTRODUCTION: Despite the exalted status of sputum mycobacterial load for gauging pulmonary tuberculosis treatment and progress, Chest X-rays supplement valuable information for taking instantaneous therapeutic decisions, especially during the COVID-19 pandemic. Even though literature on individual parameters is overwhelming, few studies have explored the interaction between radiographic parameters denoting severity with mycobacterial burden signifying infectivity. By using a sophisticated approach of integrating Chest X-ray parameters with sputum mycobacterial characteristics, evaluated at all the three crucial time points of TB treatment namely pre-treatment, end of intensive phase and completion of treatment, utilizing the interactive Cox Proportional Hazards model, we aimed to precisely deduce predictors of unfavorable response to TB treatment. MATERIALS AND METHOD: We extracted de-identified data from well characterized clinical trial cohorts that recruited rifampicin-sensitive Pulmonary TB patients without any comorbidities, taking their first spell of anti-tuberculosis therapy under supervision and meticulous follow up for 24 months post treatment completion, to accurately predict TB outcomes. Radiographic data independently obtained, interpreted by two experienced pulmonologists was collated with demographic details and, sputum smear and culture grades of participants by an independent statistician and analyzed using the Cox Proportional Hazards model, to not only adjust for confounding factors including treatment effect, but also explore the interaction between radiological and bacteriological parameters for better therapeutic application. RESULTS: Of 667 TB patients with data available, cavitation, extent of involvement, lower zone involvement, smear and culture grade at baseline were significant parameters predisposing to an unfavorable TB treatment outcome in the univariate analysis. Reduction in radiological lesions in Chest X-ray by at least 50% at 2 months and 75% at the end of treatment helped in averting unfavorable responses. Smear and Culture conversion at the end of 2 months was highly significant as a predictor (p<0.001). In the multivariate analysis, the adjusted hazards ratios (HR) for an unfavorable response to TB therapy for extent of involvement, baseline cavitation and persistence (post treatment) were 1.21 (95% CI: 1.01-1.44), 1.73 (95% CI: 1.05-2.84) and 2.68 (95% CI: 1.4-5.12) respectively. A 3+ smear had an HR of 1.94 (95% CI: 0.81-4.64). Further probing into the interaction, among patients with 3+ and 2+ smears, HRs for cavitation were 3.26 (95% CI: 1.33-8.00) and 1.92 (95% CI: 0.80-4.60) while for >2 zones, were 3.05 (95% CI: 1.12-8.23) and 1.92 (95% CI: 0.72-5.08) respectively. Patients without cavitation, zonal involvement <2, and a smear grade less than 2+ had a better prognosis and constituted minimal disease. CONCLUSION: Baseline Cavitation, Opacities occupying >2 zones and 3+ smear grade individually and independently forecasted a poorer TB outcome. The interaction model revealed that Zonal involvement confined to 2 zones, without a cavity and smear grade up to 2+, constituting "minimal disease", had a better prognosis. Radiological clearance >50% along with smear conversion at the end of intensive phase of treatment, observed to be a reasonable alternative to culture conversion in predicting a successful outcome. These parameters may potentially take up key positions as stratification factors for future trials contemplating on shorter TB regimens.


Subject(s)
Mycobacterium tuberculosis/physiology , Rifampin/therapeutic use , Sputum/microbiology , Tuberculosis, Pulmonary/diagnostic imaging , Tuberculosis, Pulmonary/drug therapy , Adult , Female , Humans , Kaplan-Meier Estimate , Male , Multivariate Analysis , Proportional Hazards Models , Rifampin/pharmacology , Treatment Outcome , Tuberculosis, Pulmonary/microbiology , Young Adult
3.
Microbiologyopen ; 10(3): e1211, 2021 06.
Article in English | MEDLINE | ID: covidwho-1281235

ABSTRACT

Tuberculosis (TB) is the leading cause of death in humans by a single infectious agent worldwide with approximately two billion humans latently infected with the bacterium Mycobacterium tuberculosis. Currently, the accepted method for controlling the disease is Tuberculosis Directly Observed Treatment Shortcourse (TB-DOTS). This program is not preventative and individuals may transmit disease before diagnosis, thus better understanding of disease transmission is essential. Using whole-genome sequencing and single nucleotide polymorphism analysis, we analyzed genomes of 145 M. tuberculosis clinical isolates from active TB cases from the Rubaga Division of Kampala, Uganda. We established that these isolates grouped into M. tuberculosis complex (MTBC) lineages 1, 2, 3, and 4, with the most isolates grouping into lineage 4. Possible transmission pairs containing ≤12 SNPs were identified in lineages 1, 3, and 4 with the prevailing transmission in lineages 3 and 4. Furthermore, investigating DNA codon changes as a result of specific SNPs in prominent virulence genes including plcA and plcB could indicate potentially important modifications in protein function. Incorporating this analysis with corresponding epidemiological data may provide a blueprint for the integration of public health interventions to decrease TB transmission in a region.


Subject(s)
Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/isolation & purification , Polymorphism, Single Nucleotide , Tuberculosis/microbiology , Bacterial Proteins/genetics , Cities/statistics & numerical data , Cross-Sectional Studies , Genome, Bacterial , Genotype , Humans , Mycobacterium tuberculosis/classification , Mycobacterium tuberculosis/physiology , Phylogeny , Tuberculosis/epidemiology , Tuberculosis/transmission , Uganda/epidemiology , Virulence Factors/genetics , Whole Genome Sequencing
4.
PLoS One ; 16(6): e0253169, 2021.
Article in English | MEDLINE | ID: covidwho-1278188

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has created a remarkable and varying impact in every country, inciting calls for broad attention. Recently, the Bacillus Calmette-Guérin (BCG) vaccination has been regarded as a potential candidate to explain this difference. Herein, we hypothesised that the past epidemic of Mycobacterium tuberculosis (M. tuberculosis) may act as a latent explanatory factor for the worldwide differences seen in COVID-19 impact on mortality and incidence. We compared two indicators of past epidemic of M. tuberculosis, specifically, incidence (90 countries in 1990) and mortality (28 countries in 1950), with the mortality and incidence of COVID-19. We determined that an inverse relationship existed between the past epidemic indicators of M. tuberculosis and current COVID-19 impact. The rate ratio of the cumulative COVID-19 mortality per 1 million was 2.70 (95% confidence interval [CI]: 1.09-6.68) per 1 unit decrease in the incidence rate of tuberculosis (per 100,000 people). The rate ratio of the cumulative COVID-19 incidence per 1 million was 2.07 (95% CI: 1.30-3.30). This association existed even after adjusting for potential confounders (rate of people aged 65 over, diabetes prevalence, the mortality rate from cardiovascular disease, and gross domestic product per capita), leading to an adjusted rate ratio of COVID-19 mortality of 2.44, (95% CI: 1.32-4.52) and a COVID-19 incidence of 1.31 (95% CI: 0.97-1.78). After latent infection, Mycobacterium survives in the human body and may continue to stimulate trained immunity. This study suggests a possible mechanism underlying the region-based variation in the COVID-19 impact.


Subject(s)
BCG Vaccine/immunology , COVID-19/prevention & control , Mycobacterium tuberculosis/immunology , SARS-CoV-2/isolation & purification , Tuberculosis/immunology , COVID-19/epidemiology , COVID-19/virology , Epidemics , Humans , Incidence , Models, Theoretical , Mycobacterium tuberculosis/physiology , Prevalence , SARS-CoV-2/physiology , Survival Rate , Tuberculosis/epidemiology , Tuberculosis/microbiology , Vaccination
5.
Front Immunol ; 12: 633297, 2021.
Article in English | MEDLINE | ID: covidwho-1133913

ABSTRACT

The C-X-C motif chemokine ligand 17 (CXCL17) is chemotactic for myeloid cells, exhibits bactericidal activity, and exerts anti-viral functions. This chemokine is constitutively expressed in the respiratory tract, suggesting a role in lung defenses. However, little is known about the participation of CXCL17 against relevant respiratory pathogens in humans. Here, we evaluated the serum levels and lung tissue expression pattern of CXCL17 in a cohort of patients with severe pandemic influenza A(H1N1) from Mexico City. Peripheral blood samples obtained on admission and seven days after hospitalization were processed for determinations of serum CXCL17 levels by enzyme-linked immunosorbent assay (ELISA). The expression of CXCL17 was assessed by immunohistochemistry (IHQ) in lung autopsy specimens from patients that succumbed to the disease. Serum CXCL17 levels were also analyzed in two additional comparative cohorts of coronavirus disease 2019 (COVID-19) and pulmonary tuberculosis (TB) patients. Additionally, the expression of CXCL17 was tested in lung autopsy specimens from COVID-19 patients. A total of 122 patients were enrolled in the study, from which 68 had pandemic influenza A(H1N1), 24 had COVID-19, and 30 with PTB. CXCL17 was detected in post-mortem lung specimens from patients that died of pandemic influenza A(H1N1) and COVID-19. Interestingly, serum levels of CXCL17 were increased only in patients with pandemic influenza A(H1N1), but not COVID-19 and PTB. CXCL17 not only differentiated pandemic influenza A(H1N1) from other respiratory infections but showed prognostic value for influenza-associated mortality and renal failure in machine-learning algorithms and regression analyses. Using cell culture assays, we also identified that human alveolar A549 cells and peripheral blood monocyte-derived macrophages increase their CXCL17 production capacity after influenza A(H1N1) pdm09 virus infection. Our results for the first time demonstrate an induction of CXCL17 specifically during pandemic influenza A(H1N1), but not COVID-19 and PTB in humans. These findings could be of great utility to differentiate influenza and COVID-19 and to predict poor prognosis specially at settings of high incidence of pandemic A(H1N1). Future studies on the role of CXCL17 not only in severe pandemic influenza, but also in seasonal influenza, COVID-19, and PTB are required to validate our results.


Subject(s)
Biomarkers/metabolism , Chemokines, CXC/metabolism , Influenza A Virus, H1N1 Subtype/physiology , Influenza, Human/diagnosis , Lung/metabolism , Mycobacterium tuberculosis/physiology , SARS-CoV-2/physiology , Adult , Aged , COVID-19/diagnosis , COVID-19/mortality , Chemokines, CXC/genetics , Chemokines, CXC/immunology , Cohort Studies , Disease Progression , Female , Humans , Influenza, Human/mortality , Lung/pathology , Male , Mexico , Middle Aged , Pandemics , Patient Outcome Assessment , Prognosis , Survival Analysis , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/mortality , Young Adult
6.
Front Immunol ; 11: 594572, 2020.
Article in English | MEDLINE | ID: covidwho-1083323

ABSTRACT

Mycobacterium tuberculosis (Mtb), the causative organism of pulmonary tuberculosis (PTB) now infects more than half of the world population. The efficient transmission strategy of the pathogen includes first remaining dormant inside the infected host, next undergoing reactivation to cause post-primary tuberculosis of the lungs (PPTBL) and then transmit via aerosol to the community. In this review, we are exploring recent findings on the role of bone marrow (BM) stem cell niche in Mtb dormancy and reactivation that may underlie the mechanisms of PPTBL development. We suggest that pathogen's interaction with the stem cell niche may be relevant in potential inflammation induced PPTBL reactivation, which need significant research attention for the future development of novel preventive and therapeutic strategies for PPTBL, especially in a post COVID-19 pandemic world. Finally, we put forward potential animal models to study the stem cell basis of Mtb dormancy and reactivation.


Subject(s)
Bone Marrow Cells/microbiology , Mycobacterium tuberculosis/physiology , Tuberculosis, Pulmonary , Virus Activation/physiology , Virus Latency/physiology , COVID-19 , Humans , Mesenchymal Stem Cells/microbiology , SARS-CoV-2 , Stem Cell Niche/physiology , Tuberculosis, Pulmonary/microbiology , Tuberculosis, Pulmonary/transmission
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