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The Lancet. Microbe Feb 2024Clinical bedaquiline resistance predominantly involves mutations in mmpR5 (Rv0678). However, mmpR5 resistance-associated variants (RAVs) have a variable relationship... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Clinical bedaquiline resistance predominantly involves mutations in mmpR5 (Rv0678). However, mmpR5 resistance-associated variants (RAVs) have a variable relationship with phenotypic Mycobacterium tuberculosis resistance. We did a systematic review to assess the maximal sensitivity of sequencing bedaquiline resistance-associated genes and evaluate the association between RAVs and phenotypic resistance, using traditional and machine-based learning techniques.
METHODS
We screened public databases for articles published from database inception until Oct 31, 2022. Eligible studies performed sequencing of at least mmpR5 and atpE on clinically sourced M tuberculosis isolates and measured bedaquiline minimum inhibitory concentrations (MICs). A bias risk scoring tool was used to identify bias. Individual genetic mutations and corresponding MICs were aggregated, and odds ratios calculated to determine association of mutations with resistance. Machine-based learning methods were used to define test characteristics of parsimonious sets of diagnostic RAVs, and mmpR5 mutations were mapped to the protein structure to highlight mechanisms of resistance. This study was registered in the PROSPERO database (CRD42022346547).
FINDINGS
18 eligible studies were identified, comprising 975 M tuberculosis isolates containing at least one potential RAV (mutation in mmpR5, atpE, atpB, or pepQ), with 201 (20·6%) showing phenotypic bedaquiline resistance. 84 (29·5%) of 285 resistant isolates had no candidate gene mutation. Sensitivity and positive predictive value of taking an any mutation approach was 69% and 14%, respectively. 13 mutations, all in mmpR5, had a significant association with a resistant MIC (adjusted p<0·05). Gradient-boosted machine classifier models for predicting intermediate or resistant and resistant phenotypes both had receiver operator characteristic c statistic of 0·73 (95% CI 0·70-0·76). Frameshift mutations clustered in the α1 helix DNA-binding domain, and substitutions in the α2 and α3 helix hinge region and in the α4 helix-binding domain.
INTERPRETATION
Sequencing candidate genes is insufficiently sensitive to diagnose clinical bedaquiline resistance, but where identified, some mutations should be assumed to be associated with resistance. Genomic tools are most likely to be effective in combination with rapid phenotypic diagnostics. This study was limited by selective sampling in contributing studies and only considering single genetic loci as causative of resistance.
FUNDING
Francis Crick Institute and National Institute of Allergy and Infectious Diseases at the National Institutes of Health.
Topics: United States; Humans; Antitubercular Agents; Diarylquinolines; Tuberculosis; Mycobacterium tuberculosis; Genomics
PubMed: 38215766
DOI: 10.1016/S2666-5247(23)00317-8 -
IBRO Neuroscience Reports Dec 2023, the pathogen that causes human leprosy, has a unique affinity for infecting and persisting inside Schwann cells, the principal glia of the peripheral nervous system.... (Review)
Review
, the pathogen that causes human leprosy, has a unique affinity for infecting and persisting inside Schwann cells, the principal glia of the peripheral nervous system. Several studies have focused on this intricate host-pathogen interaction as an attempt to advance the current knowledge of the mechanisms governing nerve destruction and disease progression. However, during the chronic course of leprosy neuropathy, Schwann cells can respond to and internalize both live and dead and bacilli-derived antigens, and this may result in divergent cellular pathobiological responses. This may also distinctly contribute to tissue degeneration, failure to repair, inflammatory reactions, and nerve fibrosis, hallmarks of the disease. Therefore, the present study systematically searched for published studies on -Schwann cell interaction to summarize the findings and provide a focused discussion of Schwann cell dynamics following challenge with leprosy bacilli.
PubMed: 38204570
DOI: 10.1016/j.ibneur.2023.05.009 -
Journal of Clinical Tuberculosis and... Feb 2024Tuberculosis is an infectious disease caused by and leads to serious complications if left untreated. Some strains of are multi-drug resistant and require treatment... (Review)
Review
BACKGROUND
Tuberculosis is an infectious disease caused by and leads to serious complications if left untreated. Some strains of are multi-drug resistant and require treatment with newer drugs. Bedaquiline based treatment regimens have been used in patients who are diagnosed with drug resistant tuberculosis. The aim of this study is to assess the efficacy and safety profile of bedaquiline-based treatment regimens using a systematic review of existing literature and -analysis.
METHODS
In this study, an electronic search was carried out on PubMed, ScienceDirect, and Cochrane library to find relevant literature from March 2021 onwards. Random-effects model was used to assess pooled treatment success rate and 95 % CIs. p-value of <0.05 was suggestive of publication bias. The review is registered with PROSPERO: CRD42023432748.
RESULTS
A total of 543 articles were retrieved by database searching, out of which 12 new studies met the inclusion criteria. The total number of articles included in the review was 41 including 36 observational studies (having a total of 9,934 patients) and 5 experimental studies (having a total of 468 patients). The pooled treatment success rate was 76.9 % (95 % CI, 72.9-80.4) in the observational studies and 81.7 % (95 % CI, 67.2-90.7) in the experimental studies. Further subgroup analysis was done on the basis of treatment regimens containing bedaquiline only and treatment regimens containing bedaquiline and delamanid. The pooled treatment success rate in the studies consisting of patients who were treated with regimens containing bedaquiline only was 78.4 % (95 % CI, 74.2-82.1) and 73.6 % (95 % CI, 64.6-81.0) in studies consisting of patients who were treated with regimens containing bedaquiline and delamanid. There was no evidence of publication bias.
CONCLUSIONS
In patients of drug resistant tuberculosis having highly resistant strains of undergoing treatment with bedaquiline-based regimen demonstrate high rates of culture conversion and treatment success. Moreover, the safety profile of bedaquiline-based regimens is well-established in all studies.
PubMed: 38152568
DOI: 10.1016/j.jctube.2023.100405 -
Tuberkuloz Ve Toraks Dec 2023Non-tuberculous mycobacteria (NTM) can cause diseases not only in individuals with compromised immune systems but also in those with normal immune function. This study...
Non-tuberculous mycobacteria (NTM) can cause diseases not only in individuals with compromised immune systems but also in those with normal immune function. This study aimed to compare the prevalence of NTM in Türkiye and worldwide between 2012 and 2022. This study was designed following the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) procedure. A systematic search was conducted between January 2012 and September 2022 using different electronic databases, including Pubmed, Medline, Embase, Web of Science, Ebsco, Scopus, Türk Medline, and Google Scholar. During the literature review process, titles and abstracts were examined and the full texts of the studies were accessed. In 13 research articles from Türkiye included in the study, a total of 17.293 samples were studied and a total of 1304 NTM (7.54%) strains were isolated from these samples. Among the 1304 NTM strains reported from Türkiye, the top three most frequently isolated species were M. abscessus (29.83%), M. lentiflavum (14.97%), M. fortuitum (14.38%). In 35 studies included from around the world, a total of 512.626 samples were studied and a total of 12.631 NTM (2.46%) strains were isolated from these samples. Among the 12631 NTM strains isolated, the top three most frequently isolated species were M. intracellulare (28.13%), M. avium (17.70%) and M. abscessus (14.88%). This study unveiled the global prevalence of NTM-infected patients, detailing species distribution and microbiological diagnostic methods. Variations in NTM spread were observed, influenced by diverse factors.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Prevalence; Turkey
PubMed: 38152011
DOI: 10.5578/tt.20239609 -
International Journal of... 2023Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively...
BACKGROUND
Mycobacterium nebraskense is a rare, slow growing nontuberculous mycobacterium species with limited documented cases. This systematic review aims to comprehensively analyze the clinical characteristics, presentation, and management of M. nebraskense infections by analyzing the available literature, including a newly reported case that we present in this article.
METHODS
A comprehensive search was conducted using PubMed and Google Scholar to identify relevant cases up to October 2023. Only seven reported cases were found, highlighting the scarcity of information on this pathogen.
RESULTS
Our analysis revealed several key findings. First, gender disparities were observed, with females being more susceptible to M. nebraskense infections. Additionally, a significant portion of patients presented with asymptomatic infections. Most affected individuals were over the age of 60, emphasizing potential age-related susceptibility. Comorbidity profiles varied widely among cases, and patients with preexisting lung comorbidities were at an increased risk of infection. The decision to treat or observe depended on clinical presentation, with even immunosuppressed individuals not always requiring treatment. Regarding treatment, we proposed an empirical approach with amikacin, clarithromycin, or rifabutin, considering the reported resistance to doxycycline and minocycline. Combination therapy was commonly employed to minimize resistance development, consistent with mycobacterial infection management.
CONCLUSION
This study underscores the need for further research to validate these findings and enhance our understanding of M. nebraskense infections. As limited data are available, this review aims to provide valuable insights into a rare and emerging pathogen to guide clinical practice and future research endeavors.
Topics: Female; Humans; Mycobacterium Infections, Nontuberculous; Mycobacterium; Nontuberculous Mycobacteria; Clarithromycin; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 38149541
DOI: 10.4103/ijmy.ijmy_167_23 -
Pharmaceutics Dec 2023The emergence and persistence of drug-resistant tuberculosis is a major threat to global public health. Our objective was to assess the applicability of whole-genome... (Review)
Review
UNLABELLED
The emergence and persistence of drug-resistant tuberculosis is a major threat to global public health. Our objective was to assess the applicability of whole-genome sequencing (WGS) to detect genomic markers of drug resistance and explore their association with treatment outcomes for multidrug-resistant/extensively drug-resistant tuberculosis (MDR/XDR-TB).
METHODS
Five electronic databases were searched for studies published in English from the year 2000 onward. Two reviewers independently conducted the article screening, relevant data extraction, and quality assessment. The data of the included studies were synthesized with a narrative method and are presented in a tabular format.
RESULTS
The database search identified 949 published articles and 8 studies were included. An unfavorable treatment outcome was reported for 26.6% (488/1834) of TB cases, which ranged from 9.7 to 51.3%. Death was reported in 10.5% (194/1834) of total cases. High-level fluoroquinolone resistance (due to 94AAC and 94GGC mutations) was correlated as the cause of unfavorable treatment outcomes and reported in three studies. Other drug resistance mutations, like kanamycin high-level resistance mutations ( 1401G), Ile491Phe, and mutations, conferring prothionamide resistance were also reported. The secondary findings from this systematic review involved laboratory aspects of WGS, including correlations with phenotypic DST, cost, and turnaround time, or the impact of WGS results on public health actions, such as determining transmission events within outbreaks.
CONCLUSIONS
WGS has a significant capacity to provide accurate and comprehensive drug resistance data for MDR/XDR-TB, which can inform personalized drug therapy to optimize treatment outcomes.
PubMed: 38140122
DOI: 10.3390/pharmaceutics15122782 -
Microorganisms Nov 2023Antibiotic resistance is a significant threat to public health worldwide. Genome-wide association studies (GWAS) have emerged as a powerful tool to identify genetic... (Review)
Review
Antibiotic resistance is a significant threat to public health worldwide. Genome-wide association studies (GWAS) have emerged as a powerful tool to identify genetic variants associated with this antibiotic resistance. By analyzing large datasets of bacterial genomes, GWAS can provide valuable insights into the resistance mechanisms and facilitate the discovery of new drug targets. The present study aimed to undertake a systematic review of different GWAS approaches used for detecting genetic variants associated with antibiotic resistance. We comprehensively searched the PubMed and Scopus databases to identify relevant studies published from 2013 to February 2023. A total of 40 studies met our inclusion criteria. These studies explored a wide range of bacterial species, antibiotics, and study designs. Notably, most of the studies were centered around human pathogens such as , , , and . The review seeks to explore the several GWAS approaches utilized to investigate the genetic mechanisms associated with antibiotic resistance. Furthermore, it examines the contributions of GWAS approaches in identifying resistance-associated genetic variants through binary and continuous phenotypes. Overall, GWAS holds great potential to enhance our understanding of bacterial resistance and improve strategies to combat infectious diseases.
PubMed: 38138010
DOI: 10.3390/microorganisms11122866 -
The Journal of Antimicrobial... Feb 2024Non-tuberculous mycobacteria (NTM) infections are increasing in incidence and associated mortality. NTM are naturally resistant to a variety of antibiotics, complicating... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Non-tuberculous mycobacteria (NTM) infections are increasing in incidence and associated mortality. NTM are naturally resistant to a variety of antibiotics, complicating treatment. We conducted a literature assessment on the efficacy of bedaquiline in treating NTM species in vitro and in vivo (animal models and humans); meta-analyses were performed where possible.
METHOD
Four databases were searched using specific terms. Publications were included according to predefined criteria. Bedaquiline's impact on NTM in vitro, MICs and epidemiological cut-off (ECOFF) values were evaluated. A meta-analysis of bedaquiline efficacy against NTM infections in animal models was performed. Culture conversion, cure and/or relapse-free cure were used to evaluate the efficacy of bedaquiline in treating NTM infection in humans.
RESULTS
Fifty studies met the inclusion criteria: 33 assessed bedaquiline's impact on NTM in vitro, 9 in animal models and 8 in humans. Three studies assessed bedaquiline's efficacy both in vitro and in vivo. Due to data paucity, an ECOFF value of 0.5 mg/mL was estimated for Mycobacterium abscessus only. Meta-analysis of animal studies showed a 1.86× reduction in bacterial load in bedaquiline-treated versus no treatment within 30 days. In humans, bedaquiline-including regimens were effective in treating NTM extrapulmonary infection but not pulmonary infection.
CONCLUSIONS
Bedaquiline demonstrated strong antibacterial activity against various NTM species and is a promising drug to treat NTM infections. However, data on the genomic mutations associated with bedaquiline resistance were scarce, preventing statistical analyses for most mutations and NTM species. Further studies are urgently needed to better inform treatment strategies.
Topics: Humans; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Diarylquinolines; Anti-Bacterial Agents
PubMed: 38134888
DOI: 10.1093/jac/dkad372 -
Pathogens (Basel, Switzerland) Dec 2023is an intracellular bacillus that causes leprosy, a neglected disease that affects macrophages and Schwann cells. Leprosy reactions are acute inflammatory responses to... (Review)
Review
BACKGROUND
is an intracellular bacillus that causes leprosy, a neglected disease that affects macrophages and Schwann cells. Leprosy reactions are acute inflammatory responses to mycobacterial antigens, classified as type1 (T1R), a predominant cellular immune response, or type2 (T2R), a humoral phenomenon, leading to a high number of bacilli in infected cells and nerve structures. Xenophagy is a type of selective autophagy that targets intracellular bacteria for lysosomal degradation; however, its immune mechanisms during leprosy reactions are still unclear. This review summarizes the relationship between the autophagic process and elimination during leprosy reactions.
METHODS
Three databases, PubMed/Medline (n = 91), Scopus (n = 73), and ScienceDirect (n = 124), were searched. After applying the eligibility criteria, articles were selected for independent peer reviewers in August 2023.
RESULTS
From a total of 288 studies retrieved, eight were included. In multibacillary (MB) patients who progressed to T1R, xenophagy blockade and increased inflammasome activation were observed, with IL-1β secretion before the reactional episode occurrence. On the other hand, recent data actually observed increased IL-15 levels before the reaction began, as well as IFN-γ production and xenophagy induction.
CONCLUSION
Our search results showed a dichotomy in the T1R development and their relationship with xenophagy. No T2R studies were found.
PubMed: 38133338
DOI: 10.3390/pathogens12121455 -
Journal of Clinical Immunology Dec 2023Non-tuberculous mycobacteria (NTM) infections in hematopoietic stem cell transplantation (HSCT) recipients represent a diagnostic and therapeutic challenge. Here, we... (Meta-Analysis)
Meta-Analysis
Prevalence and Characteristics of Non-tuberculous Mycobacteria (NTM) Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation: a Systematic Review and Meta-analysis.
PURPOSE
Non-tuberculous mycobacteria (NTM) infections in hematopoietic stem cell transplantation (HSCT) recipients represent a diagnostic and therapeutic challenge. Here, we aimed to review and analyze current literature on incidence, clinical presentation, and outcome of NTM infection after allogeneic HSCT.
METHODS
We performed a systematic review and meta-analysis of available literature regarding NTM infection in children and adults receiving allogeneic HSCT.
RESULTS
We identified 56 articles eligible for the analysis. Among 15 studies, describing 15,798 allogeneic HSCT, we estimated a prevalence of 1.26% (95% CI 0.72, 1.93) of NTM after transplant. Analysis of 175 patients with NTM infection showed a median time of diagnosis of 318 days after HSCT, an increased prevalence in adults (82.9%), and a most frequent pulmonary involvement (44%). Comparison between children and adults revealed an earlier post-transplant disease onset (median 130 days vs 287 days) and most frequent non-pulmonary presentation in children. A vast heterogeneity of therapeutic approach reflected the lack of universal recommendations regarding drug combination and duration of therapy. Overall, NTM-related mortality accounted for 33% in this systematic review.
CONCLUSION
Although rare, NTM infections can complicate post-transplant course with a high mortality rate in children and adults. The lack of prospective studies and guidelines prevents identification of risk factors and therapeutic recommendations.
Topics: Adult; Child; Humans; Nontuberculous Mycobacteria; Prevalence; Hematopoietic Stem Cell Transplantation; Risk Factors; Transplant Recipients; Retrospective Studies
PubMed: 38129624
DOI: 10.1007/s10875-023-01615-3