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Hetta HF, Ramadan YN, Rashed ZI, Alharbi AA, Alsharef S, Alkindy TT, Alkhamali A, Albalawi AS, Battah B, Donadu MG. Quorum Sensing Inhibitors: An Alternative Strategy to Win the Battle against Multidrug-Resistant (MDR) Bacteria. Molecules 2024; 29:3466. [PMID: 39124871 PMCID: PMC11313800 DOI: 10.3390/molecules29153466] [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: 05/07/2024] [Revised: 06/29/2024] [Accepted: 07/22/2024] [Indexed: 08/12/2024] Open
Abstract
Antibiotic resistance is a major problem and a major global health concern. In total, there are 16 million deaths yearly from infectious diseases, and at least 65% of infectious diseases are caused by microbial communities that proliferate through the formation of biofilms. Antibiotic overuse has resulted in the evolution of multidrug-resistant (MDR) microbial strains. As a result, there is now much more interest in non-antibiotic therapies for bacterial infections. Among these revolutionary, non-traditional medications is quorum sensing inhibitors (QSIs). Bacterial cell-to-cell communication is known as quorum sensing (QS), and it is mediated by tiny diffusible signaling molecules known as autoinducers (AIs). QS is dependent on the density of the bacterial population. QS is used by Gram-negative and Gram-positive bacteria to control a wide range of processes; in both scenarios, QS entails the synthesis, identification, and reaction to signaling chemicals, also known as auto-inducers. Since the usual processes regulated by QS are the expression of virulence factors and the creation of biofilms, QS is being investigated as an alternative solution to antibiotic resistance. Consequently, the use of QS-inhibiting agents, such as QSIs and quorum quenching (QQ) enzymes, to interfere with QS seems like a good strategy to prevent bacterial infections. This review sheds light on QS inhibition strategy and mechanisms and discusses how using this approach can aid in winning the battle against resistant bacteria.
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Affiliation(s)
- Helal F. Hetta
- Division of Microbiology, Immunology and Biotechnology, Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.A.); (S.A.); (T.T.A.)
| | - Yasmin N. Ramadan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Assiut University, Assiut 71515, Egypt; (Y.N.R.); (Z.I.R.)
| | - Zainab I. Rashed
- Department of Microbiology and Immunology, Faculty of Pharmacy, Assiut University, Assiut 71515, Egypt; (Y.N.R.); (Z.I.R.)
| | - Ahmad A. Alharbi
- Division of Microbiology, Immunology and Biotechnology, Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.A.); (S.A.); (T.T.A.)
| | - Shomokh Alsharef
- Division of Microbiology, Immunology and Biotechnology, Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.A.); (S.A.); (T.T.A.)
| | - Tala T. Alkindy
- Division of Microbiology, Immunology and Biotechnology, Department of Natural Products and Alternative Medicine, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.A.); (S.A.); (T.T.A.)
| | - Alanoud Alkhamali
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.); (A.S.A.)
| | - Abdullah S. Albalawi
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk 71491, Saudi Arabia; (A.A.); (A.S.A.)
| | - Basem Battah
- Department of Biochemistry and Microbiology, Faculty of Pharmacy, Antioch Syrian Private University, Maaret Siadnaya 22734, Syria
| | - Matthew G. Donadu
- Hospital Pharmacy, Giovanni Paolo II Hospital, ASL Gallura, 07026 Olbia, Italy;
- Department of Medicine, Surgery and Pharmacy, Scuola di Specializzazione in Farmacia Ospedaliera, University of Sassari, 07100 Sassari, Italy
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Michaelis S, Chen T, Schmid C, Hilbi H. Nitric oxide signaling through three receptors regulates virulence, biofilm formation, and phenotypic heterogeneity of Legionella pneumophila. mBio 2024; 15:e0071024. [PMID: 38682908 PMCID: PMC11237717 DOI: 10.1128/mbio.00710-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 03/25/2024] [Indexed: 05/01/2024] Open
Abstract
The causative agent of Legionnaires' disease, Legionella pneumophila, is an environmental bacterium, that replicates in macrophages, parasitizes amoeba, and forms biofilms. L. pneumophila employs the Legionella quorum sensing (Lqs) system and the transcription factor LvbR to control various bacterial traits, including virulence and biofilm architecture. LvbR negatively regulates the nitric oxide (NO) receptor Hnox1, linking quorum sensing to NO signaling. Here, we assessed the response of L. pneumophila to NO and investigated bacterial receptors underlying this process. Chemical NO donors, such as dipropylenetriamine (DPTA) NONOate and sodium nitroprusside (SNP), delayed and reduced the expression of the promoters for flagellin (PflaA) and the 6S small regulatory RNA (P6SRNA). Marker-less L. pneumophila mutant strains lacking individual (Hnox1, Hnox2, or NosP) or all three NO receptors (triple knockout, TKO) grew like the parental strain in media. However, in the TKO strain, the reduction of PflaA expression by DPTA NONOate was less pronounced, suggesting that the NO receptors are implicated in NO signaling. In the ΔnosP mutant, the lvbR promoter was upregulated, indicating that NosP negatively regulates LvbR. The single and triple NO receptor mutant strains were impaired for growth in phagocytes, and phenotypic heterogeneity of non-growing/growing bacteria in amoebae was regulated by the NO receptors. The single NO receptor and TKO mutant strains showed altered biofilm architecture and lack of response of biofilms to NO. In summary, we provide evidence that L. pneumophila regulates virulence, intracellular phenotypic heterogeneity, and biofilm formation through NO and three functionally non-redundant NO receptors, Hnox1, Hnox2, and NosP. IMPORTANCE The highly reactive diatomic gas molecule nitric oxide (NO) is produced by eukaryotes and bacteria to promote short-range and transient signaling within and between neighboring cells. Despite its importance as an inter-kingdom and intra-bacterial signaling molecule, the bacterial response and the underlying components of the signaling pathways are poorly characterized. The environmental bacterium Legionella pneumophila forms biofilms and replicates in protozoan and mammalian phagocytes. L. pneumophila harbors three putative NO receptors, one of which crosstalks with the Legionella quorum sensing (Lqs)-LvbR network to regulate various bacterial traits, including virulence and biofilm architecture. In this study, we used pharmacological, genetic, and cell biological approaches to assess the response of L. pneumophila to NO and to demonstrate that the putative NO receptors are implicated in NO detection, bacterial replication in phagocytes, intracellular phenotypic heterogeneity, and biofilm formation.
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Affiliation(s)
- Sarah Michaelis
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Tong Chen
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Camille Schmid
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
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3
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Barbosa A, Azevedo NF, Goeres DM, Cerqueira L. Ecology of Legionella pneumophila biofilms: The link between transcriptional activity and the biphasic cycle. Biofilm 2024; 7:100196. [PMID: 38601816 PMCID: PMC11004079 DOI: 10.1016/j.bioflm.2024.100196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 03/10/2024] [Accepted: 03/29/2024] [Indexed: 04/12/2024] Open
Abstract
There has been considerable discussion regarding the environmental life cycle of Legionella pneumophila and its virulence potential in natural and man-made water systems. On the other hand, the bacterium's morphogenetic mechanisms within host cells (amoeba and macrophages) have been well documented and are linked to its ability to transition from a non-virulent, replicative state to an infectious, transmissive state. Although the morphogenetic mechanisms associated with the formation and detachment of the L. pneumophila biofilm have also been described, the capacity of the bacteria to multiply extracellularly is not generally accepted. However, several studies have shown genetic pathways within the biofilm that resemble intracellular mechanisms. Understanding the functionality of L. pneumophila cells within a biofilm is fundamental for assessing the ecology and evaluating how the biofilm architecture influences L. pneumophila survival and persistence in water systems. This manuscript provides an overview of the biphasic cycle of L. pneumophila and its implications in associated intracellular mechanisms in amoeba. It also examines the molecular pathways and gene regulation involved in L. pneumophila biofilm formation and dissemination. A holistic analysis of the transcriptional activities in L. pneumophila biofilms is provided, combining the information of intracellular mechanisms in a comprehensive outline. Furthermore, this review discusses the techniques that can be used to study the morphogenetic states of the bacteria within biofilms, at the single cell and population levels.
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Affiliation(s)
- Ana Barbosa
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE – Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Nuno F. Azevedo
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE – Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
| | - Darla M. Goeres
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE – Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- The Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Laura Cerqueira
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
- ALiCE – Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465, Porto, Portugal
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Dadole I, Blaha D, Personnic N. The macrophage-bacterium mismatch in persister formation. Trends Microbiol 2024:S0966-842X(24)00049-0. [PMID: 38443279 DOI: 10.1016/j.tim.2024.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
Many pathogens are hard to eradicate, even in the absence of genetically detectable antimicrobial resistance mechanisms and despite proven antibiotic susceptibility. The fraction of clonal bacteria that temporarily elude effective antibiotic treatments is commonly known as 'antibiotic persisters.' Over the past decade, there has been a growing body of research highlighting the pivotal role played by the cellular host in the development of persisters. In parallel, this research has also sought to elucidate the molecular mechanisms underlying the formation of intracellular antibiotic persisters and has demonstrated a prominent role for the bacterial stress response. However, questions remain regarding the conditions leading to the formation of stress-induced persisters among a clonal population of intracellular bacteria and despite an ostensibly uniform environment. In this opinion, following a brief review of the current state of knowledge regarding intracellular antibiotic persisters, we explore the ways in which macrophage functional heterogeneity and bacterial phenotypic heterogeneity may contribute to the emergence of these persisters. We propose that the degree of mismatch between the macrophage permissiveness and the bacterial preparedness to invade and thrive intracellularly may explain the formation of stress-induced nonreplicating intracellular persisters.
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Affiliation(s)
- Iris Dadole
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France
| | - Didier Blaha
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France
| | - Nicolas Personnic
- CIRI - Centre International de Recherche en Infectiologie, CNRS, INSERM, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France; Group Persistence and single-cell dynamics of respiratory pathogens, CIRI, Lyon, France.
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5
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Neuber J, Lang C, Aurass P, Flieger A. Tools and mechanisms of vacuolar escape leading to host egress in Legionella pneumophila infection: Emphasis on bacterial phospholipases. Mol Microbiol 2024; 121:368-384. [PMID: 37891705 DOI: 10.1111/mmi.15183] [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: 06/28/2023] [Revised: 09/29/2023] [Accepted: 10/06/2023] [Indexed: 10/29/2023]
Abstract
The phenomenon of host cell escape exhibited by intracellular pathogens is a remarkably versatile occurrence, capable of unfolding through lytic or non-lytic pathways. Among these pathogens, the bacterium Legionella pneumophila stands out, having adopted a diverse spectrum of strategies to disengage from their host cells. A pivotal juncture that predates most of these host cell escape modalities is the initial escape from the intracellular compartment. This critical step is increasingly supported by evidence suggesting the involvement of several secreted pathogen effectors, including lytic proteins. In this intricate landscape, L. pneumophila emerges as a focal point for research, particularly concerning secreted phospholipases. While nestled within its replicative vacuole, the bacterium deftly employs both its type II (Lsp) and type IVB (Dot/Icm) secretion systems to convey phospholipases into either the phagosomal lumen or the host cell cytoplasm. Its repertoire encompasses numerous phospholipases A (PLA), including three enzymes-PlaA, PlaC, and PlaD-bearing the GDSL motif. Additionally, there are 11 patatin-like phospholipases A as well as PlaB. Furthermore, the bacterium harbors three extracellular phospholipases C (PLCs) and one phospholipase D. Within this comprehensive review, we undertake an exploration of the pivotal role played by phospholipases in the broader context of phagosomal and host cell egress. Moreover, we embark on a detailed journey to unravel the established and potential functions of the secreted phospholipases of L. pneumophila in orchestrating this indispensable process.
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Affiliation(s)
- Jonathan Neuber
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Philipp Aurass
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institute, Wernigerode, Germany
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Scharte F, Franzkoch R, Hensel M. Flagella-mediated cytosolic motility of Salmonella enterica Paratyphi A aids in evasion of xenophagy but does not impact egress from host cells. Mol Microbiol 2024; 121:413-430. [PMID: 37278220 DOI: 10.1111/mmi.15104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 05/19/2023] [Accepted: 05/23/2023] [Indexed: 06/07/2023]
Abstract
Salmonella enterica is a common foodborne, facultative intracellular enteropathogen. Typhoidal serovars like Paratyphi A (SPA) are human restricted and cause severe systemic diseases, while many serovars like Typhimurium (STM) have a broad host range, and usually lead to self-limiting gastroenteritis. There are key differences between typhoidal and non-typhoidal Salmonella in pathogenesis, but underlying mechanisms remain largely unknown. Transcriptomes and phenotypes in epithelial cells revealed induction of motility, flagella and chemotaxis genes for SPA but not STM. SPA exhibited cytosolic motility mediated by flagella. In this study, we applied single-cell microscopy to analyze triggers and cellular consequences of cytosolic motility. Live-cell imaging (LCI) revealed that SPA invades host cells in a highly cooperative manner. Extensive membrane ruffling at invasion sites led to increased membrane damage in nascent Salmonella-containing vacuole, and subsequent cytosolic release. After release into the cytosol, motile bacteria showed the same velocity as under culture conditions in media. Reduced capture of SPA by autophagosomal membranes was observed by LCI and electron microscopy. Prior work showed that SPA does not use flagella-mediated motility for cell exit via the intercellular spread. However, cytosolic motile SPA was invasion-primed if released from host cells. Our results reveal flagella-mediated cytosolic motility as a possible xenophagy evasion mechanism that could drive disease progression and contributes to the dissemination of systemic infection.
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Affiliation(s)
- Felix Scharte
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
| | - Rico Franzkoch
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- Universität Osnabrück, iBiOs-Integrated Bioimaging Facility, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Universität Osnabrück, Osnabrück, Germany
- Universität Osnabrück, CellNanOs-Center of Cellular Nanoanalytics, Osnabrück, Germany
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7
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Hiller M, Diwo M, Wamp S, Gutsmann T, Lang C, Blankenfeldt W, Flieger A. Structure-function relationships underpin disulfide loop cleavage-dependent activation of Legionella pneumophila lysophospholipase A PlaA. Mol Microbiol 2024; 121:497-512. [PMID: 38130174 DOI: 10.1111/mmi.15201] [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: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 12/23/2023]
Abstract
Legionella pneumophila, the causative agent of a life-threatening pneumonia, intracellularly replicates in a specialized compartment in lung macrophages, the Legionella-containing vacuole (LCV). Secreted proteins of the pathogen govern important steps in the intracellular life cycle including bacterial egress. Among these is the type II secreted PlaA which, together with PlaC and PlaD, belongs to the GDSL phospholipase family found in L. pneumophila. PlaA shows lysophospholipase A (LPLA) activity which increases after secretion and subsequent processing by the zinc metalloproteinase ProA within a disulfide loop. Activity of PlaA contributes to the destabilization of the LCV in the absence of the type IVB-secreted effector SdhA. We here present the 3D structure of PlaA which shows a typical α/β-hydrolase fold and reveals that the uncleaved disulfide loop forms a lid structure covering the catalytic triad S30/D278/H282. This leads to reduction of substrate access before activation; however, the catalytic site gets more accessible when the disulfide loop is processed. After structural modeling, a similar activation process is suggested for the GDSL hydrolase PlaC, but not for PlaD. Furthermore, the size of the PlaA substrate-binding site indicated preference toward phospholipids comprising ~16 carbon fatty acid residues which was verified by lipid hydrolysis, suggesting a molecular ruler mechanism. Indeed, mutational analysis changed the substrate profile with respect to fatty acid chain length. In conclusion, our analysis revealed the structural basis for the regulated activation and substrate preference of PlaA.
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Affiliation(s)
- Miriam Hiller
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Maurice Diwo
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sabrina Wamp
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Thomas Gutsmann
- Research Center Borstel, Leibniz Lung Center, Division of Biophysics, Borstel, Germany
- CSSB-Centre for Structural Systems Biology, Hamburg, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Wulf Blankenfeldt
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
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Mellini M, Letizia M, Caruso L, Guiducci A, Meneghini C, Heeb S, Williams P, Cámara M, Visca P, Imperi F, Leoni L, Rampioni G. RsaL-driven negative regulation promotes heterogeneity in Pseudomonas aeruginosa quorum sensing. mBio 2023; 14:e0203923. [PMID: 37843294 PMCID: PMC10746200 DOI: 10.1128/mbio.02039-23] [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: 07/31/2023] [Accepted: 09/05/2023] [Indexed: 10/17/2023] Open
Abstract
IMPORTANCE Single-cell analyses can reveal that despite experiencing identical physico-chemical conditions, individual bacterial cells within a monoclonal population may exhibit variations in gene expression. Such phenotypic heterogeneity has been described for several aspects of bacterial physiology, including QS activation. This study demonstrates that the transition of non-quorate cells to the quorate state is a graded process that does not occur at a specific cell density and that subpopulations of non-quorate cells also persist at high cell density. Here, we provide a mechanistic explanation for this phenomenon, showing that a negative feedback regulatory loop integrated into the las system has a pivotal role in promoting cell-to-cell variation in the QS activation state and in limiting the transition of non-quorate cells to the quorate state in P. aeruginosa.
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Affiliation(s)
- Marta Mellini
- Department of Science, University Roma Tre, Rome, Italy
| | | | | | | | | | - Stephan Heeb
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paul Williams
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Miguel Cámara
- National Biofilms Innovation Centre, Biodiscovery Institute and School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Paolo Visca
- Department of Science, University Roma Tre, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesco Imperi
- Department of Science, University Roma Tre, Rome, Italy
- NBFC, National Biodiversity Future Center, Palermo, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Livia Leoni
- Department of Science, University Roma Tre, Rome, Italy
| | - Giordano Rampioni
- Department of Science, University Roma Tre, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
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Moreira de Gouveia MI, Reuter A, Garrivier A, Daniel J, Bernalier-Donadille A, Jubelin G. Design and validation of a dual-fluorescence reporter system to monitor bacterial gene expression in the gut environment. Appl Microbiol Biotechnol 2023; 107:7301-7312. [PMID: 37750914 DOI: 10.1007/s00253-023-12788-7] [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: 06/22/2023] [Revised: 09/04/2023] [Accepted: 09/10/2023] [Indexed: 09/27/2023]
Abstract
Fluorescence-based reporter systems are valuable tools for studying gene expression dynamics in living cells. However, available strategies to follow gene expression in bacteria within their natural ecosystem that can be typically rich and complex are scarce. In this work, we designed a plasmid-based tool ensuring both the identification of a strain of interest in complex environments and the monitoring of gene expression through the combination of two distinct fluorescent proteins as reporter genes. The tool was validated in Escherichia coli to monitor the expression of eut genes involved in the catabolism of ethanolamine. We demonstrated that the constructed reporter strain gradually responds with a bimodal output to increasing ethanolamine concentrations during in vitro cultures. The reporter strain was next inoculated to mice, and flow cytometry was used to detect the reporter strain among the dense microbiota of intestinal samples and to analyze specifically the expression of eut genes. This novel dual-fluorescent reporter system would be helpful to evaluate transcriptional processes in bacteria within complex environments. KEY POINTS: • A reporter tool was developed to monitor bacterial gene expression in complex environments. • Ethanolamine utilization (eut) genes are expressed by commensal E. coli in the mouse gut. • Expression of eut genes follows a bimodal distribution.
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Affiliation(s)
| | - Audrey Reuter
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France
| | - Annie Garrivier
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France
| | - Julien Daniel
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France
| | | | - Gregory Jubelin
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
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10
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Vormittag S, Ende RJ, Derré I, Hilbi H. Pathogen vacuole membrane contact sites - close encounters of the fifth kind. MICROLIFE 2023; 4:uqad018. [PMID: 37223745 PMCID: PMC10117887 DOI: 10.1093/femsml/uqad018] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/30/2023] [Accepted: 04/06/2023] [Indexed: 05/25/2023]
Abstract
Vesicular trafficking and membrane fusion are well-characterized, versatile, and sophisticated means of 'long range' intracellular protein and lipid delivery. Membrane contact sites (MCS) have been studied in far less detail, but are crucial for 'short range' (10-30 nm) communication between organelles, as well as between pathogen vacuoles and organelles. MCS are specialized in the non-vesicular trafficking of small molecules such as calcium and lipids. Pivotal MCS components important for lipid transfer are the VAP receptor/tether protein, oxysterol binding proteins (OSBPs), the ceramide transport protein CERT, the phosphoinositide phosphatase Sac1, and the lipid phosphatidylinositol 4-phosphate (PtdIns(4)P). In this review, we discuss how these MCS components are subverted by bacterial pathogens and their secreted effector proteins to promote intracellular survival and replication.
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Affiliation(s)
| | | | - Isabelle Derré
- Corresponding author. Department of Microbiology, Immunology and Cancer Biology, University of Virginia, 1340 Jefferson Park Ave, Charlottesville, VA 22908, United States. Tel: +1-434-924-2330; E-mail:
| | - Hubert Hilbi
- Corresponding author. Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006 Zürich, Switzerland. Tel: +41-44-634-2650; E-mail:
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Personnic N, Doublet P, Jarraud S. Intracellular persister: A stealth agent recalcitrant to antibiotics. Front Cell Infect Microbiol 2023; 13:1141868. [PMID: 37065203 PMCID: PMC10102521 DOI: 10.3389/fcimb.2023.1141868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/06/2023] [Indexed: 04/03/2023] Open
Abstract
The bulk of bacteria transiently evading appropriate antibiotic regimes and recovered from non-resolutive infections are commonly refer to as persisters. In this mini-review, we discuss how antibiotic persisters stem from the interplay between the pathogen and the cellular defenses mechanisms and its underlying heterogeneity.
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Affiliation(s)
- Nicolas Personnic
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Persistence and Single-Cell Dynamics of Respiratory Pathogens, Lyon, France
- *Correspondence: Nicolas Personnic,
| | - Patricia Doublet
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
| | - Sophie Jarraud
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
- National Reference Centre for Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France
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12
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Patel R, Soni M, Soyantar B, Shivangi S, Sutariya S, Saraf M, Goswami D. A clash of quorum sensing vs quorum sensing inhibitors: an overview and risk of resistance. Arch Microbiol 2023; 205:107. [PMID: 36881156 DOI: 10.1007/s00203-023-03442-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 02/08/2023] [Accepted: 02/15/2023] [Indexed: 03/08/2023]
Abstract
Indiscriminate use of antibiotics to treat microbial pathogens has caused emergence of multiple drug resistant strains. Most infectious diseases are caused by microbes that are capable of intercommunication using signaling molecules, which is known as quorum sensing (QS). Such pathogens express their pathogenicity through various QS-regulated virulence factors. Interference of QS could lead to decisive results in controlling such pathogenicity. Hence, QS inhibition has become an attractive new approach for the development of novel drugs. Many quorum sensing inhibitors (QSIs) of diverse origins have been reported. It is imperative that more such anti-QS compounds be found and studied, as they have significant effect on microbial pathogenicity. This review attempts to give a brief account of QS mechanism, its inhibition and describes some compounds with anti-QS potential. Also discussed is the possibility of emergence of quorum sensing resistance.
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Affiliation(s)
- Rohit Patel
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Mansi Soni
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Bilv Soyantar
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Suruchi Shivangi
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Swati Sutariya
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Meenu Saraf
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India
| | - Dweipayan Goswami
- Department of Microbiology and Biotechnology, University School of Sciences, Gujarat University, Ahmedabad, Gujarat, 380009, India.
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13
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Vormittag S, Hüsler D, Haneburger I, Kroniger T, Anand A, Prantl M, Barisch C, Maaß S, Becher D, Letourneur F, Hilbi H. Legionella- and host-driven lipid flux at LCV-ER membrane contact sites promotes vacuole remodeling. EMBO Rep 2023; 24:e56007. [PMID: 36588479 PMCID: PMC9986823 DOI: 10.15252/embr.202256007] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 01/03/2023] Open
Abstract
Legionella pneumophila replicates in macrophages and amoeba within a unique compartment, the Legionella-containing vacuole (LCV). Hallmarks of LCV formation are the phosphoinositide lipid conversion from PtdIns(3)P to PtdIns(4)P, fusion with ER-derived vesicles and a tight association with the ER. Proteomics of purified LCVs indicate the presence of membrane contact sites (MCS) proteins possibly implicated in lipid exchange. Using dually fluorescence-labeled Dictyostelium discoideum amoeba, we reveal that VAMP-associated protein (Vap) and the PtdIns(4)P 4-phosphatase Sac1 localize to the ER, and Vap also localizes to the LCV membrane. Furthermore, Vap as well as Sac1 promote intracellular replication of L. pneumophila and LCV remodeling. Oxysterol binding proteins (OSBPs) preferentially localize to the ER (OSBP8) or the LCV membrane (OSBP11), respectively, and restrict (OSBP8) or promote (OSBP11) bacterial replication and LCV expansion. The sterol probes GFP-D4H* and filipin indicate that sterols are rapidly depleted from LCVs, while PtdIns(4)P accumulates. In addition to Sac1, the PtdIns(4)P-subverting L. pneumophila effector proteins LepB and SidC also support LCV remodeling. Taken together, the Legionella- and host cell-driven PtdIns(4)P gradient at LCV-ER MCSs promotes Vap-, OSBP- and Sac1-dependent pathogen vacuole maturation.
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Affiliation(s)
- Simone Vormittag
- Institute of Medical MicrobiologyUniversity of ZürichZürichSwitzerland
| | - Dario Hüsler
- Institute of Medical MicrobiologyUniversity of ZürichZürichSwitzerland
| | - Ina Haneburger
- Institute of Medical MicrobiologyUniversity of ZürichZürichSwitzerland
| | - Tobias Kroniger
- Institute of MicrobiologyUniversity of GreifswaldGreifswaldGermany
| | - Aby Anand
- Division of Molecular Infection Biology and Center for Cellular NanoanalyticsUniversity of OsnabrückOsnabrückGermany
| | - Manuel Prantl
- Institute of Medical MicrobiologyUniversity of ZürichZürichSwitzerland
| | - Caroline Barisch
- Division of Molecular Infection Biology and Center for Cellular NanoanalyticsUniversity of OsnabrückOsnabrückGermany
| | - Sandra Maaß
- Institute of MicrobiologyUniversity of GreifswaldGreifswaldGermany
| | - Dörte Becher
- Institute of MicrobiologyUniversity of GreifswaldGreifswaldGermany
| | - François Letourneur
- Laboratory of Pathogen Host InteractionsUniversité de Montpellier, CNRS, INSERMMontpellierFrance
| | - Hubert Hilbi
- Institute of Medical MicrobiologyUniversity of ZürichZürichSwitzerland
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14
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Lockwood DC, Amin H, Costa TRD, Schroeder GN. The Legionella pneumophila Dot/Icm type IV secretion system and its effectors. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35639581 DOI: 10.1099/mic.0.001187] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To prevail in the interaction with eukaryotic hosts, many bacterial pathogens use protein secretion systems to release virulence factors at the host–pathogen interface and/or deliver them directly into host cells. An outstanding example of the complexity and sophistication of secretion systems and the diversity of their protein substrates, effectors, is the Defective in organelle trafficking/Intracellular multiplication (Dot/Icm) Type IVB secretion system (T4BSS) of
Legionella pneumophila
and related species.
Legionella
species are facultative intracellular pathogens of environmental protozoa and opportunistic human respiratory pathogens. The Dot/Icm T4BSS translocates an exceptionally large number of effectors, more than 300 per
L. pneumophila
strain, and is essential for evasion of phagolysosomal degradation and exploitation of protozoa and human macrophages as replicative niches. Recent technological advancements in the imaging of large protein complexes have provided new insight into the architecture of the T4BSS and allowed us to propose models for the transport mechanism. At the same time, significant progress has been made in assigning functions to about a third of
L. pneumophila
effectors, discovering unprecedented new enzymatic activities and concepts of host subversion. In this review, we describe the current knowledge of the workings of the Dot/Icm T4BSS machinery and provide an overview of the activities and functions of the to-date characterized effectors in the interaction of
L. pneumophila
with host cells.
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Affiliation(s)
- Daniel C Lockwood
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
| | - Himani Amin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Tiago R D Costa
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Gunnar N Schroeder
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
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15
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Hochstrasser R, Michaelis S, Brülisauer S, Sura T, Fan M, Maaß S, Becher D, Hilbi H. Migration of Acanthamoeba through Legionella biofilms is regulated by the bacterial Lqs-LvbR network, effector proteins and the flagellum. Environ Microbiol 2022; 24:3672-3692. [PMID: 35415862 PMCID: PMC9544456 DOI: 10.1111/1462-2920.16008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 11/30/2022]
Abstract
The environmental bacterium Legionella pneumophila causes the pneumonia Legionnaires' disease. The opportunistic pathogen forms biofilms and employs the Icm/Dot type IV secretion system (T4SS) to replicate in amoebae and macrophages. A regulatory network comprising the Legionella quorum sensing (Lqs) system and the transcription factor LvbR controls bacterial motility, virulence and biofilm architecture. Here we show by comparative proteomics that in biofilms formed by the L. pneumophila ΔlqsR or ΔlvbR regulatory mutants the abundance of proteins encoded by a genomic ‘fitness island’, metabolic enzymes, effector proteins and flagellar components (e.g. FlaA) varies. ∆lqsR or ∆flaA mutants form ‘patchy’ biofilms like the parental strain JR32, while ∆lvbR forms a ‘mat‐like’ biofilm. Acanthamoeba castellanii amoebae migrated more slowly through biofilms of L. pneumophila lacking lqsR, lvbR, flaA, a functional Icm/Dot T4SS (∆icmT), or secreted effector proteins. Clusters of bacteria decorated amoebae in JR32, ∆lvbR or ∆icmT biofilms but not in ∆lqsR or ∆flaA biofilms. The amoeba‐adherent bacteria induced promoters implicated in motility (PflaA) or virulence (PsidC, PralF). Taken together, the Lqs‐LvbR network (quorum sensing), FlaA (motility) and the Icm/Dot T4SS (virulence) regulate migration of A. castellanii through L. pneumophila biofilms, and – apart from the T4SS – govern bacterial cluster formation on the amoebae.
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Affiliation(s)
- Ramon Hochstrasser
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland
| | - Sarah Michaelis
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland
| | - Sabrina Brülisauer
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland
| | - Thomas Sura
- Institute of Microbiology, University of Greifswald, Felix-Hausdorff-Strasse 8, 17489, Greifswald, Germany
| | - Mingzhen Fan
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland
| | - Sandra Maaß
- Institute of Microbiology, University of Greifswald, Felix-Hausdorff-Strasse 8, 17489, Greifswald, Germany
| | - Dörte Becher
- Institute of Microbiology, University of Greifswald, Felix-Hausdorff-Strasse 8, 17489, Greifswald, Germany
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006, Zürich, Switzerland
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16
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The Legionella Lqs-LvbR Regulatory Network Controls Temperature-Dependent Growth Onset and Bacterial Cell Density. Appl Environ Microbiol 2022; 88:e0237021. [PMID: 34985976 DOI: 10.1128/aem.02370-21] [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] [Indexed: 11/20/2022] Open
Abstract
Legionella species are facultative intracellular pathogens that cause a life-threatening pneumonia termed Legionnaires' disease. Legionella pneumophila employs the Lqs-LvbR (Legionella quorum sensing-Legionella virulence and biofilm regulator) network to regulate virulence and motility, but its role for growth in media is ill-defined. Here, we report that compared to the L. pneumophila reference strain JR32, a ΔlqsR mutant showed a reduced lag phase at 30°C and reached a higher cell density at 45°C, while the ΔlqsA, ΔlqsS, and ΔlqsT mutants showed a longer lag phase and reached a lower cell density. A ΔlvbR mutant resumed growth like the parental strain at 30°C but exhibited a substantially reduced cell density at 45°C. Thus, LvbR is an important cell density regulator at elevated temperatures. Environmental and clinical L. pneumophila strains grew in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES)-buffered yeast extract (AYE) medium after distinct lag phases with similar rates at 30°C, reached different cell densities at the optimal growth temperature of 40°C, and no longer grew at 50°C. Legionella longbeachae reached a rather low cell density at 40°C and did not grow at and beyond 45°C. Genes encoding components of the Lqs-LvbR network were present in the genomes of the environmental and clinical L. pneumophila isolates, and upon growth at 30°C or 45°C, the PlqsR, PlqsA, PlqsS, and PlvbR promoters from strain JR32 were expressed in these strains with distinct patterns. Taken together, our results indicate that the Lqs-LvbR network governs the temperature-dependent growth onset and cell density of the L. pneumophila reference strain JR32 and possibly also of environmental and clinical L. pneumophila isolates. IMPORTANCE Environmental bacteria of the genus Legionella are the causative agents of the severe pneumonia Legionnaires' disease, the incidence of which is on the rise worldwide. Legionella pneumophila and Legionella longbeachae are the clinically most relevant species. The opportunistic pathogens are inhaled through contaminated aerosols and replicate in human lung macrophages with a mechanism similar to that in their natural hosts, free-living amoebae. Given their prevalence in natural and technical water systems, an efficient control of Legionella spp. by physical, chemical, or biological means will reduce the incidence of Legionnaires' disease. Here, we show that the Legionella quorum sensing (Lqs) system and the pleiotropic transcription factor LvbR govern the temperature-dependent growth onset and cell density of bacterial cultures. Hence, the growth of L. pneumophila in water systems is determined not only by the temperature and nutrient availability but also by quorum sensing, i.e., density- and signaling molecule-dependent gene regulation.
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17
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Petit TJ, Lebreton A. Adaptations of intracellular bacteria to vacuolar or cytosolic niches. Trends Microbiol 2022; 30:736-748. [DOI: 10.1016/j.tim.2022.01.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 12/28/2022]
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18
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Striednig B, Hilbi H. Bacterial quorum sensing and phenotypic heterogeneity: how the collective shapes the individual. Trends Microbiol 2021; 30:379-389. [PMID: 34598862 DOI: 10.1016/j.tim.2021.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/09/2021] [Accepted: 09/06/2021] [Indexed: 01/09/2023]
Abstract
Bacteria communicate with each other through a plethora of small, diffusible organic molecules called autoinducers. This cell-density-dependent regulatory principle is termed quorum sensing, and in many cases the process indeed coordinates group behavior of bacterial populations. Yet, even clonal bacterial populations are not uniform entities; rather, they adopt phenotypic heterogeneity to cope with consecutive, rapid, and frequent environmental fluctuations (bet-hedging) or to concurrently interact with each other by exerting different, often complementary, functions (division of labor). Quorum sensing is mainly regarded as a coordinator of bacterial collective behavior. However, it can also be a driver or a target of individual phenotypic heterogeneity. Hence, quorum sensing increases the overall fitness of a bacterial community by orchestrating group behavior as well as individual traits.
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Affiliation(s)
- Bianca Striednig
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006 Zürich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Gloriastrasse 30, 8006 Zürich, Switzerland.
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