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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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2
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Prashar A, Gimenez MC, Moussaoui S, Khan IS, Terebiznik MR. Filamentous Bacteria as Targets to Study Phagocytosis. Methods Mol Biol 2023; 2692:91-107. [PMID: 37365463 DOI: 10.1007/978-1-0716-3338-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Filamentous targets are internalized via phagocytic cups that last for several minutes before closing to form a phagosome. This characteristic offers the possibility to study key events in phagocytosis with greater spatial and temporal resolution than is possible to achieve using spherical particles, for which the transition from a phagocytic cup to an enclosed phagosome occurs within a few seconds after particle attachment. In this chapter, we provide methodologies to prepare filamentous bacteria and describe how they can be used as targets to study different aspects of phagocytosis.
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Affiliation(s)
- Akriti Prashar
- Program in Cell Biology, Peter Gilgan Centre of Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
| | - Maria Cecilia Gimenez
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Serene Moussaoui
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Iram Sobia Khan
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada.
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada.
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3
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Rangarajan AA, Chia HE, Azaldegui CA, Olszewski MH, Pereira GV, Koropatkin NM, Biteen JS. Ruminococcus bromii enables the growth of proximal Bacteroides thetaiotaomicron by releasing glucose during starch degradation. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35471195 DOI: 10.1099/mic.0.001180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Complex carbohydrates shape the gut microbiota, and the collective fermentation of resistant starch by gut microbes positively affects human health through enhanced butyrate production. The keystone species Ruminococcus bromii (Rb) is a specialist in degrading resistant starch; its degradation products are used by other bacteria including Bacteroides thetaiotaomicron (Bt). We analysed the metabolic and spatial relationships between Rb and Bt during potato starch degradation and found that Bt utilizes glucose that is released from Rb upon degradation of resistant potato starch and soluble potato amylopectin. Additionally, we found that Rb produces a halo of glucose around it when grown on solid media containing potato amylopectin and that Bt cells deficient for growth on potato amylopectin (∆sus Bt) can grow within the halo. Furthermore, when these ∆sus Bt cells grow within this glucose halo, they have an elongated cell morphology. This long-cell phenotype depends on the glucose concentration in the solid media: longer Bt cells are formed at higher glucose concentrations. Together, our results indicate that starch degradation by Rb cross-feeds other bacteria in the surrounding region by releasing glucose. Our results also elucidate the adaptive morphology of Bt cells under different nutrient and physiological conditions.
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Affiliation(s)
| | - Hannah E Chia
- Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Monica H Olszewski
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Gabriel V Pereira
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan, USA.,Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, USA
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4
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Shukla SK, Sarode A, Kanabar DD, Muth A, Kunda NK, Mitragotri S, Gupta V. Bioinspired particle engineering for non-invasive inhaled drug delivery to the lungs. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 128:112324. [PMID: 34474875 DOI: 10.1016/j.msec.2021.112324] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 05/02/2021] [Accepted: 07/12/2021] [Indexed: 02/08/2023]
Abstract
Pulmonary drug delivery is governed by several biophysical parameters of delivery carriers, such as particle size, shape, density, charge, and surface modifications. Although much attention has been given to other parameters, particle shape effects have rarely been explored. In this work, we assess the influence of particle shape of inhaled delivery carriers on their aerodynamic properties and macrophage uptake by using polymeric microparticles of different geometries ranging in various sizes. Doxorubicin was conjugated to the polymer particles and the bioconjugates were characterized. Interestingly, the results of in-vitro lung deposition, performed using a next generation impactor, demonstrated a significant improvement in the aerodynamic properties of the rod-shaped particles with a high aspect ratio as compared to spherical particles with the same equivalent volume. The results of a macrophage uptake experiment demonstrate that the high aspect ratio particles were phagocytosed less than spherical particles. Furthermore, the cytotoxicity of these doxorubicin-conjugated particles was determined against murine macrophages, resulting in reduced toxicity when treated with high aspect ratio particles as compared to spherical particles. This project provides valuable insights into the influence of particle shape on aerodynamic properties and primary defense mechanisms in the peripheral lungs, while using polymeric microparticles of various sizes and geometries. Further systematic development can help translate these findings to preclinical and clinical studies for designing efficient inhalable delivery carriers.
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Affiliation(s)
- Snehal K Shukla
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA
| | - Apoorva Sarode
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Dipti D Kanabar
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA
| | - Aaron Muth
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA
| | - Nitesh K Kunda
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA
| | - Samir Mitragotri
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Vivek Gupta
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Queens, NY 11439, USA.
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5
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Graham CI, Patel PG, Tanner JR, Hellinga J, MacMartin TL, Hausner G, Brassinga AKC. Autorepressor PsrA is required for optimal Legionella pneumophila growth in Acanthamoeba castellanii protozoa. Mol Microbiol 2021; 116:624-647. [PMID: 34018265 DOI: 10.1111/mmi.14760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/16/2021] [Accepted: 05/16/2021] [Indexed: 11/26/2022]
Abstract
Legionella pneumophila possesses a unique intracellular lifecycle featuring distinct morphological stages that include replicative forms and transmissive cyst forms. Expression of genes associated with virulence traits and cyst morphogenesis is concomitant, and governed by a complex stringent response based-regulatory network and the stationary phase sigma factor RpoS. In Pseudomonas spp., rpoS expression is controlled by the autorepressor PsrA, and orthologs of PsrA and RpoS are required for cyst formation in Azotobacter. Here we report that the L. pneumophila psrA ortholog, expressed as a leaderless monocistronic transcript, is also an autorepressor, but is not a regulator of rpoS expression. Further, the binding site sequence recognized by L. pneumophila PsrA is different from that of Pseudomonas PsrA, suggesting a repertoire of target genes unique to L. pneumophila. While PsrA was dispensable for growth in human U937-derived macrophages, lack of PsrA affected bacterial intracellular growth in Acanthamoeba castellanii protozoa, but also increased the quantity of poly-3-hydroxybutyrate (PHB) inclusions in matured transmissive cysts. Interestingly, overexpression of PsrA increased the size and bacterial load of the replicative vacuole in both host cell types. Taken together, we report that PsrA is a host-specific requirement for optimal temporal progression of L. pneumophila intracellular lifecycle in A. castellanii.
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Affiliation(s)
- Christopher I Graham
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Palak G Patel
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Jennifer R Tanner
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Jacqueline Hellinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Teassa L MacMartin
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Georg Hausner
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
| | - Ann Karen C Brassinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, MB, Canada
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Chauhan D, Shames SR. Pathogenicity and Virulence of Legionella: Intracellular replication and host response. Virulence 2021; 12:1122-1144. [PMID: 33843434 PMCID: PMC8043192 DOI: 10.1080/21505594.2021.1903199] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Bacteria of the genus Legionella are natural pathogens of amoebae that can cause a severe pneumonia in humans called Legionnaires’ Disease. Human disease results from inhalation of Legionella-contaminated aerosols and subsequent bacterial replication within alveolar macrophages. Legionella pathogenicity in humans has resulted from extensive co-evolution with diverse genera of amoebae. To replicate intracellularly, Legionella generates a replication-permissive compartment called the Legionella-containing vacuole (LCV) through the concerted action of hundreds of Dot/Icm-translocated effector proteins. In this review, we present a collective overview of Legionella pathogenicity including infection mechanisms, secretion systems, and translocated effector function. We also discuss innate and adaptive immune responses to L. pneumophila, the implications of Legionella genome diversity and future avenues for the field.
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Affiliation(s)
- Deepika Chauhan
- Division of Biology, Kansas State University, Manhattan, Kansas, USA
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FitzGerald ES, Luz NF, Jamieson AM. Competitive Cell Death Interactions in Pulmonary Infection: Host Modulation Versus Pathogen Manipulation. Front Immunol 2020; 11:814. [PMID: 32508813 PMCID: PMC7248393 DOI: 10.3389/fimmu.2020.00814] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
In the context of pulmonary infection, both hosts and pathogens have evolved a multitude of mechanisms to regulate the process of host cell death. The host aims to rapidly induce an inflammatory response at the site of infection, promote pathogen clearance, quickly resolve inflammation, and return to tissue homeostasis. The appropriate modulation of cell death in respiratory epithelial cells and pulmonary immune cells is central in the execution of all these processes. Cell death can be either inflammatory or anti-inflammatory depending on regulated cell death (RCD) modality triggered and the infection context. In addition, diverse bacterial pathogens have evolved many means to manipulate host cell death to increase bacterial survival and spread. The multitude of ways that hosts and bacteria engage in a molecular tug of war to modulate cell death dynamics during infection emphasizes its relevance in host responses and pathogen virulence at the host pathogen interface. This narrative review outlines several current lines of research characterizing bacterial pathogen manipulation of host cell death pathways in the lung. We postulate that understanding these interactions and the dynamics of intracellular and extracellular bacteria RCD manipulation, may lead to novel therapeutic approaches for the treatment of intractable respiratory infections.
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Affiliation(s)
- Ethan S FitzGerald
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
| | - Nivea F Luz
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
| | - Amanda M Jamieson
- Division of Biology and Medicine, Department of Molecular Microbiology and Immunology, Brown University, Providence, RI, United States
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8
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Anuj SA, Gajera HP, Hirpara DG, Golakiya BA. The impact of bacterial size on their survival in the presence of cationic particles of nano-silver. J Trace Elem Med Biol 2020; 61:126517. [PMID: 32447152 DOI: 10.1016/j.jtemb.2020.126517] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Microbial surface area is one of the battlegrounds for invading microbes and host defense. Hence, infectious diseases caused by drug resistant microbes with large surface area are more difficult to treat than small size microbes. Nanobiology offers opportunities to re-explore the biological properties of conventional drugs at molecular level to combat these microbes. The purpose of the present study was to examine size depended susceptibility of Gram-positive bacteria towards nano-silver particles. METHODS This study investigated the growth, surface charge, and morphology of emerging B. megaterium MTCC 7192 and re-emerging S. aureus MTCC 3160 cells in order to observe the susceptibility of these bacteria towards cationic nano-silver particles. Nano-silver particles were applied into wells formed on the Nutrient agar plates containing 108 CFU/mL of the bacteria. Surface potential of normal and treated cells was measured by Microtrac and the effects of nano-silver particles on bacterial cells were assessed by Scanning Electron Microscopy (SEM). RESULTS In this work, synthesized nano-silver particles were found to be more effective against B. megaterium MTCC 7192 than S. aureus MTCC 3160. For B. megaterium MTCC 7192, a 0.30 fold increase in inhibition zone was observed after the addition of nano-silver particles in the wells. From our studies, it is reasonable to state that alternation of zeta potential may affect the cell morphology, which was further confirmed by SEM. CONCLUSION The present study concluded that nano-silver particles appears to interact with a larger surface area more effectively.
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Affiliation(s)
- Samir A Anuj
- School of Science, RK University, Rajkot, 360020, Gujarat, India.
| | - Harsukh P Gajera
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
| | - Darshna G Hirpara
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
| | - Baljibhai A Golakiya
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
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9
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Regulation of filamentation by bacteria and its impact on the productivity of compounds in biotechnological processes. Appl Microbiol Biotechnol 2020; 104:4631-4642. [DOI: 10.1007/s00253-020-10590-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 12/29/2022]
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10
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Jena P, Bhattacharya M, Bhattacharjee G, Satpati B, Mukherjee P, Senapati D, Srinivasan R. Bimetallic gold-silver nanoparticles mediate bacterial killing by disrupting the actin cytoskeleton MreB. NANOSCALE 2020; 12:3731-3749. [PMID: 31993609 DOI: 10.1039/c9nr10700b] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The actin cytoskeleton is required for the maintenance of the cell shape and viability of bacteria. It remains unknown to which extent nanoparticles (NPs) can orchestrate the mechanical instability by disrupting the cytoskeletal network in bacterial cells. Our work demonstrates that Au-Ag NPs disrupt the bacterial actin cytoskeleton specifically, fluidize the inner membrane and lead to killing of bacterial cells. In this study, we have tried to emphasize on the key parameters important for NP-cell interactions and found that the shape, specific elemental surface localization and enhanced electrostatic interaction developed due to the acquired partial positive charge by silver atoms in the aggregated NPs are some of the major factors contributing towards better NP interactions and subsequent cell death. In vivo studies in bacterial cells showed that the NPs exerted a mild perturbation of the membrane potential. However, its most striking effect was on the actin cytoskeleton MreB resulting in morphological changes in the bacterial cell shape from rods to predominantly spheres. Exposure to NPs resulted in the delocalization of MreB patches from the membrane but not the tubulin homologue FtsZ. Concomitant with the redistribution of MreB localization, a dramatic increase of membrane fluid regions was observed. Our studies reveal for the first time that Au-Ag NPs can mediate bacterial killing and disrupt the actin cytoskeletal functions in bacteria.
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Affiliation(s)
- Prajna Jena
- Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, JD-2, sector -3, Salt Lake City, Kolkata, India.
| | - Maireyee Bhattacharya
- Chemical Sciences Division, Saha Institute of Nuclear Physics, HBNI, 1/AF, Bidhannagar, Kolkata-700064, India.
| | - Gourab Bhattacharjee
- Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, HBNI, 1/AF, Bidhannagar, Kolkata-700064, India
| | - Biswarup Satpati
- Surface Physics and Materials Science Division, Saha Institute of Nuclear Physics, HBNI, 1/AF, Bidhannagar, Kolkata-700064, India
| | - Prasun Mukherjee
- Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, JD-2, sector -3, Salt Lake City, Kolkata, India.
| | - Dulal Senapati
- Chemical Sciences Division, Saha Institute of Nuclear Physics, HBNI, 1/AF, Bidhannagar, Kolkata-700064, India.
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research (NISER), HBNI, Bhubaneswar, Odisha 752050, India.
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Grilli DJ, Mansilla ME, Giménez MC, Sohaefer N, Ruiz MS, Terebiznik MR, Sosa M, Arenas GN. Pseudobutyrivibrio xylanivorans adhesion to epithelial cells. Anaerobe 2019; 56:1-7. [PMID: 30615946 DOI: 10.1016/j.anaerobe.2019.01.001] [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: 09/13/2018] [Revised: 12/06/2018] [Accepted: 01/02/2019] [Indexed: 01/09/2023]
Abstract
The ruminal bacteria Pseudobutyrivibrio xylanivorans strain 2 (P. xylanivorans 2), that mediates the digestion of plant fiber, is considered an attractive candidate for probiotics. Adherence to the epithelium of the digestive tract of the host is one of the major requirements for probiotics. In this study, we assessed the adhesion of P. xylanivorans 2 to SW480 cells and characterized this process utilizing multiple microscopy approaches. Our results indicate that a multiplicity of infection of 200 CFU/cell allows the highest bacteria to cell binding ratio, with a lower percentage of auto-agglutination events. The comparison of the adherence capacity subjected heat-shock treatment (100 °C, 1 min), which produces the denaturalization of proteins at the bacterial surface, as opposed untreated P. xylanivorans, suggested that this bacteria may attach to SW480 cells utilizing a proteinaceous structure. Confocal microscopy analyses indicate that P. xylanivorans 2 attachment induces the formation of F-actin-enriched areas on the surface of SW480 cells. Transmission electron microscopy (TEM) revealed the formation of a structure similar to a pedestal in the area of the epithelial cell surface, where the bacterium rests. Finally, a casual finding of TEM analysis of transverse and longitudinal thin-sections of P. xylanivorans 2, revealed irregular intra-cytoplasmic structures compatibles with the so-called bacterial microcompartments. This is the first ultrastructural description of bacterial microcompartments-like structures in the genus Pseudobutyrivibrio.
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Affiliation(s)
- Diego Javier Grilli
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina; Instituto de Histología y Embriología de Mendoza, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina; Área de Microbiología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina.
| | - Maria Eugenia Mansilla
- Instituto de Histología y Embriología de Mendoza, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina; Facultad de Farmacia y Bioquímica, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina
| | - María Cecilia Giménez
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina; Instituto de Histología y Embriología de Mendoza, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina; Departments of Biological Sciences and Cell and Systems Biology, University of Toronto at Scarborough, Toronto, Ontario, Canada
| | - Noelia Sohaefer
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina
| | - María Soledad Ruiz
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina
| | - Mauricio R Terebiznik
- Departments of Biological Sciences and Cell and Systems Biology, University of Toronto at Scarborough, Toronto, Ontario, Canada
| | - Miguel Sosa
- Instituto de Histología y Embriología de Mendoza, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina
| | - Graciela Nora Arenas
- Facultad de Ciencias Veterinarias y Ambientales, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina; Área de Microbiología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, CP 5500, Mendoza, Argentina; Facultad de Farmacia y Bioquímica, Universidad Juan Agustín Maza, Av. Acceso Este Lateral Sur 2245, CP 5519, Mendoza, Argentina
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Ultee E, Ramijan K, Dame RT, Briegel A, Claessen D. Stress-induced adaptive morphogenesis in bacteria. Adv Microb Physiol 2019; 74:97-141. [PMID: 31126537 DOI: 10.1016/bs.ampbs.2019.02.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful pathogens.
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Affiliation(s)
- Eveline Ultee
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Karina Ramijan
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Remus T Dame
- Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands; Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CE Leiden, the Netherlands
| | - Ariane Briegel
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
| | - Dennis Claessen
- Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, the Netherlands; Centre for Microbial Cell Biology, Leiden University, Leiden, the Netherlands
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13
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Prashar A, Ortiz ME, Lucarelli S, Barker E, Tabatabeiyazdi Z, Shamoun F, Raju D, Antonescu C, Guyard C, Terebiznik MR. Small Rho GTPases and the Effector VipA Mediate the Invasion of Epithelial Cells by Filamentous Legionella pneumophila. Front Cell Infect Microbiol 2018; 8:133. [PMID: 29774203 PMCID: PMC5943596 DOI: 10.3389/fcimb.2018.00133] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 04/17/2018] [Indexed: 12/13/2022] Open
Abstract
Legionella pneumophila (Lp) exhibits different morphologies with varying degrees of virulence. Despite their detection in environmental sources of outbreaks and in respiratory tract secretions and lung autopsies from patients, the filamentous morphotype of Lp remains poorly studied. We previously demonstrated that filamentous Lp invades lung epithelial cells (LECs) and replicates intracellularly in a Legionella containing vacuole. Filamentous Lp activates β1integrin and E-cadherin receptors at the surface of LECs leading to the formation of actin-rich cell membrane structures we termed hooks and membrane wraps. These structures entrap segments of an Lp filament on host cell surface and mediate bacterial internalization. Here we investigated the molecular mechanisms responsible for the actin rearrangements needed for the formation and elongation of these membrane wraps and bacterial internalization. We combined genetic and pharmacological approaches to assess the contribution of signaling downstream of β1integrin and E-cadherin receptors, and Lp Dot/Icm secretion system- translocated effectors toward the invasion process. Our studies demonstrate a multi-stage mechanism of LEC invasion by filamentous Lp. Bacterial attachment to host cells depends on signaling downstream of β1integrin and E-cadherin activation, leading to Rho GTPases-dependent activation of cellular actin nucleating proteins, Arp2/3 and mDia. This mediates the formation of primordial membrane wraps that entrap the filamentous bacteria on the cell surface. Following this, in a second phase of the invasion process the Dot/Icm translocated effector VipA mediates rapid membrane wrap elongation, leading to the engulfment of the filamentous bacteria by the LECs. Our findings provide the first description of Rho GTPases and a Dot/Icm effector VipA regulating the actin dynamics needed for the invasion of epithelial cells by Lp.
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Affiliation(s)
- Akriti Prashar
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - María Eugenia Ortiz
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Stefanie Lucarelli
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Elizabeth Barker
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Zohreh Tabatabeiyazdi
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Feras Shamoun
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Deepa Raju
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada
| | - Costin Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Cyril Guyard
- Bioaster, Lyon, France.,Molecular Microbiology, Public Health Ontario, Toronto, ON, Canada
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Scarborough, ON, Canada.,Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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14
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THP-1-derived macrophages render lung epithelial cells hypo-responsive to Legionella pneumophila - a systems biology study. Sci Rep 2017; 7:11988. [PMID: 28931863 PMCID: PMC5607273 DOI: 10.1038/s41598-017-12154-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 09/04/2017] [Indexed: 11/25/2022] Open
Abstract
Immune response in the lung has to protect the huge alveolar surface against pathogens while securing the delicate lung structure. Macrophages and alveolar epithelial cells constitute the first line of defense and together orchestrate the initial steps of host defense. In this study, we analysed the influence of macrophages on type II alveolar epithelial cells during Legionella pneumophila-infection by a systems biology approach combining experimental work and mathematical modelling. We found that L. pneumophila-infected THP-1-derived macrophages provoke a pro-inflammatory activation of neighboring lung epithelial cells, but in addition render them hypo-responsive to direct infection with the same pathogen. We generated a kinetic mathematical model of macrophage activation and identified a paracrine mechanism of macrophage-secreted IL-1β inducing a prolonged IRAK-1 degradation in lung epithelial cells. This intercellular crosstalk may help to avoid an overwhelming inflammatory response by preventing excessive local secretion of pro-inflammatory cytokines and thereby negatively regulating the recruitment of immune cells to the site of infection. This suggests an important but ambivalent immunomodulatory role of macrophages in lung infection.
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15
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van Teeseling MCF, de Pedro MA, Cava F. Determinants of Bacterial Morphology: From Fundamentals to Possibilities for Antimicrobial Targeting. Front Microbiol 2017; 8:1264. [PMID: 28740487 PMCID: PMC5502672 DOI: 10.3389/fmicb.2017.01264] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/23/2017] [Indexed: 12/11/2022] Open
Abstract
Bacterial morphology is extremely diverse. Specific shapes are the consequence of adaptive pressures optimizing bacterial fitness. Shape affects critical biological functions, including nutrient acquisition, motility, dispersion, stress resistance and interactions with other organisms. Although the characteristic shape of a bacterial species remains unchanged for vast numbers of generations, periodical variations occur throughout the cell (division) and life cycles, and these variations can be influenced by environmental conditions. Bacterial morphology is ultimately dictated by the net-like peptidoglycan (PG) sacculus. The species-specific shape of the PG sacculus at any time in the cell cycle is the product of multiple determinants. Some morphological determinants act as a cytoskeleton to guide biosynthetic complexes spatiotemporally, whereas others modify the PG sacculus after biosynthesis. Accumulating evidence supports critical roles of morphogenetic processes in bacteria-host interactions, including pathogenesis. Here, we review the molecular determinants underlying morphology, discuss the evidence linking bacterial morphology to niche adaptation and pathogenesis, and examine the potential of morphological determinants as antimicrobial targets.
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Affiliation(s)
- Muriel C F van Teeseling
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
| | - Miguel A de Pedro
- Centro de Biología Molecular "Severo Ochoa" - Consejo Superior de Investigaciones Científicas, Universidad Autónoma de MadridMadrid, Spain
| | - Felipe Cava
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden
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16
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Xiong L, Yamasaki S, Chen H, Shi L, Mo Z. Intracellular Growth and Morphological Characteristics of Legionella pneumophila during Invasion and Proliferation in Different Cells. Biol Pharm Bull 2017; 40:1035-1042. [PMID: 28674246 DOI: 10.1248/bpb.b17-00033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Various studies have been made to attempt to study the interaction between Legionella pneumophila and the host cells. In this research, we successfully constructed a L. pneumophila mutant strain that stably expressed high levels of green fluorescent protein and used this strain to evaluate the adherence, invasion and proliferation of L. pneumophila in association with several cell lines, including seven cell lines [human macrophage-like cell lines (U937, THP-1), murine macrophage-like cell lines (J774.1A, Raw264.7), human bronchial epithelial cell lines (16HBE, Beas-2B) and human cerrical cancer cell line (HeLa)] which have been used as the host models of L. pneumophila, and two breast carcinoma cell lines (MCF-7 and MDA-MB-231). Our results showed that the two newly tested cell lines are able to support the intracellular proliferation of L. pneumophila, and there were some morphological variations during the invasion and intracellular replication of L. pneumophila in different cell lines. These results can help us find out the common and special patterns of invasion and proliferation of L. pneumophila within different hosts. This is conducive to our knowledge on the relationship and interaction between bacteria and host.
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Affiliation(s)
- Lina Xiong
- School of Food Science and Technology, South China University of Technology
| | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University
| | - Hongsheng Chen
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University
| | - Lei Shi
- School of Food Science and Technology, South China University of Technology.,Jinan University
| | - Ziyao Mo
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University
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17
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Prashar A, Khan SIS, Terebiznik MR. Filamentous Bacteria as Targets to Study Phagocytosis. Methods Mol Biol 2017; 1519:311-323. [PMID: 27815889 DOI: 10.1007/978-1-4939-6581-6_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Filamentous targets are internalized via phagocytic cups that last for several minutes before closing to form a phagosome. This characteristic offers the possibility to study key events in phagocytosis with greater spatial and temporal resolution than is possible to achieve using spherical particles, for which the transition from a phagocytic cup to an enclosed phagosome occurs within a few seconds after particle attachment. In this chapter, we provide methodologies to prepare filamentous bacteria and describe how they can be used as targets to study different aspects of phagocytosis.
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Affiliation(s)
- Akriti Prashar
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4
| | - Sana I S Khan
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4
| | - Mauricio R Terebiznik
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, Canada, M1C 1A4.
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18
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Kawamoto Y, Morinaga Y, Kimura Y, Kaku N, Kosai K, Uno N, Hasegawa H, Yanagihara K. TNF-α inhibits the growth of Legionella pneumophila in airway epithelial cells by inducing apoptosis. J Infect Chemother 2016; 23:51-55. [PMID: 27865699 DOI: 10.1016/j.jiac.2016.09.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/21/2016] [Accepted: 09/28/2016] [Indexed: 12/11/2022]
Abstract
BACKGROUND TNF-α plays an important role in the pathogenesis of Legionella pneumophila (Lp)-induced pneumonia. Patients undergoing anti-TNF-α therapy are at an increased risk of Lp infection. Lp infects both phagocytic and non-phagocytic cells such as airway epithelial cells; however, the role of TNF-α in airway epithelial cells is unknown. METHODS Human airway epithelial cell line NCI-H292 was infected with Lp NUL1 strain. After infection, both intracellular growth of Lp and cell death were evaluated after treating the cells with or without TNF-α. Apoptosis was examined by performing activated caspase-3/7 staining and by using a pan-caspase inhibitor. RESULTS Lp infected and replicated in NCI-H292 cells in a time-dependent manner, and TNF-α treatment of Lp-infected NCI-H292 cells inhibited Lp replication. Inhibitory effects of TNF-α on Lp replication were suppressed after treatment with a TNF-α-neutralizing antibody. Lp infection increased extracellular lactate dehydrogenase levels and decreased the number of living cells. Increased number of Lp-infected NCI-H292 cells showed caspase-3/7 activation, indicating they underwent apoptosis. TNF-α treatment inhibited Lp replication by increasing the apoptosis of NCI-H292 cells. CONCLUSIONS Thus, our results suggested that airway epithelial cells were involved in the pathogenesis of Lp infection and that TNF-α played a protective role by inhibiting the intracellular replication of Lp and by increasing the apoptosis of Lp-infected airway epithelial cells. However, Lp infection should be investigated further in patients undergoing anti-TNF-α therapy who develop pneumonia.
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Affiliation(s)
- Yasuhide Kawamoto
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Yoshitomo Morinaga
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan.
| | - Yumiko Kimura
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Norihito Kaku
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Kosuke Kosai
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Naoki Uno
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Hiroo Hasegawa
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
| | - Katsunori Yanagihara
- Department of Laboratory Medicine, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 851-2128, Japan
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19
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Kirschner AK. Determination of viable legionellae in engineered water systems: Do we find what we are looking for? WATER RESEARCH 2016; 93:276-288. [PMID: 26928563 PMCID: PMC4913838 DOI: 10.1016/j.watres.2016.02.016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/06/2016] [Accepted: 02/09/2016] [Indexed: 05/06/2023]
Abstract
In developed countries, legionellae are one of the most important water-based bacterial pathogens caused by management failure of engineered water systems. For routine surveillance of legionellae in engineered water systems and outbreak investigations, cultivation-based standard techniques are currently applied. However, in many cases culture-negative results are obtained despite the presence of viable legionellae, and clinical cases of legionellosis cannot be traced back to their respective contaminated water source. Among the various explanations for these discrepancies, the presence of viable but non-culturable (VBNC) Legionella cells has received increased attention in recent discussions and scientific literature. Alternative culture-independent methods to detect and quantify legionellae have been proposed in order to complement or even substitute the culture method in the future. Such methods should detect VBNC Legionella cells and provide a more comprehensive picture of the presence of legionellae in engineered water systems. However, it is still unclear whether and to what extent these VBNC legionellae are hazardous to human health. Current risk assessment models to predict the risk of legionellosis from Legionella concentrations in the investigated water systems contain many uncertainties and are mainly based on culture-based enumeration. If VBNC legionellae should be considered in future standard analysis, quantitative risk assessment models including VBNC legionellae must be proven to result in better estimates of human health risk than models based on cultivation alone. This review critically evaluates current methods to determine legionellae in the VBNC state, their potential to complement the standard culture-based method in the near future, and summarizes current knowledge on the threat that VBNC legionellae may pose to human health.
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Affiliation(s)
- Alexander K.T. Kirschner
- Medical University Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene, Kinderspitalgasse 15, A-1090 Vienna, Austria
- Interuniversity Cooperation Centre for Water & Health, Austria
- Medical University Vienna, Institute for Hygiene and Applied Immunology, Water Hygiene Kinderspitalgasse 16, A-1090 Vienna, Austria . URL: http://www.waterandhealth.at
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20
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Staying in Shape: the Impact of Cell Shape on Bacterial Survival in Diverse Environments. Microbiol Mol Biol Rev 2016; 80:187-203. [PMID: 26864431 DOI: 10.1128/mmbr.00031-15] [Citation(s) in RCA: 159] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacteria display an abundance of cellular forms and can change shape during their life cycle. Many plausible models regarding the functional significance of cell morphology have emerged. A greater understanding of the genetic programs underpinning morphological variation in diverse bacterial groups, combined with assays of bacteria under conditions that mimic their varied natural environments, from flowing freshwater streams to diverse human body sites, provides new opportunities to probe the functional significance of cell shape. Here we explore shape diversity among bacteria, at the levels of cell geometry, size, and surface appendages (both placement and number), as it relates to survival in diverse environments. Cell shape in most bacteria is determined by the cell wall. A major challenge in this field has been deconvoluting the effects of differences in the chemical properties of the cell wall and the resulting cell shape perturbations on observed fitness changes. Still, such studies have begun to reveal the selective pressures that drive the diverse forms (or cell wall compositions) observed in mammalian pathogens and bacteria more generally, including efficient adherence to biotic and abiotic surfaces, survival under low-nutrient or stressful conditions, evasion of mammalian complement deposition, efficient dispersal through mucous barriers and tissues, and efficient nutrient acquisition.
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21
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Lu C, Nakayasu ES, Zhang LQ, Luo ZQ. Identification of Fic-1 as an enzyme that inhibits bacterial DNA replication by AMPylating GyrB, promoting filament formation. Sci Signal 2016; 9:ra11. [PMID: 26814232 DOI: 10.1126/scisignal.aad0446] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The morphology of bacterial cells is important for virulence, evasion of the host immune system, and coping with environmental stresses. The widely distributed Fic proteins (filamentation induced by cAMP) are annotated as proteins involved in cell division because of the presence of the HPFx[D/E]GN[G/K]R motif. We showed that the presence of Fic-1 from Pseudomonas fluorescens significantly reduced the yield of plasmid DNA when expressed in Escherichia coli or P. fluorescens. Fic-1 interacted with GyrB, a subunit of DNA gyrase, which is essential for bacterial DNA replication. Fic-1 catalyzed the AMPylation of GyrB at Tyr(109), a residue critical for binding ATP, and exhibited auto-AMPylation activity. Mutation of the Fic-1 auto-AMPylated site greatly reduced AMPylation activity toward itself and toward GyrB. Fic-1-dependent AMPylation of GyrB triggered the SOS response, indicative of DNA replication stress or DNA damage. Fic-1 also promoted the formation of elongated cells when the SOS response was blocked. We identified an α-inhibitor protein that we named anti-Fic-1 (AntF), encoded by a gene immediately upstream of Fic-1. AntF interacted with Fic-1, inhibited the AMPylation activity of Fic-1 for GyrB in vitro, and blocked Fic-1-mediated inhibition of DNA replication in bacteria, suggesting that Fic-1 and AntF comprise a toxin-antitoxin module. Our work establishes Fic-1 as an AMPylating enzyme that targets GyrB to inhibit DNA replication and may target other proteins to regulate bacterial morphology.
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Affiliation(s)
- Canhua Lu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China. Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Ernesto S Nakayasu
- The Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
| | - Li-Qun Zhang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA.
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22
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So EC, Mattheis C, Tate EW, Frankel G, Schroeder GN. Creating a customized intracellular niche: subversion of host cell signaling by Legionella type IV secretion system effectors. Can J Microbiol 2015; 61:617-35. [PMID: 26059316 DOI: 10.1139/cjm-2015-0166] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Gram-negative facultative intracellular pathogen Legionella pneumophila infects a wide range of different protozoa in the environment and also human alveolar macrophages upon inhalation of contaminated aerosols. Inside its hosts, it creates a defined and unique compartment, termed the Legionella-containing vacuole (LCV), for survival and replication. To establish the LCV, L. pneumophila uses its Dot/Icm type IV secretion system (T4SS) to translocate more than 300 effector proteins into the host cell. Although it has become apparent in the past years that these effectors subvert a multitude of cellular processes and allow Legionella to take control of host cell vesicle trafficking, transcription, and translation, the exact function of the vast majority of effectors still remains unknown. This is partly due to high functional redundancy among the effectors, which renders conventional genetic approaches to elucidate their role ineffective. Here, we review the current knowledge about Legionella T4SS effectors, highlight open questions, and discuss new methods that promise to facilitate the characterization of T4SS effector functions in the future.
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Affiliation(s)
- Ernest C So
- a MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK.,b Department of Chemistry, South Kensington Campus, Imperial College, London, SW7 2AZ, UK
| | - Corinna Mattheis
- a MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Edward W Tate
- b Department of Chemistry, South Kensington Campus, Imperial College, London, SW7 2AZ, UK
| | - Gad Frankel
- a MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Gunnar N Schroeder
- a MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
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Robertson P, Abdelhady H, Garduño RA. The many forms of a pleomorphic bacterial pathogen-the developmental network of Legionella pneumophila. Front Microbiol 2014; 5:670. [PMID: 25566200 PMCID: PMC4273665 DOI: 10.3389/fmicb.2014.00670] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 11/18/2014] [Indexed: 01/18/2023] Open
Abstract
Legionella pneumophila is a natural intracellular bacterial parasite of free-living freshwater protozoa and an accidental human pathogen that causes Legionnaires' disease. L. pneumophila differentiates, and does it in style. Recent experimental data on L. pneumophila's differentiation point at the existence of a complex network that involves many developmental forms. We intend readers to: (i) understand the biological relevance of L. pneumophila's forms found in freshwater and their potential to transmit Legionnaires' disease, and (ii) learn that the common depiction of L. pneumophila's differentiation as a biphasic developmental cycle that alternates between a replicative and a transmissive form is but an oversimplification of the actual process. Our specific objectives are to provide updates on the molecular factors that regulate L. pneumophila's differentiation (Section The Differentiation Process and Its Regulation), and describe the developmental network of L. pneumophila (Section Dissecting Lp's Developmental Network), which for clarity's sake we have dissected into five separate developmental cycles. Finally, since each developmental form seems to contribute differently to the human pathogenic process and the transmission of Legionnaires' disease, readers are presented with a challenge to develop novel methods to detect the various L. pneumophila forms present in water (Section Practical Implications), as a means to improve our assessment of risk and more effectively prevent legionellosis outbreaks.
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Affiliation(s)
- Peter Robertson
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada
| | - Hany Abdelhady
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada
| | - Rafael A Garduño
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada ; Division of Infectious Diseases, Department of Medicine, Dalhousie University Halifax, NS, Canada
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Prashar A, Terebiznik MR. Legionella pneumophila: homeward bound away from the phagosome. Curr Opin Microbiol 2014; 23:86-93. [PMID: 25461578 DOI: 10.1016/j.mib.2014.11.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 12/18/2022]
Abstract
The intracellular pathogen Legionella pneumophila (Lp) survives and replicates inside a specialized vacuolar compartment that evades canonical phagosomal maturation. Through the action of a large number of effectors translocated into the host cytosol via the Dot/Icm type IV secretion system, Lp subverts host cell pathways to convert its nascent phagosome into an ER-derived compartment, the Legionella containing vacuole (LCV), which serves as bacterial replication niche.
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Affiliation(s)
- Akriti Prashar
- Biological Sciences, University of Toronto at Scarborough, 1265 Military Trail, Scarborough, Ontario, Canada M1C 1A4; Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5
| | - Mauricio R Terebiznik
- Biological Sciences, University of Toronto at Scarborough, 1265 Military Trail, Scarborough, Ontario, Canada M1C 1A4; Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5.
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25
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Justice SS, Harrison A, Becknell B, Mason KM. Bacterial differentiation, development, and disease: mechanisms for survival. FEMS Microbiol Lett 2014; 360:1-8. [PMID: 25228010 DOI: 10.1111/1574-6968.12602] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 09/04/2014] [Accepted: 09/11/2014] [Indexed: 12/27/2022] Open
Abstract
Bacteria have the exquisite ability to maintain a precise diameter, cell length, and shape. The dimensions of bacteria size and shape are a classical metric in the distinction of bacterial species. Much of what we know about the particular morphology of any given species is the result of investigations of planktonic cultures. As we explore deeper into the natural habitats of bacteria, it is increasingly clear that bacteria can alter their morphology in response to the environment in which they reside. Specific morphologies are also becoming recognized as advantageous for survival in hostile environments. This is of particular importance in the context of both colonization and infection in the host. There are multiple examples of bacterial pathogens that use morphological changes as a mechanism for evasion of host immune responses and continued persistence. This review will focus on two systems where specific morphological changes are essential for persistence in animal models of human disease. We will also offer insight into the mechanism underlying the morphological changes and how these morphotypes aid in persistence. Additional examples of morphological changes associated with survival will be presented.
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Affiliation(s)
- Sheryl S Justice
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; The Ohio State University School of Medicine, Columbus, OH, USA
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26
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Prashar A, Bhatia S, Gigliozzi D, Martin T, Duncan C, Guyard C, Terebiznik MR. Filamentous morphology of bacteria delays the timing of phagosome morphogenesis in macrophages. ACTA ACUST UNITED AC 2014; 203:1081-97. [PMID: 24368810 PMCID: PMC3871431 DOI: 10.1083/jcb.201304095] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Uptake of bacterial filaments by macrophages is characterized by a prolonged phagocytic cup stage and diminished microbicidal activity during phagosome maturation. Although filamentous morphology in bacteria has been associated with resistance to phagocytosis, our understanding of the cellular mechanisms behind this process is limited. To investigate this, we followed the phagocytosis of both viable and dead Legionella pneumophila filaments. The engulfment of these targets occurred gradually and along the longitudinal axis of the filament, therefore defining a long-lasting phagocytic cup stage that determined the outcome of phagocytosis. We found that these phagocytic cups fused with endosomes and lysosomes, events linked to the maturation of phagosomes according to the canonical pathway, and not with the remodeling of phagocytic cups. Nevertheless, despite acquiring phagolysosomal features these phagocytic cups failed to develop hydrolytic capacity before their sealing. This phenomenon hampered the microbicidal activity of the macrophage and enhanced the capacity of viable filamentous L. pneumophila to escape phagosomal killing in a length-dependent manner. Our results demonstrate that key aspects in phagocytic cup remodeling and phagosomal maturation could be influenced by target morphology.
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Affiliation(s)
- Akriti Prashar
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
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Rozycki M, Lodyga M, Lam J, Miranda MZ, Fátyol K, Speight P, Kapus A. The fate of the primary cilium during myofibroblast transition. Mol Biol Cell 2014; 25:643-57. [PMID: 24403605 PMCID: PMC3937090 DOI: 10.1091/mbc.e13-07-0429] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Myofibroblasts, the culprit of organ fibrosis, can originate from mesenchymal and epithelial precursors through fibroblast-myofibroblast and epithelial-myofibroblast transition (EMyT). Because certain ciliopathies are associated with fibrogenesis, we sought to explore the fate and potential role of the primary cilium during myofibroblast formation. Here we show that myofibroblast transition from either precursor results in the loss of the primary cilium. During EMyT, initial cilium growth is followed by complete deciliation. Both EMyT and cilium loss require two-hit conditions: disassembly/absence of intercellular contacts and transforming growth factor-β1 (TGFβ) exposure. Loss of E-cadherin-dependent junctions induces cilium elongation, whereas both stimuli are needed for deciliation. Accordingly, in a scratch-wounded epithelium, TGFβ provokes cilium loss exclusively along the wound edge. Increased contractility, a key myofibroblast feature, is necessary and sufficient for deciliation, since constitutively active RhoA, Rac1, or myosin triggers, and down-regulation of myosin or myocardin-related transcription factor prevents, this process. Sustained myosin phosphorylation and consequent deciliation are mediated by a Smad3-, Rac1-, and reactive oxygen species-dependent process. Transitioned myofibroblasts exhibit impaired responsiveness to platelet-derived growth factor-AA and sonic hedgehog, two cilium-associated stimuli. Although the cilium is lost during EMyT, its initial presence contributes to the transition. Thus myofibroblasts represent a unique cilium-less entity with profoundly reprogrammed cilium-related signaling.
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Affiliation(s)
- Matthew Rozycki
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, and Department of Surgery, University of Toronto, Toronto, ON M5B 1T8, Canada
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The Legionella pneumophila collagen-like protein mediates sedimentation, autoaggregation, and pathogen-phagocyte interactions. Appl Environ Microbiol 2013; 80:1441-54. [PMID: 24334670 DOI: 10.1128/aem.03254-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Although only partially understood, multicellular behavior is relatively common in bacterial pathogens. Bacterial aggregates can resist various host defenses and colonize their environment more efficiently than planktonic cells. For the waterborne pathogen Legionella pneumophila, little is known about the roles of autoaggregation or the parameters which allow cell-cell interactions to occur. Here, we determined the endogenous and exogenous factors sufficient to allow autoaggregation to take place in L. pneumophila. We show that isolates from Legionella species which do not produce the Legionella collagen-like protein (Lcl) are deficient in autoaggregation. Targeted deletion of the Lcl-encoding gene (lpg2644) and the addition of Lcl ligands impair the autoaggregation of L. pneumophila. In addition, Lcl-induced autoaggregation requires divalent cations. Escherichia coli producing surface-exposed Lcl is able to autoaggregate and shows increased biofilm production. We also demonstrate that L. pneumophila infection of Acanthamoeba castellanii and Hartmanella vermiformis is potentiated under conditions which promote Lcl dependent autoaggregation. Overall, this study shows that L. pneumophila is capable of autoaggregating in a process that is mediated by Lcl in a divalent-cation-dependent manner. It also reveals that Lcl potentiates the ability of L. pneumophila to come in contact, attach, and infect amoebae.
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Abdelhady H, Garduño RA. The progeny ofLegionella pneumophilain human macrophages shows unique developmental traits. FEMS Microbiol Lett 2013; 349:99-107. [DOI: 10.1111/1574-6968.12300] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/14/2013] [Indexed: 11/30/2022] Open
Affiliation(s)
- Hany Abdelhady
- Department of Microbiology and Immunology; Dalhousie University; Halifax NS Canada
| | - Rafael A. Garduño
- Department of Microbiology and Immunology; Dalhousie University; Halifax NS Canada
- Department of Medicine-Division of Infectious Diseases; Dalhousie University; Halifax NS Canada
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Abdel-Nour M, Duncan C, Low DE, Guyard C. Biofilms: the stronghold of Legionella pneumophila. Int J Mol Sci 2013; 14:21660-75. [PMID: 24185913 PMCID: PMC3856027 DOI: 10.3390/ijms141121660] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/07/2013] [Accepted: 10/14/2013] [Indexed: 11/28/2022] Open
Abstract
Legionellosis is mostly caused by Legionella pneumophila and is defined as a severe respiratory illness with a case fatality rate ranging from 5% to 80%. L. pneumophila is ubiquitous in natural and anthropogenic water systems. L. pneumophila is transmitted by inhalation of contaminated aerosols produced by a variety of devices. While L. pneumophila replicates within environmental protozoa, colonization and persistence in its natural environment are also mediated by biofilm formation and colonization within multispecies microbial communities. There is now evidence that some legionellosis outbreaks are correlated with the presence of biofilms. Thus, preventing biofilm formation appears as one of the strategies to reduce water system contamination. However, we lack information about the chemical and biophysical conditions, as well as the molecular mechanisms that allow the production of biofilms by L. pneumophila. Here, we discuss the molecular basis of biofilm formation by L. pneumophila and the roles of other microbial species in L. pneumophila biofilm colonization. In addition, we discuss the protective roles of biofilms against current L. pneumophila sanitation strategies along with the initial data available on the regulation of L. pneumophila biofilm formation.
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Affiliation(s)
- Mena Abdel-Nour
- Ontario Agency for Health Protection and Promotion (OAHPP), Toronto, ON M9P 3T1, Canada; E-Mails: (M.A.-N.); (C.D.)
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Carla Duncan
- Ontario Agency for Health Protection and Promotion (OAHPP), Toronto, ON M9P 3T1, Canada; E-Mails: (M.A.-N.); (C.D.)
| | - Donald E. Low
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Cyril Guyard
- Ontario Agency for Health Protection and Promotion (OAHPP), Toronto, ON M9P 3T1, Canada; E-Mails: (M.A.-N.); (C.D.)
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON M5S 1A8, Canada
- Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-416-880-1339; Fax: +1-416-235-6281
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Integrins and small GTPases as modulators of phagocytosis. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 302:321-54. [PMID: 23351714 DOI: 10.1016/b978-0-12-407699-0.00006-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phagocytosis is the mechanism whereby cells engulf large particles. This process has long been recognized as a critical component of the innate immune response, which constitutes the organism's defense against microorganisms. In addition, phagocytic internalization of apoptotic cells or cell fragments plays important roles in tissue homeostasis and remodeling. Phagocytosis requires target interactions with receptors on the plasma membrane of the phagocytic cell. Integrins have been identified as important mediators of particle clearance, in addition to their well-established roles in cell adhesion, migration and mechanotransduction. Indeed, these ubiquitously expressed proteins impart phagocytic capacity to epithelial, endothelial and mesenchymal cell types. The importance of integrins in particle internalization is emphasized by the ability of microbial and viral pathogens to exploit their signaling pathways to invade host cells, and by the wide variety of disorders that arise from abnormalities in integrin-dependent phagocytic uptake.
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Escoll P, Rolando M, Gomez-Valero L, Buchrieser C. From amoeba to macrophages: exploring the molecular mechanisms of Legionella pneumophila infection in both hosts. Curr Top Microbiol Immunol 2013; 376:1-34. [PMID: 23949285 DOI: 10.1007/82_2013_351] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Legionella pneumophila is a Gram-negative bacterium and the causative agent of Legionnaires' disease. It replicates within amoeba and infects accidentally human macrophages. Several similarities are seen in the L. pneumophila-infection cycle in both hosts, suggesting that the tools necessary for macrophage infection may have evolved during co-evolution of L. pneumophila and amoeba. The establishment of the Legionella-containing vacuole (LCV) within the host cytoplasm requires the remodeling of the LCV surface and the hijacking of vesicles and organelles. Then L. pneumophila replicates in a safe intracellular niche in amoeba and macrophages. In this review we will summarize the existing knowledge of the L. pneumophila infection cycle in both hosts at the molecular level and compare the factors involved within amoeba and macrophages. This knowledge will be discussed in the light of recent findings from the Acanthamoeba castellanii genome analyses suggesting the existence of a primitive immune-like system in amoeba.
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Affiliation(s)
- Pedro Escoll
- Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS UMR, 3525, Paris, France
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