1
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Elsen S, Simon V, Attrée I. Cross-regulation and cross-talk of conserved and accessory two-component regulatory systems orchestrate Pseudomonas copper resistance. PLoS Genet 2024; 20:e1011325. [PMID: 38861577 DOI: 10.1371/journal.pgen.1011325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024] Open
Abstract
Bacteria use diverse strategies and molecular machinery to maintain copper homeostasis and to cope with its toxic effects. Some genetic elements providing copper resistance are acquired by horizontal gene transfer; however, little is known about how they are controlled and integrated into the central regulatory network. Here, we studied two copper-responsive systems in a clinical isolate of Pseudomonas paraeruginosa and deciphered the regulatory and cross-regulation mechanisms. To do so, we combined mutagenesis, transcriptional fusion analyses and copper sensitivity phenotypes. Our results showed that the accessory CusRS two-component system (TCS) responds to copper and activates both its own expression and that of the adjacent nine-gene operon (the pcoA2 operon) to provide resistance to elevated levels of extracellular copper. The same locus was also found to be regulated by two core-genome-encoded TCSs-the copper-responsive CopRS and the zinc-responsive CzcRS. Although the target palindromic sequence-ATTCATnnATGTAAT-is the same for the three response regulators, transcriptional outcomes differ. Thus, depending on the operon/regulator pair, binding can result in different activation levels (from none to high), with the systems demonstrating considerable plasticity. Unexpectedly, although the classical CusRS and the noncanonical CopRS TCSs rely on distinct signaling mechanisms (kinase-based vs. phosphatase-based), we discovered cross-talk in the absence of the cognate sensory kinases. This cross-talk occurred between the proteins of these two otherwise independent systems. The cusRS-pcoA2 locus is part of an Integrative and Conjugative Element, and was found in other Pseudomonas strains where its expression could provide copper resistance under appropriate conditions. The results presented here illustrate how acquired genetic elements can become part of endogenous regulatory networks, providing a physiological advantage. They also highlight the potential for broader effects of accessory regulatory proteins through interference with core regulatory proteins.
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Affiliation(s)
- Sylvie Elsen
- University Grenoble Alpes, Institute of Structural Biology, UMR5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Victor Simon
- University Grenoble Alpes, Institute of Structural Biology, UMR5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Ina Attrée
- University Grenoble Alpes, Institute of Structural Biology, UMR5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
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2
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Trouillon J, Attrée I, Elsen S. The regulation of bacterial two-partner secretion systems. Mol Microbiol 2023; 120:159-177. [PMID: 37340956 DOI: 10.1111/mmi.15112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 06/01/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023]
Abstract
Two-partner secretion (TPS) systems, also known as Type Vb secretion systems, allow the translocation of effector proteins across the outer membrane of Gram-negative bacteria. By secreting different classes of effectors, including cytolysins and adhesins, TPS systems play important roles in bacterial pathogenesis and host interactions. Here, we review the current knowledge on TPS systems regulation and highlight specific and common regulatory mechanisms across TPS functional classes. We discuss in detail the specific regulatory networks identified in various bacterial species and emphasize the importance of understanding the context-dependent regulation of TPS systems. Several regulatory cues reflecting host environment during infection, such as temperature and iron availability, are common determinants of expression for TPS systems, even across relatively distant species. These common regulatory pathways often affect TPS systems across subfamilies with different effector functions, representing conserved global infection-related regulatory mechanisms.
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Affiliation(s)
- Julian Trouillon
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Ina Attrée
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
| | - Sylvie Elsen
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, Grenoble, France
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3
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Bajire SK, Prabhu A, Bhandary YP, Irfan KM, Shastry RP. 7-Ethoxycoumarin rescued Caenorhabditis elegans from infection of COPD derived clinical isolate Pseudomonas aeruginosa through virulence and biofilm inhibition via targeting Rhl and Pqs quorum sensing systems. World J Microbiol Biotechnol 2023; 39:208. [PMID: 37231227 DOI: 10.1007/s11274-023-03655-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 05/18/2023] [Indexed: 05/27/2023]
Abstract
Pseudomonas aeruginosa is an ambidextrous Gram-negative contagium with density convoluted network defined quorum sensing, which enables the persistent survival within the host environment, contributing to various lung related diseases including Chronic Obstructive Pulmonary Disease (COPD). It is clear that P. aeruginosa is a powerful, exquisite pathogen that has adopted a variety of virulence properties through quorum sensing (QS) regulated phenomenon and that it dominates both in the development and exacerbations of COPD. Interestingly, 7-Ethoxycoumarin (7-EC), a compound that adequately mimics QS signaling molecule of P. aeruginosa, was introduced as part of the process of developing novel ways to treat the severe exacerbations. The results showed that, introduction of 7-EC significantly decreased exopolysaccharide-mediated biofilm development of strains isolated from COPD sputum, as evidenced by SEM analysis. Furthermore, 7-EC was able to modulate a variety of virulence factors and motility without subjecting planktonic cells to any selection pressure. Bacterial invasion assay revealed the potential activity of the 7-EC in preventing the active entry to A549 cells without causing any damage to the cells and found functionally active in protecting the C. elegans from P. aeruginosa infection and being non-toxic to the worms. Docking analysis was further proved that 7-EC to be the potential anti-QS compound competing specifically with Rhl and Pqs Systems. Therefore, 7-EC in the utilisation against the P. aeruginosa based infections, may open an avenue for the futuristic mechanistic study in chronic respiratory diseases and a initiator for the development of non-antibiotic based antibacterial therapy.
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Affiliation(s)
- Sukesh Kumar Bajire
- Division of Microbiology and Biotechnology, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangaluru, 575018, India
| | - Ashwini Prabhu
- Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangaluru, 575018, India
| | - Yashodhar P Bhandary
- Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangaluru, 575018, India
| | - K M Irfan
- Department of Pulmonary Medicine, Yenepoya Medical College Hospital, Deralakatte, Mangaluru, 575018, India
| | - Rajesh P Shastry
- Division of Microbiology and Biotechnology, Yenepoya Research Centre, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangaluru, 575018, India.
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4
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Gui Y, Zeng Y, Chen B, Yang Y, Ma J, Li C. A smart pathogen detector engineered from intracellular hydrogelation of DNA-decorated macrophages. Nat Commun 2023; 14:2927. [PMID: 37217531 DOI: 10.1038/s41467-023-38733-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 05/12/2023] [Indexed: 05/24/2023] Open
Abstract
Bacterial infection is a major threat to global public health, which urgently requires useful tools to rapidly analyze pathogens in the early stages of infection. Herein, we develop a smart macrophage (Mø)-based bacteria detector, which can recognize, capture, enrich and detect different bacteria and their secreted exotoxins. We transform the fragile native Møs into robust gelated cell particles (GMøs) using photo-activated crosslinking chemistry, which retains membrane integrity and recognition capacity for different microbes. Meanwhile, these GMøs equipped with magnetic nanoparticles and DNA sensing elements can not only respond to an external magnet for facile bacteria collection, but allow the detection of multiple types of bacteria in a single assay. Additionally, we design a propidium iodide-based staining assay to rapidly detect pathogen-associated exotoxins at ultralow concentrations. Overall, these nanoengineered cell particles have broad applicability in the analysis of bacteria, and could potentially be used for the management and diagnosis of infectious diseases.
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Affiliation(s)
- Yueyue Gui
- School of Food and Biological Engineering, Hefei University of Technology, 230009, Hefei, P. R. China
| | - Yujing Zeng
- State Key Laboratory of Analytical Chemistry for Life Science, School of Life Sciences, Nanjing University, 210023, Nanjing, P. R. China
| | - Binrui Chen
- School of Food and Biological Engineering, Hefei University of Technology, 230009, Hefei, P. R. China
| | - Yueping Yang
- School of Food and Biological Engineering, Hefei University of Technology, 230009, Hefei, P. R. China
| | - Jiehua Ma
- Tongren Hospital, Shanghai Jiao Tong University School of Medicine, 200336, Shanghai, P. R. China
| | - Chao Li
- School of Food and Biological Engineering, Hefei University of Technology, 230009, Hefei, P. R. China.
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5
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Jin Y, Fu L. Engineer a double team of short-lived and glucose-sensing bacteria for cancer eradication. Cell Rep Med 2023:101043. [PMID: 37192627 DOI: 10.1016/j.xcrm.2023.101043] [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: 10/12/2022] [Revised: 02/13/2023] [Accepted: 04/19/2023] [Indexed: 05/18/2023]
Abstract
Rationally designed and engineered bacteria represent an emerging unique approach for cancer treatment. Here, we engineer a short-lived bacterium, mp105, that is effective against diverse cancer types and safe for intravenous administration. We reveal that mp105 combats cancer by direct oncolysis, depletion of tumor-associated macrophages, and elicitation of CD4+ T cell immunity. We further engineer a glucose-sensing bacterium named m6001 that selectively colonizes solid tumors. When intratumorally injected, m6001 clears tumors more efficiently than mp105 due to its post-delivery replication in tumors and potent oncolytic capacity. Finally, we combine intravenous injection of mp105 and intratumoral injection of m6001, forming a double team against cancer. The double team enhances cancer therapy compared with single treatment for subjects carrying both intratumorally injectable and uninjectable tumors. The two anticancer bacteria and their combination are applicable to different scenarios, turning bacterial therapy for cancer into a feasible solution.
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Affiliation(s)
- Ye Jin
- New Portal Limited, 130-132 Des Voeux Road Central, Hong Kong.
| | - Li Fu
- Guangdong Province Key Laboratory of Regional Immunity and Diseases, Department of Pharmacology and International Cancer Center, Shenzhen University Medical School, Shenzhen University, Shenzhen, China
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6
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Wood SJ, Goldufsky JW, Seu MY, Dorafshar AH, Shafikhani SH. Pseudomonas aeruginosa Cytotoxins: Mechanisms of Cytotoxicity and Impact on Inflammatory Responses. Cells 2023; 12:cells12010195. [PMID: 36611990 PMCID: PMC9818787 DOI: 10.3390/cells12010195] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 01/05/2023] Open
Abstract
Pseudomonas aeruginosa is one of the most virulent opportunistic Gram-negative bacterial pathogens in humans. It causes many acute and chronic infections with morbidity and mortality rates as high as 40%. P. aeruginosa owes its pathogenic versatility to a large arsenal of cell-associated and secreted virulence factors which enable this pathogen to colonize various niches within hosts and protect it from host innate immune defenses. Induction of cytotoxicity in target host cells is a major virulence strategy for P. aeruginosa during the course of infection. P. aeruginosa has invested heavily in this strategy, as manifested by a plethora of cytotoxins that can induce various forms of cell death in target host cells. In this review, we provide an in-depth review of P. aeruginosa cytotoxins based on their mechanisms of cytotoxicity and the possible consequences of their cytotoxicity on host immune responses.
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Affiliation(s)
- Stephen J. Wood
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Josef W. Goldufsky
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
| | - Michelle Y. Seu
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Amir H. Dorafshar
- Department of Surgery, Division of Plastic and Reconstructive Surgery, Rush University Medical Center, Chicago, IL 60612, USA
| | - Sasha H. Shafikhani
- Department of Medicine, Division of Hematology, Oncology and Cell Therapy, Rush University Medical Center, Chicago, IL 60612, USA
- Department of Microbial Pathogens and Immunity, Rush University Medical Center, Chicago, IL 60612, USA
- Cancer Center, Rush University Medical Center, Chicago, IL 60612, USA
- Correspondence:
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7
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Rudra B, Duncan L, Shah AJ, Shah HN, Gupta RS. Phylogenomic and comparative genomic studies robustly demarcate two distinct clades of Pseudomonas aeruginosa strains: proposal to transfer the strains from an outlier clade to a novel species Pseudomonas paraeruginosa sp. nov. Int J Syst Evol Microbiol 2022; 72. [PMID: 36355412 DOI: 10.1099/ijsem.0.005542] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The strains of
Pseudomonas aeruginosa
exhibit considerable differences in their genotypic and pathogenic properties. To clarify their evolutionary/taxonomic relationships, comprehensive phylogenomic and comparative genomic studies were conducted on the genome sequences of 212
P
.
aeruginosa
strains covering their genetic diversity. In a phylogenomic tree based on 118 conserved proteins, the analysed strains formed two distinct clades. One of these clades, Clade-1, encompassing >70 % of the strains including the type strain DSM 50071T, represents the species P. aeruginosa sensu stricto. Clade-2, referred to in earlier work as the outlier group, with NCTC 13628T as its type strain, constitutes a novel species level lineage. The average nucleotide identity, average amino acid identity and digital DNA–DNA hybridization values between the strains from Clade-1 and Clade-2 are in the range of 93.4–93.7, 95.1–95.3 and 52–53 %, respectively. The 16S rRNA gene of
P. aeruginosa
DSM 50071T also shows 98.3 % similarity to that of NCTC 13628T. These values are lower than the suggested cut-off values for species distinction, indicating that the Clade-2 strains (NCTC 13628T) constitute a new species. We also report the identification of 12 conserved signature indels in different proteins and 24 conserved signature proteins that are exclusively found in either Clade-1 or Clade-2, providing a reliable means for distinguishing these clades. Additionally, in contrast to swimming motility, twitching motility is only present in Clade-1 strains. Based on earlier work, the strains from these two clades also differ in their pathogenic mechanisms (presence/absence of Type III secretion system), production of biosurfactants, phenazines and siderophores, and several other genomic characteristics. Based on the evidence from different studies, we propose that the Clade-2 strains constitute a novel species for which the name Pseudomonas paraeruginosa is proposed. The type strain is NCTC 13628T (=PA7T=ATCC 9027T). The description of
Pseudomonas aeruginosa
is also emended to include information for different molecular markers specific for this species.
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Affiliation(s)
- Bashudev Rudra
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton L8N 3Z5, Canada
| | - Louise Duncan
- School of Cancer and Pharmaceutical Sciences, King's College London, London SE1 9NH, UK
| | - Ajit J Shah
- Department of Natural Sciences, Middlesex University, London NW4 4BT, UK
| | - Haroun N Shah
- Department of Natural Sciences, Middlesex University, London NW4 4BT, UK
| | - Radhey S Gupta
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton L8N 3Z5, Canada
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8
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Gemler BT, Mukherjee C, Howland CA, Huk D, Shank Z, Harbo LJ, Tabbaa OP, Bartling CM. Function-based classification of hazardous biological sequences: Demonstration of a new paradigm for biohazard assessments. Front Bioeng Biotechnol 2022; 10:979497. [PMID: 36277394 PMCID: PMC9585941 DOI: 10.3389/fbioe.2022.979497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/31/2022] [Indexed: 12/04/2022] Open
Abstract
Bioengineering applies analytical and engineering principles to identify functional biological building blocks for biotechnology applications. While these building blocks are leveraged to improve the human condition, the lack of simplistic, machine-readable definition of biohazards at the function level is creating a gap for biosafety practices. More specifically, traditional safety practices focus on the biohazards of known pathogens at the organism-level and may not accurately consider novel biodesigns with engineered functionalities at the genetic component-level. This gap is motivating the need for a paradigm shift from organism-centric procedures to function-centric biohazard identification and classification practices. To address this challenge, we present a novel methodology for classifying biohazards at the individual sequence level, which we then compiled to distinguish the biohazardous property of pathogenicity at the whole genome level. Our methodology is rooted in compilation of hazardous functions, defined as a set of sequences and associated metadata that describe coarse-level functions associated with pathogens (e.g., adherence, immune subversion). We demonstrate that the resulting database can be used to develop hazardous “fingerprints” based on the functional metadata categories. We verified that these hazardous functions are found at higher levels in pathogens compared to non-pathogens, and hierarchical clustering of the fingerprints can distinguish between these two groups. The methodology presented here defines the hazardous functions associated with bioengineering functional building blocks at the sequence level, which provide a foundational framework for classifying biological hazards at the organism level, thus leading to the improvement and standardization of current biosecurity and biosafety practices.
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9
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Liao C, Huang X, Wang Q, Yao D, Lu W. Virulence Factors of Pseudomonas Aeruginosa and Antivirulence Strategies to Combat Its Drug Resistance. Front Cell Infect Microbiol 2022; 12:926758. [PMID: 35873152 PMCID: PMC9299443 DOI: 10.3389/fcimb.2022.926758] [Citation(s) in RCA: 68] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/09/2022] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial infections in severely ill and immunocompromised patients. Ubiquitously disseminated in the environment, especially in hospitals, it has become a major threat to human health due to the constant emergence of drug-resistant strains. Multiple resistance mechanisms are exploited by P. aeruginosa, which usually result in chronic infections difficult to eradicate. Diverse virulence factors responsible for bacterial adhesion and colonization, host immune suppression, and immune escape, play important roles in the pathogenic process of P. aeruginosa. As such, antivirulence treatment that aims at reducing virulence while sparing the bacterium for its eventual elimination by the immune system, or combination therapies, has significant advantages over traditional antibiotic therapy, as the former imposes minimal selective pressure on P. aeruginosa, thus less likely to induce drug resistance. In this review, we will discuss the virulence factors of P. aeruginosa, their pathogenic roles, and recent advances in antivirulence drug discovery for the treatment of P. aeruginosa infections.
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Affiliation(s)
- Chongbing Liao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Xin Huang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Qingxia Wang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Dan Yao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Wuyuan Lu
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China.,Shanghai Institute of Infectious Disease and Biosecurity, School of Public Health, Fudan University, Shanghai, China
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10
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Job V, Gomez-Valero L, Renier A, Rusniok C, Bouillot S, Chenal-Francisque V, Gueguen E, Adrait A, Robert-Genthon M, Jeannot K, Panchev P, Elsen S, Fauvarque MO, Couté Y, Buchrieser C, Attrée I. Genomic erosion and horizontal gene transfer shape functional differences of the ExlA toxin in Pseudomonas spp. iScience 2022; 25:104596. [PMID: 35789842 PMCID: PMC9250014 DOI: 10.1016/j.isci.2022.104596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/15/2022] [Accepted: 06/08/2022] [Indexed: 12/31/2022] Open
Abstract
Two-partner secretion (TPS) is widespread in the bacterial world. The pore-forming TPS toxin ExlA of Pseudomonas aeruginosa is conserved in pathogenic and environmental Pseudomonas. While P. chlororaphis and P. entomophila displayed ExlA-dependent killing, P. putida did not cause damage to eukaryotic cells. ExlA proteins interacted with epithelial cell membranes; however, only ExlAPch induced the cleavage of the adhesive molecule E-cadherin. ExlA proteins participated in insecticidal activity toward the larvae of Galleria mellonella and the fly Drosophila melanogaster. Evolutionary analyses demonstrated that the differences in the C-terminal domains are partly due to horizontal movements of the operon within the genus Pseudomonas. Reconstruction of the evolutionary history revealed the complex horizontal acquisitions. Together, our results provide evidence that conserved TPS toxins in environmental Pseudomonas play a role in bacteria-insect interactions and discrete differences in CTDs may determine their specificity and mode of action toward eukaryotic cells. ExlA is a two-partner secreted toxin conserved across Pseudomonas spp. Environmental Pseudomonas strains encode ExlA with different cytotoxic activities ExlA of environmental Pseudomonas strains play a role in bacteria-insect interactions ExlBA operon shows a complex evolutionary history of horizontal gene transfer
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Affiliation(s)
- Viviana Job
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | - Laura Gomez-Valero
- Institut Pasteur, Université de Paris, CNRS UMR 6047, Unité Biologie des Bactéries Intracellulaires, 75015 Paris, France
| | - Adèle Renier
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | - Christophe Rusniok
- Institut Pasteur, Université de Paris, CNRS UMR 6047, Unité Biologie des Bactéries Intracellulaires, 75015 Paris, France
| | - Stephanie Bouillot
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | - Viviane Chenal-Francisque
- Institut Pasteur, Université de Paris, CNRS UMR 6047, Unité Biologie des Bactéries Intracellulaires, 75015 Paris, France
| | - Erwan Gueguen
- University of Lyon, Université Lyon 1, INSA de Lyon, CNRS UMR 5240 Microbiologie Adaptation et Pathogénie, Lyon, France
| | - Annie Adrait
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, Grenoble, France
| | - Mylène Robert-Genthon
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | - Katy Jeannot
- Centre National de Référence de la Résistance aux Antibiotiques, Laboratoire de Bactériologie, Centre Hospitalier Universitaire Jean Minjoz, UMR6249 CNRS, Université de Bourgogne-Franche Comté, Besançon, France
| | - Peter Panchev
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | - Sylvie Elsen
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
| | | | - Yohann Couté
- Université Grenoble Alpes, INSERM, CEA, UMR BioSanté U1292, Grenoble, France
- CNRS, CEA, FR2048, Grenoble, France
| | - Carmen Buchrieser
- Institut Pasteur, Université de Paris, CNRS UMR 6047, Unité Biologie des Bactéries Intracellulaires, 75015 Paris, France
- Corresponding author
| | - Ina Attrée
- Université Grenoble Alpes, Institute of Structural Biology, Bacterial Pathogenesis and Cellular Responses Team, UMR5075 CNRS, IRIG, CEA, Grenoble, France
- Corresponding author
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11
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Huber P. ExlA: A New Contributor to Pseudomonas aeruginosa Virulence. Front Cell Infect Microbiol 2022; 12:929150. [PMID: 35811671 PMCID: PMC9260685 DOI: 10.3389/fcimb.2022.929150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/19/2022] [Indexed: 11/17/2022] Open
Abstract
ExlA (also called exolysin) is a recently discovered virulence factor secreted by a subset of Pseudomonas aeruginosa strains in which a type 3 secretion system is lacking. exlA-positive strains were identified worldwide in the clinic, causing several types of infectious diseases, and were detected in various locations in the environment. ExlA possesses pore-forming activity and is cytolytic for most human cell types. It belongs to a class of poorly characterized bacterial toxins, sharing a similar protein domain organization and a common secretion pathway. This review summarizes the recent findings regarding ExlA synthesis, its secretion pathway, and its toxic behavior for host cells.
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12
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Hardy KS, Tuckey AN, Housley NA, Andrews J, Patel M, Al-Mehdi AB, Barrington RA, Cassel SL, Sutterwala FS, Audia JP. The Pseudomonas aeruginosa Type III Secretion System Exoenzyme Effector ExoU Induces Mitochondrial Damage in a Murine Bone Marrow-Derived Macrophage Infection Model. Infect Immun 2022; 90:e0047021. [PMID: 35130452 PMCID: PMC8929383 DOI: 10.1128/iai.00470-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 01/18/2022] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative, opportunistic pathogen that causes nosocomial pneumonia, urinary tract infections, and bacteremia. A hallmark of P. aeruginosa pathogenesis is disruption of host cell function by the type III secretion system (T3SS) and its cognate exoenzyme effectors. The T3SS effector ExoU is phospholipase A2 (PLA2) that targets the host cell plasmalemmal membrane to induce cytolysis and is an important virulence factor that mediates immune avoidance. In addition, ExoU has been shown to subvert the host inflammatory response in a noncytolytic manner. In primary bone marrow-derived macrophages (BMDMs), P. aeruginosa infection is sensed by the nucleotide-binding domain containing leucine-rich repeats-like receptor 4 (NLRC4) inflammasome, which triggers caspase-1 activation and inflammation. ExoU transiently inhibits NLRC4 inflammasome-mediated activation of caspase-1 and its downstream target, interleukin 1β (IL-1β), to suppress activation of inflammation. In the present study, we sought to identify additional noncytolytic virulence functions for ExoU and discovered an unexpected association between ExoU, host mitochondria, and NLRC4. We show that infection of BMDMs with P. aeruginosa strains expressing ExoU elicited mitochondrial oxidative stress. In addition, mitochondria and mitochondrion-associated membrane fractions enriched from infected cells exhibited evidence of autophagy activation, indicative of damage. The observation that ExoU elicited mitochondrial stress and damage suggested that ExoU may also associate with mitochondria during infection. Indeed, ExoU phospholipase A2 enzymatic activity was present in enriched mitochondria and mitochondrion-associated membrane fractions isolated from P. aeruginosa-infected BMDMs. Intriguingly, enriched mitochondria and mitochondrion-associated membrane fractions isolated from infected Nlrc4 homozygous knockout BMDMs displayed significantly lower levels of ExoU enzyme activity, suggesting that NLRC4 plays a role in the ExoU-mitochondrion association. These observations prompted us to assay enriched mitochondria and mitochondrion-associated membrane fractions for NLRC4, caspase-1, and IL-1β. NLRC4 and pro-caspase-1 were detected in enriched mitochondria and mitochondrion-associated membrane fractions isolated from noninfected BMDMs, and active caspase-1 and active IL-1β were detected in response to P. aeruginosa infection. Interestingly, ExoU inhibited mitochondrion-associated caspase-1 and IL-1β activation. The implications of ExoU-mediated effects on mitochondria and the NLRC4 inflammasome during P. aeruginosa infection are discussed.
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Affiliation(s)
- Kierra S. Hardy
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Amanda N. Tuckey
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Nicole A. Housley
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Joel Andrews
- Mitchell Cancer Institute, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Mita Patel
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Abu-Bakr Al-Mehdi
- Department of Pharmcology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Robert A. Barrington
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
| | - Suzanne L. Cassel
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Fayyaz S. Sutterwala
- Women’s Guild Lung Institute, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile, Alabama, USA
- Center for Lung Biology, University of South Alabama College of Medicine, Mobile, Alabama, USA
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13
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Li H, Tan Y, Zhang D. Genomic discovery and structural dissection of a novel type of polymorphic toxin system in gram-positive bacteria. Comput Struct Biotechnol J 2022; 20:4517-4531. [PMID: 36051883 PMCID: PMC9424270 DOI: 10.1016/j.csbj.2022.08.036] [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: 05/12/2022] [Revised: 08/15/2022] [Accepted: 08/15/2022] [Indexed: 11/26/2022] Open
Abstract
Bacteria have developed several molecular conflict systems to facilitate kin recognition and non-kin competition to gain advantages in the acquisition of growth niches and of limited resources. One such example is a large class of so-called polymorphic toxin systems (PTSs), which comprise a variety of the toxin proteins secreted via T2SS, T5SS, T6SS, T7SS and many others. These systems are highly divergent in terms of sequence/structure, domain architecture, toxin-immunity association, and organization of the toxin loci, which makes it difficult to identify and characterize novel systems using traditional experimental and bioinformatic strategies. In recent years, we have been developing and utilizing unique genome-mining strategies and pipelines, based on the organizational principles of both domain architectures and genomic loci of PTSs, for an effective and comprehensive discovery of novel PTSs, dissection of their components, and prediction of their structures and functions. In this study, we present our systematic discovery of a new type of PTS (S8-PTS) in several gram-positive bacteria. We show that the S8-PTS contains three components: a peptidase of the S8 family (subtilases), a polymorphic toxin, and an immunity protein. We delineated the typical organization of these polymorphic toxins, in which a N-terminal signal peptide is followed by a potential receptor binding domain, BetaH, and one of 16 toxin domains. We classified each toxin domain by the distinct superfamily to which it belongs, identifying nine BECR ribonucleases, one Restriction Endonuclease, one HNH nuclease, two novel toxin domains homologous to the VOC enzymes, one toxin domain with the Frataxin-like fold, and several other unique toxin families such as Ntox33 and HicA. Accordingly, we identified 20 immunity families and classified them into different classes of folds. Further, we show that the S8-PTS-associated peptidases are analogous to many other processing peptidases found in T5SS, T7SS, T9SS, and many proprotein-processing peptidases, indicating that they function to release the toxin domains during secretion. The S8-PTSs are mostly found in animal and plant-associated bacteria, including many pathogens. We propose S8-PTSs will facilitate the competition of these bacteria with other microbes or contribute to the pathogen-host interactions.
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Affiliation(s)
- Huan Li
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
| | - Yongjun Tan
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
| | - Dapeng Zhang
- Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA
- Program of Bioinformatics and Computational Biology, College of Arts & Sciences, Saint Louis University, MO 63103, USA
- Corresponding author at: Department of Biology, College of Arts & Sciences, Saint Louis University, Saint Louis, MO 63103, USA.
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14
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Trouillon J, Imbert L, Villard AM, Vernet T, Attrée I, Elsen S. Determination of the two-component systems regulatory network reveals core and accessory regulations across Pseudomonas aeruginosa lineages. Nucleic Acids Res 2021; 49:11476-11490. [PMID: 34718721 PMCID: PMC8599809 DOI: 10.1093/nar/gkab928] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/24/2021] [Accepted: 09/28/2021] [Indexed: 01/01/2023] Open
Abstract
Pseudomonas aeruginosa possesses one of the most complex bacterial regulatory networks, which largely contributes to its success as a pathogen. However, most of its transcription factors (TFs) are still uncharacterized and the potential intra-species variability in regulatory networks has been mostly ignored so far. Here, we used DAP-seq to map the genome-wide binding sites of all 55 DNA-binding two-component systems (TCSs) response regulators (RRs) across the three major P. aeruginosa lineages. The resulting networks encompass about 40% of all genes in each strain and contain numerous new regulatory interactions across most major physiological processes. Strikingly, about half of the detected targets are specific to only one or two strains, revealing a previously unknown large functional diversity of TFs within a single species. Three main mechanisms were found to drive this diversity, including differences in accessory genome content, as exemplified by the strain-specific plasmid in IHMA87 outlier strain which harbors numerous binding sites of conserved chromosomally-encoded RRs. Additionally, most RRs display potential auto-regulation or RR-RR cross-regulation, bringing to light the vast complexity of this network. Overall, we provide the first complete delineation of the TCSs regulatory network in P. aeruginosa that will represent an important resource for future studies on this pathogen.
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Affiliation(s)
- Julian Trouillon
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, 38044 Grenoble, France
| | - Lionel Imbert
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, 38044 Grenoble, France
- Université Grenoble Alpes, CNRS, CEA, EMBL, ISBG UAR 3518, 38044 Grenoble, France
| | - Anne-Marie Villard
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, 38044 Grenoble, France
| | - Thierry Vernet
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, 38044 Grenoble, France
| | - Ina Attrée
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, 38044 Grenoble, France
| | - Sylvie Elsen
- Université Grenoble Alpes, CNRS, CEA, IBS UMR 5075, Team Bacterial Pathogenesis and Cellular Responses, 38044 Grenoble, France
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15
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Campoccia D, Montanaro L, Arciola CR. Tracing the origins of extracellular DNA in bacterial biofilms: story of death and predation to community benefit. BIOFOULING 2021; 37:1022-1039. [PMID: 34823431 DOI: 10.1080/08927014.2021.2002987] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
Extracellular DNA (eDNA) is a macromolecule copiously found in various natural microenvironments, but its origin and significance still remain partly mysterious phenomena. Here, the multifaceted origins of eDNA in bacterial biofilms are explored. The release of eDNA can follow a suicidal programmed bacterial apoptosis or a fratricide-induced death, under the control of quorum sensing systems or triggered by specific stressors. eDNA can be released into the extracellular space or as a free macromolecule or enclosed within membrane vesicles or even through an explosion of bubbles. eDNA can also be derived from host tissue cells through bacterial cytolytic/proapoptotic toxins or stolen from neutrophil extracellular traps (NETs). eDNA can alternatively be produced by lysis-independent mechanisms. Sub-inhibitory doses of antibiotics, by killing a fraction of bacteria, result in stimulating the release of eDNA. Even phages appear to play a role in favoring eDNA release. Unveiling the origins of eDNA is critical to correctly address biofilm-associated infections.
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Affiliation(s)
- Davide Campoccia
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Lucio Montanaro
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Carla Renata Arciola
- Laboratorio di Patologia delle Infezioni Associate all'Impianto, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Laboratorio di Immunoreumatologia e Rigenerazione Tissutale, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
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16
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Deruelle V, Berry A, Bouillot S, Job V, Maillard AP, Elsen S, Huber P. ExlA Pore-Forming Toxin: Localization at the Bacterial Membrane, Regulation of Secretion by Cyclic-Di-GMP, and Detection In Vivo. Toxins (Basel) 2021; 13:toxins13090645. [PMID: 34564649 PMCID: PMC8472254 DOI: 10.3390/toxins13090645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/31/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
ExlA is a highly virulent pore-forming toxin that has been recently discovered in outlier strains from Pseudomonas aeruginosa. ExlA is part of a two-partner secretion system, in which ExlA is the secreted passenger protein and ExlB the transporter embedded in the bacterial outer membrane. In previous work, we observed that ExlA toxicity in a host cell was contact-dependent. Here, we show that ExlA accumulates at specific points of the outer membrane, is likely entrapped within ExlB pore, and is pointing outside. We further demonstrate that ExlA is maintained at the membrane in conditions where the intracellular content of second messenger cyclic-di-GMP is high; lowering c-di-GMP levels enhances ExlB-dependent ExlA secretion. In addition, we set up an ELISA to detect ExlA, and we show that ExlA is poorly secreted in liquid culture, while it is highly detectable in broncho-alveolar lavage fluids of mice infected with an exlA+ strain. We conclude that ExlA translocation is halted at mid-length in the outer membrane and its secretion is regulated by c-di-GMP. In addition, we developed an immunological test able to quantify ExlA in biological samples.
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Affiliation(s)
- Vincent Deruelle
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Unité de Biochimie des Interactions Macromoléculaires, Département de Biologie Structurale et Chimie, CNRS UMR 3528, Institut Pasteur, 75015 Paris, France
| | - Alice Berry
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
| | - Stéphanie Bouillot
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Institut de Biologie Structurale (IBS), Université Grenoble-Alpes, CNRS, CEA, 38044 Grenoble, France
| | - Viviana Job
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Institut de Biologie Structurale (IBS), Université Grenoble-Alpes, CNRS, CEA, 38044 Grenoble, France
| | - Antoine P. Maillard
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Institut de Biologie Structurale (IBS), Université Grenoble-Alpes, CNRS, CEA, 38044 Grenoble, France
| | - Sylvie Elsen
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Institut de Biologie Structurale (IBS), Université Grenoble-Alpes, CNRS, CEA, 38044 Grenoble, France
| | - Philippe Huber
- Unité de Biologie Cellulaire et Infection, Université Grenoble-Alpes, CEA, INSERM, CNRS, 38054 Grenoble, France; (V.D.); (A.B.); (S.B.); (V.J.); (A.P.M.); (S.E.)
- Center for Immunology of Viral, Auto-Immune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), Université Paris-Saclay, Inserm, CEA, 92265 Fontenay-aux-Roses, France
- Correspondence:
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17
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Environmental Free-Living Amoebae Can Predate on Diverse Antibiotic-Resistant Human Pathogens. Appl Environ Microbiol 2021; 87:e0074721. [PMID: 34232736 PMCID: PMC8388808 DOI: 10.1128/aem.00747-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Here, we sought to test the resistance of human pathogens to unaltered environmental free-living amoebae. Amoebae are ubiquitous eukaryotic microorganisms and important predators of bacteria. Environmental amoebae have also been proposed to serve as both potential reservoirs and training grounds for human pathogens. However, studies addressing their relationships with human pathogens often rely on a few domesticated amoebae that have been selected to feed on rich medium, thereby possibly overestimating the resistance of pathogens to these predatory phagocytes. From an open-air composting site, we recovered over 100 diverse amoebae that were able to feed on Acinetobacter baumannii and Klebsiella pneumoniae. In a standardized and quantitative assay for predation, the isolated amoebae showed a broad predation spectrum, killing clinical isolates of A. baumannii, K. pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Interestingly, A. baumannii, which was previously reported to resist predation by laboratory strains of Acanthamoeba, was efficiently consumed by closely related environmental amoebae. The isolated amoebae were capable of feeding on highly virulent carbapenem-resistant or methicillin-resistant clinical isolates. In conclusion, the natural environment is a rich source of amoebae with broad-spectrum bactericidal activities, including against antibiotic-resistant isolates. IMPORTANCE Free-living amoebae have been proposed to play an important role in hosting and disseminating various human pathogens. The resistance of human pathogens to predation by amoebae is often derived from in vitro experiments using model amoebae. Here, we sought to isolate environmental amoebae and to test their predation on diverse human pathogens, with results that challenge conclusions based on model amoebae. We found that the natural environment is a rich source of diverse amoebae with broad-spectrum predatory activities against human pathogens, including highly virulent and antibiotic-resistant clinical isolates.
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18
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García-Reyes S, Moustafa DA, Attrée I, Goldberg JB, Quiroz-Morales SE, Soberón-Chávez G. Vfr or CyaB promote the expression of the pore-forming toxin exlBA operon in Pseudomonas aeruginosa ATCC 9027 without increasing its virulence in mice. MICROBIOLOGY-SGM 2021; 167. [PMID: 34424157 DOI: 10.1099/mic.0.001083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pseudomonas aeruginosa is a wide-spread γ-proteobacterium that produces the biosurfactant rhamnolipid that has a great commercial value due to excellent properties of low toxicity and high biodegradability. However, this bacterium is an opportunist pathogen that constitutes an important health hazard due to its production of virulence-associated traits and its high antibiotic resistance. Thus, it is highly desirable to have a non-virulent P. aeruginosa strain for rhamnolipid production. It has been reported that strain ATCC 9027 is avirulent in mouse models of infection, and it is still able to produce rhamnolipid. Thus, it has been proposed to be suitable for it industrial production, since it encodes a defective LasR quorum sensing (QS) transcriptional regulator that is the head of this regulatory network. However, the restoration of virulence factor production by overexpression of rhlR (the gene encoding a QS-transcriptional regulator which is under the transcriptional control of LasR) is not sufficient to restore its virulence in mice. It is desirable to obtain a deeper understanding of ATCC 9027 attenuated-virulence phenotype and to assess the safety of this strain to be used at an industrial scale. In this work we determined whether increasing the expression of the pore-forming toxin encoded by the exlBA operon in strain ATCC 9027 had an impact on its virulence using Galleria mellonella and mouse models of infections. We increased the expression of the exlBA operon by overexpressing from a plasmid its transcriptional activator Vfr or of the Vfr ligand cyclic AMP produced by CyaB. We found that in G. mellonella ATCC 9027/pUCP24-vfr and ATCC 9027/pUCP24-cyaB gained a virulent phenotype, but these strains remained avirulent in murine models of P. aeruginosa infection. These results reinforce the possibility of using ATCC 9027 for industrial biosurfactants production.
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Affiliation(s)
- Selene García-Reyes
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
| | - Dina A Moustafa
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA.,Emory Children's Centre for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Ina Attrée
- Univ. Grenoble Alpes, CNRS, CEA, IBS, F-38000 Grenoble, Grenoble, France
| | - Joanna B Goldberg
- Division of Pulmonary, Allergy and Immunology, Cystic Fibrosis, and Sleep, Emory University School of Medicine, Atlanta, Georgia, USA.,Emory Children's Centre for Cystic Fibrosis and Airway Disease Research, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Sara E Quiroz-Morales
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
| | - Gloria Soberón-Chávez
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México. Ciudad Universitaria, Apdo. Postal 70228, C. P. 04510, CDMX, México
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19
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Swietnicki W. Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens. Biomolecules 2021; 11:892. [PMID: 34203937 PMCID: PMC8232601 DOI: 10.3390/biom11060892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/13/2021] [Accepted: 06/14/2021] [Indexed: 01/18/2023] Open
Abstract
Bacterial secretory systems are essential for virulence in human pathogens. The systems have become a target of alternative antibacterial strategies based on small molecules and antibodies. Strategies to use components of the systems to design prophylactics have been less publicized despite vaccines being the preferred solution to dealing with bacterial infections. In the current review, strategies to design vaccines against selected pathogens are presented and connected to the biology of the system. The examples are given for Y. pestis, S. enterica, B. anthracis, S. flexneri, and other human pathogens, and discussed in terms of effectiveness and long-term protection.
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Affiliation(s)
- Wieslaw Swietnicki
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, ul. R. Weigla 12, 53-114 Wroclaw, Poland
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20
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Sivakumar K, Kannappan S, Vijayakumar B, Jithendran KP, Balasubramaniam S, Panigrahi A. Molecular docking study of bio-inhibitors extracted from marine macro-alga Ulva fasciata against hemolysin protein of luminescence disease-causing Vibrio harveyi. Arch Microbiol 2021; 203:4243-4258. [PMID: 34097104 DOI: 10.1007/s00203-021-02408-1] [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: 12/04/2020] [Revised: 05/11/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022]
Abstract
Shrimp grow-out and hatchery systems are being affected by bacterial disease particularly Vibrios. The use of chemotherapeutic agents in aquaculture practices has to lead to the development of resistance among aquatic bacteria. Thus, health management becomes of major importance in aquaculture. Under this situation, progressing bio-inhibitors from marine resources are most appropriate to be considered against pathogenic bacteria. Molecular docking is an appropriate tool in structural biology and computer-assisted drug design to predict and neutralize a target protein of known diseases. In this study, marine macro-alga Ulva fasciata was aimed at developing inhibitors against luminescence disease-causing pathogenic bacteria Vibrio harveyi. U. fasciata was collected from Thoothukudi, Tamil Nadu, India. Extract of U. fasciata was tested against growth and virulence factors of V. harveyi during Penaeus monodon larviculture. Further U. fasciata extract was subjected to GC-MS analysis to identify the biomolecules. The homology modeling of virulent protein, hemolysin of V. harveyi was designed in this study. Hence, it was aimed for molecular docking against the biomolecules identified from U. fasciata extract. During shrimp larviculture, the extract of U. fasciata (200 μg mL-1) exhibited reduction on Cumulative Percentage of Mortality (32.40%) in postlarvae against challenge of V. harveyi infection. Biomolecule Methyl dehydroabietate had showed highest binding affinity among the compounds was evaluated in molecular docking study. Statistical analysis had revealed significant differences (p < 0.05) in trials. Therefore, it was proved that the bio-inhibitors from U. fasciata will be a better option for controlling luminescence disease-causing V. harveyi in shrimp grow-out practices.
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Affiliation(s)
- Krishnamoorthy Sivakumar
- ICAR-Krishi Vigyan Kendra, Tamil Nadu Veterinary and Animal Sciences University, Kattupakkam, Chennai, Tamil Nadu, 603203, India. .,Crustacean Culture Division, ICAR-Central Institute of Brackishwater Aquaculture, Chennai, Tamil Nadu, 600028, India.
| | - Sudalayandi Kannappan
- Crustacean Culture Division, ICAR-Central Institute of Brackishwater Aquaculture, Chennai, Tamil Nadu, 600028, India
| | - Balakrishnan Vijayakumar
- Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Chennai, Tamil Nadu, 600025, India.,McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin At Madison, Madison, WI, 53705, USA
| | | | - Sivamani Balasubramaniam
- Genetics and Biotechnology Unit, ICAR-Central Institute of Brackishwater Aquaculture, Chennai, Tamil Nadu, 600028, India
| | - Akshaya Panigrahi
- Crustacean Culture Division, ICAR-Central Institute of Brackishwater Aquaculture, Chennai, Tamil Nadu, 600028, India
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21
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King M, Kubo A, Kafer L, Braga R, McLeod D, Khanam S, Conway T, Patrauchan MA. Calcium-Regulated Protein CarP Responds to Multiple Host Signals and Mediates Regulation of Pseudomonas aeruginosa Virulence by Calcium. Appl Environ Microbiol 2021; 87:e00061-21. [PMID: 33674436 PMCID: PMC8117776 DOI: 10.1128/aem.00061-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/27/2021] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing life-threatening infections. Previously, we showed that elevated calcium (Ca2+) levels increase the production of virulence factors in P. aeruginosa In an effort to characterize the Ca2+ regulatory network, we identified a Ca2+-regulated β-propeller protein, CarP, and showed that expression of the encoding gene is controlled by the Ca2+-regulated two-component system CarSR. Here, by using a Galleria melonella model, we showed that CarP plays a role in regulating P. aeruginosa virulence. By using transcriptome sequencing (RNA-Seq), reverse transcription (RT)-PCR, quantitative RT-PCR (RT-qPCR), and promoter fusions, we determined that carP is transcribed into at least two transcripts and regulated by several bacterial and host factors. The transcription of carP is elevated in response to Ca2+ in P. aeruginosa cystic fibrosis isolates and PAO1 laboratory strain. Elevated Fe2+ also induces carP The simultaneous addition of Ca2+ and Fe2+ increased the carP promoter activity synergistically, which requires the presence of CarR. In silico analysis of the intergenic sequence upstream of carP predicted recognition sites of RhlR/LasR, OxyR, and LexA, suggesting regulation by quorum sensing (QS) and oxidative stress. In agreement, the carP promoter was activated in response to stationary-phase PAO1 supernatant and required the presence of elevated Ca2+ and CarR but remained silent in the triple mutant lacking rhlI, lasI, and pqsA synthases. We also showed that carP transcription is regulated by oxidative stress and that CarP contributes to P. aeruginosa Ca2+-dependent H2O2 tolerance. The multifactorial regulation of carP suggests that CarP plays an important role in P. aeruginosa adaptations to host environments.IMPORTANCEP. aeruginosa is a human pathogen causing life-threatening infections. It is particularly notorious for its ability to adapt to diverse environments within the host. Understanding the signals and the signaling pathways enabling P. aeruginosa adaptation is imperative for developing effective therapies to treat infections caused by this organism. One host signal of particular importance is calcium. Previously, we identified a component of the P. aeruginosa calcium-signaling network, CarP, whose expression is induced by elevated levels of calcium. Here, we show that carP plays an important role in P. aeruginosa virulence and is upregulated in P. aeruginosa strains isolated from sputa of patients with cystic fibrosis. We also identified several bacterial and host factors that regulate the transcription of carP Such multifactorial regulation highlights the interconnectedness between regulatory circuits and, together with the pleotropic effect of CarP on virulence, suggests the importance of this protein in P. aeruginosa adaptations to the host.
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Affiliation(s)
- Michelle King
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Aya Kubo
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Leah Kafer
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Reygan Braga
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Daniel McLeod
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Sharmily Khanam
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Tyrrell Conway
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Marianna A Patrauchan
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, Oklahoma, USA
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22
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Das S, Howlader DR, Zheng Q, Ratnakaram SSK, Whittier SK, Lu T, Keith JD, Picking WD, Birket SE, Picking WL. Development of a Broadly Protective, Self-Adjuvanting Subunit Vaccine to Prevent Infections by Pseudomonas aeruginosa. Front Immunol 2020; 11:583008. [PMID: 33281815 PMCID: PMC7705240 DOI: 10.3389/fimmu.2020.583008] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
Infections caused by the opportunistic pathogen Pseudomonas aeruginosa can be difficult to treat due to innate and acquired antibiotic resistance and this is exacerbated by the emergence of multi-drug resistant strains. Unfortunately, no licensed vaccine yet exists to prevent Pseudomonas infections. Here we describe a novel subunit vaccine that targets the P. aeruginosa type III secretion system (T3SS). This vaccine is based on the novel antigen PaF (Pa Fusion), a fusion of the T3SS needle tip protein, PcrV, and the first of two translocator proteins, PopB. Additionally, PaF is made self-adjuvanting by the N-terminal fusion of the A1 subunit of the mucosal adjuvant double-mutant heat-labile enterotoxin (dmLT). Here we show that this triple fusion, designated L-PaF, can activate dendritic cells in vitro and elicits strong IgG and IgA titers in mice when administered intranasally. This self-adjuvanting vaccine expedites the clearance of P. aeruginosa from the lungs of challenged mice while stimulating host expression of IL-17A, which may be important for generating a protective immune response in humans. L-PaF's protective capacity was recapitulated in a rat pneumonia model, further supporting the efficacy of this novel fusion vaccine.
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Affiliation(s)
- Sayan Das
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Debaki R Howlader
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Qi Zheng
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Siva Sai Kumar Ratnakaram
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Sean K Whittier
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States.,Hafion LLC, Lawrence, KS, United States
| | - Ti Lu
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Johnathan D Keith
- Department of Medicine and Gregory Fleming James Cystic Fibrosis Research Center, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - William D Picking
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Susan E Birket
- Department of Medicine and Gregory Fleming James Cystic Fibrosis Research Center, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Wendy L Picking
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States.,Hafion LLC, Lawrence, KS, United States
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23
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Bouillot S, Pont S, Gallet B, Moriscot C, Deruelle V, Attrée I, Huber P. Inflammasome activation by Pseudomonas aeruginosa's ExlA pore-forming toxin is detrimental for the host. Cell Microbiol 2020; 22:e13251. [PMID: 32779854 DOI: 10.1111/cmi.13251] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 07/24/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023]
Abstract
During acute Pseudomonas aeruginosa infection, the inflammatory response is essential for bacterial clearance. Neutrophil recruitment can be initiated following the assembly of an inflammasome within sentinel macrophages, leading to activation of caspase-1, which in turn triggers macrophage pyroptosis and IL-1β/IL-18 maturation. Inflammasome formation can be induced by a number of bacterial determinants, including Type III secretion systems (T3SSs) or pore-forming toxins, or, alternatively, by lipopolysaccharide (LPS) via caspase-11 activation. Surprisingly, previous studies indicated that a T3SS-induced inflammasome increased pathogenicity in mouse models of P. aeruginosa infection. Here, we investigated the immune reaction of mice infected with a T3SS-negative P. aeruginosa strain (IHMA879472). Virulence of this strain relies on ExlA, a secreted pore-forming toxin. IHMA879472 promoted massive neutrophil infiltration in infected lungs, owing to efficient priming of toll-like receptors, and thus enhanced the expression of inflammatory proteins including pro-IL-1β and TNF-α. However, mature-IL-1β and IL-18 were undetectable in wild-type mice, suggesting that ExlA failed to effectively activate caspase-1. Nevertheless, caspase-1/11 deficiency improved survival following infection with IHMA879472, as previously described for T3SS+ bacteria. We conclude that the detrimental effect associated with the ExlA-induced inflammasome is probably not due to hyperinflammation, rather it stems from another inflammasome-dependent process.
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Affiliation(s)
- Stéphanie Bouillot
- Unité de Biologie Cellulaire et Infection, CEA, INSERM, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Stéphane Pont
- Unité de Biologie Cellulaire et Infection, CEA, INSERM, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Benoit Gallet
- Institut de Biologie Structurale, CEA, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Christine Moriscot
- Institut de Biologie Structurale, CEA, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Vincent Deruelle
- Unité de Biologie Cellulaire et Infection, CEA, INSERM, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Ina Attrée
- Unité de Biologie Cellulaire et Infection, CEA, INSERM, CNRS, Université Grenoble-Alpes, Grenoble, France
| | - Philippe Huber
- Unité de Biologie Cellulaire et Infection, CEA, INSERM, CNRS, Université Grenoble-Alpes, Grenoble, France
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24
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Sun J, LaRock DL, Skowronski EA, Kimmey JM, Olson J, Jiang Z, O'Donoghue AJ, Nizet V, LaRock CN. The Pseudomonas aeruginosa protease LasB directly activates IL-1β. EBioMedicine 2020; 60:102984. [PMID: 32979835 PMCID: PMC7511813 DOI: 10.1016/j.ebiom.2020.102984] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Pulmonary damage by Pseudomonas aeruginosa during cystic fibrosis lung infection and ventilator-associated pneumonia is mediated both by pathogen virulence factors and host inflammation. Impaired immune function due to tissue damage and inflammation, coupled with pathogen multidrug resistance, complicates the management of these deep-seated infections. Pathological inflammation during infection is driven by interleukin-1β (IL-1β), but the molecular processes involved are not fully understood. METHODS We examined IL-1β activation in a pulmonary model infection of Pseudomonas aeruginosa and in vitro using genetics, specific inhibitors, recombinant proteins, and targeted reporters of protease activity and IL-1β bioactivity. FINDINGS Caspase-family inflammasome proteases canonically regulate maturation of this proinflammatory cytokine, but we report that plasticity in IL-1β proteolytic activation allows for its direct maturation by the pseudomonal protease LasB. LasB promotes IL-1β activation, neutrophilic inflammation, and destruction of lung architecture characteristic of severe P. aeruginosa pulmonary infection. INTERPRETATION Preservation of lung function and effective immune clearance may be enhanced by selectively controlling inflammation. Discovery of this IL-1β regulatory mechanism provides a distinct target for anti-inflammatory therapeutics, such as matrix metalloprotease inhibitors that inhibit LasB and limit inflammation and pathology during P. aeruginosa pulmonary infections. FUNDING Full details are provided in the Acknowledgements section.
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Affiliation(s)
- Josh Sun
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Doris L LaRock
- Department of Microbiology and Immunology, Emory School of Medicine, Atlanta GA, United States
| | - Elaine A Skowronski
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | | | - Joshua Olson
- Department of Pediatrics, UC San Diego, La Jolla, CA, United States
| | - Zhenze Jiang
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Anthony J O'Donoghue
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA, United States; Department of Pediatrics, UC San Diego, La Jolla, CA, United States
| | - Christopher N LaRock
- Department of Microbiology and Immunology, Emory School of Medicine, Atlanta GA, United States; Division of Infectious Diseases, Emory School of Medicine, Atlanta GA, United States; Antimicrobial Resistance Center, Emory University, Atlanta GA, United States.
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25
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Medina-Rojas M, Stribling W, Snesrud E, Garry BI, Li Y, Gann PM, Demons ST, Tyner SD, Zurawski DV, Antonic V. Comparison of Pseudomonas aeruginosa strains reveals that Exolysin A toxin plays an additive role in virulence. Pathog Dis 2020; 78:5804881. [PMID: 32167551 DOI: 10.1093/femspd/ftaa010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 02/18/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Pseudomonas aeruginosa possesses an array of virulence genes ensuring successful infection development. A two-partner secretion system Exolysin BA (ExlBA) is expressed in the PA7-like genetic outliers consisting of ExlA, a pore-forming toxin and ExlB transporter protein. Presence of exlBA in multidrug-resistant (MDR) strains has not been investigated, particularly in the strains isolated from wounded soldiers. METHODS We screened whole genome sequences of 2439 MDR- P. aeruginosa strains for the presence of exlBA. We compiled all exlBA positive strains and compared them with a diversity set for demographics, antimicrobial profiles and phenotypic characteristics: surface motility, biofilm formation, pyocyanin production and hemolysis. We compared the virulence of strains with comparable phenotypic characteristics in Galleria mellonella. RESULTS We identified 33 exlBA-positive strains (1.5%). These strains have increased antibiotic resistance, they are more motile, produce more robust biofilms and have comparable pyocianin production with the diversity set despite the phenotypic differences within the group. In in vivo infection models, these strains were less virulent than Type III Secretion System (T3SS) positive counterparts. CONCLUSIONS exlBA-positive strains are wide spread among the PA7-like outliers. While not as virulent as strains possessing T3SS, these strains exhibit phenotypic features associated with virulence and are still lethal in vivo.
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Affiliation(s)
- Maria Medina-Rojas
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - William Stribling
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Erik Snesrud
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Brittany I Garry
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Yuanzhang Li
- Walter Reed Army Institute of Research, Preventive Medicine, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Patrick Mc Gann
- Walter Reed Army Institute of Research, Multidrug-Resistant Organism Repository and Surveillance Network, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Samandra T Demons
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Stuart D Tyner
- Walter Reed Army Institute of Research, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Daniel V Zurawski
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
| | - Vlado Antonic
- Walter Reed Army Institute of Research, Wound Infections Department, Bacterial Disease Branch, 503 Robert Grant Ave, Silver Spring MD, 20910, USA
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26
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Antimicrobial resistance and virulence of Pseudomonas spp. among healthy animals: concern about exolysin ExlA detection. Sci Rep 2020; 10:11667. [PMID: 32669597 PMCID: PMC7363818 DOI: 10.1038/s41598-020-68575-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 06/26/2020] [Indexed: 12/25/2022] Open
Abstract
Pseudomonas is a ubiquitous genus that also causes human, animal and plant diseases. Most studies have focused on clinical P. aeruginosa strains from humans, but they are scarce on animal strains. This study was aimed to determine the occurrence of Pseudomonas spp. among faecal samples of healthy animals, and to analyse their antimicrobial resistance, and pathogenicity. Among 704 animal faecal samples analysed, 133 Pseudomonas spp. isolates (23 species) were recovered from 46 samples (6.5%), and classified in 75 different PFGE patterns. Low antimicrobial resistance levels were found, being the highest to aztreonam (50.3%). Five sequence-types (ST1648, ST1711, ST2096, ST2194, ST2252), two serotypes (O:3, O:6), and three virulotypes (analysing 15 virulence and quorum-sensing genes) were observed among the 9 P. aeruginosa strains. Type-3-Secretion System genes were absent in the six O:3-serotype strains that additionally showed high cytotoxicity and produced higher biofilm biomass, phenazine pigments and motility than PAO1 control strain. In these six strains, the exlAB locus, and other virulence genotypes (e.g. RGP69 pathogenicity island) exclusive of PA7 outliers were detected by whole genome sequencing. This is the first description of the presence of the ExlA exolysin in P. aeruginosa from healthy animals, highlighting their pathological importance.
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27
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Exolysin (ExlA) from Pseudomonas aeruginosa Punctures Holes into Target Membranes Using a Molten Globule Domain. J Mol Biol 2020; 432:4466-4480. [DOI: 10.1016/j.jmb.2020.05.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 12/19/2022]
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28
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Panayidou S, Georgiades K, Christofi T, Tamana S, Promponas VJ, Apidianakis Y. Pseudomonas aeruginosa core metabolism exerts a widespread growth-independent control on virulence. Sci Rep 2020; 10:9505. [PMID: 32528034 PMCID: PMC7289854 DOI: 10.1038/s41598-020-66194-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/13/2020] [Indexed: 02/04/2023] Open
Abstract
To assess the role of core metabolism genes in bacterial virulence - independently of their effect on growth - we correlated the genome, the transcriptome and the pathogenicity in flies and mice of 30 fully sequenced Pseudomonas strains. Gene presence correlates robustly with pathogenicity differences among all Pseudomonas species, but not among the P. aeruginosa strains. However, gene expression differences are evident between highly and lowly pathogenic P. aeruginosa strains in multiple virulence factors and a few metabolism genes. Moreover, 16.5%, a noticeable fraction of the core metabolism genes of P. aeruginosa strain PA14 (compared to 8.5% of the non-metabolic genes tested), appear necessary for full virulence when mutated. Most of these virulence-defective core metabolism mutants are compromised in at least one key virulence mechanism independently of auxotrophy. A pathway level analysis of PA14 core metabolism, uncovers beta-oxidation and the biosynthesis of amino-acids, succinate, citramalate, and chorismate to be important for full virulence. Strikingly, the relative expression among P. aeruginosa strains of genes belonging in these metabolic pathways is indicative of their pathogenicity. Thus, P. aeruginosa strain-to-strain virulence variation, remains largely obscure at the genome level, but can be dissected at the pathway level via functional transcriptomics of core metabolism.
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Affiliation(s)
- Stavria Panayidou
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Kaliopi Georgiades
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.,Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Theodoulakis Christofi
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Stella Tamana
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus
| | - Vasilis J Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
| | - Yiorgos Apidianakis
- Infection and Cancer Laboratory, Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
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29
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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30
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Cui J, Hu J, Du X, Yan C, Xue G, Li S, Cui Z, Huang H, Yuan J. Genomic Analysis of Putative Virulence Factors Affecting Cytotoxicity of Cronobacter. Front Microbiol 2020; 10:3104. [PMID: 32117082 PMCID: PMC7019382 DOI: 10.3389/fmicb.2019.03104] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 12/23/2019] [Indexed: 01/07/2023] Open
Abstract
Cronobacter spp. can cause systemic infections, such as meningitis, sepsis, and necrotizing enterocolitis, in immunocompromised patients, especially neonates. Although some virulence factors have been reported previously, the pathogenesis of Cronobacter remains unclear. In this study, we compared genome sequences from different Cronobacter species, sequence types, and sources, with the virulence genes in the virulence factor database. The results showed that Cronobacter has species specificity for these virulence genes. Additionally, two gene clusters, including sfp encoding fimbriae and hly encoding hemolysin, were discovered. Through cell adhesion, cytotoxicity, and hemolysis assays, we found that the isolates possessing the two gene clusters had higher cytotoxicity and stronger hemolysis capacity than those of other isolates in this study. Moreover, analysis of type VI secretion system (T6SS) cluster and putative fimbria gene clusters of Cronobacter revealed that T6SS have species specificity and isolates with high cytotoxicity possessed more complete T6SS cluster construction than that of the rest. In conclusion, the two novel gene clusters and T6SS cluster were involved in the mechanism underlying the cytotoxicity of Cronobacter.
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Affiliation(s)
- Jinghua Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China.,State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jinrui Hu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xiaoli Du
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Chao Yan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Guanhua Xue
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Shaoli Li
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Zhigang Cui
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hua Huang
- Beijing Products Quality Supervision and Inspection Institute, Beijing, China
| | - Jing Yuan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
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Sameni N, Shahbeik M, Dabiri H. Investigating the Presence of Type IV Pilin Subgenus in Pseudomonas Aeruginosa Isolated from Clinical and Non-Clinical Samples. IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY 2019. [DOI: 10.30699/ijmm.13.3.164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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32
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Wei X, Ran D, Campeau A, Xiao C, Zhou J, Dehaini D, Jiang Y, Kroll AV, Zhang Q, Gao W, Gonzalez DJ, Fang RH, Zhang L. Multiantigenic Nanotoxoids for Antivirulence Vaccination against Antibiotic-Resistant Gram-Negative Bacteria. NANO LETTERS 2019. [PMID: 31184899 DOI: 10.1021/acs.nanolett.9b0184410.1021/acs.nanolett.9b01844.s001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Infections caused by multidrug-resistant Gram-negative bacteria have emerged as a major threat to public health worldwide. The high mortality and prevalence, along with the slow pace of new antibiotic discovery, highlight the necessity for new disease management paradigms. Here, we report on the development of a multiantigenic nanotoxoid vaccine based on macrophage membrane-coated nanoparticles for eliciting potent immunity against pathogenic Pseudomonas aeruginosa. The design of this biomimetic nanovaccine leverages the specific role of macrophages in clearing pathogens and their natural affinity for various virulence factors secreted by the bacteria. It is demonstrated that the macrophage nanotoxoid is able to display a wide range of P. aeruginosa antigens, and the safety of the formulation is confirmed both in vitro and in vivo. When used to vaccinate mice via different administration routes, the nanotoxoid is capable of eliciting strong humoral immune responses that translate into enhanced protection against live bacterial infection in a pneumonia model. Overall, the work presented here provides new insights into the design of safe, multiantigenic antivirulence vaccines using biomimetic nanotechnology and the application of these nanovaccines toward the prevention of difficult-to-treat Gram-negative infections.
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Affiliation(s)
- Xiaoli Wei
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Danni Ran
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Anaamika Campeau
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Crystal Xiao
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Jiarong Zhou
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Diana Dehaini
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Yao Jiang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Ashley V Kroll
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Qiangzhe Zhang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Weiwei Gao
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - David J Gonzalez
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences , University of California San Diego , La Jolla , California 92093 , United States
| | - Ronnie H Fang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
| | - Liangfang Zhang
- Department of NanoEngineering and Chemical Engineering Program , University of California San Diego , La Jolla , California 92093 , United States
- Moores Cancer Center , University of California San Diego , La Jolla , California 92093 , United States
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Wei X, Ran D, Campeau A, Xiao C, Zhou J, Dehaini D, Jiang Y, Kroll AV, Zhang Q, Gao W, Gonzalez DJ, Fang RH, Zhang L. Multiantigenic Nanotoxoids for Antivirulence Vaccination against Antibiotic-Resistant Gram-Negative Bacteria. NANO LETTERS 2019; 19:4760-4769. [PMID: 31184899 PMCID: PMC6711367 DOI: 10.1021/acs.nanolett.9b01844] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Infections caused by multidrug-resistant Gram-negative bacteria have emerged as a major threat to public health worldwide. The high mortality and prevalence, along with the slow pace of new antibiotic discovery, highlight the necessity for new disease management paradigms. Here, we report on the development of a multiantigenic nanotoxoid vaccine based on macrophage membrane-coated nanoparticles for eliciting potent immunity against pathogenic Pseudomonas aeruginosa. The design of this biomimetic nanovaccine leverages the specific role of macrophages in clearing pathogens and their natural affinity for various virulence factors secreted by the bacteria. It is demonstrated that the macrophage nanotoxoid is able to display a wide range of P. aeruginosa antigens, and the safety of the formulation is confirmed both in vitro and in vivo. When used to vaccinate mice via different administration routes, the nanotoxoid is capable of eliciting strong humoral immune responses that translate into enhanced protection against live bacterial infection in a pneumonia model. Overall, the work presented here provides new insights into the design of safe, multiantigenic antivirulence vaccines using biomimetic nanotechnology and the application of these nanovaccines toward the prevention of difficult-to-treat Gram-negative infections.
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Affiliation(s)
- Xiaoli Wei
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Danni Ran
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Anaamika Campeau
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Crystal Xiao
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Jiarong Zhou
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Diana Dehaini
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Yao Jiang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Ashley V. Kroll
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Qiangzhe Zhang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Weiwei Gao
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - David J. Gonzalez
- Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA 92093
| | - Ronnie H. Fang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Liangfang Zhang
- Department of NanoEngineering and Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
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Sentausa E, Basso P, Berry A, Adrait A, Bellement G, Couté Y, Lory S, Elsen S, Attrée I. Insertion sequences drive the emergence of a highly adapted human pathogen. Microb Genom 2019; 6. [PMID: 30946644 PMCID: PMC7643977 DOI: 10.1099/mgen.0.000265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pseudomonas aeruginosa is a highly adaptive opportunistic pathogen that can have serious health consequences in patients with lung disorders. Taxonomic outliers of P. aeruginosa of environmental origin have recently emerged as infectious for humans. Here, we present the first genome-wide analysis of an isolate that caused fatal haemorrhagic pneumonia. In two clones, CLJ1 and CLJ3, sequentially recovered from a patient with chronic pulmonary disease, insertion of a mobile genetic element into the P. aeruginosa chromosome affected major virulence-associated phenotypes and led to increased resistance to the antibiotics used to combat the infection. Comparative genome, proteome and transcriptome analyses revealed that this ISL3-family insertion sequence disrupted the genes for flagellar components, type IV pili, O-specific antigens, translesion polymerase and enzymes producing hydrogen cyanide. Seven-fold more insertions were detected in the later isolate, CLJ3, than in CLJ1, some of which modified strain susceptibility to antibiotics by disrupting the genes for the outer-membrane porin OprD and the regulator of β-lactamase expression AmpD. In the Galleria mellonella larvae model, the two strains displayed different levels of virulence, with CLJ1 being highly pathogenic. This study revealed insertion sequences to be major players in enhancing the pathogenic potential of a P. aeruginosa taxonomic outlier by modulating both its virulence and its resistance to antimicrobials, and explains how this bacterium adapts from the environment to a human host.
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Affiliation(s)
- Erwin Sentausa
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France.,Present address: Evotec ID (Lyon) SAS, Marcy l'Étoile, France
| | - Pauline Basso
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France.,Present address: Department of Microbiology and Immunology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Alice Berry
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France
| | - Annie Adrait
- Université Grenoble Alpes, CEA, Inserm, BIG-BGE, 38000 Grenoble, France
| | - Gwendoline Bellement
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France.,Université Grenoble Alpes, CEA, Inserm, BIG-BGE, 38000 Grenoble, France.,Present address: Biozentrum, University of Basel, Basel, Switzerland
| | - Yohann Couté
- Université Grenoble Alpes, CEA, Inserm, BIG-BGE, 38000 Grenoble, France
| | - Stephen Lory
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - Sylvie Elsen
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France
| | - Ina Attrée
- Université Grenoble Alpes, CNRS ERL5261, INSERM U1036, CEA, Laboratory Biology of Cancer and Infection, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, 38000 Grenoble, France
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Platelets inhibit apoptotic lung epithelial cell death and protect mice against infection-induced lung injury. Blood Adv 2019; 3:432-445. [PMID: 30733303 PMCID: PMC6373758 DOI: 10.1182/bloodadvances.2018026286] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 01/09/2019] [Indexed: 12/17/2022] Open
Abstract
Thrombocytopenia is associated with worse outcomes in patients with acute respiratory distress syndrome, which is most commonly caused by infection and marked by alveolar-capillary barrier disruption. However, the mechanisms by which platelets protect the lung alveolar-capillary barrier during infectious injury remain unclear. We found that natively thrombocytopenic Mpl -/- mice deficient in the thrombopoietin receptor sustain severe lung injury marked by alveolar barrier disruption and hemorrhagic pneumonia with early mortality following acute intrapulmonary Pseudomonas aeruginosa (PA) infection; barrier disruption was attenuated by platelet reconstitution. Although PA infection was associated with a brisk neutrophil influx, depletion of airspace neutrophils failed to substantially mitigate PA-triggered alveolar barrier disruption in Mpl -/- mice. Rather, PA cell-free supernatant was sufficient to induce lung epithelial cell apoptosis in vitro and in vivo and alveolar barrier disruption in both platelet-depleted mice and Mpl -/- mice in vivo. Cell-free supernatant from PA with genetic deletion of the type 2 secretion system, but not the type 3 secretion system, mitigated lung epithelial cell death in vitro and lung injury in Mpl -/- mice. Moreover, platelet releasates reduced poly (ADP ribose) polymerase cleavage and lung injury in Mpl -/- mice, and boiling of platelet releasates, but not apyrase treatment, abrogated PA supernatant-induced lung epithelial cell cytotoxicity in vitro. These findings indicate that while neutrophil airspace influx does not potentiate infectious lung injury in the thrombocytopenic host, platelets and their factors protect against severe pulmonary complications from pathogen-secreted virulence factors that promote host cell death even in the absence of overt infection.
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Sood U, Hira P, Kumar R, Bajaj A, Rao DLN, Lal R, Shakarad M. Comparative Genomic Analyses Reveal Core-Genome-Wide Genes Under Positive Selection and Major Regulatory Hubs in Outlier Strains of Pseudomonas aeruginosa. Front Microbiol 2019; 10:53. [PMID: 30787911 PMCID: PMC6372532 DOI: 10.3389/fmicb.2019.00053] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/14/2019] [Indexed: 12/11/2022] Open
Abstract
Genomic information for outlier strains of Pseudomonas aeruginosa is exiguous when compared with classical strains. We sequenced and constructed the complete genome of an environmental strain CR1 of P. aeruginosa and performed the comparative genomic analysis. It clustered with the outlier group, hence we scaled up the analyses to understand the differences in environmental and clinical outlier strains. We identified eight new regions of genomic plasticity and a plasmid pCR1 with a VirB/D4 complex followed by trimeric auto-transporter that can induce virulence phenotype in the genome of strain CR1. Virulence genotype analysis revealed that strain CR1 lacked hemolytic phospholipase C and D, three genes for LPS biosynthesis and had reduced antibiotic resistance genes when compared with clinical strains. Genes belonging to proteases, bacterial exporters and DNA stabilization were found to be under strong positive selection, thus facilitating pathogenicity and survival of the outliers. The outliers had the complete operon for the production of vibrioferrin, a siderophore present in plant growth promoting bacteria. The competence to acquire multidrug resistance and new virulence factors makes these strains a potential threat. However, we identified major regulatory hubs that can be used as drug targets against both the classical and outlier groups.
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Affiliation(s)
- Utkarsh Sood
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
| | - Princy Hira
- Department of Zoology, University of Delhi, New Delhi, India
| | - Roshan Kumar
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
- Department of Veterinary & Biomedical Sciences, South Dakota State University, Brookings, SD, United States
| | - Abhay Bajaj
- Department of Zoology, University of Delhi, New Delhi, India
- National Centre for Microbial Resource, National Centre for Cell Science, Pune, India
| | | | - Rup Lal
- Department of Zoology, University of Delhi, New Delhi, India
- PhiXGen Private Limited, Gurugram, India
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Ghosh C, Sarkar P, Issa R, Haldar J. Alternatives to Conventional Antibiotics in the Era of Antimicrobial Resistance. Trends Microbiol 2019; 27:323-338. [PMID: 30683453 DOI: 10.1016/j.tim.2018.12.010] [Citation(s) in RCA: 345] [Impact Index Per Article: 69.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 11/30/2018] [Accepted: 12/19/2018] [Indexed: 02/07/2023]
Abstract
As more antibiotics are rendered ineffective by drug-resistant bacteria, focus must be shifted towards alternative therapies for treating infections. Although several alternatives already exist in nature, the challenge is to implement them in clinical use. Advancements within biotechnology, genetic engineering, and synthetic chemistry have opened up new avenues towards the search for therapies that can substitute for antibiotics. This review provides an introduction to the various promising approaches that have been adopted in this regard. Whilst the use of bacteriophages and antibodies has been partly implemented, other promising strategies, such as probiotics, lysins, and antimicrobial peptides, are in various stages of development. Propitious concepts such as genetically modified phages, antibacterial oligonucleotides, and CRISPR-Cas9 are also discussed.
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Affiliation(s)
- Chandradhish Ghosh
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Paramita Sarkar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India
| | - Rahaf Issa
- Department of Infection, Immunity and Cardiovascular Diseases, The University of Sheffield, Sheffield, UK
| | - Jayanta Haldar
- Antimicrobial Research Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru 560064, India.
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Laventie BJ, Sangermani M, Estermann F, Manfredi P, Planes R, Hug I, Jaeger T, Meunier E, Broz P, Jenal U. A Surface-Induced Asymmetric Program Promotes Tissue Colonization by Pseudomonas aeruginosa. Cell Host Microbe 2018; 25:140-152.e6. [PMID: 30581112 DOI: 10.1016/j.chom.2018.11.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 09/28/2018] [Accepted: 10/22/2018] [Indexed: 12/24/2022]
Abstract
The opportunistic human pathogen Pseudomonas aeruginosa effectively colonizes host epithelia using pili as primary adhesins. Here we uncover a surface-specific asymmetric virulence program that enhances P. aeruginosa host colonization. We show that when P. aeruginosa encounters surfaces, the concentration of the second messenger c-di-GMP increases within a few seconds. This leads to surface adherence and virulence induction by stimulating pili assembly through activation of the c-di-GMP receptor FimW. Surface-attached bacteria divide asymmetrically to generate a piliated, surface-committed progeny (striker) and a flagellated, motile offspring that leaves the surface to colonize distant sites (spreader). Cell differentiation is driven by a phosphodiesterase that asymmetrically positions to the flagellated pole, thereby maintaining c-di-GMP levels low in the motile offspring. Infection experiments demonstrate that cellular asymmetry strongly boosts infection spread and tissue damage. Thus, P. aeruginosa promotes surface colonization and infection transmission through a cooperative virulence program that we termed Touch-Seed-and-Go.
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Affiliation(s)
| | - Matteo Sangermani
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Fabienne Estermann
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Pablo Manfredi
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | | | - Isabelle Hug
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Tina Jaeger
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | | | - Petr Broz
- Department of Biochemistry, University of Lausanne, Lausanne, Switzerland
| | - Urs Jenal
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland.
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Lang C, Fruth A, Holland G, Laue M, Mühlen S, Dersch P, Flieger A. Novel type of pilus associated with a Shiga-toxigenic E. coli hybrid pathovar conveys aggregative adherence and bacterial virulence. Emerg Microbes Infect 2018; 7:203. [PMID: 30514915 PMCID: PMC6279748 DOI: 10.1038/s41426-018-0209-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 11/09/2018] [Accepted: 11/11/2018] [Indexed: 01/31/2023]
Abstract
A large German outbreak in 2011 was caused by a locus of enterocyte effacement (LEE)-negative enterohemorrhagic E. coli (EHEC) strain of the serotype O104:H4. This strain harbors markers that are characteristic of both EHEC and enteroaggregative E. coli (EAEC), including aggregative adhesion fimbriae (AAF) genes. Such rare EHEC/EAEC hybrids are highly pathogenic due to their possession of a combination of genes promoting severe toxicity and aggregative adhesion. We previously identified novel EHEC/EAEC hybrids and observed that one strain exhibited aggregative adherence but had no AAF genes. In this study, a genome sequence analysis showed that this strain belongs to the genoserotype O23:H8, MLST ST26, and harbors a 5.2 Mb chromosome and three plasmids. One plasmid carries some EAEC marker genes, such as aatA and genes with limited protein homology (11–61%) to those encoding the bundle-forming pilus (BFP) of enteropathogenic E. coli. Due to significant protein homology distance to known pili, we designated these as aggregate-forming pili (AFP)-encoding genes and the respective plasmid as pAFP. The afp operon was arranged similarly to the operon of BFP genes but contained an additional gene, afpA2, which is homologous to afpA. The deletion of the afp operon, afpA, or a nearby gene (afpR) encoding an AraC-like regulator, but not afpA2, led to a loss of pilin production, piliation, bacterial autoaggregation, and importantly, a >80% reduction in adhesion and cytotoxicity toward epithelial cells. Gene sets similar to the afp operon were identified in a variety of aatA-positive but AAF-negative intestinal pathogenic E. coli. In summary, we characterized widely distributed and novel fimbriae that are essential for aggregative adherence and cytotoxicity in a LEE-negative Shiga-toxigenic hybrid.
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Affiliation(s)
- Christina Lang
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institut, Wernigerode, Saxony-Anhalt, 38855, Germany
| | - Angelika Fruth
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institut, Wernigerode, Saxony-Anhalt, 38855, Germany
| | - Gudrun Holland
- Division of Advanced Light and Electron Microscopy, Robert Koch Institut, Berlin, 13353, Germany
| | - Michael Laue
- Division of Advanced Light and Electron Microscopy, Robert Koch Institut, Berlin, 13353, Germany
| | - Sabrina Mühlen
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Lower Saxony, 38124, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Lower Saxony, 38124, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch Institut, Wernigerode, Saxony-Anhalt, 38855, Germany.
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40
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cAMP and Vfr Control Exolysin Expression and Cytotoxicity of Pseudomonas aeruginosa Taxonomic Outliers. J Bacteriol 2018; 200:JB.00135-18. [PMID: 29632090 DOI: 10.1128/jb.00135-18] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/04/2018] [Indexed: 12/22/2022] Open
Abstract
The two-partner secretion system ExlBA, expressed by strains of Pseudomonas aeruginosa belonging to the PA7 group, induces hemorrhage in lungs due to disruption of host cellular membranes. Here we demonstrate that the exlBA genes are controlled by a pathway consisting of cAMP and the virulence factor regulator (Vfr). Upon interaction with cAMP, Vfr binds directly to the exlBA promoter with high affinity (equilibrium binding constant [Keq] of ≈2.5 nM). The exlB and exlA expression was diminished in the Vfr-negative mutant and upregulated with increased intracellular cAMP levels. The Vfr binding sequence in the exlBA promoter was mutated in situ, resulting in reduced cytotoxicity of the mutant, showing that Vfr is required for the exlBA expression during intoxication of epithelial cells. Vfr also regulates function of type 4 pili previously shown to facilitate ExlA activity on epithelial cells, which indicates that the cAMP/Vfr pathway coordinates these two factors needed for full cytotoxicity. As in most P. aeruginosa strains, the adenylate cyclase CyaB is the main provider of cAMP for Vfr regulation during both in vitro growth and eukaryotic cell infection. We discovered that the absence of functional Vfr in the reference strain PA7 is caused by a frameshift in the gene and accounts for its reduced cytotoxicity, revealing the conservation of ExlBA control by the CyaB-cAMP/Vfr pathway in P. aeruginosa taxonomic outliers.IMPORTANCE The human opportunistic pathogen Pseudomonas aeruginosa provokes severe acute and chronic human infections associated with defined sets of virulence factors. The main virulence determinant of P. aeruginosa taxonomic outliers is exolysin, a membrane-disrupting pore-forming toxin belonging to the two-partner secretion system ExlBA. In this work, we demonstrate that the conserved CyaB-cAMP/Vfr pathway controls cytotoxicity of outlier clinical strains through direct transcriptional activation of the exlBA operon. Therefore, despite the fact that the type III secretion system and exolysin are mutually exclusive in classical and outlier strains, respectively, these two major virulence determinants share similarities in their mechanisms of regulation.
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41
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Golovkine G, Reboud E, Huber P. Pseudomonas aeruginosa Takes a Multi-Target Approach to Achieve Junction Breach. Front Cell Infect Microbiol 2018; 7:532. [PMID: 29379773 PMCID: PMC5770805 DOI: 10.3389/fcimb.2017.00532] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/20/2017] [Indexed: 01/17/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen which uses a number of strategies to cross epithelial and endothelial barriers at cell–cell junctions. In this review, we describe how the coordinated actions of P. aeruginosa's virulence factors trigger various molecular mechanisms to disarm the junctional gate responsible for tissue integrity.
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Affiliation(s)
- Guillaume Golovkine
- Centre National de la Recherche Scientifique ERL5261, CEA BIG-BCI, Institut National de la Santé et de la Recherche Médicale UMR1036, Université Grenoble Alpes, Grenoble, France
| | - Emeline Reboud
- Centre National de la Recherche Scientifique ERL5261, CEA BIG-BCI, Institut National de la Santé et de la Recherche Médicale UMR1036, Université Grenoble Alpes, Grenoble, France
| | - Philippe Huber
- Centre National de la Recherche Scientifique ERL5261, CEA BIG-BCI, Institut National de la Santé et de la Recherche Médicale UMR1036, Université Grenoble Alpes, Grenoble, France
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Wallez Y, Bouillot S, Soleilhac E, Huber P, Attrée I, Faudry E. CLIQ-BID: A method to quantify bacteria-induced damage to eukaryotic cells by automated live-imaging of bright nuclei. Sci Rep 2018; 8:5. [PMID: 29311668 PMCID: PMC5758606 DOI: 10.1038/s41598-017-18501-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 12/07/2017] [Indexed: 11/09/2022] Open
Abstract
Pathogenic bacteria induce eukaryotic cell damage which range from discrete modifications of signalling pathways, to morphological alterations and even to cell death. Accurate quantitative detection of these events is necessary for studying host-pathogen interactions and for developing strategies to protect host organisms from bacterial infections. Investigation of morphological changes is cumbersome and not adapted to high-throughput and kinetics measurements. Here, we describe a simple and cost-effective method based on automated analysis of live cells with stained nuclei, which allows real-time quantification of bacteria-induced eukaryotic cell damage at single-cell resolution. We demonstrate that this automated high-throughput microscopy approach permits screening of libraries composed of interference-RNA, bacterial strains, antibodies and chemical compounds in ex vivo infection settings. The use of fluorescently-labelled bacteria enables the concomitant detection of changes in bacterial growth. Using this method named CLIQ-BID (Cell Live Imaging Quantification of Bacteria Induced Damage), we were able to distinguish the virulence profiles of different pathogenic bacterial species and clinical strains.
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Affiliation(s)
- Yann Wallez
- UGA, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France
| | - Stéphanie Bouillot
- UGA, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France
| | - Emmanuelle Soleilhac
- UGA, CEA, INSERM; Genetics & Chemogenomics, CMBA Platform, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France
| | - Philippe Huber
- UGA, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France
| | - Ina Attrée
- UGA, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France
| | - Eric Faudry
- UGA, CEA, INSERM, CNRS, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, Grenoble, France.
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Reboud E, Basso P, Maillard AP, Huber P, Attrée I. Exolysin Shapes the Virulence of Pseudomonas aeruginosa Clonal Outliers. Toxins (Basel) 2017; 9:toxins9110364. [PMID: 29120408 PMCID: PMC5705979 DOI: 10.3390/toxins9110364] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 10/30/2017] [Accepted: 11/02/2017] [Indexed: 12/12/2022] Open
Abstract
Bacterial toxins are important weapons of toxicogenic pathogens. Depending on their origin, structure and targets, they show diverse mechanisms of action and effects on eukaryotic cells. Exolysin is a secreted 170 kDa pore-forming toxin employed by clonal outliers of Pseudomonas aeruginosa providing to some strains a hyper-virulent behaviour. This group of strains lacks the major virulence factor used by classical strains, the Type III secretion system. Here, we review the structural features of the toxin, the mechanism of its secretion and the effects of the pore formation on eukaryotic cells.
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Affiliation(s)
- Emeline Reboud
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, 17 rue des Martyrs, CEA-Grenoble, 38054 Grenoble, France.
| | - Pauline Basso
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, 17 rue des Martyrs, CEA-Grenoble, 38054 Grenoble, France.
| | - Antoine P Maillard
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, 17 rue des Martyrs, CEA-Grenoble, 38054 Grenoble, France.
| | - Philippe Huber
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, 17 rue des Martyrs, CEA-Grenoble, 38054 Grenoble, France.
| | - Ina Attrée
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, 17 rue des Martyrs, CEA-Grenoble, 38054 Grenoble, France.
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Dopp E, Richard J, Dwidjosiswojo Z, Simon A, Wingender J. Influence of the copper-induced viable but non-culturable state on the toxicity of Pseudomonas aeruginosa towards human bronchial epithelial cells in vitro. Int J Hyg Environ Health 2017; 220:1363-1369. [PMID: 28941772 DOI: 10.1016/j.ijheh.2017.09.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 08/29/2017] [Accepted: 09/14/2017] [Indexed: 11/30/2022]
Abstract
The viable but non-culturable (VBNC) state of the opportunistic bacterium Pseudomonas aeruginosa was previously shown to be induced by copper ions in concentrations relevant to those in drinking water plumbing systems. This decrease of bacterial culturability without loss of viability might have an influence on human health due to an underestimation of the actual contamination in drinking water systems. The aim of this study was to investigate the influence of culturable P. aeruginosa, viable but not culturable as well as culturable again after resuscitation from the VBNC state on human bronchial epithelial cells (BEAS-2B) in vitro. Cyto- and genotoxic effects of P. aeruginosa at different states were studied using trypan blue, MTT, xCELLigence as well as the micronucleus assay. While P. aeruginosa in the VBNC state did not have any cytotoxic or genotoxic effect on BEAS-2B cells, untreated (culturable) and resuscitated P. aeruginosa did show cell damage, including disruption of cell membranes, inhibition of mitochondrial activity and cell proliferation as well as DNA-damaging effects. We conclude from our study that P. aeruginosa after resuscitation from the VBNC state regains its viability and cyto-/genotoxicity and therefore might influence human health.
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Affiliation(s)
- Elke Dopp
- IWW Water Center, Mülheim an der Ruhr, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany.
| | - Jessica Richard
- Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | | | - Anne Simon
- IWW Water Center, Mülheim an der Ruhr, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany
| | - Jost Wingender
- IWW Water Center, Mülheim an der Ruhr, Germany; Centre for Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany; Biofilm Centre, University of Duisburg-Essen, Essen, Germany
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Reboud E, Bouillot S, Patot S, Béganton B, Attrée I, Huber P. Pseudomonas aeruginosa ExlA and Serratia marcescens ShlA trigger cadherin cleavage by promoting calcium influx and ADAM10 activation. PLoS Pathog 2017; 13:e1006579. [PMID: 28832671 PMCID: PMC5584975 DOI: 10.1371/journal.ppat.1006579] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/05/2017] [Accepted: 08/12/2017] [Indexed: 12/20/2022] Open
Abstract
Pore-forming toxins are potent virulence factors secreted by a large array of bacteria. Here, we deciphered the action of ExlA from Pseudomonas aeruginosa and ShlA from Serratia marcescens on host cell-cell junctions. ExlA and ShlA are two members of a unique family of pore-forming toxins secreted by a two-component secretion system. Bacteria secreting either toxin induced an ExlA- or ShlA-dependent rapid cleavage of E-cadherin and VE-cadherin in epithelial and endothelial cells, respectively. Cadherin proteolysis was executed by ADAM10, a host cell transmembrane metalloprotease. ADAM10 activation is controlled in the host cell by cytosolic Ca2+ concentration. We show that Ca2+ influx, induced by ExlA or ShlA pore formation in the plasma membrane, triggered ADAM10 activation, thereby leading to cadherin cleavage. Our data suggest that ADAM10 is not a cellular receptor for ExlA and ShlA, further confirming that ADAM10 activation occurred via Ca2+ signalling. In conclusion, ExlA- and ShlA-secreting bacteria subvert a regulation mechanism of ADAM10 to activate cadherin shedding, inducing intercellular junction rupture, cell rounding and loss of tissue barrier integrity. Pore-forming toxins are the most widespread toxins delivered by pathogenic bacteria and are required for full virulence. Pore-forming toxins perforate membranes of host cells for intracellular delivery of bacterial factors, for bacterial escape from phagosomes or in order to kill cells. Loss of membrane integrity, especially the plasma membrane, has broad implications on cell and tissue physiology. Here, we show that two members of a unique family of pore-forming toxins, secreted by Pseudomonas aeruginosa and Serratia marcescens, have the capacity to disrupt cell-cell junctions of epithelial and endothelial cells, hence breaching two major tissue barriers.
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Affiliation(s)
- Emeline Reboud
- Université Grenoble Alpes, CNRS ERL5261, CEA BIG-BCI, INSERM UMR1036, Grenoble, France
| | - Stéphanie Bouillot
- Université Grenoble Alpes, CNRS ERL5261, CEA BIG-BCI, INSERM UMR1036, Grenoble, France
| | - Sabine Patot
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon 1, Ecole Normale Supérieure de Lyon, CNRS UMR 5308, Lyon, France
| | - Benoît Béganton
- Université Grenoble Alpes, CNRS ERL5261, CEA BIG-BCI, INSERM UMR1036, Grenoble, France
| | - Ina Attrée
- Université Grenoble Alpes, CNRS ERL5261, CEA BIG-BCI, INSERM UMR1036, Grenoble, France
| | - Philippe Huber
- Université Grenoble Alpes, CNRS ERL5261, CEA BIG-BCI, INSERM UMR1036, Grenoble, France
- * E-mail:
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Basso P, Wallet P, Elsen S, Soleilhac E, Henry T, Faudry E, Attrée I. Multiple Pseudomonas species secrete exolysin-like toxins and provoke Caspase-1-dependent macrophage death. Environ Microbiol 2017; 19:4045-4064. [PMID: 28654176 DOI: 10.1111/1462-2920.13841] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/02/2017] [Accepted: 06/19/2017] [Indexed: 12/19/2022]
Abstract
Pathogenic bacteria secrete protein toxins that provoke apoptosis or necrosis of eukaryotic cells. Here, we developed a live-imaging method, based on incorporation of a DNA-intercalating dye into membrane-damaged host cells, to study the kinetics of primary bone marrow-derived macrophages (BMDMs) mortality induced by opportunistic pathogen Pseudomonas aeruginosa expressing either Type III Secretion System (T3SS) toxins or the pore-forming toxin, Exolysin (ExlA). We found that ExlA promotes the activation of Caspase-1 and maturation of interleukin-1β. BMDMs deficient for Caspase-1 and Caspase-11 were resistant to ExlA-induced death. Furthermore, by using KO BMDMs, we determined that the upstream NLRP3/ASC complex leads to the Caspase-1 activation. We also demonstrated that Pseudomonas putida and Pseudomonas protegens and the Drosophila pathogen Pseudomonas entomophila, which naturally express ExlA-like toxins, are cytotoxic toward macrophages and provoke the same type of pro-inflammatory death as does ExlA+ P. aeruginosa. These results demonstrate that ExlA-like toxins of two-partner secretion systems from diverse Pseudomonas species activate the NLRP3 inflammasome and provoke inflammatory pyroptotic death of macrophages.
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Affiliation(s)
- Pauline Basso
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, France
| | - Pierre Wallet
- CIRI, Centre International de Recherche en Infectiologie, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Normale Supérieure de Lyon, Univ Lyon, Lyon, F-69007, France
| | - Sylvie Elsen
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, France
| | - Emmanuelle Soleilhac
- CMBA Platform, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, CEA, INSERM; Genetics & Chemogenomics, France
| | - Thomas Henry
- CIRI, Centre International de Recherche en Infectiologie, INSERM, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Normale Supérieure de Lyon, Univ Lyon, Lyon, F-69007, France
| | - Eric Faudry
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, France
| | - Ina Attrée
- CNRS-ERL5261, INSERM, U1036, CEA, Bacterial Pathogenesis and Cellular Responses, Biosciences and Biotechnology Institute of Grenoble, University Grenoble Alpes, France
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Guérin J, Bigot S, Schneider R, Buchanan SK, Jacob-Dubuisson F. Two-Partner Secretion: Combining Efficiency and Simplicity in the Secretion of Large Proteins for Bacteria-Host and Bacteria-Bacteria Interactions. Front Cell Infect Microbiol 2017; 7:148. [PMID: 28536673 PMCID: PMC5422565 DOI: 10.3389/fcimb.2017.00148] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/10/2017] [Indexed: 12/31/2022] Open
Abstract
Initially identified in pathogenic Gram-negative bacteria, the two-partner secretion (TPS) pathway, also known as Type Vb secretion, mediates the translocation across the outer membrane of large effector proteins involved in interactions between these pathogens and their hosts. More recently, distinct TPS systems have been shown to secrete toxic effector domains that participate in inter-bacterial competition or cooperation. The effects of these systems are based on kin vs. non-kin molecular recognition mediated by specific immunity proteins. With these new toxin-antitoxin systems, the range of TPS effector functions has thus been extended from cytolysis, adhesion, and iron acquisition, to genome maintenance, inter-bacterial killing and inter-bacterial signaling. Basically, a TPS system is made up of two proteins, the secreted TpsA effector protein and its TpsB partner transporter, with possible additional factors such as immunity proteins for protection against cognate toxic effectors. Structural studies have indicated that TpsA proteins mainly form elongated β helices that may be followed by specific functional domains. TpsB proteins belong to the Omp85 superfamily. Open questions remain on the mechanism of protein secretion in the absence of ATP or an electrochemical gradient across the outer membrane. The remarkable dynamics of the TpsB transporters and the progressive folding of their TpsA partners at the bacterial surface in the course of translocation are thought to be key elements driving the secretion process.
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Affiliation(s)
- Jeremy Guérin
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, USA
| | - Sarah Bigot
- Molecular Microbiology and Structural Biochemistry, Centre National de La Recherche Scientifique UMR 5086-Université Lyon 1, Institute of Biology and Chemistry of ProteinsLyon, France
| | - Robert Schneider
- NMR and Molecular Interactions, Université de Lille, Centre National de La Recherche Scientifique, UMR 8576-Unité de Glycobiologie Structurale et FonctionnelleLille, France
| | - Susan K Buchanan
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesda, MD, USA
| | - Françoise Jacob-Dubuisson
- Université de Lille, Centre National de La Recherche Scientifique, Institut National de La Santé et de La Recherche Médicale, CHU Lille, Institut Pasteur de Lille, U1019-UMR 8204-Centre d'Infection et d'Immunité de LilleLille, France
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