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Xu F, Jiang M, Li D, Yu P, Ma H, Lu H. Protective effects of antibiotic resistant bacteria on susceptibles in biofilm: Influential factors, mechanism, and modeling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172668. [PMID: 38663625 DOI: 10.1016/j.scitotenv.2024.172668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 05/05/2024]
Abstract
In environmental biofilms, antibiotic-resistant bacteria facilitate the persistence of susceptible counterparts under antibiotic stresses, contributing to increased community-level resistance. However, there is a lack of quantitative understanding of this protective effect and its influential factors, hindering accurate risk assessment of biofilm resistance in diverse environment. This study isolated an opportunistic Escherichia coli pathogen from soil, and engineered it with plasmids conferring antibiotic resistance. Protective effects of the ampicillin resistant strain (AmpR) on their susceptible counterparts (AmpS) were observed in ampicillin-stress colony biofilms. The concentration of ampicillin delineated protective effects into 3 zones: continuous protection (<1 MIC of AmpS), initial AmpS/R dependent (1-8 MIC of AmpS), and ineffective (>8 MIC of AmpS). Intriguingly, Zone 2 exhibited a surprising "less is more" phenomenon tuned by the initial AmpS/R ratio, where biofilm with an initially lower AmpR (1:50 vs 50:1) harbored 30-90 % more AmpR after 24 h growth under antibiotic stress. Compared to AmpS, AmpR displayed superiority in adhesion, antibiotic degradation, motility, and quorum sensing, allowing them to preferentially colonize biofilm edge and areas with higher ampicillin. An agent-based model incorporating protective effects successfully simulated tempo-spatial dynamics of AmpR and AmpS influenced by antibiotic stress and initial AmpS/R. This study provides a holistic view on the pervasive but poorly understood protective effects in biofilm, enabling development of better risk assessment and precisely targeted control strategies of biofilm resistance in diverse environment.
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Affiliation(s)
- Fengqian Xu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Minxi Jiang
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, USA
| | - Dan Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University, Shanghai 200438, China
| | - Pingfeng Yu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - He Ma
- Institute of Process Equipment, College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
| | - Huijie Lu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China.
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2
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Sarkar S, Banerjee A, Bandopadhyay R. Bacterial Polysaccharide-Stabilized Silver Nanoparticles Photocatalytically Decolorize Azo Dyes. Appl Biochem Biotechnol 2024; 196:2466-2486. [PMID: 37477844 DOI: 10.1007/s12010-023-04648-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/04/2023] [Indexed: 07/22/2023]
Abstract
Bacterial polysaccharide is advantageous over plant, algal, and fungal polysaccharides in terms of stability, non-toxicity, and biodegradable nature. In addition, bacterial cell wall polysaccharide (CPs) is very little explored compared to exopolysaccharide. In this study, CPs have been isolated from thermotolerant Chryseobacterium geocarposphaerae DD3 (CPs3) from textile industry dye effluent. Structural characterization of the CPs was done by different techniques, viz., scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). CPs3 demonstrated compact non-porous amorphous surface composed of evenly distributed macromolecular lumps. TGA revealed a high thermostability (~ 350 °C) of the polysaccharide. FTIR and NMR confirm the polysaccharidic nature of the polymer, consisting of glucose units linked by both β-(1 → 3) and β-(1 → 4) glycosidic bonds. The functional properties of CPs3 were evaluated for industrial use as additive, especially antibacterial, emulsification, and flocculation capacities. A single-step green synthesis of silver nanoparticle (AgNP) was performed using CPs3. AgNP was characterized using ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), AFM, and particle size analyses. The CPs3-stabilized AgNP exhibited potential photocatalytic activity against a broad range of azo dyes, congo red (88.33 ± 0.48%), methyl red (76.81 ± 1.03%), and malachite green (47.34 ± 0.90%) after only 3 h of reaction. According to our knowledge, this is the first report on CPs from C. geocarposphaerae. The results demonstrated multifunctionality of CPs3 in both prospective, CPs3 as additive in biotechnology industry as well as Cps3-stabilized AgNP for bioremediation of azo dye.
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Affiliation(s)
- Shrabana Sarkar
- UGC-Center of Advanced Study, Department of Botany, The University of Burdwan, Golapbag, Bardhaman, West Bengal, 713104, India
- Centro de Investigación de Estudios Avanzados del Maule, Vicerrectoría de Investigación Y Postgrado, Universidad Católica del Maule, 3466706, Talca, Chile
| | - Aparna Banerjee
- Instituto de Ciencias Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile, 3467987, Talca, Chile
| | - Rajib Bandopadhyay
- UGC-Center of Advanced Study, Department of Botany, The University of Burdwan, Golapbag, Bardhaman, West Bengal, 713104, India.
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3
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Lee TH, Charchar P, Separovic F, Reid GE, Yarovsky I, Aguilar MI. The intricate link between membrane lipid structure and composition and membrane structural properties in bacterial membranes. Chem Sci 2024; 15:3408-3427. [PMID: 38455013 PMCID: PMC10915831 DOI: 10.1039/d3sc04523d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024] Open
Abstract
It is now evident that the cell manipulates lipid composition to regulate different processes such as membrane protein insertion, assembly and function. Moreover, changes in membrane structure and properties, lipid homeostasis during growth and differentiation with associated changes in cell size and shape, and responses to external stress have been related to drug resistance across mammalian species and a range of microorganisms. While it is well known that the biomembrane is a fluid self-assembled nanostructure, the link between the lipid components and the structural properties of the lipid bilayer are not well understood. This perspective aims to address this topic with a view to a more detailed understanding of the factors that regulate bilayer structure and flexibility. We describe a selection of recent studies that address the dynamic nature of bacterial lipid diversity and membrane properties in response to stress conditions. This emerging area has important implications for a broad range of cellular processes and may open new avenues of drug design for selective cell targeting.
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Affiliation(s)
- Tzong-Hsien Lee
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
| | - Patrick Charchar
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
| | - Gavin E Reid
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
- Department of Biochemistry and Pharmacology, University of Melbourne Parkville VIC 3010 Australia
| | - Irene Yarovsky
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
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4
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Strach M, Koch F, Fiedler S, Liebeton K, Graumann PL. Protein secretion zones during overexpression of amylase within the Gram-positive cell wall. BMC Biol 2023; 21:206. [PMID: 37794427 PMCID: PMC10552229 DOI: 10.1186/s12915-023-01684-1] [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: 12/14/2022] [Accepted: 08/16/2023] [Indexed: 10/06/2023] Open
Abstract
BACKGROUND Whereas the translocation of proteins across the cell membrane has been thoroughly investigated, it is still unclear how proteins cross the cell wall in Gram-positive bacteria, which are widely used for industrial applications. We have studied the secretion of α-amylase AmyE within two different Bacillus strains, B. subtilis and B. licheniformis. RESULTS We show that a C-terminal fusion of AmyE with the fluorescent reporter mCherry is secreted via discrete patches showing very low dynamics. These are visible at many places within the cell wall for many minutes. Expression from a high copy number plasmid was required to be able to see these structures we term "secretion zones". Zones corresponded to visualized AmyE activity on the surface of cells, showing that they release active enzymes. They overlapped with SecA signals but did not frequently co-localize with the secretion ATPase. Single particle tracking showed higher dynamics of SecA and of SecDF, involved in AmyE secretion, at the cell membrane than AmyE. These experiments suggest that SecA initially translocates AmyE molecules through the cell membrane, and then diffuses to a different translocon. Single molecule tracking of SecA suggests the existence of three distinct diffusive states of SecA, which change during AmyE overexpression, but increased AmyE secretion does not appear to overwhelm the system. CONCLUSIONS Because secretion zones were only found during the transition to and within the stationary phase, diffusion rather than passive transport based on cell wall growth from inside to outside may release AmyE and, thus, probably secreted proteins in general. Our findings suggest active transport through the cell membrane and slow, passive transition through the cell wall, at least for overexpressed proteins, in bacteria of the genus Bacillus.
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Affiliation(s)
- Manuel Strach
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, 35032, Germany
| | - Felicitas Koch
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, 35032, Germany
| | - Svenja Fiedler
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, 35032, Germany
| | - Klaus Liebeton
- BRAIN Biotech AG, Darmstädter Str. 34-36, Zwingenberg, 64673, Germany
| | - Peter L Graumann
- Centre for Synthetic Microbiology (SYNMIKRO) and Fachbereich Chemie, Philipps-Universität Marburg, Marburg, 35032, Germany.
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Ago R, Tahara YO, Yamaguchi H, Saito M, Ito W, Yamasaki K, Kasai T, Okamoto S, Chikada T, Oshima T, Osaka I, Miyata M, Niki H, Shiomi D. Relationship between the Rod complex and peptidoglycan structure in Escherichia coli. Microbiologyopen 2023; 12:e1385. [PMID: 37877652 PMCID: PMC10561026 DOI: 10.1002/mbo3.1385] [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: 08/28/2023] [Revised: 09/21/2023] [Accepted: 09/25/2023] [Indexed: 10/26/2023] Open
Abstract
Peptidoglycan for elongation in Escherichia coli is synthesized by the Rod complex, which includes RodZ. Although various mutant strains of the Rod complex have been isolated, the relationship between the activity of the Rod complex and the overall physical and chemical structures of the peptidoglycan have not been reported. We constructed a RodZ mutant, termed RMR, and analyzed the growth rate, morphology, and other characteristics of cells producing the Rod complexes containing RMR. The growth and morphology of RMR cells were abnormal, and we isolated suppressor mutants from RMR cells. Most of the suppressor mutations were found in components of the Rod complex, suggesting that these suppressor mutations increase the integrity and/or the activity of the Rod complex. We purified peptidoglycan from wild-type, RMR, and suppressor mutant cells and observed their structures in detail. We found that the peptidoglycan purified from RMR cells had many large holes and different compositions of muropeptides from those of WT cells. The Rod complex may be a determinant not only for the whole shape of peptidoglycan but also for its highly dense structure to support the mechanical strength of the cell wall.
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Affiliation(s)
- Risa Ago
- Department of Life Science, College of ScienceRikkyo UniversityTokyoJapan
| | - Yuhei O. Tahara
- Graduate School of ScienceOsaka Metropolitan UniversityOsakaJapan
- The OMU Advanced Research Center for Natural Science and TechnologyOsaka Metropolitan UniversityOsakaJapan
| | - Honoka Yamaguchi
- Department of Life Science, College of ScienceRikkyo UniversityTokyoJapan
| | - Motoya Saito
- Department of Biotechnology, Faculty of EngineeringToyama Prefectural UniversityImizuToyamaJapan
| | - Wakana Ito
- Department of Biotechnology, Faculty of EngineeringToyama Prefectural UniversityImizuToyamaJapan
| | - Kaito Yamasaki
- Department of Pharmaceutical Engineering, Faculty of EngineeringToyama Prefectural UniversityImizuToyamaJapan
| | - Taishi Kasai
- Department of Life Science, College of ScienceRikkyo UniversityTokyoJapan
| | - Sho Okamoto
- Microbial Physiology Laboratory, Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
| | - Taiki Chikada
- Department of Life Science, College of ScienceRikkyo UniversityTokyoJapan
| | - Taku Oshima
- Department of Biotechnology, Faculty of EngineeringToyama Prefectural UniversityImizuToyamaJapan
| | - Issey Osaka
- Department of Pharmaceutical Engineering, Faculty of EngineeringToyama Prefectural UniversityImizuToyamaJapan
| | - Makoto Miyata
- Graduate School of ScienceOsaka Metropolitan UniversityOsakaJapan
- The OMU Advanced Research Center for Natural Science and TechnologyOsaka Metropolitan UniversityOsakaJapan
| | - Hironori Niki
- Microbial Physiology Laboratory, Department of Gene Function and PhenomicsNational Institute of GeneticsMishimaShizuokaJapan
- Department of GeneticsThe Graduate University for Advanced Studies, SOKENDAIMishimaShizuokaJapan
| | - Daisuke Shiomi
- Department of Life Science, College of ScienceRikkyo UniversityTokyoJapan
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6
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Guo M, Zhang X, Ismail BB, He Q, Yang Z, Xianyu Y, Liu W, Zhou J, Ye X, Liu D. Super Antibacterial Capacity and Cell Envelope-Disruptive Mechanism of Ultrasonically Grafted N-Halamine PBAT/PBF Films against Escherichia coli. ACS APPLIED MATERIALS & INTERFACES 2023; 15:38910-38929. [PMID: 37550824 DOI: 10.1021/acsami.3c05378] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Antibacterial materials are urgently needed to combat bacterial contamination, growth, or attachment on contact surfaces, as bacterial infections remain a public health crisis worldwide. Here, a novel ultrasound-assisted method is utilized for the first time to fabricate oxidative chlorine-loaded AH@PBAT/PBF-Cl films with more superior grafting efficiency and rechargeable antibacterial effect than those from conventional techniques. The films remarkably inactivate 99.9999% Escherichia coli and Staphylococcus aureus cells, inducing noticeable cell deformations and mechanical instability. The specific antibacterial mechanism against E. coli used as a model organism is unveiled using several cell envelope structural and functional analyses combined with proteomics, peptidoglycomics, and fluorescence probe techniques. Film treatment partially neutralizes the bacterial surface charge, induces oxidative stress and cytoskeleton deformity, alters membrane properties, and disrupts the expression of key proteins involved in the synthesis and transport of the lipopolysaccharide and peptidoglycan, indicating the cell envelope as the primary target. The films specifically target lipopolysaccharides, resulting in structural impairment of the polysaccharide and lipid A components, and inhibit peptidoglycan precursor synthesis. Together, these lead to metabolic disorders, membrane dysfunction, structural collapse, and eventual death. Given the films' antibacterial effects via the disruption of key cell envelope components, they can potentially combat a wide range of bacteria. These findings lay a theoretical basis for developing efficient antibacterial materials for food safety or biomedical applications.
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Affiliation(s)
- Mingming Guo
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
- Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Xinhui Zhang
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
| | - Balarabe B Ismail
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
| | - Qiao He
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
| | - Zhehao Yang
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
| | - Yunlei Xianyu
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
- Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Wentao Liu
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Jianwei Zhou
- School of Mechatronics and Energy Engineering, NingboTech University, Ningbo 315100, China
| | - Xingqian Ye
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
- Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Donghong Liu
- College of Biosystems Engineering and Food Science, National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang Key Laboratory for Agro-Food Processing, Integrated Research Base of Southern Fruit and Vegetable Preservation Technology, Zhejiang International Scientific and Technological Cooperation Base of Health Food Manufacturing and Quality Control, Zhejiang University, Hangzhou 310058, China
- Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
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7
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Skalnik CJ, Cheah SY, Yang MY, Wolff MB, Spangler RK, Talman L, Morrison JH, Peirce SM, Agmon E, Covert MW. Whole-cell modeling of E. coli colonies enables quantification of single-cell heterogeneity in antibiotic responses. PLoS Comput Biol 2023; 19:e1011232. [PMID: 37327241 DOI: 10.1371/journal.pcbi.1011232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 06/01/2023] [Indexed: 06/18/2023] Open
Abstract
Antibiotic resistance poses mounting risks to human health, as current antibiotics are losing efficacy against increasingly resistant pathogenic bacteria. Of particular concern is the emergence of multidrug-resistant strains, which has been rapid among Gram-negative bacteria such as Escherichia coli. A large body of work has established that antibiotic resistance mechanisms depend on phenotypic heterogeneity, which may be mediated by stochastic expression of antibiotic resistance genes. The link between such molecular-level expression and the population levels that result is complex and multi-scale. Therefore, to better understand antibiotic resistance, what is needed are new mechanistic models that reflect single-cell phenotypic dynamics together with population-level heterogeneity, as an integrated whole. In this work, we sought to bridge single-cell and population-scale modeling by building upon our previous experience in "whole-cell" modeling, an approach which integrates mathematical and mechanistic descriptions of biological processes to recapitulate the experimentally observed behaviors of entire cells. To extend whole-cell modeling to the "whole-colony" scale, we embedded multiple instances of a whole-cell E. coli model within a model of a dynamic spatial environment, allowing us to run large, parallelized simulations on the cloud that contained all the molecular detail of the previous whole-cell model and many interactive effects of a colony growing in a shared environment. The resulting simulations were used to explore the response of E. coli to two antibiotics with different mechanisms of action, tetracycline and ampicillin, enabling us to identify sub-generationally-expressed genes, such as the beta-lactamase ampC, which contributed greatly to dramatic cellular differences in steady-state periplasmic ampicillin and was a significant factor in determining cell survival.
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Affiliation(s)
- Christopher J Skalnik
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Sean Y Cheah
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Mica Y Yang
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Mattheus B Wolff
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Ryan K Spangler
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Lee Talman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Jerry H Morrison
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
| | - Shayn M Peirce
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States of America
| | - Eran Agmon
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
- Center for Cell Analysis and Modeling, University of Connecticut School of Medicine, Farmington, Connecticut, United States of America
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, California, United States of America
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8
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Shlosman I, Fivenson EM, Gilman MSA, Sisley TA, Walker S, Bernhardt TG, Kruse AC, Loparo JJ. Allosteric activation of cell wall synthesis during bacterial growth. Nat Commun 2023; 14:3439. [PMID: 37301887 PMCID: PMC10257715 DOI: 10.1038/s41467-023-39037-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
The peptidoglycan (PG) cell wall protects bacteria against osmotic lysis and determines cell shape, making this structure a key antibiotic target. Peptidoglycan is a polymer of glycan chains connected by peptide crosslinks, and its synthesis requires precise spatiotemporal coordination between glycan polymerization and crosslinking. However, the molecular mechanism by which these reactions are initiated and coupled is unclear. Here we use single-molecule FRET and cryo-EM to show that an essential PG synthase (RodA-PBP2) responsible for bacterial elongation undergoes dynamic exchange between closed and open states. Structural opening couples the activation of polymerization and crosslinking and is essential in vivo. Given the high conservation of this family of synthases, the opening motion that we uncovered likely represents a conserved regulatory mechanism that controls the activation of PG synthesis during other cellular processes, including cell division.
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Affiliation(s)
- Irina Shlosman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Elayne M Fivenson
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Morgan S A Gilman
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Tyler A Sisley
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Suzanne Walker
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Thomas G Bernhardt
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA.
| | - Joseph J Loparo
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, 02115, USA.
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9
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Elsbroek L, Amiteye D, Schreiber S, Herrmann F. Molecular Imaging of Isolated Escherichia coli DH5α Peptidoglycan Sacculi Identifies the Mechanism of Action of Cell Wall-Inhibiting Antibiotics. ACS Chem Biol 2023; 18:848-860. [PMID: 36893440 DOI: 10.1021/acschembio.2c00945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Antibiotic resistance of pathogenic bacteria needs to be urgently addressed by the development of new antibacterial entities. Although the prokaryotic cell wall comprises a valuable target for this purpose, development of novel cell wall-active antibiotics is mostly missing today. This is mainly caused by hindrances in the assessment of isolated enzymes of the co-dependent murein synthesis machineries, e.g., the elongasome and divisome. We therefore present imaging methodologies to evaluate inhibitors of bacterial cell wall synthesis by high-resolution atomic force microscopy on isolated Escherichia coli murein sacculi. With the ability to elucidate the peptidoglycan ultrastructure of E. coli cells, unprecedented molecular insights into the mechanisms of antibiotics were established. The nanoscopic impairments introduced by ampicillin, amoxicillin, and fosfomycin were not only identified by AFM but readily correlated with their known mechanism of action. These valuable in vitro capabilities will facilitate the identification and evaluation of new antibiotic leads in the future.
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Affiliation(s)
- Leonardo Elsbroek
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, D-48149 Münster, Germany
| | - Daniel Amiteye
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, D-48149 Münster, Germany
| | - Sebastian Schreiber
- Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, D-48149 Münster, Germany
| | - Fabian Herrmann
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, D-48149 Münster, Germany
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10
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Xu Y, Ji L, Xu S, Bilal M, Ehrenreich A, Deng Z, Cheng H. Membrane-bound sorbitol dehydrogenase is responsible for the unique oxidation of D-galactitol to L-xylo-3-hexulose and D-tagatose in Gluconobacter oxydans. Biochim Biophys Acta Gen Subj 2023; 1867:130289. [PMID: 36503080 DOI: 10.1016/j.bbagen.2022.130289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 11/27/2022] [Accepted: 12/02/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Gluconobacter oxydans, is used in biotechnology because of its ability to oxidize a wide variety of carbohydrates, alcohols, and polyols in a stereo- and regio-selective manner by membrane-bound dehydrogenases located in periplasmic space. These reactions obey the well-known Bertrand-Hudson's rule. In our previous study (BBA-General Subjects, 2021, 1865:129740), we discovered that Gluconobacter species, including G. oxydans and G. cerinus strain can regio-selectively oxidize the C-3 and C-5 hydroxyl groups of D-galactitol to rare sugars D-tagatose and L-xylo-3-hexulose, which represents an exception to Bertrand Hudson's rule. The enzyme catalyzing this reaction is located in periplasmic space or membrane-bound and is PQQ (pyrroloquinoline quinine) and Ca2+-dependent; we were encouraged to determine which type of enzyme(s) catalyze this unique reaction. METHODS Enzyme was identified by complementation of multi-deletion strain of Gluconobacter oxydans 621H with all putative membrane-bound dehydrogenase genes. RESULTS AND CONCLUSIONS In this study, we identified this gene encoding the membrane-bound PQQ-dependent dehydrogenase that catalyzes the unique galactitol oxidation reaction in its 3'-OH and 5'-OH. Complement experiments in multi-deletion G. oxydans BP.9 strains established that the enzyme mSLDH (encoded by GOX0855-0854, sldB-sldA) is responsible for galactitol's unique oxidation reaction. Additionally, we demonstrated that the small subunit SldB of mSLDH was membrane-bound and served as an anchor protein by fusing it to a red fluorescent protein (mRubby), and heterologously expressed in E. coli and the yeast Yarrowia lipolytica. The SldB subunit was required to maintain the holo-enzymatic activity that catalyzes the conversion of D-galactitol to L-xylo-3-hexulose and D-tagatose. The large subunit SldA encoded by GOX0854 was also characterized, and it was discovered that its 24 amino acids signal peptide is required for the dehydrogenation activity of the mSLDH protein. GENERAL SIGNIFICANCE In this study, the main membrane-bound polyol dehydrogenase mSLDH in G. oxydans 621H was proved to catalyze the unique galactitol oxidation, which represents an exception to the Bertrand Hudson's rule, and broadens its substrate ranges of mSLDH. Further deciphering the explicit enzymatic mechanism will prove this theory.
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Affiliation(s)
- Yirong Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Liyun Ji
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Shuo Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Muhammad Bilal
- Institute of Chemical Technology and Engineering, Faculty of Chemical Technology, Poznan University of Technology, Berdychowo 4, PL-60695 Poznan, Poland.
| | - Armin Ehrenreich
- Lehrstuhl für Mikrobiologie, Technische Universität München, Emil-Ramann-Strasse, Freising, Germany.
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
| | - Hairong Cheng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
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11
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Sheng Q, Zhang MY, Liu SM, Chen ZW, Yang PL, Zhang HS, Liu MY, Li K, Zhao LS, Liu NH, Liu LN, Chen XL, Hobbs JK, Foster SJ, Zhang YZ, Su HN. In situ visualization of Braun's lipoprotein on E. coli sacculi. SCIENCE ADVANCES 2023; 9:eadd8659. [PMID: 36662863 PMCID: PMC9858504 DOI: 10.1126/sciadv.add8659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Braun's lipoprotein (Lpp) plays a major role in stabilizing the integrity of the cell envelope in Escherichia coli, as it provides a covalent cross-link between the outer membrane and the peptidoglycan layer. An important challenge in elucidating the physiological role of Lpp lies in attaining a detailed understanding of its distribution on the peptidoglycan layer. Here, using atomic force microscopy, we visualized Lpp directly on peptidoglycan sacculi. Lpp is homogeneously distributed over the outer surface of the sacculus at a high density. However, it is absent at the constriction site during cell division, revealing its role in the cell division process with Pal, another cell envelope-associated protein. Collectively, we have established a framework to elucidate the distribution of Lpp and other peptidoglycan-bound proteins via a direct imaging modality.
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Affiliation(s)
- Qi Sheng
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
| | - Meng-Yao Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Si-Min Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Zhuo-Wei Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Pei-Ling Yang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Hong-Su Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Meng-Yun Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Kang Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Long-Sheng Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Ning-Hua Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Lu-Ning Liu
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Jamie K. Hobbs
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - Simon J. Foster
- The Florey Institute for Host-Pathogen Interactions, University of Sheffield, Sheffield, UK
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Yu-Zhong Zhang
- College of Marine Life Sciences and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Hai-Nan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology, Qingdao 266237, China
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12
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Lund V, Gangotra H, Zhao Z, Sutton JAF, Wacnik K, DeMeester K, Liang H, Santiago C, Leimkuhler Grimes C, Jones S, Foster SJ. Coupling Novel Probes with Molecular Localization Microscopy Reveals Cell Wall Homeostatic Mechanisms in Staphylococcus aureus. ACS Chem Biol 2022; 17:3298-3305. [PMID: 36414253 PMCID: PMC9764285 DOI: 10.1021/acschembio.2c00741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Bacterial cell wall peptidoglycan is essential for viability, and its synthesis is targeted by antibiotics, including penicillin. To determine how peptidoglycan homeostasis controls cell architecture, growth, and division, we have developed novel labeling approaches. These are compatible with super-resolution fluorescence microscopy to examine peptidoglycan synthesis, hydrolysis, and the localization of the enzymes required for its biosynthesis (penicillin binding proteins (PBPs)). Synthesis of a cephalosporin-based fluorescent probe revealed a pattern of PBPs at the septum during division, supporting a model of dispersed peptidoglycan synthesis. Metabolic and hydroxylamine-based probes respectively enabled the synthesis of glycan strands and associated reducing termini of the peptidoglycan to be mapped. Foci and arcs of reducing termini appear as a result of both synthesis of glycan strands and glucosaminidase activity of the major peptidoglycan hydrolase, SagB. Our studies provide molecular level details of how essential peptidoglycan dynamics are controlled during growth and division.
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Affiliation(s)
- Victoria
A. Lund
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Haneesh Gangotra
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Zhen Zhao
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom
| | - Joshua A. F. Sutton
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Katarzyna Wacnik
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Kristen DeMeester
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Hai Liang
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Cintia Santiago
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Catherine Leimkuhler Grimes
- Department
of Chemistry and Biochemistry and Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Simon Jones
- The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Department of Chemistry, University of Sheffield, Sheffield S3 7HF, United Kingdom,E-mail:
| | - Simon J. Foster
- School
of Biosciences, University of Sheffield, Sheffield S10 2TN, United Kingdom,The
Florey Institute for Host−Pathogen Interactions, University of Sheffield, Sheffield S10 2TN, United Kingdom,E-mail:
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13
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Abstract
Dental caries is a major lifestyle concern as dental components affect the face of an individual. The issue of tooth decay occurs in every age group throughout the globe. Researchers are probing incipient implements and techniques to develop filling agents for decayed teeth. Zinc oxide (ZnO) powder is utilized mostly as a filling agent. Nanotechnology enhanced the efficiency of compounds of metal oxides utilized for dental caries. The present study aims to investigate the properties of ZnO nanoparticles (NPs) synthesized chemically (using ZnCl2 and NaOH) as well as biologically (using aqueous leaf extract of Murraya paniculata). The XRD patterns confirm that ZnO NPs have a hexagonal crystalline structure with particle sizes of 47 nm and 55 nm for chemically and biologically synthesized NPs, respectively. The FE-SEM data confirm the nanorod and spherical/cubical shape morphologies for the chemically and biologically synthesized ZnO NPs, respectively. FTIR data show the peaks between 4000 and 450 cm−1 of the functional groups of –OH, C-O, –C-H-, and Zn-O bonds. The UV–Vis absorption study indicates a peak around 370 nm and a hump around 360 nm corresponding to the chemically and biologically synthesized ZnO NPs, respectively. An antibacterial bioassay was performed and compared with commercially available ZnO bulk powder against tooth decaying pathogens, viz., Streptococcus mutans, Staphylococcus aureus, E. coli, and Lactobacillus fermentum, and found that both ZnO NPs had results closer to those of the standard drug (rifampicin). Thus, the synthesized ZnO NPs may be utilized as nano-drugs for the application of tooth decaying filling agents. Even biologically synthesized ZnO NPs may be considered more environmentally friendly and less toxic to human health concerns.
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14
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Attaibi M, den Blaauwen T. An Updated Model of the Divisome: Regulation of the Septal Peptidoglycan Synthesis Machinery by the Divisome. Int J Mol Sci 2022; 23:3537. [PMID: 35408901 PMCID: PMC8998562 DOI: 10.3390/ijms23073537] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 02/06/2023] Open
Abstract
The synthesis of a peptidoglycan septum is a fundamental part of bacterial fission and is driven by a multiprotein dynamic complex called the divisome. FtsW and FtsI are essential proteins that synthesize the peptidoglycan septum and are controlled by the regulatory FtsBLQ subcomplex and the activator FtsN. However, their mode of regulation has not yet been uncovered in detail. Understanding this process in detail may enable the development of new compounds to combat the rise in antibiotic resistance. In this review, recent data on the regulation of septal peptidoglycan synthesis is summarized and discussed. Based on structural models and the collected data, multiple putative interactions within FtsWI and with regulators are uncovered. This elaborates on and supports an earlier proposed model that describes active and inactive conformations of the septal peptidoglycan synthesis complex that are stabilized by these interactions. Furthermore, a new model on the spatial organization of the newly synthesized peptidoglycan and the synthesis complex is presented. Overall, the updated model proposes a balance between several allosteric interactions that determine the state of septal peptidoglycan synthesis.
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Affiliation(s)
| | - Tanneke den Blaauwen
- Bacterial Cell Biology and Physiology, Swammerdam Institute for Life Science, University of Amsterdam, 1098 XH Amsterdam, The Netherlands;
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15
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Glycan-mediated molecular interactions in bacterial pathogenesis. Trends Microbiol 2022; 30:254-267. [PMID: 34274195 PMCID: PMC8758796 DOI: 10.1016/j.tim.2021.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/10/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023]
Abstract
Glycans are expressed on the surface of nearly all host and bacterial cells. Not surprisingly, glycan-mediated molecular interactions play a vital role in bacterial pathogenesis and host responses against pathogens. Glycan-mediated host-pathogen interactions can benefit the pathogen, host, or both. Here, we discuss (i) bacterial glycans that play a critical role in bacterial colonization and/or immune evasion, (ii) host glycans that are utilized by bacteria for pathogenesis, and (iii) bacterial and host glycans involved in immune responses against pathogens. We further discuss (iv) opportunities and challenges for transforming these research findings into more effective antibacterial strategies, and (v) technological advances in glycoscience that have helped to accelerate progress in research. These studies collectively offer valuable insights into new perspectives on antibacterial strategies that may effectively tackle the drug-resistant pathogens that are rapidly spreading globally.
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16
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Deng Y, Chen LX, Zhu BJ, Zhao J, Li SP. A quantitative method for polysaccharides based on endo-enzymatic released specific oligosaccharides: A case of Lentinus edodes. Int J Biol Macromol 2022; 205:15-22. [PMID: 35181321 DOI: 10.1016/j.ijbiomac.2022.02.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 01/05/2023]
Abstract
Polysaccharides exhibit multiple pharmacological activities, which are closely related to their structural characteristics. Therefore, quantitative quality control of polysaccharides based on chemical properties is of importance for their applications. However, polysaccharides are mixed macromolecular compounds that are difficult to separate, and the lack of standards made direct quantification more difficult. In this study, we proposed a new quantitative method based on the released specific oligosaccharides for polysaccharides from Lentinus edodes (shiitake) and other related fungi. Specific oligosaccharides were firstly released from polysaccharides using 1,3-β-glucanase, then derivatized with 2-aminobenzamide (2-AB), which further separated by hydrophilic interaction chromatography (HILIC) and quantitatively determined by UPLC coupled with fluorescence detector (FLR). Laminaritriose was used as the universal standard for quantification of all the oligosaccharides. This method was validated according to linearity, limit of detection, limit of quantitation, precision, accuracy, repeatability and stability. In addition, the four specific oligosaccharides released from polysaccharides in L. edodes were qualitatively analyzed by extracted ion chromatogram (EIC) from UPLC-MS profiles, which were identified to be disaccharide, trisaccharide and tetrasccharide. The proposed strategy not only realized the quantitative analysis of polysaccharides by UPLC-FLR, but also could achieve the qualitative distinction of different polysaccharides.
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Affiliation(s)
- Yong Deng
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China; Joint Laboratory of Chinese Herbal Glycoengineering and Testing Technology, University of Macau, Macao SAR, China
| | - Ling-Xiao Chen
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China; Joint Laboratory of Chinese Herbal Glycoengineering and Testing Technology, University of Macau, Macao SAR, China
| | - Bao-Jie Zhu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China; Joint Laboratory of Chinese Herbal Glycoengineering and Testing Technology, University of Macau, Macao SAR, China
| | - Jing Zhao
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China; Joint Laboratory of Chinese Herbal Glycoengineering and Testing Technology, University of Macau, Macao SAR, China.
| | - Shao-Ping Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China; Joint Laboratory of Chinese Herbal Glycoengineering and Testing Technology, University of Macau, Macao SAR, China.
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17
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Katan T, Kargl R, Mohan T, Steindorfer T, Mozetič M, Kovač J, Stana Kleinschek K. Solid Phase Peptide Synthesis on Chitosan Thin Films. Biomacromolecules 2022; 23:731-742. [PMID: 35023341 PMCID: PMC8924862 DOI: 10.1021/acs.biomac.1c01155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Stable chitosan thin
films can be promising substrates for creating
nanometric peptide-bound polyglucosamine layers. Those are of scientific
interest since they can have certain structural similarities to bacterial
peptidoglycans. Such films were deposited by spin coating from chitosan
solutions and modified by acetylation and N-protected
amino acids. The masses of deposited materials and their stability
in aqueous solutions at different pH values and water interaction
were determined with a quartz crystal microbalance with dissipation
(QCM-D). The evolution of the surface composition was followed by
X-ray photoelectron (XPS) and attenuated total reflectance infrared
(ATR-IR) spectroscopy. Morphological changes were measured by atomic
force microscopy (AFM), while the surface wettability was monitored
by by static water contact angle measurements. The combination of
the characterization techniques enabled an insight into the surface
chemistry for each treatment step and confirmed the acetylation and
coupling of N-protected glycine peptides. The developed
procedures are seen as first steps toward preparing thin layers of
acetylated chitin, potentially imitating the nanometric peptide substituted
glycan layers found in bacterial cell walls.
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Affiliation(s)
- Tadeja Katan
- Institute of Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Rupert Kargl
- Institute of Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Tamilselvan Mohan
- Institute of Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Tobias Steindorfer
- Institute of Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Miran Mozetič
- Department of Surface Engineering, Jožef Stefan Institute (IJS), Jamova 39, 1000 Ljubljana, Slovenia
| | - Janez Kovač
- Department of Surface Engineering, Jožef Stefan Institute (IJS), Jamova 39, 1000 Ljubljana, Slovenia
| | - Karin Stana Kleinschek
- Institute of Chemistry and Technology of Biobased Systems (IBioSys), Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
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18
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Graham CLB, Newman H, Gillett FN, Smart K, Briggs N, Banzhaf M, Roper DI. A Dynamic Network of Proteins Facilitate Cell Envelope Biogenesis in Gram-Negative Bacteria. Int J Mol Sci 2021; 22:12831. [PMID: 34884635 PMCID: PMC8657477 DOI: 10.3390/ijms222312831] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 01/01/2023] Open
Abstract
Bacteria must maintain the ability to modify and repair the peptidoglycan layer without jeopardising its essential functions in cell shape, cellular integrity and intermolecular interactions. A range of new experimental techniques is bringing an advanced understanding of how bacteria regulate and achieve peptidoglycan synthesis, particularly in respect of the central role played by complexes of Sporulation, Elongation or Division (SEDs) and class B penicillin-binding proteins required for cell division, growth and shape. In this review we highlight relationships implicated by a bioinformatic approach between the outer membrane, cytoskeletal components, periplasmic control proteins, and cell elongation/division proteins to provide further perspective on the interactions of these cell division, growth and shape complexes. We detail the network of protein interactions that assist in the formation of peptidoglycan and highlight the increasingly dynamic and connected set of protein machinery and macrostructures that assist in creating the cell envelope layers in Gram-negative bacteria.
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Affiliation(s)
- Chris L. B. Graham
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
| | - Hector Newman
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
| | - Francesca N. Gillett
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK;
| | - Katie Smart
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
| | - Nicholas Briggs
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
| | - Manuel Banzhaf
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK;
| | - David I. Roper
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK; (C.L.B.G.); (H.N.); (F.N.G.); (K.S.); (N.B.)
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19
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Patel AV, Turner RD, Rifflet A, Acosta-Martin AE, Nichols A, Awad MM, Lyras D, Gomperts Boneca I, Bern M, Collins MO, Mesnage S. PGFinder, a novel analysis pipeline for the consistent, reproducible, and high-resolution structural analysis of bacterial peptidoglycans. eLife 2021; 10:70597. [PMID: 34579805 PMCID: PMC8478412 DOI: 10.7554/elife.70597] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 08/08/2021] [Indexed: 12/12/2022] Open
Abstract
Many software solutions are available for proteomics and glycomics studies, but none are ideal for the structural analysis of peptidoglycan (PG), the essential and major component of bacterial cell envelopes. It icomprises glycan chains and peptide stems, both containing unusual amino acids and sugars. This has forced the field to rely on manual analysis approaches, which are time-consuming, labour-intensive, and prone to error. The lack of automated tools has hampered the ability to perform high-throughput analyses and prevented the adoption of a standard methodology. Here, we describe a novel tool called PGFinder for the analysis of PG structure and demonstrate that it represents a powerful tool to quantify PG fragments and discover novel structural features. Our analysis workflow, which relies on open-access tools, is a breakthrough towards a consistent and reproducible analysis of bacterial PGs. It represents a significant advance towards peptidoglycomics as a full-fledged discipline.
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Affiliation(s)
- Ankur V Patel
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
| | - Robert D Turner
- Department of Computer Science, University of Sheffield, Sheffield, United Kingdom
| | - Aline Rifflet
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France.,INSERM, Équipe Avenir, Paris, France.,CNRS, UMR 2001 "Microbiologie intégrative et moléculaire", Paris, France
| | - Adelina E Acosta-Martin
- biOMICS Facility, Faculty of Science Mass Spectrometry Centre, University of Sheffield, Sheffield, United Kingdom
| | | | - Milena M Awad
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia
| | - Dena Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Clayton, Australia.,Department of Microbiology, Monash University, Clayton, Australia
| | - Ivo Gomperts Boneca
- Institut Pasteur, Unité Biologie et Génétique de la Paroi Bactérienne, Paris, France.,INSERM, Équipe Avenir, Paris, France.,CNRS, UMR 2001 "Microbiologie intégrative et moléculaire", Paris, France
| | | | - Mark O Collins
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom.,biOMICS Facility, Faculty of Science Mass Spectrometry Centre, University of Sheffield, Sheffield, United Kingdom
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, United Kingdom
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20
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Abstract
Most bacteria are surrounded by a peptidoglycan cell wall that defines their shape and protects them from osmotic lysis. The expansion and division of this structure therefore plays an integral role in bacterial growth and division. Additionally, the biogenesis of the peptidoglycan layer is the target of many of our most effective antibiotics. Thus, a better understanding of how the cell wall is built will enable the development of new therapies to combat the rise of drug-resistant bacterial infections. This review covers recent advances in defining the mechanisms involved in assembling the peptidoglycan layer with an emphasis on discoveries related to the function and regulation of the cell elongation and division machineries in the model organisms Escherichia coli and Bacillus subtilis. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Patricia D A Rohs
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Current affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Thomas G Bernhardt
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115, USA; .,Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
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21
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Su Z, Liu T, Li X, Graham N, Yu W. Beneficial impacts of natural biopolymers during surface water purification by membrane nanofiltration. WATER RESEARCH 2021; 201:117330. [PMID: 34134038 DOI: 10.1016/j.watres.2021.117330] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 05/30/2021] [Accepted: 06/01/2021] [Indexed: 06/12/2023]
Abstract
Membrane filtration in various forms has become an increasingly used treatment method worldwide for the supply of safe drinking water. The fouling of membranes is commonly considered to be the major operational limitation to its wider application since it leads to frequent backwashing and a shortening of membrane life, and increased production costs. The components of natural organic matter (NOM) in surface waters have been reported previously to be important foulants of nanofiltration (NF) membranes, however, the potential beneficial effect of particular components of these 'foulants' has not been investigated or demonstrated to date. In this study, we have considered the roles of different organic materials including autochthonous NOM (e.g., biopolymers) and allochthonous NOM (e.g., humic substances) on the fouling of NF membranes by bench-scale tests with samples of two representative source waters (UK) taken in two different seasons (autumn and winter). Microfiltration (MF) and ultrafiltration (UF) were employed to generate two permeates, between which the presence of biopolymers (30 kDa - 90 kDa) is the major difference. We developed sequential filtration (MF/UF-NF) to investigate biopolymers' behaviours in NF process. The results showed that the accumulation of biopolymers on NF membranes can mitigate fouling by providing a protective layer in which medium-low molecular weight (MW) materials (e.g. humic substances) are separated by adsorption and/or size exclusion. The protective layers assisted by biopolymers were seen to be thicker under scanning electron microscope (SEM) observation and characterized by higher roughness (i.e. three-dimensional, spacial structure) and greater adsorptive capacity. Moreover, improvement on NF membrane fouling mitigation could be more significant in autumn, comparing to that in winter. The findings in this study were found to be repeatable in similar tests with samples of comparable raw waters in China, and will be important to the practical application of NF membrane systems in terms of a new approach to combating fouling in long-term operation.
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Affiliation(s)
- Zhaoyang Su
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100024, China.
| | - Ting Liu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China.
| | - Xing Li
- College of Architecture and Civil Engineering, Beijing University of Technology, Beijing 100024, China.
| | - Nigel Graham
- Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
| | - Wenzheng Yu
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
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22
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Yan J, Sun B, Xie C, Liu Y, Song Z, Xu H, Wang Z. The influence of different liquid environments on the atomic force microscopy detection of living bEnd.3 cells. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:2384-2390. [PMID: 33970977 DOI: 10.1039/d1ay00567g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Atomic force microscopy (AFM) is one of the most important tools in the field of biomedical science, and it can be used to perform the high-resolution three-dimensional imaging of samples in liquid environments to obtain their physical properties (such as surface potentials and mechanical properties). The influence of the liquid environment on the image quality of the sample and the detection results cannot be ignored. In this work, quantitative imaging (QI) mode AFM imaging and mechanical detection were performed on mouse brain microvascular endothelial (bEnd.3) cells in different liquid environments. The gray-level variance product (SMD2) function was used to evaluate the imaging quality of the cells in liquids with different physical properties, and the variations in cell mechanical properties were quantitatively analyzed. An AFM detection liquid containing less ions and organics compared with the traditional culture medium, which is beneficial for improving the imaging quality, is introduced, and it shows similar mechanical detection results within 3 h. This can greatly reduce the detection costs and could have positive significance in the field of AFM living-cell detection.
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Affiliation(s)
- Jin Yan
- International Research Centre for Nano Handling and Manufacturing of China, Changchun University of Science and Technology, Changchun 130022, China.
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23
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Bhat SV, Price JDW, Dahms TES. AFM-Based Correlative Microscopy Illuminates Human Pathogens. Front Cell Infect Microbiol 2021; 11:655501. [PMID: 34026660 PMCID: PMC8138568 DOI: 10.3389/fcimb.2021.655501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/08/2021] [Indexed: 12/25/2022] Open
Abstract
Microbes have an arsenal of virulence factors that contribute to their pathogenicity. A number of challenges remain to fully understand disease transmission, fitness landscape, antimicrobial resistance and host heterogeneity. A variety of tools have been used to address diverse aspects of pathogenicity, from molecular host-pathogen interactions to the mechanisms of disease acquisition and transmission. Current gaps in our knowledge include a more direct understanding of host-pathogen interactions, including signaling at interfaces, and direct phenotypic confirmation of pathogenicity. Correlative microscopy has been gaining traction to address the many challenges currently faced in biomedicine, in particular the combination of optical and atomic force microscopy (AFM). AFM, generates high-resolution surface topographical images, and quantifies mechanical properties at the pN scale under physiologically relevant conditions. When combined with optical microscopy, AFM probes pathogen surfaces and their physical and molecular interaction with host cells, while the various modes of optical microscopy view internal cellular responses of the pathogen and host. Here we review the most recent advances in our understanding of pathogens, recent applications of AFM to the field, how correlative AFM-optical microspectroscopy and microscopy have been used to illuminate pathogenicity and how these methods can reach their full potential for studying host-pathogen interactions.
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Affiliation(s)
- Supriya V Bhat
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Jared D W Price
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
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24
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Frederiksen CØ, Cohn MT, Skov LK, Schmidt EGW, Schnorr KM, Buskov S, Leppänen M, Maasilta I, Perez-Calvo E, Lopez-Ulibarri R, Klausen M. A muramidase from Acremonium alcalophilum hydrolyse peptidoglycan found in the gastrointestinal tract of broiler chickens. J Ind Microbiol Biotechnol 2021; 48:6128676. [PMID: 33693885 PMCID: PMC9113140 DOI: 10.1093/jimb/kuab008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/20/2021] [Indexed: 12/19/2022]
Abstract
This study evaluates peptidoglycan hydrolysis by a microbial muramidase from the
fungus Acremonium alcalophilum in vitro and in the
gastrointestinal tract of broiler chickens. Peptidoglycan used for in
vitro studies was derived from 5 gram-positive chicken gut isolate
type strains. In vitro peptidoglycan hydrolysis was studied by
three approaches: (a) helium ion microscopy to identify visual phenotypes of
hydrolysis, (b) reducing end assay to quantify solubilization of peptidoglycan
fragments, and (c) mass spectroscopy to estimate relative abundances of soluble
substrates and reaction products. Visual effects of peptidoglycan hydrolysis
could be observed by helium ion microscopy and the increase in abundance of
soluble peptidoglycan due to hydrolysis was quantified by a reducing end assay.
Mass spectroscopy confirmed the release of hydrolysis products and identified
muropeptides from the five different peptidoglycan sources. Peptidoglycan
hydrolysis in chicken crop, jejunum, and caecum samples was measured by
quantifying the total and soluble muramic acid content. A significant increase
in the proportion of the soluble muramic acid was observed in all three segments
upon inclusion of the microbial muramidase in the diet.
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Affiliation(s)
| | | | | | | | | | | | - Miika Leppänen
- Department of Biological and Environmental Sciences and Department of Physics, University of Jyvaskyla, Jyvaskyla, FI-40014, Finland
| | - Ilari Maasilta
- Department of Physics, University of Jyvaskyla, Jyvaskyla, FI-40014, Finland
| | - Estefania Perez-Calvo
- Research Centre for Animal Nutrition and Health, DSM Nutritional Products, Village-Neuf, F-68305 Saint Louis, France
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25
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CwlQ Is Required for Swarming Motility but Not Flagellar Assembly in Bacillus subtilis. J Bacteriol 2021; 203:JB.00029-21. [PMID: 33649146 DOI: 10.1128/jb.00029-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/22/2021] [Indexed: 11/20/2022] Open
Abstract
Lytic enzymes play an essential role in the remodeling of bacterial peptidoglycan (PG), an extracellular mesh-like structure that retains the membrane in the context of high internal osmotic pressure. Peptidoglycan must be unfailingly stable to preserve cell integrity, but must also be dynamically remodeled for the cell to grow, divide, and insert macromolecular machines. The flagellum is one such macromolecular machine that transits the PG, and flagellar insertion is aided by localized activity of a dedicated PG lyase in Gram-negative bacteria. To date, there is no known dedicated lyase in Gram-positive bacteria for the insertion of flagella. Here, we take a reverse-genetic candidate-gene approach and find that cells mutated for the lytic transglycosylase CwlQ exhibit a severe defect in flagellum-dependent swarming motility. We further show that CwlQ is expressed by the motility sigma factor SigD and is secreted by the type III secretion system housed inside the flagellum. Nonetheless, cells with mutations of CwlQ remain proficient for flagellar biosynthesis even when mutated in combination with four other lyases related to motility (LytC, LytD, LytF, and CwlO). The PG lyase (or lyases) essential for flagellar synthesis in B. subtilis, if any, remains unknown.IMPORTANCE Bacteria are surrounded by a wall of peptidoglycan and early work in Bacillus subtilis was the first to suggest that bacteria needed to enzymatically remodel the wall to permit insertion of the flagellum. No PG remodeling enzyme alone or in combination, however, has been found to be essential for flagellar assembly in B. subtilis Here, we take a reverse-genetic candidate-gene approach and find that the PG lytic transglycosylase CwlQ is required for swarming motility. Subsequent characterization determined that while CwlQ was coexpressed with motility genes and is secreted by the flagellar secretion apparatus, it was not required for flagellar synthesis. The PG lyase needed for flagellar assembly in B. subtilis remains unknown.
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26
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Wong F, Stokes JM, Cervantes B, Penkov S, Friedrichs J, Renner LD, Collins JJ. Cytoplasmic condensation induced by membrane damage is associated with antibiotic lethality. Nat Commun 2021; 12:2321. [PMID: 33875652 PMCID: PMC8055701 DOI: 10.1038/s41467-021-22485-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 03/15/2021] [Indexed: 11/17/2022] Open
Abstract
Bactericidal antibiotics kill bacteria by perturbing various cellular targets and processes. Disruption of the primary antibiotic-binding partner induces a cascade of molecular events, leading to overproduction of reactive metabolic by-products. It remains unclear, however, how these molecular events contribute to bacterial cell death. Here, we take a single-cell physical biology approach to probe antibiotic function. We show that aminoglycosides and fluoroquinolones induce cytoplasmic condensation through membrane damage and subsequent outflow of cytoplasmic contents as part of their lethality. A quantitative model of membrane damage and cytoplasmic leakage indicates that a small number of nanometer-scale membrane defects in a single bacterium can give rise to the cellular-scale phenotype of cytoplasmic condensation. Furthermore, cytoplasmic condensation is associated with the accumulation of reactive metabolic by-products and lipid peroxidation, and pretreatment of cells with the antioxidant glutathione attenuates cytoplasmic condensation and cell death. Our work expands our understanding of the downstream molecular events that are associated with antibiotic lethality, revealing cytoplasmic condensation as a phenotypic feature of antibiotic-induced bacterial cell death. The detailed mechanisms of action of bactericidal antibiotics remain unclear. Here, Wong et al. show that these antibiotics induce cytoplasmic condensation through membrane damage and outflow of cytoplasmic contents, as well as accumulation of reactive metabolic by-products and lipid peroxidation, as part of their lethality.
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Affiliation(s)
- Felix Wong
- Institute for Medical Engineering & Science and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jonathan M Stokes
- Institute for Medical Engineering & Science and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Bernardo Cervantes
- Institute for Medical Engineering & Science and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA.,Microbiology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sider Penkov
- Institute for Clinical Chemistry and Laboratory Medicine at the University Clinic and Medical Faculty of TU Dresden, Dresden, Germany
| | - Jens Friedrichs
- Leibniz Institute of Polymer Research and the Max Bergmann Center of Biomaterials, Dresden, Germany
| | - Lars D Renner
- Leibniz Institute of Polymer Research and the Max Bergmann Center of Biomaterials, Dresden, Germany.
| | - James J Collins
- Institute for Medical Engineering & Science and Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA. .,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
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27
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Dufrêne YF, Viljoen A, Mignolet J, Mathelié-Guinlet M. AFM in cellular and molecular microbiology. Cell Microbiol 2021; 23:e13324. [PMID: 33710716 DOI: 10.1111/cmi.13324] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022]
Abstract
The unique capabilities of the atomic force microscope (AFM), including super-resolution imaging, piconewton force-sensitivity, nanomanipulation and ability to work under physiological conditions, have offered exciting avenues for cellular and molecular biology research. AFM imaging has helped unravel the fine architectures of microbial cell envelopes at the nanoscale, and how these are altered by antimicrobial treatment. Nanomechanical measurements have shed new light on the elasticity, tensile strength and turgor pressure of single cells. Single-molecule and single-cell force spectroscopy experiments have revealed the forces and dynamics of receptor-ligand interactions, the nanoscale distribution of receptors on the cell surface and the elasticity and adhesiveness of bacterial pili. Importantly, recent force spectroscopy studies have demonstrated that extremely stable bonds are formed between bacterial adhesins and their cognate ligands, originating from a catch bond behaviour allowing the pathogen to reinforce adhesion under shear or tensile stress. Here, we survey how the versatility of AFM has enabled addressing crucial questions in microbiology, with emphasis on bacterial pathogens. TAKE AWAYS: AFM topographic imaging unravels the ultrastructure of bacterial envelopes. Nanomechanical mapping shows what makes cell envelopes stiff and resistant to drugs. Force spectroscopy characterises the molecular forces in pathogen adhesion. Stretching pili reveals a wealth of mechanical and adhesive responses.
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Affiliation(s)
- Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Albertus Viljoen
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Johann Mignolet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Marion Mathelié-Guinlet
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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28
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Gilmore MC, Ritzl-Rinkenberger B, Cava F. An updated toolkit for exploring bacterial cell wall structure and dynamics. Fac Rev 2021; 10:14. [PMID: 33659932 PMCID: PMC7894271 DOI: 10.12703/r/10-14] [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: 11/15/2022] Open
Abstract
The bacterial cell wall is made primarily from peptidoglycan, a complex biomolecule which forms a bag-like exoskeleton that envelops the cell. As it is unique to bacteria and typically essential for their growth and survival, it represents one of the most successful targets for antibiotics. Although peptidoglycan has been studied intensively for over 50 years, the past decade has seen major steps in our understanding of this molecule because of the advent of new analytical and imaging methods. Here, we outline the most recent developments in tools that have helped to elucidate peptidoglycan structure and dynamics.
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Affiliation(s)
- Michael C Gilmore
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Barbara Ritzl-Rinkenberger
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
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29
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New approaches and techniques for bacterial cell wall analysis. Curr Opin Microbiol 2021; 60:88-95. [PMID: 33631455 DOI: 10.1016/j.mib.2021.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 12/17/2022]
Abstract
Peptidoglycan (PG) has remained for decades in the spotlight of the never-ending battle against pathogenic bacteria as this essential bacterial structure is one of the most successful targets for antibiotics. Most of our current understanding about the composition, architecture, and dynamics of the PG relies on techniques which have experienced great technological and methodological improvements in the past years. Here we summarize recent advances in these methods with the intention to furnish a valuable resource for both PG experts and newcomers.
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30
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Hennell James R, Deme JC, Kjӕr A, Alcock F, Silale A, Lauber F, Johnson S, Berks BC, Lea SM. Structure and mechanism of the proton-driven motor that powers type 9 secretion and gliding motility. Nat Microbiol 2021; 6:221-233. [PMID: 33432152 PMCID: PMC7116788 DOI: 10.1038/s41564-020-00823-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/28/2020] [Indexed: 12/11/2022]
Abstract
Three classes of ion-driven protein motors have been identified to date: ATP synthase, the bacterial flagellar motor and a proton-driven motor that powers gliding motility and the type 9 protein secretion system in Bacteroidetes bacteria. Here, we present cryo-electron microscopy structures of the gliding motility/type 9 protein secretion system motors GldLM from Flavobacterium johnsoniae and PorLM from Porphyromonas gingivalis. The motor is an asymmetric inner membrane protein complex in which the single transmembrane helices of two periplasm-spanning GldM/PorM proteins are positioned inside a ring of five GldL/PorL proteins. Mutagenesis and single-molecule tracking identify protonatable amino acid residues in the transmembrane domain of the complex that are important for motor function. Our data provide evidence for a mechanism in which proton flow results in rotation of the periplasm-spanning GldM/PorM dimer inside the intra-membrane GldL/PorL ring to drive processes at the bacterial outer membrane.
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Affiliation(s)
- Rory Hennell James
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Justin C Deme
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK
| | - Andreas Kjӕr
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Felicity Alcock
- Department of Biochemistry, University of Oxford, Oxford, UK
- CBCB, Newcastle University, Newcastle upon Tyne, UK
| | - Augustinas Silale
- Department of Biochemistry, University of Oxford, Oxford, UK
- CBCB, Newcastle University, Newcastle upon Tyne, UK
| | - Frédéric Lauber
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Steven Johnson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ben C Berks
- Department of Biochemistry, University of Oxford, Oxford, UK.
| | - Susan M Lea
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK.
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31
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Garde S, Chodisetti PK, Reddy M. Peptidoglycan: Structure, Synthesis, and Regulation. EcoSal Plus 2021; 9:eESP-0010-2020. [PMID: 33470191 PMCID: PMC11168573 DOI: 10.1128/ecosalplus.esp-0010-2020] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Indexed: 02/06/2023]
Abstract
Peptidoglycan is a defining feature of the bacterial cell wall. Initially identified as a target of the revolutionary beta-lactam antibiotics, peptidoglycan has become a subject of much interest for its biology, its potential for the discovery of novel antibiotic targets, and its role in infection. Peptidoglycan is a large polymer that forms a mesh-like scaffold around the bacterial cytoplasmic membrane. Peptidoglycan synthesis is vital at several stages of the bacterial cell cycle: for expansion of the scaffold during cell elongation and for formation of a septum during cell division. It is a complex multifactorial process that includes formation of monomeric precursors in the cytoplasm, their transport to the periplasm, and polymerization to form a functional peptidoglycan sacculus. These processes require spatio-temporal regulation for successful assembly of a robust sacculus to protect the cell from turgor and determine cell shape. A century of research has uncovered the fundamentals of peptidoglycan biology, and recent studies employing advanced technologies have shed new light on the molecular interactions that govern peptidoglycan synthesis. Here, we describe the peptidoglycan structure, synthesis, and regulation in rod-shaped bacteria, particularly Escherichia coli, with a few examples from Salmonella and other diverse organisms. We focus on the pathway of peptidoglycan sacculus elongation, with special emphasis on discoveries of the past decade that have shaped our understanding of peptidoglycan biology.
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Affiliation(s)
- Shambhavi Garde
- These authors contributed equally
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India 500007
| | - Pavan Kumar Chodisetti
- These authors contributed equally
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India 500007
| | - Manjula Reddy
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India 500007
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32
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Beaussart A, Feuillie C, El-Kirat-Chatel S. The microbial adhesive arsenal deciphered by atomic force microscopy. NANOSCALE 2020; 12:23885-23896. [PMID: 33289756 DOI: 10.1039/d0nr07492f] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microbes employ a variety of strategies to adhere to abiotic and biotic surfaces, as well as host cells. In addition to their surface physicochemical properties (e.g. charge, hydrophobic balance), microbes produce appendages (e.g. pili, fimbriae, flagella) and express adhesion proteins embedded in the cell wall or cell membrane, with adhesive domains targeting specific ligands or chemical properties. Atomic force microscopy (AFM) is perfectly suited to deciphering the adhesive properties of microbial cells. Notably, AFM imaging has revealed the cell wall topographical organization of live cells at unprecedented resolution, and AFM has a dual capability to probe adhesion at the single-cell and single-molecule levels. AFM is thus a powerful tool for unravelling the molecular mechanisms of microbial adhesion at scales ranging from individual molecular interactions to the behaviours of entire cells. In this review, we cover some of the major breakthroughs facilitated by AFM in deciphering the microbial adhesive arsenal, including the exciting development of anti-adhesive strategies.
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33
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Abstract
Single-celled organisms must adapt their physiology to persist and propagate across a wide range of environmental conditions. The growth and division of bacterial cells depend on continuous synthesis of an essential extracellular barrier: the peptidoglycan cell wall, a polysaccharide matrix that counteracts turgor pressure and confers cell shape. Unlike many other essential processes and structures within the bacterial cell, the peptidoglycan cell wall and its synthesis machinery reside at the cell surface and are thus uniquely vulnerable to the physicochemical environment and exogenous threats. In addition to the diversity of stressors endangering cell wall integrity, defects in peptidoglycan metabolism require rapid repair in order to prevent osmotic lysis, which can occur within minutes. Here, we review recent work that illuminates mechanisms that ensure robust peptidoglycan metabolism in response to persistent and acute environmental stress. Advances in our understanding of bacterial cell wall quality control promise to inform the development and use of antimicrobial agents that target the synthesis and remodeling of this essential macromolecule.IMPORTANCE Nearly all bacteria are encased in a peptidoglycan cell wall, an essential polysaccharide structure that protects the cell from osmotic rupture and reinforces cell shape. The integrity of this protective barrier must be maintained across the diversity of environmental conditions wherein bacteria replicate. However, at the cell surface, the cell wall and its synthesis machinery face unique challenges that threaten their integrity. Directly exposed to the extracellular environment, the peptidoglycan synthesis machinery encounters dynamic and extreme physicochemical conditions, which may impair enzymatic activity and critical protein-protein interactions. Biotic and abiotic stressors-including host defenses, cell wall active antibiotics, and predatory bacteria and phage-also jeopardize peptidoglycan integrity by introducing lesions, which must be rapidly repaired to prevent cell lysis. Here, we review recently discovered mechanisms that promote robust peptidoglycan synthesis during environmental and acute stress and highlight the opportunities and challenges for the development of cell wall active therapeutics.
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34
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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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35
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Lee I, Cheon HJ, Adhikari MD, Tran TD, Yeon KM, Kim MI, Kim J. Glucose oxidase-copper hybrid nanoflowers embedded with magnetic nanoparticles as an effective antibacterial agent. Int J Biol Macromol 2020; 155:1520-1531. [DOI: 10.1016/j.ijbiomac.2019.11.129] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 01/10/2023]
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36
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Engineering microbial cell morphology and membrane homeostasis toward industrial applications. Curr Opin Biotechnol 2020; 66:18-26. [PMID: 32569960 DOI: 10.1016/j.copbio.2020.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/25/2020] [Accepted: 05/12/2020] [Indexed: 01/03/2023]
Abstract
Microbial cell factory performance is significantly affected by the cell morphology and membrane homeostasis. It is important to ensure that cell factories are able to regulate cell morphology and maintain membrane homeostasis. Cell morphology can be controlled by regulating the formation of elongasomes and divisomes, which change the shapes of cells from rods to fibers, large spheres, or mini-cells. Membrane homeostasis can also be controlled by regulating the homeostasis of membrane lipids and proteins, thereby improving the robustness of microbes in toxic environments. In the present review, we discuss promising developments in cell morphology and membrane homeostasis engineering that have improved microbial cell factory performance.
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37
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Harper CE, Hernandez CJ. Cell biomechanics and mechanobiology in bacteria: Challenges and opportunities. APL Bioeng 2020; 4:021501. [PMID: 32266323 PMCID: PMC7113033 DOI: 10.1063/1.5135585] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/27/2020] [Indexed: 12/11/2022] Open
Abstract
Physical forces play a profound role in the survival and function of all known forms of life. Advances in cell biomechanics and mechanobiology have provided key insights into the physiology of eukaryotic organisms, but much less is known about the roles of physical forces in bacterial physiology. This review is an introduction to bacterial mechanics intended for persons familiar with cells and biomechanics in mammalian cells. Bacteria play a major role in human health, either as pathogens or as beneficial commensal organisms within the microbiome. Although bacteria have long been known to be sensitive to their mechanical environment, understanding the effects of physical forces on bacterial physiology has been limited by their small size (∼1 μm). However, advancements in micro- and nano-scale technologies over the past few years have increasingly made it possible to rigorously examine the mechanical stress and strain within individual bacteria. Here, we review the methods currently used to examine bacteria from a mechanical perspective, including the subcellular structures in bacteria and how they differ from those in mammalian cells, as well as micro- and nanomechanical approaches to studying bacteria, and studies showing the effects of physical forces on bacterial physiology. Recent findings indicate a large range in mechanical properties of bacteria and show that physical forces can have a profound effect on bacterial survival, growth, biofilm formation, and resistance to toxins and antibiotics. Advances in the field of bacterial biomechanics have the potential to lead to novel antibacterial strategies, biotechnology approaches, and applications in synthetic biology.
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Affiliation(s)
- Christine E. Harper
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
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38
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Pasquina-Lemonche L, Burns J, Turner RD, Kumar S, Tank R, Mullin N, Wilson JS, Chakrabarti B, Bullough PA, Foster SJ, Hobbs JK. The architecture of the Gram-positive bacterial cell wall. Nature 2020; 582:294-297. [PMID: 32523118 PMCID: PMC7308169 DOI: 10.1038/s41586-020-2236-6] [Citation(s) in RCA: 189] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/25/2020] [Indexed: 02/05/2023]
Abstract
The primary structural component of the bacterial cell wall is peptidoglycan, which is essential for viability and the synthesis of which is the target for crucial antibiotics1,2. Peptidoglycan is a single macromolecule made of glycan chains crosslinked by peptide side branches that surrounds the cell, acting as a constraint to internal turgor1,3. In Gram-positive bacteria, peptidoglycan is tens of nanometres thick, generally portrayed as a homogeneous structure that provides mechanical strength4-6. Here we applied atomic force microscopy7-12 to interrogate the morphologically distinct Staphylococcus aureus and Bacillus subtilis species, using live cells and purified peptidoglycan. The mature surface of live cells is characterized by a landscape of large (up to 60 nm in diameter), deep (up to 23 nm) pores constituting a disordered gel of peptidoglycan. The inner peptidoglycan surface, consisting of more nascent material, is much denser, with glycan strand spacing typically less than 7 nm. The inner surface architecture is location dependent; the cylinder of B. subtilis has dense circumferential orientation, while in S. aureus and division septa for both species, peptidoglycan is dense but randomly oriented. Revealing the molecular architecture of the cell envelope frames our understanding of its mechanical properties and role as the environmental interface13,14, providing information complementary to traditional structural biology approaches.
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Affiliation(s)
- L Pasquina-Lemonche
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
- The Florey Institute, University of Sheffield, Sheffield, UK
| | - J Burns
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - R D Turner
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
- Department of Computer Science, University of Sheffield, Sheffield, UK
| | - S Kumar
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - R Tank
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - N Mullin
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - J S Wilson
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - B Chakrabarti
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - P A Bullough
- Krebs Institute, University of Sheffield, Sheffield, UK
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - S J Foster
- Krebs Institute, University of Sheffield, Sheffield, UK.
- The Florey Institute, University of Sheffield, Sheffield, UK.
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.
| | - J K Hobbs
- Krebs Institute, University of Sheffield, Sheffield, UK.
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK.
- The Florey Institute, University of Sheffield, Sheffield, UK.
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39
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Tulum I, Tahara YO, Miyata M. Peptidoglycan layer and disruption processes in Bacillus subtilis cells visualized using quick-freeze, deep-etch electron microscopy. Microscopy (Oxf) 2020; 68:441-449. [PMID: 31690940 DOI: 10.1093/jmicro/dfz033] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/08/2019] [Accepted: 08/08/2019] [Indexed: 12/22/2022] Open
Abstract
Peptidoglycan, which is the main component of the bacterial cell wall, is a heterogeneous polymer of glycan strands cross-linked with short peptides and is synthesized in cooperation with the cell division cycle. Although it plays a critical role in bacterial survival, its architecture is not well understood. Herein, we visualized the architecture of the peptidoglycan surface in Bacillus subtilis at the nanometer resolution, using quick-freeze, deep-etch electron microscopy (EM). Filamentous structures were observed on the entire surface of the cell, where filaments about 11 nm wide formed concentric circles on cell poles, filaments about 13 nm wide formed a circumferential mesh-like structure on the cylindrical part and a 'piecrust' structure was observed at the boundary. When growing cells were treated with lysozyme, the entire cell mass migrated to one side and came out from the cell envelope. Fluorescence labeling showed that lysozyme preferentially bound to a cell pole and cell division site, where the peptidoglycan synthesis was not complete. Ruffling of surface structures was observed during EM. When cells were treated with penicillin, the cell mass came out from a cleft around the cell division site. Outward curvature of the protoplast at the cleft seen using EM suggested that turgor pressure was applied as the peptidoglycan was not damaged at other positions. When muropeptides were depleted, surface filaments were lost while the rod shape of the cell was maintained. These changes can be explained on the basis of the working points of the chemical structure of peptidoglycan.
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Affiliation(s)
- Isil Tulum
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.,The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka 558-8585, Japan
| | - Yuhei O Tahara
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.,The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka 558-8585, Japan
| | - Makoto Miyata
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.,The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, Osaka 558-8585, Japan
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40
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Abstract
Gram-negative bacteria are protected by a multicompartmental molecular architecture known as the cell envelope that contains two membranes and a thin cell wall. As the cell envelope controls influx and efflux of molecular species, in recent years both experimental and computational studies of such architectures have seen a resurgence due to the implications for antibiotic development. In this article we review recent progress in molecular simulations of bacterial membranes. We show that enormous progress has been made in terms of the lipidic and protein compositions of bacterial systems. The simulations have moved away from the traditional setup of one protein surrounded by a large patch of the same lipid type toward a more bio-logically representative viewpoint. Simulations with multiple cell envelope components are also emerging. We review some of the key method developments that have facilitated recent progress, discuss some current limitations, and offer a perspective on future directions.
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Affiliation(s)
- Wonpil Im
- Departments of Biological Sciences and Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, Republic of Korea
| | - Syma Khalid
- School of Chemistry, University of Southampton, Southampton S017 1BJ, United Kingdom
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41
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Zhang W, Cao S, Ding W, Wang M, Fan S, Yang B, Mcminn A, Wang M, Xie BB, Qin QL, Chen XL, He J, Zhang YZ. Structure and function of the Arctic and Antarctic marine microbiota as revealed by metagenomics. MICROBIOME 2020; 8:47. [PMID: 32241287 PMCID: PMC7119284 DOI: 10.1186/s40168-020-00826-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/13/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND The Arctic and Antarctic are the two most geographically distant bioregions on earth. Recent sampling efforts and following metagenomics have shed light on the global ocean microbial diversity and function, yet the microbiota of polar regions has not been included in such global analyses. RESULTS Here a metagenomic study of seawater samples (n = 60) collected from different depths at 28 locations in the Arctic and Antarctic zones was performed, together with metagenomes from the Tara Oceans. More than 7500 (19%) polar seawater-derived operational taxonomic units could not be identified in the Tara Oceans datasets, and more than 3,900,000 protein-coding gene orthologs had no hits in the Ocean Microbial Reference Gene Catalog. Analysis of 214 metagenome assembled genomes (MAGs) recovered from the polar seawater microbiomes, revealed strains that are prevalent in the polar regions while nearly undetectable in temperate seawater. Metabolic pathway reconstruction for these microbes suggested versatility for saccharide and lipids biosynthesis, nitrate and sulfate reduction, and CO2 fixation. Comparison between the Arctic and Antarctic microbiomes revealed that antibiotic resistance genes were enriched in the Arctic while functions like DNA recombination were enriched in the Antarctic. CONCLUSIONS Our data highlight the occurrence of dominant and locally enriched microbes in the Arctic and Antarctic seawater with unique functional traits for environmental adaption, and provide a foundation for analyzing the global ocean microbiome in a more complete perspective. Video abstract.
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Affiliation(s)
- Weipeng Zhang
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373 China
| | - Shunan Cao
- The Key Laboratory for Polar Science SOA, Polar Research Institute of China, Shanghai, 200136 China
| | - Wei Ding
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Meng Wang
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Shen Fan
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Bo Yang
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Andrew Mcminn
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Min Wang
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
| | - Bin-bin Xie
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237 China
| | - Qi-Long Qin
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237 China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237 China
| | - Jianfeng He
- The Key Laboratory for Polar Science SOA, Polar Research Institute of China, Shanghai, 200136 China
| | - Yu-Zhong Zhang
- College of Marine Life Science, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003 China
- Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373 China
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237 China
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42
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Abstract
The bacterial cell envelope is essential for viability, the environmental gatekeeper and first line of defense against external stresses. For most bacteria, the envelope biosynthesis is also the site of action of some of the most important groups of antibiotics. It is a complex, often multicomponent structure, able to withstand the internally generated turgor pressure. Thus, elucidating the architecture and dynamics of the cell envelope is important, to unravel not only the complexities of cell morphology and maintenance of integrity but also how interventions such as antibiotics lead to death. To address these questions requires the capacity to visualize the cell envelope in situ via high-spatial resolution approaches. In recent years, atomic force microscopy (AFM) has brought novel molecular insights into the assembly, dynamics, and functions of bacterial cell envelopes. The ultrafine resolution and physical sensitivity of the technique have revealed a wealth of ultrastructural features that are invisible to traditional optical microscopy techniques or imperceptible in their true physiological state by electron microscopy. Here, we discuss recent progress in our use of AFM imaging for understanding the architecture and dynamics of the bacterial envelope. We survey recent studies that demonstrate the power of the technique to observe isolated membranes and live cells at (sub)nanometer resolution and under physiological conditions and to track in vitro structural dynamics in response to growth or to drugs.
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43
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Özbaykal G, Wollrab E, Simon F, Vigouroux A, Cordier B, Aristov A, Chaze T, Matondo M, van Teeffelen S. The transpeptidase PBP2 governs initial localization and activity of the major cell-wall synthesis machinery in E. coli. eLife 2020; 9:50629. [PMID: 32077853 PMCID: PMC7089770 DOI: 10.7554/elife.50629] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 02/19/2020] [Indexed: 12/15/2022] Open
Abstract
Bacterial shape is physically determined by the peptidoglycan cell wall. The cell-wall-synthesis machinery responsible for rod shape in Escherichia coli is the processive 'Rod complex'. Previously, cytoplasmic MreB filaments were thought to govern formation and localization of Rod complexes based on local cell-envelope curvature. Using single-particle tracking of the transpeptidase and Rod-complex component PBP2, we found that PBP2 binds to a substrate different from MreB. Depletion and localization experiments of other putative Rod-complex components provide evidence that none of those provide the sole rate-limiting substrate for PBP2 binding. Consistently, we found only weak correlations between MreB and envelope curvature in the cylindrical part of cells. Residual correlations do not require curvature-based Rod-complex initiation but can be attributed to persistent rotational motion. We therefore speculate that the local cell-wall architecture provides the cue for Rod-complex initiation, either through direct binding by PBP2 or through an unknown intermediate.
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Affiliation(s)
- Gizem Özbaykal
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France.,Université Paris Diderot, Sorbonne-Paris-Cité, Paris, France
| | - Eva Wollrab
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France
| | - Francois Simon
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France
| | - Antoine Vigouroux
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France.,Synthetic Biology Lab, Institut Pasteur, Paris, France.,Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Baptiste Cordier
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France
| | - Andrey Aristov
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Paris, France
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44
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Beaussart A, El-Kirat-Chatel S. Microbial adhesion and ultrastructure from the single-molecule to the single-cell levels by Atomic Force Microscopy. Cell Surf 2019; 5:100031. [PMID: 32743147 PMCID: PMC7389263 DOI: 10.1016/j.tcsw.2019.100031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 12/29/2022] Open
Abstract
In the last decades, atomic force microscopy (AFM) has evolved towards an accurate and lasting tool to study the surface of living cells in physiological conditions. Through imaging, single-molecule force spectroscopy and single-cell force spectroscopy modes, AFM allows to decipher at multiple scales the morphology and the molecular interactions taking place at the cell surface. Applied to microbiology, these approaches have been used to elucidate biophysical properties of biomolecules and to directly link the molecular structures to their function. In this review, we describe the main methods developed for AFM-based microbial surface analysis that we illustrate with examples of molecular mechanisms unravelled with unprecedented resolution.
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45
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Khanna K, Lopez-Garrido J, Zhao Z, Watanabe R, Yuan Y, Sugie J, Pogliano K, Villa E. The molecular architecture of engulfment during Bacillus subtilis sporulation. eLife 2019; 8:45257. [PMID: 31282858 PMCID: PMC6684271 DOI: 10.7554/elife.45257] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/04/2019] [Indexed: 01/08/2023] Open
Abstract
The study of bacterial cell biology is limited by difficulties in visualizing cellular structures at high spatial resolution within their native milieu. Here, we visualize Bacillus subtilis sporulation using cryo-electron tomography coupled with cryo-focused ion beam milling, allowing the reconstruction of native-state cellular sections at molecular resolution. During sporulation, an asymmetrically-positioned septum generates a larger mother cell and a smaller forespore. Subsequently, the mother cell engulfs the forespore. We show that the septal peptidoglycan is not completely degraded at the onset of engulfment. Instead, the septum is uniformly and only slightly thinned as it curves towards the mother cell. Then, the mother cell membrane migrates around the forespore in tiny finger-like projections, whose formation requires the mother cell SpoIIDMP protein complex. We propose that a limited number of SpoIIDMP complexes tether to and degrade the peptidoglycan ahead of the engulfing membrane, generating an irregular membrane front.
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Affiliation(s)
- Kanika Khanna
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Javier Lopez-Garrido
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Ziyi Zhao
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Reika Watanabe
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Yuan Yuan
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Joseph Sugie
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Kit Pogliano
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
| | - Elizabeth Villa
- Division of Biological SciencesUniversity of California, San DiegoLa JollaUnited States
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46
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Porfírio S, Carlson RW, Azadi P. Elucidating Peptidoglycan Structure: An Analytical Toolset. Trends Microbiol 2019; 27:607-622. [DOI: 10.1016/j.tim.2019.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 01/16/2019] [Accepted: 01/29/2019] [Indexed: 01/04/2023]
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47
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Bacillus subtilis cell diameter is determined by the opposing actions of two distinct cell wall synthetic systems. Nat Microbiol 2019; 4:1294-1305. [PMID: 31086310 PMCID: PMC6656618 DOI: 10.1038/s41564-019-0439-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 03/28/2019] [Indexed: 11/08/2022]
Abstract
Rod-shaped bacteria grow by adding material into their cell wall via the action of two spatially distinct enzymatic systems: the Rod complex moves around the cell circumference, whereas class A penicillin-binding proteins (aPBPs) do not. To understand how the combined action of these two systems defines bacterial dimensions, we examined how each affects the growth and width of Bacillus subtilis as well as the mechanical anisotropy and orientation of material within their sacculi. Rod width is not determined by MreB, rather it depends on the balance between the systems: the Rod complex reduces diameter, whereas aPBPs increase it. Increased Rod-complex activity correlates with an increased density of directional MreB filaments and a greater fraction of directional PBP2a enzymes. This increased circumferential synthesis increases the relative quantity of oriented material within the sacculi, making them more resistant to stretching across their width, thereby reinforcing rod shape. Together, these experiments explain how the combined action of the two main cell wall synthetic systems builds and maintains rods of different widths. Escherichia coli Rod mutants also show the same correlation between width and directional MreB filament density, suggesting this model may be generalizable to bacteria that elongate via the Rod complex.
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48
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Joshi G, Okeyoshi K, Mitsumata T, Kaneko T. Micro-deposition control of polysaccharides on evaporative air-LC interface to design quickly swelling hydrogels. J Colloid Interface Sci 2019; 546:184-191. [PMID: 30913492 DOI: 10.1016/j.jcis.2019.03.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/17/2019] [Accepted: 03/18/2019] [Indexed: 01/07/2023]
Abstract
Uniaxial orientation is highly desirable for fabricating advanced soft materials. Liquid crystal (LC) polymer deposition was strategically manipulated at the air-LC interface, by controlling the drying temperature and initial concentration of aqueous solution of xanthan gum in a limited space. Interface-assisted orientation led to membrane-like depositions bridging the millimeter-scale gap between the substrates both, vertically and horizontally. The applicability of this approach lies in synchronization of the molecular orientation beyond their individual LC domains into the condensed state. Cross-polarized microscopy and SEM analysis correlated the orientation of the deposited polymer with the controlled mobility of xanthan gum LC domains at the evaporative interface. Subsequently, a phase diagram was prepared for the variety of oriented structures, depending upon the drying conditions. The deposited membrane behaved as an oriented hydrogel showing reversible anisotropic swelling/deswelling only along its thickness.
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Affiliation(s)
- Gargi Joshi
- Energy and Environment Area, Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Kosuke Okeyoshi
- Energy and Environment Area, Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
| | - Tetsu Mitsumata
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan
| | - Tatsuo Kaneko
- Energy and Environment Area, Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan.
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49
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Nguyen LT, Oikonomou CM, Ding HJ, Kaplan M, Yao Q, Chang YW, Beeby M, Jensen GJ. Simulations suggest a constrictive force is required for Gram-negative bacterial cell division. Nat Commun 2019; 10:1259. [PMID: 30890709 PMCID: PMC6425016 DOI: 10.1038/s41467-019-09264-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 02/28/2019] [Indexed: 11/16/2022] Open
Abstract
To divide, Gram-negative bacterial cells must remodel cell wall at the division site. It remains debated, however, whether this cell wall remodeling alone can drive membrane constriction, or if a constrictive force from the tubulin homolog FtsZ is required. Previously, we constructed software (REMODELER 1) to simulate cell wall remodeling during growth. Here, we expanded this software to explore cell wall division (REMODELER 2). We found that simply organizing cell wall synthesis complexes at the midcell is not sufficient to cause invagination, even with the implementation of a make-before-break mechanism, in which new hoops of cell wall are made inside the existing hoops before bonds are cleaved. Division can occur, however, when a constrictive force brings the midcell into a compressed state before new hoops of relaxed cell wall are incorporated between existing hoops. Adding a make-before-break mechanism drives division with a smaller constrictive force sufficient to bring the midcell into a relaxed, but not necessarily compressed, state.
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Affiliation(s)
- Lam T Nguyen
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
| | - Catherine M Oikonomou
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
| | - H Jane Ding
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
| | - Mohammed Kaplan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
| | - Qing Yao
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
| | - Yi-Wei Chang
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA, 19104, USA
| | - Morgan Beeby
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA, 91125, USA.
- Howard Hughes Medical Institute, 1200 E. California Boulevard, Pasadena, CA, 91125, USA.
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Novel Antibacterial Resin-Based Filling Material Containing Nanoparticles for the Potential One-Step Treatment of Caries. JOURNAL OF HEALTHCARE ENGINEERING 2019; 2019:6367919. [PMID: 31001408 PMCID: PMC6436334 DOI: 10.1155/2019/6367919] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/23/2018] [Accepted: 02/20/2019] [Indexed: 12/03/2022]
Abstract
The aim of this work was to study the application of resin filling containing nanomaterials for the potential treatment of caries. Zinc nanoparticles (ZnO@NP, 50 nm) were chosen for their antimicrobial capacity against aerobic bacteria, and here, they have proved to be bactericidal against anaerobic bacterial strains (Streptococcus mutans, Streptococcus mitis, and Lactobacillus spp.). Potential mechanism of action is proposed based on microbiological assays and seems to be independent of oxidative stress because the nanoparticles are effective in microaerophilic conditions. The loading of nanoparticles on the demineralized dental surface and their infiltration power were significantly improved when ZnO@NP were carried by the resin. Overall, this material seems to have a high potential to become a one-step treatment for caries lesions.
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