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Cell Chemical Biology Feb 2016When it comes to lipid diversity, no bacterial genus approaches Mycobacterium. In this issue of Cell Chemical Biology, Burbaud et al. (2016) provide a multi-genic...
When it comes to lipid diversity, no bacterial genus approaches Mycobacterium. In this issue of Cell Chemical Biology, Burbaud et al. (2016) provide a multi-genic working model for the biosynthesis of trehalose polyphleate (TPP), one of the largest known lipids in mycobacteria. They demonstrate that this lipid is made by diverse mycobacterial species, including those of medical importance.
Topics: Lipids; Membrane Lipids; Mycobacterium; Mycobacterium Infections; Mycobacterium bovis; Mycobacterium tuberculosis; Trehalose
PubMed: 26971870
DOI: 10.1016/j.chembiol.2016.02.004 -
The Journal of Dermatology Nov 2022Nontuberculous mycobacteria cause a wide range of infections, including cutaneous infections, in both immunocompromised and immunocompetent patients. Although pulmonary... (Review)
Review
Nontuberculous mycobacteria cause a wide range of infections, including cutaneous infections, in both immunocompromised and immunocompetent patients. Although pulmonary nontuberculous mycobacterial infections have increased significantly in Japan in recent years, there is less evidence on clinical and microbiological characteristics of cutaneous nontuberculous mycobacterial infections in Japan. We reviewed 86 Japanese cases reported between July 2016 and November 2021 and analyzed them in conjunction with the eight patients from our institution who were diagnosed with cutaneous nontuberculous mycobacterial infections by culture between 2015 and 2021. In the aggregate series, the average patient age was 60 years, and the ratio of immunocompromised hosts was 53%, both of which were higher than those in previous reports from other countries. No female predominance was observed, unlike in pulmonary nontuberculous mycobacteria infections. Rapidly growing mycobacteria accounted for 58% of the cases (n = 54), whereas slowly growing mycobacteria for 43% (n = 40). Mycobacterium marinum (also known as Mycobacteroides marinum) (n = 20, 21%) was the most common cause, followed by Mycobacterium chelonae (n = 18, 19%), Mycobacterium abscessus (also known as Mycobacteroides abscessus) (n = 15, 16%), and Mycobacterium ulcerans (n = 11, 12%). While clinical appearance was variable, M ulcerans infections usually presented with ulcers, while nodules were common among infections caused by M chelonae and M marinum. Disseminated infections involving multiple organs were observed in 23 patients (24%). Thirty-two cases (30%) were preceded by exposure, including raising or handling fish, trauma, and invasive medical procedures. Most patients were treated with more than two antibiotics and responded to therapy.
Topics: Animals; Japan; Skin Diseases, Bacterial; Nontuberculous Mycobacteria; Mycobacterium Infections, Nontuberculous; Mycobacterium marinum; Mycobacterium abscessus
PubMed: 35906770
DOI: 10.1111/1346-8138.16531 -
Methods in Molecular Biology (Clifton,... 2021Mycobacteria are intrinsically resistant to most antimicrobials, which is generally attributed to the impermeability of their cell wall that considerably limits drug...
Mycobacteria are intrinsically resistant to most antimicrobials, which is generally attributed to the impermeability of their cell wall that considerably limits drug uptake. Moreover, like in other pathogenic bacteria, active efflux systems have been widely characterized from diverse mycobacterial species in laboratory conditions, showing that they can promote resistance by extruding noxious compounds prior to their reaching their intended targets. Therefore, the intracellular concentration of a given compound is determined by the balance between permeability, influx, and efflux.Given the urgent need to discover and develop novel antimycobacterial compounds in order to design effective therapeutic strategies, the contributions to drug resistance made by the controlled permeability of the cell wall and the increased activity of efflux pumps must be determined. In this chapter, we will describe a method that allows (1) the measuring of permeability and the quantification of general efflux activity of mycobacteria, by the study of the transport (influx and efflux) of fluorescent compounds, such as ethidium bromide; and (2) the screening of compounds in search of agents that increase the permeability of the cell wall and efflux inhibitors that could restore the effectiveness of antimicrobials that are subject to efflux.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Biological Transport; Cell Membrane Permeability; Drug Resistance, Multiple, Bacterial; Ethidium; Fluorescent Dyes; Fluorometry; Microbial Sensitivity Tests; Mycobacterium
PubMed: 34235655
DOI: 10.1007/978-1-0716-1460-0_9 -
Emerging Infectious Diseases Mar 2021We analyzed 98 Mycobacterium tuberculosis complex isolates collected in 2 regions of Algeria in 2015-2018 from 93 cases of pulmonary tuberculosis. We identified 93/98...
We analyzed 98 Mycobacterium tuberculosis complex isolates collected in 2 regions of Algeria in 2015-2018 from 93 cases of pulmonary tuberculosis. We identified 93/98 isolates as M. tuberculosis lineage 4 and 1 isolate as M. tuberculosis lineage 2 (Beijing). We confirmed 4 isolates as M. bovis by whole-genome sequencing.
Topics: Algeria; Beijing; Humans; Mycobacterium bovis; Mycobacterium tuberculosis; Tuberculosis, Pulmonary
PubMed: 33622469
DOI: 10.3201/eid2703.191823 -
Microbiology Spectrum Aug 2014The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick,... (Review)
Review
The cell wall of Mycobacterium tuberculosis is unique in that it differs significantly from those of both Gram-negative and Gram-positive bacteria. The thick, carbohydrate- and lipid-rich cell wall with distinct lipoglycans enables mycobacteria to survive under hostile conditions such as shortage of nutrients and antimicrobial exposure. The key features of this highly complex cell wall are the mycolyl-arabinogalactan-peptidoglycan (mAGP)-based and phosphatidyl-myo-inositol-based macromolecular structures, with the latter possessing potent immunomodulatory properties. These structures are crucial for the growth, viability, and virulence of M. tuberculosis and therefore are often the targets of effective chemotherapeutic agents against tuberculosis. Over the past decade, sophisticated genomic and molecular tools have advanced our understanding of the primary structure and biosynthesis of these macromolecules. The availability of the full genome sequences of various mycobacterial species, including M. tuberculosis, Mycobacterium marinum, and Mycobacterium bovis BCG, have greatly facilitated the identification of large numbers of drug targets and antigens specific to tuberculosis. Techniques to manipulate mycobacteria have also improved extensively; the conditional expression-specialized transduction essentiality test (CESTET) is currently used to determine the essentiality of individual genes. Finally, various biosynthetic assays using either purified proteins or synthetic cell wall acceptors have been developed to study enzyme function. This article focuses on the recent advances in determining the structural details and biosynthesis of arabinogalactan, lipoarabinomannan, and related glycoconjugates.
Topics: Antitubercular Agents; Biosynthetic Pathways; Galactans; Genome, Bacterial; Lipopolysaccharides; Molecular Biology; Mycobacterium
PubMed: 26104198
DOI: 10.1128/microbiolspec.MGM2-0013-2013 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Mar 2023Steroids are a class of medicines with important physiological and pharmacological effects. In pharmaceutical industry, steroidal intermediates are mainly prepared... (Review)
Review
Steroids are a class of medicines with important physiological and pharmacological effects. In pharmaceutical industry, steroidal intermediates are mainly prepared through transformation, and then modified chemically or enzymatically into advanced steroidal compounds. Compared with the "diosgenin-dienolone" route, transformation has the advantages of abundant raw materials, cost-effective, short reaction route, high yield and environmental friendliness. Based on genomics and metabolomics, the key enzymes in the phytosterol degradation pathway of and their catalytic mechanisms are further revealed, which makes it possible for to be used as chassis cells. This review summarizes the progress in the discovery of steroid-converting enzymes from different species, the modification of genes and the overexpression of heterologous genes, and the optimization and modification of as chassis cells.
Topics: Mycobacterium; Steroids; Phytosterols; Genomics
PubMed: 36994571
DOI: 10.13345/j.cjb.220548 -
Biofouling Apr 2021The role of biofilms in pathogenicity and treatment strategies is often neglected in mycobacterial infections. In recent years, the emergence of nontuberculous... (Review)
Review
The role of biofilms in pathogenicity and treatment strategies is often neglected in mycobacterial infections. In recent years, the emergence of nontuberculous mycobacterial infections has necessitated the development of novel prophylactic strategies and elucidation of the mechanisms underlying the establishment of chronic infections. More importantly, the question arises whether members of the complex can form biofilms and contribute to latent tuberculosis and drug resistance because of the long-lasting and recalcitrant nature of its infections. This review discusses some of the molecular mechanisms by which biofilms could play a role in infection or pathological events in humans.
Topics: Biofilms; Humans; Mycobacterium; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria
PubMed: 34024206
DOI: 10.1080/08927014.2021.1925886 -
Journal of Clinical Microbiology May 2019This minireview provides an update on recent taxonomic changes for the genus with an emphasis on newly identified species isolated from humans or associated with human... (Review)
Review
This minireview provides an update on recent taxonomic changes for the genus with an emphasis on newly identified species isolated from humans or associated with human disease.
Topics: Humans; Mycobacterium; Mycobacterium Infections; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Phylogeny
PubMed: 30602442
DOI: 10.1128/JCM.01408-18 -
MBio May 2024Since the discovery of extracellular vesicles (EVs) in mycobacterial species 15 years back, we have learned that this phenomenon is conserved in the genus and has... (Review)
Review
Since the discovery of extracellular vesicles (EVs) in mycobacterial species 15 years back, we have learned that this phenomenon is conserved in the genus and has critical roles in bacterial physiology and host-pathogen interactions. (), the tuberculosis (TB) causative agent, produces EVs both and including a diverse set of biomolecules with demonstrated immunomodulatory effects. Moreover, EVs (MEVs) have been shown to possess vaccine properties and carry biomarkers with diagnostic capacity. Although information on MEV biogenesis relative to other bacterial species is scarce, recent studies have shed light on how MEVs originate and are released to the extracellular space. In this minireview, we discuss past and new information about the vesiculogenesis phenomenon in , including biogenesis, MEV cargo, aspects in the context of host-pathogen interactions, and applications that could help to develop effective tools to tackle the disease.
Topics: Extracellular Vesicles; Host-Pathogen Interactions; Humans; Mycobacterium tuberculosis; Tuberculosis; Animals; Biomarkers; Mycobacterium
PubMed: 38567992
DOI: 10.1128/mbio.02552-23 -
Chemical Reviews May 2021The biology of mycobacteria is dominated by a complex cell envelope of unique composition and structure and of exceptionally low permeability. This cell envelope is the... (Review)
Review
The biology of mycobacteria is dominated by a complex cell envelope of unique composition and structure and of exceptionally low permeability. This cell envelope is the basis of many of the pathogenic features of mycobacteria and the site of susceptibility and resistance to many antibiotics and host defense mechanisms. This review is focused on the transporters that assemble and functionalize this complex structure. It highlights both the progress and the limits of our understanding of how (lipo)polysaccharides, (glyco)lipids, and other bacterial secretion products are translocated across the different layers of the cell envelope to their final extra-cytoplasmic location. It further describes some of the unique strategies evolved by mycobacteria to import nutrients and other products through this highly impermeable barrier.
Topics: Cell Membrane; Cell Wall; Membrane Lipids; Membrane Transport Proteins; Mycobacterium; Organelle Biogenesis
PubMed: 33170669
DOI: 10.1021/acs.chemrev.0c00869