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Charkhian H, Soleimannezhadbari E, Bodaqlouei A, Lotfollahi L, Lotfi H, Yousefi N, Shojadel E, Gholinejad Z. Assessment of bacteriocin production by clinical Pseudomonas aeruginosa isolates and their potential as therapeutic agents. Microb Cell Fact 2024; 23:175. [PMID: 38872163 PMCID: PMC11170890 DOI: 10.1186/s12934-024-02450-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 06/04/2024] [Indexed: 06/15/2024] Open
Abstract
INTRODUCTION Bacterial infections and the rising antimicrobial resistance pose a significant threat to public health. Pseudomonas aeruginosa produces bacteriocins like pyocins, especially S-type pyocins, which are promising for biological applications. This research focuses on clinical P. aeruginosa isolates to assess their bacteriocin production, inhibitory spectrum, chemical structure, antibacterial agents, and preservative potential. METHODS The identification of P. aeruginosa was conducted through both phenotypic and molecular approaches. The inhibitory spectrum and antibacterial potential of the isolates were assessed. The kinetics of antibacterial peptide production were investigated, and the activity of bacteriocin was quantified in arbitrary units (AU ml-1). Physico-chemical characterization of the antibacterial peptides was performed. Molecular weight estimation was carried out using SDS-PAGE. qRT-PCR analysis was employed to validate the expression of the selected candidate gene. RESULT The antibacterial activity of P. aeruginosa was attributed to the secretion of bacteriocin compounds, which belong to the S-type pyocin family. The use of mitomycin C led to a significant 65.74% increase in pyocin production by these isolates. These S-type pyocins exhibited the ability to inhibit the growth of both Gram-negative (P. mirabilis and P. vulgaris) and Gram-positive (S. aureus, S. epidermidis, E. hirae, S. pyogenes, and S. mutans) bacteria. The molecular weight of S-type pyocin was 66 kDa, and its gene expression was confirmed through qRT-PCR. CONCLUSION These findings suggest that S-type pyocin hold significant potential as therapeutic agents against pathogenic strains. The Physico-chemical resistance of S-type pyocin underscores its potential for broad applications in the pharmaceutical, hygiene, and food industries.
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Affiliation(s)
- Hamed Charkhian
- Young Researchers Club, Urmia Branch, Islamic Azad University, Urmia, Iran
- Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Ehsan Soleimannezhadbari
- Young Researchers Club, Urmia Branch, Islamic Azad University, Urmia, Iran
- Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Amin Bodaqlouei
- Department of Pharmaceutical and Biomolecular Science, Faculty of Pharmaceutical Science, University of Milan, Milan, Italy
- Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Lida Lotfollahi
- Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
| | - Hajie Lotfi
- Cellular and Molecular Research Center, Research Institute for Prevention of Non-Communicable Disease, Qazvin University of Medical Sciences, Qazvin, Iran
| | - Nesa Yousefi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran
| | - Ehsan Shojadel
- Department of Microbiology and Virology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Zafar Gholinejad
- Department of Medical Laboratory Science, Urmia Branch, Islamic Azad University, Urmia, Iran
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2
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Goult JD, Van DCL, Taylor YV, Inns PG, Kaminska R, Vesely M, Kleanthous C, Paci E. Structural constraints of pyocin S2 import through the ferripyoverdine receptor FpvAI. PNAS NEXUS 2024; 3:pgae124. [PMID: 38577260 PMCID: PMC10994204 DOI: 10.1093/pnasnexus/pgae124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
TonB-dependent transporters (TBDTs) mediate energized transport of essential nutrients into gram-negative bacteria. TBDTs are increasingly being exploited for the delivery of antibiotics to drug-resistant bacteria. While much is known about ground state complexes of TBDTs, few details have emerged about the transport process itself. In this study, we exploit bacteriocin parasitization of a TBDT to probe the mechanics of transport. Previous work has shown that the N-terminal domain of Pseudomonas aeruginosa-specific bacteriocin pyocin S2 (PyoS2NTD) is imported through the pyoverdine receptor FpvAI. PyoS2NTD transport follows the opening of a proton-motive force-dependent pore through FpvAI and the delivery of its own TonB box that engages TonB. We use molecular models and simulations to formulate a complete translocation pathway for PyoS2NTD that we validate using protein engineering and cytotoxicity measurements. We show that following partial removal of the FpvAI plug domain which occludes the channel, the pyocin's N-terminus enters the channel by electrostatic steering and ratchets to the periplasm. Application of force, mimicking that exerted by TonB, leads to unraveling of PyoS2NTD as it squeezes through the channel. Remarkably, while some parts of PyoS2NTD must unfold, complete unfolding is not required for transport, a result we confirmed by disulfide bond engineering. Moreover, the section of the FpvAI plug that remains embedded in the channel appears to serve as a buttress against which PyoS2NTD is pushed to destabilize the domain. Our study reveals the limits of structural deformation that accompanies import through a TBDT and the role the TBDT itself plays in accommodating transport.
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Affiliation(s)
- Jonathan D Goult
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Daniel C L Van
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Yasmin V Taylor
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Patrick G Inns
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Renata Kaminska
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Martin Vesely
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Emanuele Paci
- Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna 40127, Italy
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3
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Zhuang Y, Quirk S, Stover ER, Bureau HR, Allen CR, Hernandez R. Tertiary Plasticity Drives the Efficiency of Enterocin 7B Interactions with Lipid Membranes. J Phys Chem B 2024; 128:2100-2113. [PMID: 38412510 PMCID: PMC10926100 DOI: 10.1021/acs.jpcb.3c08199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
The ability of antimicrobial peptides to efficiently kill their bacterial targets depends on the efficiency of their binding to the microbial membrane. In the case of enterocins, there is a three-part interaction: initial binding, unpacking of helices on the membrane surface, and permeation of the lipid bilayer. Helical unpacking is driven by disruption of the peptide hydrophobic core when in contact with membranes. Enterocin 7B is a leaderless enterocin antimicrobial peptide produced from Enterococcus faecalis that functions alone, or with its cognate partner enterocin 7A, to efficiently kill a wide variety of Gram-stain positive bacteria. To better characterize the role that tertiary structural plasticity plays in the ability of enterocin 7B to interact with the membranes, a series of arginine single-site mutants were constructed that destabilize the hydrophobic core to varying degrees. A series of experimental measures of structure, stability, and function, including CD spectra, far UV CD melting profiles, minimal inhibitory concentrations analysis, and release kinetics of calcein, show that decreased stabilization of the hydrophobic core is correlated with increased efficiency of a peptide to permeate membranes and in killing bacteria. Finally, using the computational technique of adaptive steered molecular dynamics, we found that the atomistic/energetic landscape of peptide mechanical unfolding leads to free energy differences between the wild type and its mutants, whose trends correlate well with our experiment.
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Affiliation(s)
- Yi Zhuang
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Stephen Quirk
- Kimberly-Clark Corporation, Atlanta, Georgia 30076-2199, United States
| | - Erica R Stover
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Hailey R Bureau
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Caley R Allen
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Rigoberto Hernandez
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
- Department of Materials Science & Engineering, Johns Hopkins University, Baltimore, Maryland 21218, United States
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4
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Premsuriya J, Mosbahi K, Atanaskovic I, Kleanthous C, Walker D. Outer membrane translocation of pyocins via the copper regulated TonB-dependent transporter CrtA. Biochem J 2023; 480:1035-1049. [PMID: 37399084 PMCID: PMC10422930 DOI: 10.1042/bcj20220552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 06/28/2023] [Accepted: 07/03/2023] [Indexed: 07/05/2023]
Abstract
Pseudomonas aeruginosa is a common cause of serious hospital-acquired infections, the leading proven cause of mortality in people with cystic fibrosis and is associated with high levels of antimicrobial resistance. Pyocins are narrow-spectrum protein antibiotics produced by P. aeruginosa that kill strains of the same species and have the potential to be developed as therapeutics targeting multi-drug resistant isolates. We have identified two novel pyocins designated SX1 and SX2. Pyocin SX1 is a metal-dependent DNase while pyocin SX2 kills cells through inhibition of protein synthesis. Mapping the uptake pathways of SX1 and SX2 shows these pyocins utilize a combination of the common polysaccharide antigen (CPA) and a previously uncharacterized TonB-dependent transporter (TBDT) PA0434 to traverse the outer membrane. In addition, TonB1 and FtsH are required by both pyocins to energize their transport into cells and catalyze their translocation across the inner membrane, respectively. Expression of PA0434 was found to be specifically regulated by copper availability and we have designated PA0434 as Copper Responsive Transporter A, or CrtA. To our knowledge these are the first S-type pyocins described that utilize a TBDT that is not involved in iron uptake.
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Affiliation(s)
- Jiraphan Premsuriya
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, U.K
- Princess Srisavangavadhana College of Medicine, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Khedidja Mosbahi
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, U.K
| | - Iva Atanaskovic
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K
| | - Daniel Walker
- School of Infection and Immunity, University of Glasgow, Glasgow G12 8TA, U.K
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, U.K
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5
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Chan DCK, Josts I, Koteva K, Wright GD, Tidow H, Burrows LL. Interactions of TonB-dependent transporter FoxA with siderophores and antibiotics that affect binding, uptake, and signal transduction. Proc Natl Acad Sci U S A 2023; 120:e2221253120. [PMID: 37043535 PMCID: PMC10120069 DOI: 10.1073/pnas.2221253120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 03/07/2023] [Indexed: 04/13/2023] Open
Abstract
The outer membrane of gram-negative bacteria prevents many antibiotics from reaching intracellular targets. However, some antimicrobials can take advantage of iron import transporters to cross this barrier. We showed previously that the thiopeptide antibiotic thiocillin exploits the nocardamine xenosiderophore transporter, FoxA, of the opportunistic pathogen Pseudomonas aeruginosa for uptake. Here, we show that FoxA also transports the xenosiderophore bisucaberin and describe at 2.5 Å resolution the crystal structure of bisucaberin bound to FoxA. Bisucaberin is distinct from other siderophores because it forms a 3:2 rather than 1:1 siderophore-iron complex. Mutations in a single extracellular loop of FoxA differentially affected nocardamine, thiocillin, and bisucaberin binding, uptake, and signal transduction. These results show that in addition to modulating ligand binding, the extracellular loops of siderophore transporters are of fundamental importance for controlling ligand uptake and its regulatory consequences, which have implications for the development of siderophore-antibiotic conjugates to treat difficult infections.
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Affiliation(s)
- Derek C. K. Chan
- David Braley Center for Antibiotic Discovery, McMaster University, Hamilton, ONL8S 4K1, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Inokentijs Josts
- The Hamburg Advanced Research Center for Bioorganic Chemistry, Hamburg22761, Germany
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg22761, Germany
| | - Kalinka Koteva
- David Braley Center for Antibiotic Discovery, McMaster University, Hamilton, ONL8S 4K1, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Gerard D. Wright
- David Braley Center for Antibiotic Discovery, McMaster University, Hamilton, ONL8S 4K1, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
| | - Henning Tidow
- The Hamburg Advanced Research Center for Bioorganic Chemistry, Hamburg22761, Germany
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg22761, Germany
| | - Lori L. Burrows
- David Braley Center for Antibiotic Discovery, McMaster University, Hamilton, ONL8S 4K1, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ONL8S 4K1, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ONL8S 4K1, Canada
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Bhattacharjee R, Nandi A, Sinha A, Kumar H, Mitra D, Mojumdar A, Patel P, Jha E, Mishra S, Rout PK, Panda PK, Suar M, Verma SK. Phage-tail-like bacteriocins as a biomedical platform to counter anti-microbial resistant pathogens. Biomed Pharmacother 2022; 155:113720. [PMID: 36162371 DOI: 10.1016/j.biopha.2022.113720] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/15/2022] [Accepted: 09/19/2022] [Indexed: 11/25/2022] Open
Abstract
Phage Tail Like bacteriocins (PTLBs) has been an area of interest in the last couple of years owing to their varied application against multi-drug resistant (MDR), anti-microbial resistant (AMR) pathogens and their evolutionary link with the dsDNA virus and bacteriophages. PTLBs are defective phages derived from Myoviridae and Siphoviridae phages, PTLBs are distinguished into R-type (Rigid type) characterized by a non-flexible contractile nanotube resembling Myoviridae phage contractile tails, and F-type (Flexible type) with a flexible non-contractile rod-like structure similar to Siphoviridae phages. In this review, we have discussed the structural association, mechanism, and characterization of PTLBs. Moreover, we have elucidated the symbiotic biological function and application of PTLBs against MDR and XDR pathogens and highlighted the evolutionary role of PTLBs. The difficulties that must be overcome to implement PTLBs clinically are also discussed. It is imperative that these issues be addressed by academics in future studies before being implemented in clinical settings. This article is novel in its way as it will not only provide us with a gateway that acts as a novel strategy for scholars to mitigate and control the uprising issue of AMR pathogens but also promote the development of clinical studies for PTLBs.
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Affiliation(s)
- Rahul Bhattacharjee
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Aditya Nandi
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Adrija Sinha
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Hrithik Kumar
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala 695551, India
| | - Disha Mitra
- University of Calcutta, 92, APC Road, Kolkata 700009, India
| | - Abhik Mojumdar
- Center for Research Equipment, Korea Basic Science Institute (KBSI), Ochang Center, Cheongju, Chungcheongbuk 28119, Republic of Korea; Department of Bio-Analytical Science, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Paritosh Patel
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Ealisha Jha
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Suman Mishra
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Prabhat Kumar Rout
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Pritam Kumar Panda
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
| | - Mrutyunjay Suar
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India.
| | - Suresh K Verma
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India; Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
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7
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Atanaskovic I, Sharp C, Press C, Kaminska R, Kleanthous C. Bacterial Competition Systems Share a Domain Required for Inner Membrane Transport of the Bacteriocin Pyocin G from Pseudomonas aeruginosa. mBio 2022; 13:e0339621. [PMID: 35343790 PMCID: PMC9040868 DOI: 10.1128/mbio.03396-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/28/2022] [Indexed: 02/06/2023] Open
Abstract
Bacteria exploit a variety of attack strategies to gain dominance within ecological niches. Prominent among these are contact-dependent inhibition (CDI), type VI secretion (T6SS), and bacteriocins. The cytotoxic endpoint of these systems is often the delivery of a nuclease to the cytosol. How such nucleases translocate across the cytoplasmic membrane of Gram-negative bacteria is unknown. Here, we identify a small, conserved, 15-kDa domain, which we refer to as the inner membrane translocation (IMT) domain, that is common to T6SS and bacteriocins and linked to nuclease effector domains. Through fluorescence microscopy assays using intact and spheroplasted cells, we demonstrate that the IMT domain of the Pseudomonas aeruginosa-specific bacteriocin pyocin G (PyoG) is required for import of the toxin nuclease domain to the cytoplasm. We also show that translocation of PyoG into the cytosol is dependent on inner membrane proteins FtsH, a AAA+ATPase/protease, and TonB1, the latter more typically associated with transport of bacteriocins across the outer membrane. Our study reveals that the IMT domain directs the cytotoxic nuclease of PyoG to cross the cytoplasmic membrane and, more broadly, has been adapted for the transport of other toxic nucleases delivered into Gram-negative bacteria by both contact-dependent and contact-independent means. IMPORTANCE Nuclease bacteriocins are potential antimicrobials for the treatment of antibiotic-resistant bacterial infections. While the mechanism of outer membrane translocation is beginning to be understood, the mechanism of inner membrane transport is not known. This study uses PyoG as a model nuclease bacteriocin and defines a conserved domain that is essential for inner membrane translocation and is widespread in other bacterial competition systems. Additionally, the presented data link two membrane proteins, FtsH and TonB1, with inner membrane translocation of PyoG. These findings point to the general importance of this domain to the cellular uptake mechanisms of nucleases delivered by otherwise diverse and distinct bacterial competition systems. The work is also of importance for the design of new protein antibiotics.
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Affiliation(s)
- Iva Atanaskovic
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Connor Sharp
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Cara Press
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Renata Kaminska
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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8
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Gdaniec BG, Bonini F, Prodon F, Braschler T, Köhler T, van Delden C. Pseudomonas aeruginosa rhamnolipid micelles deliver toxic metabolites and antibiotics into Staphylococcus aureus. iScience 2022; 25:103669. [PMID: 35028539 PMCID: PMC8741607 DOI: 10.1016/j.isci.2021.103669] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/05/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Efficient delivery of toxic compounds to bacterial competitors is essential during interspecies microbial warfare. Rhamnolipids (RLPs) are glycolipids produced by Pseudomonas and Burkholderia species involved in solubilization and uptake of environmental aliphatic hydrocarbons and perform as biosurfactants for swarming motility. Here, we show that RLPs produced by Pseudomonas aeruginosa associate to form micelles. Using high-resolution microscopy, we found that RLP micelles serve as carriers for self-produced toxic compounds, which they deliver to Staphylococcus aureus cells, thereby enhancing and accelerating S. aureus killing. RLPs also potentiated the activity of lincosamide antibiotics, suggesting that RLP micelles may transport not only self-produced but also heterologous compounds to target competing bacterial species Pseudomonas aeruginosa rhamnolipids form micelles Rhamnolipid micelles delivery pyochelin into S. aureus cells Rhamnolipid micelles potentiate activity of lincosamide antibiotics against S. aureus
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Affiliation(s)
- Bartosz Gerard Gdaniec
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland.,Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Fabien Bonini
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - François Prodon
- Bioimaging Core Facility, Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Thomas Braschler
- Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Thilo Köhler
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
| | - Christian van Delden
- Transplant Infectious Diseases Unit, University Hospitals Geneva, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland.,Department of Microbiology and Molecular Medicine, University of Geneva, 1, Rue Michel Servet, 1211 Geneva, Switzerland
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9
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Iron Homeostasis in Pseudomonas aeruginosa: Targeting Iron Acquisition and Storage as an Antimicrobial Strategy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:29-68. [DOI: 10.1007/978-3-031-08491-1_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Francis MLR, Webby MN, Housden NG, Kaminska R, Elliston E, Chinthammit B, Lukoyanova N, Kleanthous C. Porin threading drives receptor disengagement and establishes active colicin transport through Escherichia coli OmpF. EMBO J 2021; 40:e108610. [PMID: 34515361 PMCID: PMC8561637 DOI: 10.15252/embj.2021108610] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 11/24/2022] Open
Abstract
Bacteria deploy weapons to kill their neighbours during competition for resources and to aid survival within microbiomes. Colicins were the first such antibacterial system identified, yet how these bacteriocins cross the outer membrane (OM) of Escherichia coli is unknown. Here, by solving the structures of translocation intermediates via cryo‐EM and by imaging toxin import, we uncover the mechanism by which the Tol‐dependent nuclease colicin E9 (ColE9) crosses the bacterial OM. We show that threading of ColE9’s disordered N‐terminal domain through two pores of the trimeric porin OmpF causes the colicin to disengage from its primary receptor, BtuB, and reorganises the translocon either side of the membrane. Subsequent import of ColE9 through the lumen of a single OmpF subunit is driven by the proton‐motive force, which is delivered by the TolQ‐TolR‐TolA‐TolB assembly. Our study answers longstanding questions, such as why OmpF is a better translocator than OmpC, and reconciles the mechanisms by which both Tol‐ and Ton‐dependent bacteriocins cross the bacterial outer membrane.
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Affiliation(s)
| | - Melissa N Webby
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Renata Kaminska
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Emma Elliston
- Department of Biochemistry, University of Oxford, Oxford, UK
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11
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Six A, Mosbahi K, Barge M, Kleanthous C, Evans T, Walker D. Pyocin efficacy in a murine model of Pseudomonas aeruginosa sepsis. J Antimicrob Chemother 2021; 76:2317-2324. [PMID: 34142136 PMCID: PMC8361349 DOI: 10.1093/jac/dkab199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 05/20/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Bloodstream infections with antibiotic-resistant Pseudomonas aeruginosa are common and increasingly difficult to treat. Pyocins are naturally occurring protein antibiotics produced by P. aeruginosa that have potential for human use. OBJECTIVES To determine if pyocin treatment is effective in a murine model of sepsis with P. aeruginosa. METHODS Recombinant pyocins S5 and AP41 were purified and tested for efficacy in a Galleria mellonella infection model and a murine model of P. aeruginosa sepsis. RESULTS Both pyocins produced no adverse effects when injected alone into mice and showed good in vitro antipseudomonal activity. In an invertebrate model of sepsis using G. mellonella, both pyocins significantly prolonged survival from 1/10 (10%) survival in controls to 80%-100% survival among groups of 10 pyocin-treated larvae. Following injection into mice, both showed extensive distribution into different organs. When administered 5 h after infection, pyocin S5 significantly increased survival from 33% (2/6) to 83% (5/6) in a murine model of sepsis (difference significant by log-rank test, P < 0.05). CONCLUSIONS Pyocins S5 and AP41 show in vivo biological activity and can improve survival in two models of P. aeruginosa infection. They hold promise as novel antimicrobial agents for treatment of MDR infections with this microbe.
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Affiliation(s)
- Anne Six
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davis Building, University Place, Glasgow, G12 8TA, UK
| | - Khedidja Mosbahi
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davis Building, University Place, Glasgow, G12 8TA, UK
| | - Madhuri Barge
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davis Building, University Place, Glasgow, G12 8TA, UK
| | - Colin Kleanthous
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Thomas Evans
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davis Building, University Place, Glasgow, G12 8TA, UK
| | - Daniel Walker
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Sir Graeme Davis Building, University Place, Glasgow, G12 8TA, UK
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The β-encapsulation cage of rearrangement hotspot (Rhs) effectors is required for type VI secretion. Proc Natl Acad Sci U S A 2020; 117:33540-33548. [PMID: 33323487 DOI: 10.1073/pnas.1919350117] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bacteria deploy rearrangement hotspot (Rhs) proteins as toxic effectors against both prokaryotic and eukaryotic target cells. Rhs proteins are characterized by YD-peptide repeats, which fold into a large β-cage structure that encapsulates the C-terminal toxin domain. Here, we show that Rhs effectors are essential for type VI secretion system (T6SS) activity in Enterobacter cloacae (ECL). ECL rhs - mutants do not kill Escherichia coli target bacteria and are defective for T6SS-dependent export of hemolysin-coregulated protein (Hcp). The RhsA and RhsB effectors of ECL both contain Pro-Ala-Ala-Arg (PAAR) repeat domains, which bind the β-spike of trimeric valine-glycine repeat protein G (VgrG) and are important for T6SS activity in other bacteria. Truncated RhsA that retains the PAAR domain is capable of forming higher-order, thermostable complexes with VgrG, yet these assemblies fail to restore secretion activity to ∆rhsA ∆rhsB mutants. Full T6SS-1 activity requires Rhs that contains N-terminal transmembrane helices, the PAAR domain, and an intact β-cage. Although ∆rhsA ∆rhsB mutants do not kill target bacteria, time-lapse microscopy reveals that they assemble and fire T6SS contractile sheaths at ∼6% of the frequency of rhs + cells. Therefore, Rhs proteins are not strictly required for T6SS assembly, although they greatly increase secretion efficiency. We propose that PAAR and the β-cage provide distinct structures that promote secretion. PAAR is clearly sufficient to stabilize trimeric VgrG, but efficient assembly of T6SS-1 also depends on an intact β-cage. Together, these domains enforce a quality control checkpoint to ensure that VgrG is loaded with toxic cargo before assembling the secretion apparatus.
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Normant V, Josts I, Kuhn L, Perraud Q, Fritsch S, Hammann P, Mislin GLA, Tidow H, Schalk IJ. Nocardamine-Dependent Iron Uptake in Pseudomonas aeruginosa: Exclusive Involvement of the FoxA Outer Membrane Transporter. ACS Chem Biol 2020; 15:2741-2751. [PMID: 32902248 DOI: 10.1021/acschembio.0c00535] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Iron is a key nutrient for almost all living organisms. Paradoxically, it is poorly soluble and consequently poorly bioavailable. Bacteria have thus developed multiple strategies to access this metal. One of the most common consists of the use of siderophores, small compounds that chelate ferric iron with very high affinity. Many bacteria are able to produce their own siderophores or use those produced by other microorganisms (exosiderophores) in a piracy strategy. Pseudomonas aeruginosa produces two siderophores, pyoverdine and pyochelin, and is also able to use a large panel of exosiderophores. We investigated the ability of P. aeruginosa to use nocardamine (NOCA) and ferrioxamine B (DFOB) as exosiderophores under iron-limited planktonic growth conditions. Proteomic and RT-qPCR approaches showed induction of the transcription and expression of the outer membrane transporter FoxA in the presence of NOCA or DFOB in the bacterial environment. Expression of the proteins of the heme- or pyoverdine- and pyochelin-dependent iron uptake pathways was not affected by the presence of these two tris-hydroxamate siderophores. 55Fe uptake assays using foxA mutants showed ferri-NOCA to be exclusively transported by FoxA, whereas ferri-DFOB was transported by FoxA and at least one other unidentified transporter. The crystal structure of FoxA complexed with NOCA-Fe revealed very similar siderophore binding sites between NOCA-Fe and DFOB-Fe. We discuss iron uptake by hydroxamate exosiderophores in P. aeruginosa cells in light of these results.
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Affiliation(s)
- Vincent Normant
- CNRS, UMR7242, ESBS, Université de Strasbourg, Bld Sébastien Brant, F-67412 Illkirch, France
| | - Inokentijs Josts
- The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Lauriane Kuhn
- Plateforme Proteomique Strasbourg - Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS, FR1589, 15 rue Descartes, F-67084 Strasbourg Cedex, France
| | - Quentin Perraud
- CNRS, UMR7242, ESBS, Université de Strasbourg, Bld Sébastien Brant, F-67412 Illkirch, France
| | - Sarah Fritsch
- CNRS, UMR7242, ESBS, Université de Strasbourg, Bld Sébastien Brant, F-67412 Illkirch, France
| | - Philippe Hammann
- Plateforme Proteomique Strasbourg - Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS, FR1589, 15 rue Descartes, F-67084 Strasbourg Cedex, France
| | - Gaëtan L. A. Mislin
- CNRS, UMR7242, ESBS, Université de Strasbourg, Bld Sébastien Brant, F-67412 Illkirch, France
| | - Henning Tidow
- The Hamburg Centre for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
- Department of Chemistry, Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Isabelle J. Schalk
- CNRS, UMR7242, ESBS, Université de Strasbourg, Bld Sébastien Brant, F-67412 Illkirch, France
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Rooney WM, Chai R, Milner JJ, Walker D. Bacteriocins Targeting Gram-Negative Phytopathogenic Bacteria: Plantibiotics of the Future. Front Microbiol 2020; 11:575981. [PMID: 33042091 PMCID: PMC7530242 DOI: 10.3389/fmicb.2020.575981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/25/2020] [Indexed: 12/12/2022] Open
Abstract
Gram-negative phytopathogenic bacteria are a significant threat to food crops. These microbial invaders are responsible for a plethora of plant diseases and can be responsible for devastating losses in crops such as tomatoes, peppers, potatoes, olives, and rice. Current disease management strategies to mitigate yield losses involve the application of chemicals which are often harmful to both human health and the environment. Bacteriocins are small proteinaceous antibiotics produced by bacteria to kill closely related bacteria and thereby establish dominance within a niche. They potentially represent a safer alternative to chemicals when used in the field. Bacteriocins typically show a high degree of selectivity toward their targets with no off-target effects. This review outlines the current state of research on bacteriocins active against Gram-negative phytopathogenic bacteria. Furthermore, we will examine the feasibility of weaponizing bacteriocins for use as a treatment for bacterial plant diseases.
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Affiliation(s)
- William M. Rooney
- Plant Science Group, School of Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Ray Chai
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
| | - Joel J. Milner
- Plant Science Group, School of Life Sciences, Institute of Molecular, Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Daniel Walker
- College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
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