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Yan AJ, Olson AM, Weigel KM, Luabeya AK, Heiniger E, Hatherill M, Cangelosi GA, Yager P. Detection of Mycobacterium tuberculosis from tongue swabs using sonication and sequence-specific hybridization capture. PLoS One 2024; 19:e0308235. [PMID: 39146324 PMCID: PMC11326604 DOI: 10.1371/journal.pone.0308235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 07/18/2024] [Indexed: 08/17/2024] Open
Abstract
Tongue swabs hold promise as a non-invasive sample for diagnosing tuberculosis (TB). However, their utility as replacements for sputum has been limited by their varied diagnostic performance in PCR assays compared to sputum. The use of silica-based DNA extraction methods may limit sensitivity due to incomplete lysis of Mycobacterium tuberculosis (MTB) cells and co-extraction of non-target nucleic acid, which may inhibit PCR. Specificity may also be compromised because these methods are labor-intensive and prone to cross-contamination. To address these limitations, we developed a sample preparation method that combines sonication for MTB lysis and a sequence-specific MTB DNA capture method using hybridization probes immobilized on magnetic beads. In spiked tongue swabs, our hybridization capture method demonstrated a 100-fold increase in MTB DNA yield over silica-based Qiagen DNA extraction and ethanol precipitation. In a study conducted on clinical samples from South Africa, our protocol had 74% (70/94) sensitivity and 98% (41/42) specificity for detecting active pulmonary TB with sputum Xpert MTB/RIF Ultra as the reference standard. While hybridization capture did not show improved sensitivity over Qiagen DNA extraction and ethanol precipitation, it demonstrated better specificity than previously reported methods and was easier to perform. With integration into point-of-care platforms, these strategies have the potential to help enable rapid non-sputum-based TB diagnosis across key underserved patient populations.
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Affiliation(s)
- Alexander J Yan
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Alaina M Olson
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Kris M Weigel
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Angelique K Luabeya
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease & Molecular Medicine and Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Erin Heiniger
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Mark Hatherill
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease & Molecular Medicine and Department of Pathology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Gerard A Cangelosi
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington, United States of America
| | - Paul Yager
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
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2
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Nyazema KB, Shey BA, Sei CJ, Peters RP, Maningi NE, Fischer GW, Bernard Fourie P. In vitro evaluation of the binding activity of novel mouse IgG1 opsonic monoclonal antibodies to Mycobacterium tuberculosis and other selected mycobacterial species. J Clin Tuberc Other Mycobact Dis 2024; 35:100435. [PMID: 38601919 PMCID: PMC11004620 DOI: 10.1016/j.jctube.2024.100435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024] Open
Abstract
Antimicrobial resistance alongside other challenges in tuberculosis (TB) therapeutics have stirred renewed interest in host-directed interventions, including the role of antibodies as adjunct therapeutic agents. This study assessed the binding efficacy of two novel IgG1 opsonic monoclonal antibodies (MABs; GG9 & JG7) at 5, 10, and 25 µg/mL to live cultures of Mycobacterium tuberculosis, M. avium, M. bovis, M. fortuitum, M. intracellulare, and M. smegmatis American Type Culture Collection laboratory reference strains, as well as clinical susceptible, multi-drug resistant, and extensively drug resistant M. tuberculosis strains using indirect enzyme-linked immunosorbent assays. These three MAB concentrations were selected from a range of concentrations used in previous optimization (binding and functional) assays. Both MABs bound to all mycobacterial species and sub-types tested, albeit to varying degrees. Statistically significant differences in MAB binding activity were observed when comparing the highest and lowest MAB concentrations (p < 0.05) for both MABs GG9 and JG7, irrespective of the M. tuberculosis resistance profile. Binding affinity increased with an increase in MAB concentration, and optimal binding was observed at 25 µg/mL. JG7 showed better binding activity than GG9. Both MABs also bound to five MOTT species, albeit at varied levels. This non-selective binding to different mycobacterial species suggests a potential role for GG9 and JG7 as adjunctive agents in anti-TB chemotherapy with the aim to enhance bacterial killing.
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Affiliation(s)
- Kudzai B. Nyazema
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Bong-Akee Shey
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
| | - Clara J. Sei
- Vaccine and Antibody Development, Longhorn Vaccines and Diagnostics, Gaithersburg, MD, USA
| | - Remco P.H. Peters
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
- Foundation for Professional Development, Research Unit, East London, South Africa
| | - Nontuthuko E. Maningi
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
- Department of Microbiology, School of Life Sciences, University of KwaZulu-Natal, South Africa
| | - Gerald W. Fischer
- Vaccine and Antibody Development, Longhorn Vaccines and Diagnostics, Gaithersburg, MD, USA
| | - P. Bernard Fourie
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, South Africa
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3
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Brown T, Chavent M, Im W. Molecular Modeling and Simulation of the Mycobacterial Cell Envelope: From Individual Components to Cell Envelope Assemblies. J Phys Chem B 2023; 127:10941-10949. [PMID: 38091517 PMCID: PMC10758119 DOI: 10.1021/acs.jpcb.3c06136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/14/2023] [Accepted: 11/16/2023] [Indexed: 12/29/2023]
Abstract
Unlike typical Gram-positive bacteria, the cell envelope of mycobacteria is unique and composed of a mycobacterial outer membrane, also known as the mycomembrane, a peptidoglycan layer, and a mycobacterial inner membrane, which is analogous to that of Gram-negative bacteria. Despite its importance, however, our understanding of this complex cell envelope is rudimentary at best. Thus, molecular modeling and simulation of such an envelope can benefit the scientific community by proposing new hypotheses about the biophysical properties of its different layers. In this Perspective, we present recent advances in molecular modeling and simulation of the mycobacterial cell envelope from individual components to cell envelope assemblies. We also show how modeling other types of cell envelopes, such as that of Escherichia coli, may help modeling part of the mycobacterial envelopes. We hope that the studies presented here are just the beginning of the road and more and more new modeling and simulation studies help us to understand crucial questions related to mycobacteria such as antibiotic resistance or bacterial survival in the host.
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Affiliation(s)
- Turner Brown
- Department
of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Matthieu Chavent
- Institut
de Pharmacologie et Biologie Structurale, CNRS, Université
de Toulouse, 205 Route de Narbonne, 31400 Toulouse, France
| | - Wonpil Im
- Department
of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
- Departments
of Biological Sciences and Chemistry, Lehigh
University, Bethlehem, Pennsylvania 18015, United States
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4
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Shleider Carnero Canales C, Marquez Cazorla J, Furtado Torres AH, Monteiro Filardi ET, Di Filippo LD, Costa PI, Roque-Borda CA, Pavan FR. Advances in Diagnostics and Drug Discovery against Resistant and Latent Tuberculosis Infection. Pharmaceutics 2023; 15:2409. [PMID: 37896169 PMCID: PMC10610444 DOI: 10.3390/pharmaceutics15102409] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 09/23/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Latent tuberculosis infection (LTBI) represents a subclinical, asymptomatic mycobacterial state affecting approximately 25% of the global population. The substantial prevalence of LTBI, combined with the risk of progressing to active tuberculosis, underscores its central role in the increasing incidence of tuberculosis (TB). Accurate identification and timely treatment are vital to contain and reduce the spread of the disease, forming a critical component of the global strategy known as "End TB." This review aims to examine and highlight the most recent scientific evidence related to new diagnostic approaches and emerging therapeutic treatments for LTBI. While prevalent diagnostic methods include the tuberculin skin test (TST) and interferon gamma release assay (IGRA), WHO's approval of two specific IGRAs for Mycobacterium tuberculosis (MTB) marked a significant advancement. However, the need for a specific test with global application viability has propelled research into diagnostic tests based on molecular diagnostics, pulmonary immunity, epigenetics, metabolomics, and a current focus on next-generation MTB antigen-based skin test (TBST). It is within these emerging methods that the potential for accurate distinction between LTBI and active TB has been demonstrated. Therapeutically, in addition to traditional first-line therapies, anti-LTBI drugs, anti-resistant TB drugs, and innovative candidates in preclinical and clinical stages are being explored. Although the advancements are promising, it is crucial to recognize that further research and clinical evidence are needed to solidify the effectiveness and safety of these new approaches, in addition to ensuring access to new drugs and diagnostic methods across all health centers. The fight against TB is evolving with the development of more precise diagnostic tools that differentiate the various stages of the infection and with more effective and targeted treatments. Once consolidated, current advancements have the potential to transform the prevention and treatment landscape of TB, reinforcing the global mission to eradicate this disease.
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Affiliation(s)
- Christian Shleider Carnero Canales
- Facultad de Ciencias Farmacéuticas Bioquímicas y Biotecnológicas, Vicerrectorado de Investigación, Universidad Católica de Santa María, Arequipa 04000, Peru; (C.S.C.C.)
| | - Jessica Marquez Cazorla
- Facultad de Ciencias Farmacéuticas Bioquímicas y Biotecnológicas, Vicerrectorado de Investigación, Universidad Católica de Santa María, Arequipa 04000, Peru; (C.S.C.C.)
| | | | | | | | - Paulo Inácio Costa
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14801-970, SP, Brazil
| | - Cesar Augusto Roque-Borda
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14801-970, SP, Brazil
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2300 Copenhagen, Denmark
| | - Fernando Rogério Pavan
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14801-970, SP, Brazil
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5
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Abstract
Mycobacteria are responsible for several human and animal diseases. NOD2 is a pattern recognition receptor that has an important role in mycobacterial recognition. However, the mechanisms by which mutations in NOD2 alter the course of mycobacterial infection remain unclear. Herein, we aimed to review the totality of studies directly addressing the relationship between NOD2 and mycobacteria as a foundation for moving the field forward. NOD2 was linked to mycobacterial infection at 3 levels: (1) genetic, through association with mycobacterial diseases of humans; (2) chemical, through the distinct NOD2 ligand in the mycobacterial cell wall; and (3) immunologic, through heightened NOD2 signaling caused by the unique modification of the NOD2 ligand. The immune response to mycobacteria is shaped by NOD2 signaling, responsible for NF-κB and MAPK activation, and the production of various immune effectors like cytokines and nitric oxide, with some evidence linking this to bacteriologic control. Absence of NOD2 during mycobacterial infection of mice can be detrimental, but the mechanism remains unknown. Conversely, the success of immunization with mycobacteria has been linked to NOD2 signaling and NOD2 has been targeted as an avenue of immunotherapy for diseases even beyond mycobacteria. The mycobacteria-NOD2 interaction remains an important area of study, which may shed light on immune mechanisms in disease.
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Affiliation(s)
- Jean-Yves Dubé
- Department of Microbiology and Immunology, McGill University, Montréal, Canada
| | - Marcel A Behr
- Department of Medicine, McGill University Health Centre, Montréal, Canada
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6
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Sexton D, Hashimi A, Beskrovnaya P, Sibanda L, Huan T, Tocheva E. The cell envelope of Thermotogae suggests a mechanism for outer membrane biogenesis. Proc Natl Acad Sci U S A 2023; 120:e2303275120. [PMID: 37094164 PMCID: PMC10160955 DOI: 10.1073/pnas.2303275120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 03/29/2023] [Indexed: 04/26/2023] Open
Abstract
The presence of a cell membrane is one of the major structural components defining life. Recent phylogenomic analyses have supported the hypothesis that the last universal common ancestor (LUCA) was likely a diderm. Yet, the mechanisms that guided outer membrane (OM) biogenesis remain unknown. Thermotogae is an early-branching phylum with a unique OM, the toga. Here, we use cryo-electron tomography to characterize the in situ cell envelope architecture of Thermotoga maritima and show that the toga is made of extended sheaths of β-barrel trimers supporting small (~200 nm) membrane patches. Lipidomic analyses identified the same major lipid species in the inner membrane (IM) and toga, including the rare to bacteria membrane-spanning ether-bound diabolic acids (DAs). Proteomic analyses revealed that the toga was composed of multiple SLH-domain containing Ompα and novel β-barrel proteins, and homology searches detected variable conservations of these proteins across the phylum. These results highlight that, in contrast to the SlpA/OmpM superfamily of proteins, Thermotoga possess a highly diverse bipartite OM-tethering system. We discuss the implications of our findings with respect to other early-branching phyla and propose that a toga-like intermediate may have facilitated monoderm-to-diderm cell envelope transitions.
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Affiliation(s)
- Danielle L. Sexton
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver,V6T1Z3 BC, Canada
| | - Ameena Hashimi
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver,V6T1Z3 BC, Canada
| | - Polina Beskrovnaya
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver,V6T1Z3 BC, Canada
| | - Lloyd Sibanda
- Department of Chemistry, University of British Columbia, Vancouver,V6T1Z1 BC, Canada
| | - Tao Huan
- Department of Chemistry, University of British Columbia, Vancouver,V6T1Z1 BC, Canada
| | - Elitza I. Tocheva
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver,V6T1Z3 BC, Canada
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7
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Parmar S, Tocheva EI. The cell envelope of Mycobacterium abscessus and its role in pathogenesis. PLoS Pathog 2023; 19:e1011318. [PMID: 37200238 DOI: 10.1371/journal.ppat.1011318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/20/2023] Open
Abstract
Mycobacterium abscessus is a nontuberculosis mycobacterium (NTM) that has shown an exponential rise in its ability to cause disease. Due to its ubiquitous presence in the environment, M. abscessus is widely implicated in secondary exacerbations of many nosocomial infections and genetic respiratory disorders, such as cystic fibrosis (CF). Contrary to other rapidly growing NTMs, the cell envelope of M. abscessus harbors several prominent features and undergoes modifications that are responsible for its pathogenesis. Compositional changes of the mycobacterial outer membrane (MOM) significantly decrease the presence of glycopeptidolipids (GPLs) and enable the transition from a colonizing, smooth morphotype into a virulent, rough morphotype. The GPLs are transported to the MOM by the Mycobacterial membrane proteins Large (MmpL), which further act as drug efflux pumps and confer antibiotic resistance. Lastly, M. abscessus possesses 2 type VII secretion systems (T7SS): ESX-3 and ESX-4, both of which have recently been implicated in host-pathogen interactions and virulence. This review summarizes the current knowledge of M. abscessus pathogenesis and highlights the clinically relevant association between the structure and functions of its cell envelope.
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Affiliation(s)
- Shweta Parmar
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
| | - Elitza I Tocheva
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada
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8
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Li W, Yan Z, Zhang N, Zhang Z, Xiang X. Novel role of PE_PGRS47 in the alteration of mycobacterial cell wall integrity and drug resistance. Arch Microbiol 2023; 205:174. [PMID: 37022460 DOI: 10.1007/s00203-023-03515-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 03/11/2023] [Accepted: 03/23/2023] [Indexed: 04/07/2023]
Abstract
The proline-glutamic acid and proline-proline-glutamic acid (PE/PPE) family of proteins is widespread in pathogenic mycobacteria and plays different roles in mycobacterial physiology. While several PE/PPE family proteins have been studied, the exact function of most PE/PPE proteins in the physiology of Mycobacterium tuberculosis (Mtb) remains unknown. PE_PGRS47 belongs to the PE/PPE family of proteins reported to help Mtb evade protective host immune responses. In this study, we demonstrate a novel role of PE_PGRS47. Heterologous expression of the pe_pgrs47 gene in a non-pathogenic Mycobacterium smegmatis, intrinsically deficient of PE_PGRS protein, exhibits modulated colony morphology and cell wall lipid profile leading to a marked susceptibility to multiple antibiotics and environmental stressors. Using ethidium bromide/Nile red uptake assays, Mycobacterium smegmatis expressing PE_PGRS47 showed higher cell wall permeability than the control strain. Overall, these data suggested that PE_PGRS47 is cell surface exposed and influences cell wall integrity and the formation of mycobacterial colonies, ultimately potentiating the efficacy of lethal stresses against mycobacteria.
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Affiliation(s)
- Wu Li
- Key Laboratory of Regional Characteristic Agricultural Resources, College of Life Sciences, Neijiang Normal University, Neijiang, 641100, Sichuan, People's Republic of China.
| | - Zifei Yan
- Key Laboratory of Regional Characteristic Agricultural Resources, College of Life Sciences, Neijiang Normal University, Neijiang, 641100, Sichuan, People's Republic of China
| | - Nan Zhang
- Key Laboratory of Regional Characteristic Agricultural Resources, College of Life Sciences, Neijiang Normal University, Neijiang, 641100, Sichuan, People's Republic of China
| | - Zhiyong Zhang
- Key Laboratory of Regional Characteristic Agricultural Resources, College of Life Sciences, Neijiang Normal University, Neijiang, 641100, Sichuan, People's Republic of China
| | - Xiaohong Xiang
- School of Pharmacy, Chongqing Medical and Pharmaceutical College, Chongqing, 401331, People's Republic of China.
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9
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Advancing Desulfurization in the Model Biocatalyst Rhodococcus qingshengii IGTS8 via an In Locus Combinatorial Approach. Appl Environ Microbiol 2023; 89:e0197022. [PMID: 36688659 PMCID: PMC9973023 DOI: 10.1128/aem.01970-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Biodesulfurization poses as an ideal replacement to the high cost hydrodesulfurization of the recalcitrant heterocyclic sulfur compounds, such as dibenzothiophene (DBT) and its derivatives. The increasingly stringent limits on fuel sulfur content intensify the need for improved desulfurization biocatalysts, without sacrificing the calorific value of the fuel. Selective sulfur removal in a wide range of biodesulfurization strains, as well as in the model biocatalyst Rhodococcus qingshengii IGTS8, occurs via the 4S metabolic pathway that involves the dszABC operon, which encodes enzymes that catalyze the generation of 2-hydroxybiphenyl and sulfite from DBT. Here, using a homologous recombination process, we generate two recombinant IGTS8 biocatalysts, harboring native or rearranged, nonrepressible desulfurization operons, within the native dsz locus. The alleviation of sulfate-, methionine-, and cysteine-mediated dsz repression is achieved through the exchange of the native promoter Pdsz, with the nonrepressible Pkap1 promoter. The Dsz-mediated desulfurization from DBT was monitored at three growth phases, through HPLC analysis of end product levels. Notably, an 86-fold enhancement of desulfurization activity was documented in the presence of selected repressive sulfur sources for the recombinant biocatalyst harboring a combination of three targeted genetic modifications, namely, a dsz operon rearrangement, a native promoter exchange, and a dszA-dszB overlap removal. In addition, transcript level comparison highlighted the diverse effects of our genetic engineering approaches on dsz mRNA ratios and revealed a gene-specific differential increase in mRNA levels. IMPORTANCE Rhodococcus is perhaps the most promising biodesulfurization genus and is able to withstand the harsh process conditions of a biphasic biodesulfurization process. In the present work, we constructed an advanced biocatalyst harboring a combination of three genetic modifications, namely, an operon rearrangement, a promoter exchange, and a gene overlap removal. Our homologous recombination approach generated stable biocatalysts that do not require antibiotic addition, while harboring nonrepressible desulfurization operons that present very high biodesulfurization activities and are produced in simple and low-cost media. In addition, transcript level quantification validated the effects of our genetic engineering approaches on recombinant strains' dsz mRNA ratios and revealed a gene-specific differential increase in mRNA levels. Based on these findings, the present work can pave the way for further strain and process optimization studies that could eventually lead to an economically viable biodesulfurization process.
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10
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Rao KU, Li P, Welinder C, Tenland E, Gourdon P, Sturegård E, Ho JCS, Godaly G. Mechanisms of a Mycobacterium tuberculosis Active Peptide. Pharmaceutics 2023; 15:pharmaceutics15020540. [PMID: 36839864 PMCID: PMC9958537 DOI: 10.3390/pharmaceutics15020540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
Multidrug-resistant tuberculosis (MDR) continues to pose a threat to public health. Previously, we identified a cationic host defense peptide with activity against Mycobacterium tuberculosis in vivo and with a bactericidal effect against MDR M. tuberculosis at therapeutic concentrations. To understand the mechanisms of this peptide, we investigated its interactions with live M. tuberculosis and liposomes as a model. Peptide interactions with M. tuberculosis inner membranes induced tube-shaped membranous structures and massive vesicle formation, thus leading to bubbling cell death and ghost cell formation. Liposomal studies revealed that peptide insertion into inner membranes induced changes in the peptides' secondary structure and that the membranes were pulled such that they aggregated without permeabilization, suggesting that the peptide has a strong inner membrane affinity. Finally, the peptide targeted essential proteins in M. tuberculosis, such as 60 kDa chaperonins and elongation factor Tu, that are involved in mycolic acid synthesis and protein folding, which had an impact on bacterial proliferation. The observed multifaceted targeting provides additional support for the therapeutic potential of this peptide.
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Affiliation(s)
- Komal Umashankar Rao
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
| | - Ping Li
- Department of Experimental Medical Science, Lund University, SE-22362 Lund, Sweden
| | - Charlotte Welinder
- Swedish National Infrastructure for Biological Mass Spectrometry, Lund University, SE-22362 Lund, Sweden
| | - Erik Tenland
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
| | - Pontus Gourdon
- Department of Experimental Medical Science, Lund University, SE-22362 Lund, Sweden
- Department of Biomedical Sciences, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Erik Sturegård
- Department of Clinical Microbiology, Institution of Translational Medicine, Lund University, SE-21428 Malmö, Sweden
| | - James C. S. Ho
- Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637553, Singapore
| | - Gabriela Godaly
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, SE-22362 Lund, Sweden
- Correspondence:
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11
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Kaur K, Sharma S, Abhishek S, Kaur P, Saini UC, Dhillon MS, Karakousis PC, Verma I. Metabolic switching and cell wall remodelling of Mycobacterium tuberculosis during bone tuberculosis. J Infect 2023; 86:134-146. [PMID: 36549425 DOI: 10.1016/j.jinf.2022.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Bone tuberculosis (TB) is the third most common types of extrapulmonary tuberculosis. It is critical to understand mycobacterial adaptive strategies within bone lesions to identify mycobacterial factors that may have role in disease pathogenesis. METHODS Whole genome microarray was used to characterize the in-vivo transcriptome of Mycobacterium tuberculosis (M.tb) within bone TB specimens. Mycobacterial virulent proteins were identified by bioinformatic software. An in vitro osteoblast cell line model was used to study the role of these proteins in bone TB pathogenesis. RESULTS 914 mycobacterial genes were significantly overexpressed and 1688 were repressed in bone TB specimens. Pathway analysis of differentially expressed genes demonstrated a non-replicative and hypometabolic state of M.tb, reinforcement of the mycobacterial cell wall and induction of DNA damage repair responses, suggesting possible survival strategies of M.tb within bone. Bioinformatics mining of microarray data led to identification of five virulence proteins. The genes encoding these proteins were also upregulated in the in vitro MC3T3 osteoblast cell line model of bone TB. Further, exposure of osteoblast cells to two of these virulence proteins (Rv1046c and Rv3663c) significantly inhibited osteoblast differentiation. CONCLUSION M.tb alters its transcriptome to establish infection in bone by upregulating certain virulence genes which play a key role in disturbing bone homeostasis.
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Affiliation(s)
- Khushpreet Kaur
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sumedha Sharma
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sudhanshu Abhishek
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Prabhdeep Kaur
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Uttam Chand Saini
- Department of Orthopaedics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Mandeep Singh Dhillon
- Department of Orthopaedics, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Petros C Karakousis
- Centers for Tuberculosis Research and Systems Approaches for Infectious Diseases, School of Medicine, Johns Hopkins University, Baltimore, MD, United States
| | - Indu Verma
- Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
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12
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Zheng Q, Chang PV. Shedding Light on Bacterial Physiology with Click Chemistry. Isr J Chem 2023; 63:e202200064. [PMID: 37841997 PMCID: PMC10569449 DOI: 10.1002/ijch.202200064] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Indexed: 11/11/2022]
Abstract
Bacteria constitute a major lifeform on this planet and play numerous roles in ecology, physiology, and human disease. However, conventional methods to probe their activities are limited in their ability to visualize and identify their functions in these diverse settings. In the last two decades, the application of click chemistry to label these microbes has deepened our understanding of bacterial physiology. With the development of a plethora of chemical tools that target many biological molecules, it is possible to track these microorganisms in real-time and at unprecedented resolution. Here, we review click chemistry, including bioorthogonal reactions, and their applications in imaging bacterial glycans, lipids, proteins, and nucleic acids using chemical reporters. We also highlight significant advances that have enabled biological discoveries that have heretofore remained elusive.
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Affiliation(s)
- Qiuyu Zheng
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Pamela V Chang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY 14853
- Cornell Center for Immunology, Cornell University, Ithaca, NY 14853
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, NY 14853
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13
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Conformational Dynamics and Stability of Bilayers Formed by Mycolic Acids from the Mycobacterium tuberculosis Outer Membrane. Molecules 2023; 28:molecules28031347. [PMID: 36771014 PMCID: PMC9921641 DOI: 10.3390/molecules28031347] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 01/16/2023] [Accepted: 01/21/2023] [Indexed: 02/04/2023] Open
Abstract
Bilayers of mycolic acids (MAs) form the outer membrane of Mycobacterium tuberculosis that has high strength and extremely low permeability for external molecules (including antibiotics). For the first time, we were able to study them using the all-atom long-term molecular dynamic simulations (from 300 ns up to 1.2 μs) in order to investigate the conformational changes and most favorable structures of the mycobacterial membranes. The structure and properties of the membranes are crucially dependent on the initial packing of the α-mycolic acid (AMA) molecules, as well as on the presence of the secondary membrane components, keto- and methoxy mycolic acids (KMAs and MMAs). In the case of AMA-based membranes, the most labile conformation is W while other types of conformations (sU as well as sZ, eU, and eZ) are much more stable. In the multicomponent membranes, the presence of the KMA and MMA components (in the W conformation) additionally stabilizes both the W and eU conformations of AMA. The membrane in which AMA prevails in the eU conformation is much thicker and, at the same time, much denser. Such a packing of the MA molecules promotes the formation of a significantly stronger outer mycobacterial membrane that should be much more resistant to the threatening external factors.
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14
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Moopanar K, Nyide ANG, Senzani S, Mvubu NE. Clinical strains of Mycobacterium tuberculosis exhibit differential lipid metabolism-associated transcriptome changes in in vitro cholesterol and infection models. Pathog Dis 2022; 81:6889515. [PMID: 36509392 PMCID: PMC9936260 DOI: 10.1093/femspd/ftac046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/30/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Many studies have identified host-derived lipids, characterised by the abundance of cholesterol, as a major source of carbon nutrition for Mycobacterium tuberculosis during infection. Members of the Mycobacterium tuberculosis complex are biologically different with regards to degree of disease, host range, pathogenicity and transmission. Therefore, the current study aimed at elucidating transcriptome changes during early infection of pulmonary epithelial cells and on an in vitro cholesterol-rich minimal media, in M. tuberculosis clinical strains F15/LAM4/KZN and Beijing, and the laboratory H37Rv strain. Infection of pulmonary epithelial cells elicited the upregulation of fadD28 and hsaC in both the F15/LAM4/KZN and Beijing strains and the downregulation of several other lipid-associated genes. Growth curve analysis revealed F15/LAM4/KZN and Beijing to be slow growers in 7H9 medium and cholesterol-supplemented media. RNA-seq analysis revealed strain-specific transcriptomic changes, thereby affecting different metabolic processes in an in vitro cholesterol model. The differential expression of these genes suggests that the genetically diverse M. tuberculosis clinical strains exhibit strain-specific behaviour that may influence their ability to metabolise lipids, specifically cholesterol, which may account for phenotypic differences observed during infection.
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Affiliation(s)
- Kynesha Moopanar
- Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Asanda Nomfundo Graduate Nyide
- Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - Sibusiso Senzani
- Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, 1st floor, Doris Duke Medical Research Institute, Congella, Private Bag 7, Durban, 4013, South Africa
| | - Nontobeko Eunice Mvubu
- Corresponding author. Microbiology, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa.Tel: +27 31 260 7404; E-mail:
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15
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Fernandes GFS, Thompson AM, Castagnolo D, Denny WA, Dos Santos JL. Tuberculosis Drug Discovery: Challenges and New Horizons. J Med Chem 2022; 65:7489-7531. [PMID: 35612311 DOI: 10.1021/acs.jmedchem.2c00227] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Over the past 2000 years, tuberculosis (TB) has claimed more lives than any other infectious disease. In 2020 alone, TB was responsible for 1.5 million deaths worldwide, comparable to the 1.8 million deaths caused by COVID-19. The World Health Organization has stated that new TB drugs must be developed to end this pandemic. After decades of neglect in this field, a renaissance era of TB drug discovery has arrived, in which many novel candidates have entered clinical trials. However, while hundreds of molecules are reported annually as promising anti-TB agents, very few successfully progress to clinical development. In this Perspective, we critically review those anti-TB compounds published in the last 6 years that demonstrate good in vivo efficacy against Mycobacterium tuberculosis. Additionally, we highlight the main challenges and strategies for developing new TB drugs and the current global pipeline of drug candidates in clinical studies to foment fresh research perspectives.
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Affiliation(s)
- Guilherme F S Fernandes
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Andrew M Thompson
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Daniele Castagnolo
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - William A Denny
- Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Jean L Dos Santos
- School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara 14800903, Brazil
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16
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Geographically dispersed zoonotic tuberculosis in pre-contact South American human populations. Nat Commun 2022; 13:1195. [PMID: 35256608 PMCID: PMC8901693 DOI: 10.1038/s41467-022-28562-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 01/25/2022] [Indexed: 12/30/2022] Open
Abstract
AbstractPrevious ancient DNA research has shown that Mycobacterium pinnipedii, which today causes tuberculosis (TB) primarily in pinnipeds, infected human populations living in the coastal areas of Peru prior to European colonization. Skeletal evidence indicates the presence of TB in several pre-colonial South and North American populations with minimal access to marine resources— a scenario incompatible with TB transmission directly from infected pinnipeds or their tissues. In this study, we investigate the causative agent of TB in ten pre-colonial, non-coastal individuals from South America. We reconstruct M. pinnipedii genomes (10- to 15-fold mean coverage) from three contemporaneous individuals from inland Peru and Colombia, demonstrating the widespread dissemination of M. pinnipedii beyond the coast, either through human-to-human and/or animal-mediated routes. Overall, our study suggests that TB transmission in the pre-colonial era Americas involved a more complex transmission pathway than simple pinniped-to-human transfer.
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17
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Allué-Guardia A, Garcia-Vilanova A, Olmo-Fontánez AM, Peters J, Maselli DJ, Wang Y, Turner J, Schlesinger LS, Torrelles JB. Host- and Age-Dependent Transcriptional Changes in Mycobacterium tuberculosis Cell Envelope Biosynthesis Genes after Exposure to Human Alveolar Lining Fluid. Int J Mol Sci 2022; 23:ijms23020983. [PMID: 35055170 PMCID: PMC8780516 DOI: 10.3390/ijms23020983] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 12/16/2022] Open
Abstract
Tuberculosis (TB) infection, caused by the airborne pathogen Mycobacterium tuberculosis (M.tb), resulted in almost 1.4 million deaths in 2019, and the number of deaths is predicted to increase by 20% over the next 5 years due to the COVID-19 pandemic. Upon reaching the alveolar space, M.tb comes into close contact with the lung mucosa before and after its encounter with host alveolar compartment cells. Our previous studies show that homeostatic, innate soluble components of the alveolar lining fluid (ALF) can quickly alter the cell envelope surface of M.tb upon contact, defining subsequent M.tb-host cell interactions and infection outcomes in vitro and in vivo. We also demonstrated that ALF from 60+ year old elders (E-ALF) vs. healthy 18- to 45-year-old adults (A-ALF) is dysfunctional, with loss of homeostatic capacity and impaired innate soluble responses linked to high local oxidative stress. In this study, a targeted transcriptional assay shows that M.tb exposure to human ALF alters the expression of its cell envelope genes. Specifically, our results indicate that A-ALF-exposed M.tb upregulates cell envelope genes associated with lipid, carbohydrate, and amino acid metabolism, as well as genes associated with redox homeostasis and transcriptional regulators. Conversely, M.tb exposure to E-ALF shows a lesser transcriptional response, with most of the M.tb genes unchanged or downregulated. Overall, this study indicates that M.tb responds and adapts to the lung alveolar environment upon contact, and that the host ALF status, determined by factors such as age, might play an important role in determining infection outcome.
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Affiliation(s)
- Anna Allué-Guardia
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (A.G.-V.); (A.M.O.-F.)
- Correspondence: (A.A.-G.); (J.B.T.)
| | - Andreu Garcia-Vilanova
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (A.G.-V.); (A.M.O.-F.)
| | - Angélica M. Olmo-Fontánez
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (A.G.-V.); (A.M.O.-F.)
- Integrated Biomedical Sciences Program, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jay Peters
- Division of Pulmonary and Critical Care Medicine, School of Medicine, UT Health San Antonio, San Antonio, TX 78229, USA; (J.P.); (D.J.M.)
| | - Diego J. Maselli
- Division of Pulmonary and Critical Care Medicine, School of Medicine, UT Health San Antonio, San Antonio, TX 78229, USA; (J.P.); (D.J.M.)
| | - Yufeng Wang
- Department of Molecular Microbiology and Immunology, South Texas Center for Emerging Infectious Diseases, University of Texas at San Antonio, San Antonio, TX 78249, USA;
| | - Joanne Turner
- Host-Pathogen Interactions Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (J.T.); (L.S.S.)
| | - Larry S. Schlesinger
- Host-Pathogen Interactions Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (J.T.); (L.S.S.)
| | - Jordi B. Torrelles
- Population Health Program, Texas Biomedical Research Institute, San Antonio, TX 78227, USA; (A.G.-V.); (A.M.O.-F.)
- Correspondence: (A.A.-G.); (J.B.T.)
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18
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Dover LG, Thompson AR, Sutcliffe IC, Sangal V. Phylogenomic Reappraisal of Fatty Acid Biosynthesis, Mycolic Acid Biosynthesis and Clinical Relevance Among Members of the Genus Corynebacterium. Front Microbiol 2021; 12:802532. [PMID: 35003033 PMCID: PMC8733736 DOI: 10.3389/fmicb.2021.802532] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
The genus Corynebacterium encompasses many species of biotechnological, medical or veterinary significance. An important characteristic of this genus is the presence of mycolic acids in their cell envelopes, which form the basis of a protective outer membrane (mycomembrane). Mycolic acids in the cell envelope of Mycobacterium tuberculosis have been associated with virulence. In this study, we have analysed the genomes of 140 corynebacterial strains, including representatives of 126 different species. More than 50% of these strains were isolated from clinical material from humans or animals, highlighting the true scale of pathogenic potential within the genus. Phylogenomically, these species are very diverse and have been organised into 19 groups and 30 singleton strains. We find that a substantial number of corynebacteria lack FAS-I, i.e., have no capability for de novo fatty acid biosynthesis and must obtain fatty acids from their habitat; this appears to explain the well-known lipophilic phenotype of some species. In most species, key genes associated with the condensation and maturation of mycolic acids are present, consistent with the reports of mycolic acids in their species descriptions. Conversely, species reported to lack mycolic acids lacked these key genes. Interestingly, Corynebacterium ciconiae, which is reported to lack mycolic acids, appears to possess all genes required for mycolic acid biosynthesis. We suggest that although a mycolic acid-based mycomembrane is widely considered to be the target for interventions by the immune system and chemotherapeutics, the structure is not essential in corynebacteria and is not a prerequisite for pathogenicity or colonisation of animal hosts.
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19
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Hessel M van Dijk J, van der Marel GA, Codée JDC. Developments in the Synthesis of Mycobacterial Phenolic Glycolipids. CHEM REC 2021; 21:3295-3312. [PMID: 34581501 DOI: 10.1002/tcr.202100200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 11/11/2022]
Abstract
The highly lipophilic outer barrier of mycobacteria, such as M. tuberculosis and M. leprae, is key to their virulence and intrinsic antibiotic resistance. Various components of this mycomembrane interact with the host immune system but many of these interactions remain ill-understood. This review covers several chemical syntheses of one of these components, mycobacterial phenolic glycolipids (PGLs), and outlines the interaction of these PGLs with the human immune system, as established using these well-defined pure compounds.
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Affiliation(s)
- J Hessel M van Dijk
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Gijs A van der Marel
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
| | - Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands
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20
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Allué-Guardia A, Garcia-Vilanova A, M Olmo-Fontánez A, Peters J, Maselli DJ, Wang Y, Turner J, Schlesinger LS, Torrelles JB. Host- and age-dependent transcriptional changes in Mycobacterium tuberculosis cell envelope biosynthesis genes after exposure to human alveolar lining fluid. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021. [PMID: 34580670 DOI: 10.1101/2021.09.08.459334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Tuberculosis (TB) infection, caused by the airborne pathogen Mycobacterium tuberculosis ( M . tb ), resulted in almost 1.4 million deaths in 2019 and the number of deaths is predicted to increase by 20% over the next 5 years due to the COVID-19 pandemic. Upon reaching the alveolar space, M . tb comes in close contact with the lung mucosa before and after its encounter with host alveolar compartment cells. Our previous studies show that homeostatic innate soluble components of the alveolar lining fluid (ALF) can quickly alter the cell envelope surface of M . tb upon contact, defining subsequent M . tb -host cell interactions and infection outcomes in vitro and in vivo . We also demonstrated that ALF from 60+ year old elders (E-ALF) vs . healthy 18- to 45-year-old adults (A-ALF) is dysfunctional with loss of homeostatic capacity and impaired innate soluble responses linked to high local oxidative stress. In this study, a targeted transcriptional assay demonstrates that M . tb exposure to human ALF alters the expression of its cell envelope genes. Specifically, our results indicate that A-ALF-exposed M . tb upregulates cell envelope genes associated with lipid, carbohydrate, and amino acid metabolism, as well as genes associated with redox homeostasis and transcriptional regulators. Conversely, M . tb exposure to E-ALF shows lesser transcriptional response, with most of the M . tb genes unchanged or downregulated. Overall, this study indicates that M . tb responds and adapts to the lung alveolar environment upon contact, and that the host ALF status determined by factors such as age might play an important role in determining infection outcome.
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21
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Beskrovnaya P, Sexton DL, Golmohammadzadeh M, Hashimi A, Tocheva EI. Structural, Metabolic and Evolutionary Comparison of Bacterial Endospore and Exospore Formation. Front Microbiol 2021; 12:630573. [PMID: 33767680 PMCID: PMC7985256 DOI: 10.3389/fmicb.2021.630573] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
Sporulation is a specialized developmental program employed by a diverse set of bacteria which culminates in the formation of dormant cells displaying increased resilience to stressors. This represents a major survival strategy for bacteria facing harsh environmental conditions, including nutrient limitation, heat, desiccation, and exposure to antimicrobial compounds. Through dispersal to new environments via biotic or abiotic factors, sporulation provides a means for disseminating genetic material and promotes encounters with preferable environments thus promoting environmental selection. Several types of bacterial sporulation have been characterized, each involving numerous morphological changes regulated and performed by non-homologous pathways. Despite their likely independent evolutionary origins, all known modes of sporulation are typically triggered by limited nutrients and require extensive membrane and peptidoglycan remodeling. While distinct modes of sporulation have been observed in diverse species, two major types are at the forefront of understanding the role of sporulation in human health, and microbial population dynamics and survival. Here, we outline endospore and exospore formation by members of the phyla Firmicutes and Actinobacteria, respectively. Using recent advances in molecular and structural biology, we point to the regulatory, genetic, and morphological differences unique to endo- and exospore formation, discuss shared characteristics that contribute to the enhanced environmental survival of spores and, finally, cover the evolutionary aspects of sporulation that contribute to bacterial species diversification.
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Affiliation(s)
| | | | | | | | - Elitza I. Tocheva
- Department of Microbiology and Immunology, Life Sciences Institute, Health Sciences Mall, The University of British Columbia, Vancouver, BC, Canada
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22
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Rens C, Chao JD, Sexton DL, Tocheva EI, Av-Gay Y. Roles for phthiocerol dimycocerosate lipids in Mycobacterium tuberculosis pathogenesis. MICROBIOLOGY-SGM 2021; 167. [PMID: 33629944 DOI: 10.1099/mic.0.001042] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The success of Mycobacterium tuberculosis as a pathogen is well established: tuberculosis is the leading cause of death by a single infectious agent worldwide. The threat of multi- and extensively drug-resistant bacteria has renewed global concerns about this pathogen and understanding its virulence strategies will be essential in the fight against tuberculosis. The current review will focus on phthiocerol dimycocerosates (PDIMs), a long-known and well-studied group of complex lipids found in the M. tuberculosis cell envelope. Numerous studies show a role for PDIMs in several key steps of M. tuberculosis pathogenesis, with recent studies highlighting its involvement in bacterial virulence, in association with the ESX-1 secretion system. Yet, the mechanisms by which PDIMs help M. tuberculosis to control macrophage phagocytosis, inhibit phagosome acidification and modulate host innate immunity, remain to be fully elucidated.
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Affiliation(s)
- Céline Rens
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada
| | - Joseph D Chao
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada
| | - Danielle L Sexton
- Department of Microbiology & Immunology, The University of British Columbia, Vancouver, Canada
| | - Elitza I Tocheva
- Department of Microbiology & Immunology, The University of British Columbia, Vancouver, Canada
| | - Yossef Av-Gay
- Division of Infectious Disease, Department of Medicine, The University of British Columbia, Vancouver, Canada.,Department of Microbiology & Immunology, The University of British Columbia, Vancouver, Canada
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23
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Genome-wide identification of novel genes involved in Corynebacteriales cell envelope biogenesis using Corynebacterium glutamicum as a model. PLoS One 2021; 15:e0240497. [PMID: 33383576 PMCID: PMC7775120 DOI: 10.1371/journal.pone.0240497] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/16/2020] [Indexed: 01/06/2023] Open
Abstract
Corynebacteriales are Actinobacteria that possess an atypical didermic cell envelope. One of the principal features of this cell envelope is the presence of a large complex made up of peptidoglycan, arabinogalactan and mycolic acids. This covalent complex constitutes the backbone of the cell wall and supports an outer membrane, called mycomembrane in reference to the mycolic acids that are its major component. The biosynthesis of the cell envelope of Corynebacteriales has been extensively studied, in particular because it is crucial for the survival of important pathogens such as Mycobacterium tuberculosis and is therefore a key target for anti-tuberculosis drugs. In this study, we explore the biogenesis of the cell envelope of Corynebacterium glutamicum, a non-pathogenic Corynebacteriales, which can tolerate dramatic modifications of its cell envelope as important as the loss of its mycomembrane. For this purpose, we used a genetic approach based on genome-wide transposon mutagenesis. We developed a highly effective immunological test based on the use of anti-cell wall antibodies that allowed us to rapidly identify bacteria exhibiting an altered cell envelope. A very large number (10,073) of insertional mutants were screened by means of this test, and 80 were finally selected, representing 55 different loci. Bioinformatics analyses of these loci showed that approximately 60% corresponded to genes already characterized, 63% of which are known to be directly involved in cell wall processes, and more specifically in the biosynthesis of the mycoloyl-arabinogalactan-peptidoglycan complex. We identified 22 new loci potentially involved in cell envelope biogenesis, 76% of which encode putative cell envelope proteins. A mutant of particular interest was further characterized and revealed a new player in mycolic acid metabolism. Because a large proportion of the genes identified by our study is conserved in Corynebacteriales, the library described here provides a new resource of genes whose characterization could lead to a better understanding of the biosynthesis of the envelope components of these bacteria.
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24
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Guerra Maldonado JF, Vincent AT, Chenal M, Veyrier FJ. CAPRIB: a user-friendly tool to study amino acid changes and selection for the exploration of intra-genus evolution. BMC Genomics 2020; 21:832. [PMID: 33243176 PMCID: PMC7690079 DOI: 10.1186/s12864-020-07232-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 11/17/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The evolution of bacteria is shaped by different mechanisms such as mutation, gene deletion, duplication, or insertion of foreign DNA among others. These genetic changes can accumulate in the descendants as a result of natural selection. Using phylogeny and genome comparisons, evolutionary paths can be somehow retraced, with recent events being much easier to detect than older ones. For this reason, multiple tools are available to study the evolutionary events within genomes of single species, such as gene composition alterations, or subtler mutations such as SNPs. However, these tools are generally designed to compare similar genomes and require advanced skills in bioinformatics. We present CAPRIB, a unique tool developed in Java that allows to determine the amino acid changes, at the genus level, that correlate with phenotypic differences between two groups of organisms. RESULTS CAPRIB has a user-friendly graphical interface and uses databases in SQL, making it easy to compare several genomes without the need for programming or thorough knowledge in bioinformatics. This intuitive software narrows down a list of amino acid changes that are concomitant with a given phenotypic divergence at the genus scale. Each permutation found by our software is associated with two already described statistical values that indicate its potential impact on the protein's function, helping the user decide which promising candidates to further investigate. We show that CAPRIB is able to detect already known mutations and uncovers many more, and that this tool can be used to question molecular phylogeny. Finally, we exemplify the utility of CAPRIB by pinpointing amino acid changes that coincided with the emergence of slow-growing mycobacteria from their fast-growing counterparts. The software is freely available at https://github.com/BactSymEvol/Caprib . CONCLUSIONS CAPRIB is a new bioinformatics software aiming to make genus-scale comparisons accessible to all. With its intuitive graphical interface, this tool identifies key amino acid changes concomitant with a phenotypic divergence. By comparing fast and slow-growing mycobacteria, we shed light on evolutionary hotspots, such as the cytokinin pathway, that are interesting candidates for further experimentations.
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Affiliation(s)
- Juan F Guerra Maldonado
- Institut national de la recherche scientifique, Centre Armand-Frappier Santé Biotechnologie, Bacterial Symbionts Evolution, Laval, Québec, Canada
| | - Antony T Vincent
- Institut national de la recherche scientifique, Centre Armand-Frappier Santé Biotechnologie, Bacterial Symbionts Evolution, Laval, Québec, Canada
| | - Martin Chenal
- Institut national de la recherche scientifique, Centre Armand-Frappier Santé Biotechnologie, Bacterial Symbionts Evolution, Laval, Québec, Canada
| | - Frederic J Veyrier
- Institut national de la recherche scientifique, Centre Armand-Frappier Santé Biotechnologie, Bacterial Symbionts Evolution, Laval, Québec, Canada.
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25
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Bakkum T, Heemskerk MT, Bos E, Groenewold M, Oikonomeas-Koppasis N, Walburg KV, van Veen S, van der Lienden MJC, van Leeuwen T, Haks MC, Ottenhoff THM, Koster AJ, van Kasteren SI. Bioorthogonal Correlative Light-Electron Microscopy of Mycobacterium tuberculosis in Macrophages Reveals the Effect of Antituberculosis Drugs on Subcellular Bacterial Distribution. ACS CENTRAL SCIENCE 2020; 6:1997-2007. [PMID: 33274277 PMCID: PMC7706097 DOI: 10.1021/acscentsci.0c00539] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Indexed: 05/07/2023]
Abstract
Bioorthogonal correlative light-electron microscopy (B-CLEM) can give a detailed overview of multicomponent biological systems. It can provide information on the ultrastructural context of bioorthogonal handles and other fluorescent signals, as well as information about subcellular organization. We have here applied B-CLEM to the study of the intracellular pathogen Mycobacterium tuberculosis (Mtb) by generating a triply labeled Mtb through combined metabolic labeling of the cell wall and the proteome of a DsRed-expressing Mtb strain. Study of this pathogen in a B-CLEM setting was used to provide information about the intracellular distribution of the pathogen, as well as its in situ response to various clinical antibiotics, supported by flow cytometric analysis of the bacteria, after recovery from the host cell (ex cellula). The RNA polymerase-targeting drug rifampicin displayed the most prominent effect on subcellular distribution, suggesting the most direct effect on pathogenicity and/or viability, while the cell wall synthesis-targeting drugs isoniazid and ethambutol effectively rescued bacterial division-induced loss of metabolic labels. The three drugs combined did not give a more pronounced effect but rather an intermediate response, whereas gentamicin displayed a surprisingly strong additive effect on subcellular distribution.
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Affiliation(s)
- Thomas Bakkum
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
| | - Matthias T. Heemskerk
- Department
of Infectious Diseases, Leiden University
Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands
| | - Erik Bos
- Department
of Cell and Chemical Biology, Leiden University
Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Mirjam Groenewold
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
| | - Nikolaos Oikonomeas-Koppasis
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
| | - Kimberley V. Walburg
- Department
of Infectious Diseases, Leiden University
Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands
| | - Suzanne van Veen
- Department
of Infectious Diseases, Leiden University
Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands
| | - Martijn J. C. van der Lienden
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
| | - Tyrza van Leeuwen
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
| | - Marielle C. Haks
- Department
of Infectious Diseases, Leiden University
Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands
| | - Tom H. M. Ottenhoff
- Department
of Infectious Diseases, Leiden University
Medical Center, Albinusdreef 2, 2333 ZC Leiden, The Netherlands
| | - Abraham J. Koster
- Department
of Cell and Chemical Biology, Leiden University
Medical Center, Einthovenweg 20, 2333 ZC Leiden, The Netherlands
| | - Sander I. van Kasteren
- Leiden
Institute of Chemistry and The Institute of Chemical Immunology, Leiden University, Einsteinweg 55, Leiden 2300 RA, The Netherlands
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26
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Megrian D, Taib N, Witwinowski J, Beloin C, Gribaldo S. One or two membranes? Diderm Firmicutes challenge the Gram-positive/Gram-negative divide. Mol Microbiol 2020; 113:659-671. [PMID: 31975449 DOI: 10.1111/mmi.14469] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/15/2020] [Accepted: 01/17/2020] [Indexed: 12/24/2022]
Abstract
How, when and why the transition between cell envelopes with one membrane (Gram-positives or monoderms) and two (Gram-negative or diderms) occurred in Bacteria is a key unanswered question in evolutionary biology. Different hypotheses have been put forward, suggesting that either the monoderm or the diderm phenotype is ancestral. The existence of diderm members in the classically monoderm Firmicutes challenges the Gram-positive/Gram-negative divide and provides a great opportunity to tackle the issue. In this review, we present current knowledge on the diversity of bacterial cell envelopes, including these atypical Firmicutes. We discuss how phylogenomic analysis supports the hypothesis that the diderm cell envelope architecture is an ancestral character in the Firmicutes, and that the monoderm phenotype in this phylum arose multiple times independently by loss of the outer membrane. Given the overwhelming distribution of diderm phenotypes with respect to monoderm ones, this scenario likely extends to the ancestor of all bacteria. Finally, we discuss the recent development of genetic tools for Veillonella parvula, a diderm Firmicute member of the human microbiome, which indicates it as an emerging new experimental model to investigate fundamental aspects of the diderm/monoderm transition.
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Affiliation(s)
- Daniela Megrian
- Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France.,Ecole Doctorale Complexité du vivant, Sorbonne University, Paris, France
| | - Najwa Taib
- Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France.,Hub Bioinformatics and Biostatistics, Department of Computational Biology, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Jerzy Witwinowski
- Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France
| | - Christophe Beloin
- Department of Microbiology, Genetics of Biofilm Unit, Institut Pasteur, Paris, France
| | - Simonetta Gribaldo
- Department of Microbiology, Unit Evolutionary Biology of the Microbial Cell, Institut Pasteur, Paris, France
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27
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Augenstreich J, Briken V. Host Cell Targets of Released Lipid and Secreted Protein Effectors of Mycobacterium tuberculosis. Front Cell Infect Microbiol 2020; 10:595029. [PMID: 33194845 PMCID: PMC7644814 DOI: 10.3389/fcimb.2020.595029] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a very successful pathogen, strictly adapted to humans and the cause of tuberculosis. Its success is associated with its ability to inhibit host cell intrinsic immune responses by using an arsenal of virulence factors of different nature. It has evolved to synthesize a series of complex lipids which form an outer membrane and may also be released to enter host cell membranes. In addition, secreted protein effectors of Mtb are entering the host cell cytosol to interact with host cell proteins. We briefly discuss the current model, involving the ESX-1 type seven secretion system and the Mtb lipid phthiocerol dimycoserosate (PDIM), of how Mtb creates pores in the phagosomal membrane to allow Mtb proteins to access to the host cell cytosol. We provide an exhaustive list of Mtb secreted proteins that have effector functions. They modify (mostly inhibit but sometimes activate) host cell pathways such as: phagosome maturation, cell death, cytokine response, xenophagy, reactive oxygen species (ROS) response via NADPH oxidase 2 (NOX2), nitric oxide (NO) response via NO Synthase 2 (NOS2) and antigen presentation via MHC class I and class II molecules. We discuss the host cell targets for each lipid and protein effector and the importance of the Mtb effector for virulence of the bacterium.
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Affiliation(s)
| | - Volker Briken
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
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28
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Genome-wide analysis of the Firmicutes illuminates the diderm/monoderm transition. Nat Ecol Evol 2020; 4:1661-1672. [PMID: 33077930 DOI: 10.1038/s41559-020-01299-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 08/05/2020] [Indexed: 11/08/2022]
Abstract
The transition between cell envelopes with one membrane (Gram-positive or monoderm) and those with two membranes (Gram-negative or diderm) is a fundamental open question in the evolution of Bacteria. Evidence of the presence of two independent diderm lineages, the Halanaerobiales and the Negativicutes, within the classically monoderm Firmicutes has blurred the monoderm/diderm divide and specifically anticipated that other members with an outer membrane (OM) might exist in this phylum. Here, by screening 1,639 genomes of uncultured Firmicutes for signatures of an OM, we highlight a third and deep branching diderm clade, the Limnochordia, strengthening the hypothesis of a diderm ancestor and the occurrence of independent transitions leading to the monoderm phenotype. Phyletic patterns of over 176,000 protein families constituting the Firmicutes pan-proteome identify those that strongly correlate with the diderm phenotype and suggest the existence of new potential players in OM biogenesis. In contrast, we find practically no largely conserved core of monoderms, a fact possibly linked to different ways of adapting to repeated OM losses. Phylogenetic analysis of a concatenation of main OM components totalling nearly 2,000 amino acid positions illustrates the common origin and vertical evolution of most diderm bacterial envelopes. Finally, mapping the presence/absence of OM markers onto the tree of Bacteria shows the overwhelming presence of diderm phyla and the non-monophyly of monoderm ones, pointing to an early origin of two-membraned cells and the derived nature of the Gram-positive envelope following multiple OM losses.
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29
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Abstract
Tuberculosis (TB) is one of the oldest health problems in the world and it remains unresolved. Multidrug-resistant-TB and extensively resistant-TB are a serious problem for control programs. The evaluation of available antibiotics has gained importance in recent years for the treatment of resistant TB. Beta-lactam antibiotics inhibit cell wall biosynthesis in the bacteria; the presence of beta-lactamase enzyme in TB bacilli raises the question of whether this group of antibiotics can be used in treatment. As a result, it has been reported that the combination of beta-lactam antibiotics with beta-lactamase is effective against Mycobacterium tuberculosis both in vitro and in vivo. The aim of this article is to review and discuss up-to-date knowledge and future perspective on beta-lactam antibiotics and TB.
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Affiliation(s)
- Mehmet Akif Gun
- Department of Medical Microbiology, Medical School, Ondokuz Mayis University, Samsun 55139, Turkey
| | - Bulent Bozdogan
- Recombinant DNA and Recombinant Protein Research Center (REDPROM), Aydin Adnan Menderes University, Aydin 09010, Turkey
| | - Ahmet Yilmaz Coban
- Tuberculosis Research Center, Akdeniz University, Antalya 07070, Turkey.,Department of Nutrition & Dietetics, Faculty of Health Sciences, Akdeniz University, Antalya 07070, Turkey
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30
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Maitra A, Munshi T, Healy J, Martin LT, Vollmer W, Keep NH, Bhakta S. Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles' heel for the TB-causing pathogen. FEMS Microbiol Rev 2020; 43:548-575. [PMID: 31183501 PMCID: PMC6736417 DOI: 10.1093/femsre/fuz016] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis, remains one of the leading causes of mortality across the world. There is an urgent requirement to build a robust arsenal of effective antimicrobials, targeting novel molecular mechanisms to overcome the challenges posed by the increase of antibiotic resistance in TB. Mycobacterium tuberculosis has a unique cell envelope structure and composition, containing a peptidoglycan layer that is essential for maintaining cellular integrity and for virulence. The enzymes involved in the biosynthesis, degradation, remodelling and recycling of peptidoglycan have resurfaced as attractive targets for anti-infective drug discovery. Here, we review the importance of peptidoglycan, including the structure, function and regulation of key enzymes involved in its metabolism. We also discuss known inhibitors of ATP-dependent Mur ligases, and discuss the potential for the development of pan-enzyme inhibitors targeting multiple Mur ligases.
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Affiliation(s)
- Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Tulika Munshi
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Jess Healy
- Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Liam T Martin
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Nicholas H Keep
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
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31
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Dietrich C, Li de la Sierra-Gallay I, Masi M, Girard E, Dautin N, Constantinesco-Becker F, Tropis M, Daffé M, van Tilbeurgh H, Bayan N. The C-terminal domain of Corynebacterium glutamicum mycoloyltransferase A is composed of five repeated motifs involved in cell wall binding and stability. Mol Microbiol 2020; 114:1-16. [PMID: 32073722 DOI: 10.1111/mmi.14492] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/07/2020] [Indexed: 12/29/2022]
Abstract
The genomes of Corynebacteriales contain several genes encoding mycoloyltransferases (Myt) that are specific cell envelope enzymes essential for the biogenesis of the outer membrane. MytA is a major mycoloyltransferase of Corynebacterium glutamicum, displaying an N-terminal domain with esterase activity and a C-terminal extension containing a conserved repeated Leu-Gly-Phe-Pro (LGFP) sequence motif of unknown function. This motif is highly conserved in Corynebacteriales and found associated with cell wall hydrolases and with proteins of unknown function. In this study, we determined the crystal structure of MytA and found that its C-terminal domain is composed of five LGFP motifs and forms a long stalk perpendicular to the N-terminal catalytic α/β-hydrolase domain. The LGFP motifs are composed of a 4-stranded β-fold and occupy alternating orientations along the axis of the stalk. Multiple acetate binding pockets were identified in the stalk, which could correspond to putative ligand-binding sites. By using various MytA mutants and complementary in vitro and in vivo approaches, we provide evidence that the C-terminal LGFP domain interacts with the cell wall peptidoglycan-arabinogalactan polymer. We also show that the C-terminal LGFP domain is not required for the activity of MytA but rather contributes to the overall integrity of the cell envelope.
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Affiliation(s)
- Christiane Dietrich
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Ines Li de la Sierra-Gallay
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Muriel Masi
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Eric Girard
- University of Grenoble Alpes, CEA, CNRS, IBS, Grenoble, France
| | - Nathalie Dautin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | | | - Maryelle Tropis
- Institut de Pharmacologie et de Biologie Structurale, CNRS UMR 5089, Toulouse Cedex, France
| | - Mamadou Daffé
- Institut de Pharmacologie et de Biologie Structurale, CNRS UMR 5089, Toulouse Cedex, France
| | - Herman van Tilbeurgh
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Nicolas Bayan
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
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32
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Vinod V, Vijayrajratnam S, Vasudevan AK, Biswas R. The cell surface adhesins of Mycobacterium tuberculosis. Microbiol Res 2019; 232:126392. [PMID: 31841935 DOI: 10.1016/j.micres.2019.126392] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/11/2019] [Accepted: 12/07/2019] [Indexed: 02/07/2023]
Abstract
Bacterial cell surface adhesins play a major role in facilitating host colonization and subsequent establishment of infection. The surface of Mycobacterium tuberculosis, owing to the complex architecture of its cell envelope, expresses numerous adhesins with varied chemical nature, including proteins, lipids, lipoproteins, glycoproteins and glycopolymers. Studies on mycobacterial adhesins show that they bind with multifarious host receptors and extracellular matrix (ECM) components. In this review we have highlighted the adhesins that are abundantly present on the mycobacterial surface and their interactions with host receptors. M. tuberculosis interacts with various host cell surface receptors such as toll like receptors, C-type lectin receptors, scavenger receptors, and Fc and complement receptors. Apart from these, ECM components like fibronectin, collagen, elastin, laminin, fibrillin and vitronectin also provide binding sites for surface adhesins of the tubercle bacilli. M. tuberculosis adhesins include proteins with and without signal peptide sequence and transmembrane proteins. Other surface adhesin macromolecules of M. tuberculosis comprises of lipids, glycolipids and glycopolymers. The interaction between the mycobacterial adhesins and their host receptors result in adhesion of the microbe to the host cells, induction of immune response and aid in the pathogenesis of the disease. A thorough understanding of the different M. tuberculosis surface adhesins and host receptors will provide a better picture of interaction between them at molecular level. The information gained on adhesins and host receptors will prove beneficial in developing novel therapeutic strategies such as the use of anti-adhesin molecules to hinder the adhesion of bacteria to the host cells, thereby preventing establishment of infection. The surface molecules discussed in this review will also benefit in identification of new drug targets, diagnostic markers or vaccine candidates against the deadly pathogen.
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Affiliation(s)
- Vivek Vinod
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Sukhithasri Vijayrajratnam
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Anil Kumar Vasudevan
- Department of Microbiology, Amrita Institute of Medical Sciences and Research Center, Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India
| | - Raja Biswas
- Center for Nanosciences and Molecular Medicine, Amrita School of Medical Sciences and Research Center (AIMS), Amrita Vishwa Vidyapeetham, Kochi, 682041, Kerala, India.
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33
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GASMoC method: a phenol-free technique to detect acid-fast bacilli. Histochem Cell Biol 2019; 153:63-69. [PMID: 31654127 DOI: 10.1007/s00418-019-01825-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2019] [Indexed: 10/25/2022]
Abstract
The genre Mycobacterium includes a series of pathological species, such as M. tuberculosis, which is important for pathology laboratories to detect for a correct diagnosis. The Ziehl-Neelsen technique (ZNT) is the most commonly histochemical method used to detect these bacilli and uses a heated mixture of carbol-fuchsine, which contains basic fuchsine and phenol. Whereas the former component is responsible for the pinkish staining of acid-fast mycobacteria, the role of phenol is not completely understood and it has been suggested that its exclusion does not impact the detection ability of the ZNT. Since phenol is highly toxic and induces several injuries, the goal of this study is to determine the detection capacity of mycobacteria through a method that excludes the use of phenol. Accordingly, the GASMoC method, a modified ZNT that employs a solution of aqueous basic fuchsine heated at 37 °C, was tested on histological samples positive for mycobacteria and the results were compared to that of the ZNT. Data demonstrated that the GASMoC method was able to detect acid-fast bacilli (AFB) in all analyzed cases. Remarkably, microscopic inspection of mycobacteria was easier when the GASMoC method was applied. In conclusion, our study demonstrates that AFB detection does not require phenol and that the GASMoC method, a phenol-free technique, may substitute the ZNT in pathology laboratories.
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34
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Abstract
Free-living bacteria can assemble into multicellular structures called biofilms. Biofilms help bacteria tolerate multiple stresses, including antibiotics and the host immune system. Nontuberculous mycobacteria are a group of emerging opportunistic pathogens that utilize biofilms to adhere to household plumbing and showerheads and to avoid phagocytosis by host immune cells. Typically, bacteria regulate biofilm formation by controlling expression of adhesive structures to attach to surfaces and other bacterial cells. Mycobacteria harbor a unique cell wall built chiefly of long-chain mycolic acids that confers hydrophobicity and has been thought to cause constitutive aggregation in liquid media. Here we show that aggregation is instead a regulated process dictated by the balance of available carbon and nitrogen. Understanding that mycobacteria utilize metabolic cues to regulate the transition between planktonic and aggregated cells reveals an inroad to controlling biofilm formation through targeted therapeutics. Nontuberculous mycobacteria (NTM) are emerging opportunistic pathogens that colonize household water systems and cause chronic lung infections in susceptible patients. The ability of NTM to form surface-attached biofilms in the nonhost environment and corded aggregates in vivo is important to their ability to persist in both contexts. Underlying the development of these multicellular structures is the capacity of mycobacterial cells to adhere to one another. Unlike most other bacteria, NTM spontaneously and constitutively aggregate in vitro, hindering our ability to understand the transition between planktonic and aggregated cells. While culturing a model NTM, Mycobacterium smegmatis, in rich medium, we fortuitously discovered that planktonic cells accumulate after ∼3 days of growth. By providing selective pressure for bacteria that disperse earlier, we isolated a strain with two mutations in the oligopeptide permease operon (opp). A mutant lacking the opp operon (Δopp) disperses earlier than wild type (WT) due to a defect in nutrient uptake. Experiments with WT M. smegmatis revealed that growth as aggregates is favored when carbon is replete, but under conditions of low available carbon relative to available nitrogen, M. smegmatis grows as planktonic cells. By adjusting carbon and nitrogen sources in defined medium, we tuned the cellular C/N ratio such that M. smegmatis grows either as aggregates or as planktonic cells. C/N-mediated aggregation regulation is widespread among NTM with the possible exception of rough-colony Mycobacterium abscessus isolates. Altogether, we show that NTM aggregation is a controlled process that is governed by the relative availability of carbon and nitrogen for metabolism.
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35
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Mashabela GT, de Wet TJ, Warner DF. Mycobacterium tuberculosis Metabolism. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0067-2019. [PMID: 31350832 PMCID: PMC10957194 DOI: 10.1128/microbiolspec.gpp3-0067-2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Indexed: 02/06/2023] Open
Abstract
Mycobacterium tuberculosis is the cause of tuberculosis (TB), a disease which continues to overwhelm health systems in endemic regions despite the existence of effective combination chemotherapy and the widespread use of a neonatal anti-TB vaccine. For a professional pathogen, M. tuberculosis retains a surprisingly large proportion of the metabolic repertoire found in nonpathogenic mycobacteria with very different lifestyles. Moreover, evidence that additional functions were acquired during the early evolution of the M. tuberculosis complex suggests the organism has adapted (and augmented) the metabolic pathways of its environmental ancestor to persistence and propagation within its obligate human host. A better understanding of M. tuberculosis pathogenicity, however, requires the elucidation of metabolic functions under disease-relevant conditions, a challenge complicated by limited knowledge of the microenvironments occupied and nutrients accessed by bacilli during host infection, as well as the reliance in experimental mycobacteriology on a restricted number of experimental models with variable relevance to clinical disease. Here, we consider M. tuberculosis metabolism within the framework of an intimate host-pathogen coevolution. Focusing on recent advances in our understanding of mycobacterial metabolic function, we highlight unusual adaptations or departures from the better-characterized model intracellular pathogens. We also discuss the impact of these mycobacterial "innovations" on the susceptibility of M. tuberculosis to existing and experimental anti-TB drugs, as well as strategies for targeting metabolic pathways. Finally, we offer some perspectives on the key gaps in the current knowledge of fundamental mycobacterial metabolism and the lessons which might be learned from other systems.
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Affiliation(s)
- Gabriel T Mashabela
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
- Current address: Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, University of Stellenbosch, South Africa
| | - Timothy J de Wet
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
- Department of Integrative Biomedical Sciences, University of Cape Town, South Africa
| | - Digby F Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, South Africa
- Wellcome Centre for Infectious Disease Research in Africa, University of Cape Town, South Africa
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36
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Affiliation(s)
- Valerie Mizrahi
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
| | - Digby F Warner
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
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