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Luo VC, Peczuh MW. Location, Location, Location: Establishing Design Principles for New Antibacterials from Ferric Siderophore Transport Systems. Molecules 2024; 29:3889. [PMID: 39202968 PMCID: PMC11357680 DOI: 10.3390/molecules29163889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Revised: 08/09/2024] [Accepted: 08/12/2024] [Indexed: 09/03/2024] Open
Abstract
This review strives to assemble a set of molecular design principles that enables the delivery of antibiotic warheads to Gram-negative bacterial targets (ESKAPE pathogens) using iron-chelating siderophores, known as the Trojan Horse strategy for antibiotic development. Principles are derived along two main lines. First, archetypical siderophores and their conjugates are used as case studies for native iron transport. They enable the consideration of the correspondence of iron transport and antibacterial target location. The second line of study charts the rationale behind the clinical antibiotic cefiderocol. It illustrates the potential versatility for the design of new Trojan Horse-based antibiotics. Themes such as matching the warhead to a location where the siderophore delivers its cargo (i.e., periplasm vs. cytoplasm), whether or not a cleavable linker is required, and the relevance of cheaters to the effectiveness and selectivity of new conjugates will be explored. The effort to articulate rules has identified gaps in the current understanding of iron transport pathways and suggests directions for new investigations.
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Affiliation(s)
| | - Mark W. Peczuh
- Department of Chemistry, University of Connecticut, 55 N. Eagleville Road, U3060, Storrs, CT 06269, USA;
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2
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LeBlanc A, Wuest WM. Siderophores: A Case Study in Translational Chemical Biology. Biochemistry 2024; 63:1877-1891. [PMID: 39041827 PMCID: PMC11308372 DOI: 10.1021/acs.biochem.4c00276] [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: 05/22/2024] [Revised: 07/09/2024] [Accepted: 07/10/2024] [Indexed: 07/24/2024]
Abstract
Siderophores are metal-binding secondary metabolites that assist in iron homeostasis and have been of interest to the scientific community for the last half century. Foundational siderophore research has enabled several translational applications including siderophore-antibiotic and siderophore-peptide conjugates, identification of new antimicrobial targets, advances in disease imaging, and novel therapeutics. This review aims to connect the basic science research (biosynthesis, cellular uptake, gene regulation, and effects on homeostasis) of well-known siderophores with the successive translational application that results. Intertwined throughout are connections to the career of Christopher T. Walsh, his impact on the field of chemical biology, and the legacy of his trainees who continue to innovate.
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Affiliation(s)
- Andrew
R. LeBlanc
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
| | - William M. Wuest
- Department of Chemistry, Emory
University, Atlanta, Georgia 30322, United States
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3
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Motz RN, Kamyabi G, Nolan EM. Experimental methods for evaluating siderophore-antibiotic conjugates. Methods Enzymol 2024; 702:21-50. [PMID: 39155112 DOI: 10.1016/bs.mie.2024.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/20/2024]
Abstract
Siderophore-antibiotic conjugates (SACs) are of past and current interest for delivering antibacterials into Gram-negative bacterial pathogens that express siderophore receptors. Studies of SACs are often multifaceted and involve chemical and biological approaches. Major goals are to evaluate the antimicrobial activity and uptake of novel SACs and use the resulting data to inform further mode-of-action studies and molecular design strategies. In this chapter, we describe four key methods that we apply when investigating the antimicrobial activity and uptake of novel SACs based on the siderophore enterobactin (Ent). These methods are based on approaches from the siderophore literature as well as established protocols for antimicrobial activity testing, and include assays for evaluating SAC antimicrobial activity, time-kill kinetics, siderophore competition, and bacterial cell uptake using 57Fe. These assays have served us well in characterizing our Ent-based conjugates and can be applied to study SACs that use other siderophores as targeting vectors.
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Affiliation(s)
- Rachel N Motz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Ghazal Kamyabi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, United States.
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4
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Guo C, Nolan EM. Exploring the Antibacterial Activity and Cellular Fates of Enterobactin-Drug Conjugates That Target Gram-Negative Bacterial Pathogens. Acc Chem Res 2024; 57:1046-1056. [PMID: 38483177 PMCID: PMC11258919 DOI: 10.1021/acs.accounts.3c00814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Siderophores are secondary metabolites utilized by bacteria to acquire iron (Fe), an essential transition metal nutrient. Fe levels in the host environment are tightly regulated and can be further restricted to starve invading bacterial pathogens in a host-defense process known as nutritional immunity. To survive and colonize the Fe-limited host environment, bacteria produce siderophores and express cognate siderophore transport machinery. These active transport pathways present an opportunity for selective and efficient drug delivery into bacterial cells, motivating decades of research on synthetic siderophore-antibiotic conjugates (SACs) as a Trojan-horse strategy for the development of targeted antibiotics.Enterobactin (Ent) is a triscatecholate siderophore produced and utilized by many Gram-negative bacteria, including all Escherichia coli and Salmonella species. Within these species, pathogenic strains cause a variety of human diseases including urinary tract infections, gastroenteritis, and sepsis. Infections caused by these Gram-negative pathogens can be difficult to treat because of the impermeability of the outer membrane (OM). This impermeability can be overcome by utilizing siderophores as drug delivery vectors for targeting Gram-negative pathogens. Ent is a promising delivery vector because it undergoes active transport across the OM mediated by the Ent uptake machinery after scavenging Fe(III) from the extracellular environment. Despite the well-elucidated chemistry and biology of Ent, its use for SAC development was hampered by the lack of an appropriate functional group for cargo attachment. Our laboratory addressed this need by designing and synthesizing monofunctionalized Ent scaffolds. Over the past decade, we have used these scaffolds to explore Ent-based SACs with a variety of drug warheads, including β-lactam and fluoroquinolone antibiotics, and Pt(IV) prodrugs. Investigations of the antibacterial activities of these conjugates and their cellular fates have informed our design principles and revealed approaches to achieving enhanced antibacterial potency and pathogen-targeted activity. Collectively, our studies of Ent-drug conjugates have provided discoveries, understanding, and invaluable insights for future design and evaluation of SACs.In this Account, we present the story of our work on Ent-drug conjugates that began about ten years ago with the development of monofunctionalized Ent scaffolds and the design and synthesis of various conjugates based on these scaffolds. We describe the antibacterial activity profiles and uptake pathways of Ent-drug conjugates harboring traditional antibiotics and repurposed platinum anticancer agents as well as studies that address cellular targets and fates. Finally, we discuss other applications of monofunctionalized Ent scaffolds, including a siderophore-based immunization strategy. We intend for this Account to inspire further investigations into the fundamental understanding and translational applications of siderophores and siderophore-drug conjugates.
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Affiliation(s)
- Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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5
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Yang T, Zou Y, Ng HL, Kumar A, Newton SM, Klebba PE. Specificity and mechanism of TonB-dependent ferric catecholate uptake by Fiu. Front Microbiol 2024; 15:1355253. [PMID: 38601941 PMCID: PMC11005823 DOI: 10.3389/fmicb.2024.1355253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/23/2024] [Indexed: 04/12/2024] Open
Abstract
We studied the Escherichia coli outer membrane protein Fiu, a presumed transporter of monomeric ferric catecholates, by introducing Cys residues in its surface loops and modifying them with fluorescein maleimide (FM). Fiu-FM bound iron complexes of the tricatecholate siderophore enterobactin (FeEnt) and glucosylated enterobactin (FeGEnt), their dicatecholate degradation product Fe(DHBS)2 (FeEnt*), the monocatecholates dihydroxybenzoic acid (FeDHBA) and dihydroxybenzoyl serine (FeDHBS), and the siderophore antibiotics cefiderocol (FDC) and MB-1. Unlike high-affinity ligand-gated porins (LGPs), Fiu-FM had only micromolar affinity for iron complexes. Its apparent KD values for FeDHBS, FeDHBA, FeEnt*, FeEnt, FeGEnt, FeFDC, and FeMB-1 were 0.1, 0.7, 0.7, 1.0, 0.3, 0.4, and 4 μM, respectively. Despite its broad binding abilities, the transport repertoires of E. coli Fiu, as well as those of Cir and FepA, were less broad. Fiu only transported FeEnt*. Cir transported FeEnt* and FeDHBS (weakly); FepA transported FeEnt, FeEnt*, and FeDHBA. Both Cir and FepA bound FeGEnt, albeit with lower affinity. Related transporters of Acinetobacter baumannii (PiuA, PirA, BauA) had similarly moderate affinity and broad specificity for di- or monomeric ferric catecholates. Both microbiological and radioisotopic experiments showed Fiu's exclusive transport of FeEnt*, rather than ferric monocatecholate compounds. Molecular docking and molecular dynamics simulations predicted three binding sites for FeEnt*in the external vestibule of Fiu, and a fourth site deeper in its interior. Alanine scanning mutagenesis in the outermost sites (1a, 1b, and 2) decreased FeEnt* binding affinity as much as 20-fold and reduced or eliminated FeEnt* uptake. Finally, the molecular dynamics simulations suggested a pathway of FeEnt* movement through Fiu that may generally describe the process of metal transport by TonB-dependent receptors.
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Affiliation(s)
| | | | | | | | | | - Phillip E. Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
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6
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Motz RN, Guo C, Sargun A, Walker GT, Sassone-Corsi M, Raffatellu M, Nolan EM. Conjugation to Native and Nonnative Triscatecholate Siderophores Enhances Delivery and Antibacterial Activity of a β-Lactam to Gram-Negative Bacterial Pathogens. J Am Chem Soc 2024; 146:7708-7722. [PMID: 38457782 PMCID: PMC11037102 DOI: 10.1021/jacs.3c14490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2024]
Abstract
Developing new antibiotics and delivery strategies is of critical importance for treating infections caused by Gram-negative bacterial pathogens. Hijacking bacterial iron uptake machinery, such as that of the siderophore enterobactin (Ent), represents one promising approach toward these goals. Here, we report a novel Ent-inspired siderophore-antibiotic conjugate (SAC) employing an alternative siderophore moiety as the delivery vector and demonstrate the potency of our SACs harboring the β-lactam antibiotic ampicillin (Amp) against multiple pathogenic Gram-negative bacterial strains. We establish the ability of N,N',N''-(nitrilotris(ethane-2,1-diyl))tris(2,3-dihydroxybenzamide) (TRENCAM, hereafter TC), a synthetic mimic of Ent, to facilitate drug delivery across the outer membrane (OM) of Gram-negative pathogens. Conjugation of Amp to a new monofunctionalized TC scaffold affords TC-Amp, which displays markedly enhanced antibacterial activity against the gastrointestinal pathogen Salmonella enterica serovar Typhimurium (STm) compared with unmodified Amp. Bacterial uptake, antibiotic susceptibility, and microscopy studies with STm show that the TC moiety facilitates TC-Amp uptake by the OM receptors FepA and IroN and that the Amp warhead inhibits penicillin-binding proteins. Moreover, TC-Amp achieves targeted activity, selectively killing STm in the presence of a commensal lactobacillus. Remarkably, we uncover that TC-Amp and its Ent-based predecessor Ent-Amp achieve enhanced antibacterial activity against diverse Gram-negative ESKAPE pathogens that express Ent uptake machinery, including strains that possess intrinsic β-lactam resistance. TC-Amp and Ent-Amp exhibit potency comparable to that of the FDA-approved SAC cefiderocol against Gram-negative pathogens. These results demonstrate the effective application of native and appropriately designed nonnative siderophores as vectors for drug delivery across the OM of multiple Gram-negative bacterial pathogens.
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Affiliation(s)
- Rachel N. Motz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Artur Sargun
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Gregory T. Walker
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
| | - Martina Sassone-Corsi
- Department of Microbiology & Molecular Genetics, University of California Irvine, Irvine, CA 92697, USA
| | - Manuela Raffatellu
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA
- Department of Microbiology & Molecular Genetics, University of California Irvine, Irvine, CA 92697, USA
- Center for Microbiome Innovation, University of California San Diego, La Jolla, CA 92093, USA
- Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines, La Jolla, CA 92093, USA
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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7
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Abdeljelil N, Ben Miloud Yahia N, Landoulsi A, Chatti A, Wattiez R, Gillan D, Van Houdt R. Proteomic and morphological insights into the exposure of Cupriavidus metallidurans CH34 planktonic cells and biofilms to aluminium. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133403. [PMID: 38215523 DOI: 10.1016/j.jhazmat.2023.133403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/15/2023] [Accepted: 12/27/2023] [Indexed: 01/14/2024]
Abstract
Aluminium (Al) is one of the most popular materials for industrial and domestic use. Nevertheless, research has proven that this metal can be toxic to most organisms. This light metal has no known biological function and to date very few aluminium-specific biological pathways have been identified. In addition, information about the impact of this metal on microbial life is scarce. Here, we aimed to study the effect of aluminium on the metal-resistant soil bacterium Cupriavidus metallidurans CH34 in different growth modes, i.e. planktonic cells, adhered cells and mature biofilms. Our results indicated that despite a significant tolerance to aluminium (minimal inhibitory concentration of 6.25 mM Al₂(SO₄)₃.18H₂O), the exposure of C. metallidurans to a sub-inhibitory dose (0.78 mM) caused early oxidative stress and an increase in hydrolytic activity. Changes in the outer membrane surface of planktonic cells were observed, in addition to a rapid disruption of mature biofilms. On protein level, aluminium exposure increased the expression of proteins involved in metabolic activity such as pyruvate kinase, formate dehydrogenase and poly(3-hydroxybutyrate) polymerase, whereas proteins involved in chemotaxis, and the production and transport of iron scavenging siderophores were significantly downregulated.
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Affiliation(s)
- Nissem Abdeljelil
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium; Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium; Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | | | - Ahmed Landoulsi
- Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | - Abdelwaheb Chatti
- Laboratory of Biochemistry and Molecular Biology, Faculty of Sciences of Bizerte, University of Carthage, Jarzouna, Tunisia
| | - Ruddy Wattiez
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium
| | - David Gillan
- Proteomics and Microbiology Lab, Research Institute for Biosciences, Mons University, Mons, Belgium
| | - Rob Van Houdt
- Microbiology Unit, Belgian Nuclear Research Centre, SCK CEN, Mol, Belgium.
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8
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Abbas R, Chakkour M, Zein El Dine H, Obaseki EF, Obeid ST, Jezzini A, Ghssein G, Ezzeddine Z. General Overview of Klebsiella pneumonia: Epidemiology and the Role of Siderophores in Its Pathogenicity. BIOLOGY 2024; 13:78. [PMID: 38392297 PMCID: PMC10886558 DOI: 10.3390/biology13020078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/24/2024]
Abstract
The opportunistic pathogen Klebsiella pneumoniae (K. pneumoniae) can colonize mucosal surfaces and spread from mucosae to other tissues, causing fatal infections. Medical equipment and the healthcare setting can become colonized by Klebsiella species, which are widely distributed in nature and can be found in water, soil, and animals. Moreover, a substantial number of community-acquired illnesses are also caused by this organism worldwide. These infections are characterized by a high rate of morbidity and mortality as well as the capacity to spread metastatically. Hypervirulent Klebsiella strains are thought to be connected to these infections. Four components are critical to this bacterium's pathogenicity-the capsule, lipopolysaccharide, fimbriae, and siderophores. Siderophores are secondary metabolites that allow iron to sequester from the surrounding medium and transport it to the intracellular compartment of the bacteria. A number of variables may lead to K. pneumoniae colonization in a specific area. Risk factors for infection include local healthcare practices, antibiotic use and misuse, infection control procedures, nutrition, gender, and age.
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Affiliation(s)
- Rim Abbas
- Faculty of Health Sciences, Beirut Arab University, Beirut P.O. Box 11-5020, Lebanon
| | - Mohamed Chakkour
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Hiba Zein El Dine
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, 1205 Geneva, Switzerland
| | | | - Soumaya T Obeid
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Aya Jezzini
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Ghassan Ghssein
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
| | - Zeinab Ezzeddine
- Laboratory Sciences Department, Faculty of Public Health, Islamic University of Lebanon (IUL), Khalde P.O. Box 30014, Lebanon
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9
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Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. J Biol Chem 2024; 300:105554. [PMID: 38072063 PMCID: PMC10788543 DOI: 10.1016/j.jbc.2023.105554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
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Affiliation(s)
- Zongsen Zou
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John I Robinson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Lindsey K Steinberg
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Jeffrey P Henderson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
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10
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Rosa-Núñez E, Echavarri-Erasun C, Armas AM, Escudero V, Poza-Carrión C, Rubio LM, González-Guerrero M. Iron Homeostasis in Azotobacter vinelandii. BIOLOGY 2023; 12:1423. [PMID: 37998022 PMCID: PMC10669500 DOI: 10.3390/biology12111423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023]
Abstract
Iron is an essential nutrient for all life forms. Specialized mechanisms exist in bacteria to ensure iron uptake and its delivery to key enzymes within the cell, while preventing toxicity. Iron uptake and exchange networks must adapt to the different environmental conditions, particularly those that require the biosynthesis of multiple iron proteins, such as nitrogen fixation. In this review, we outline the mechanisms that the model diazotrophic bacterium Azotobacter vinelandii uses to ensure iron nutrition and how it adapts Fe metabolism to diazotrophic growth.
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Affiliation(s)
- Elena Rosa-Núñez
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
| | - Carlos Echavarri-Erasun
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
| | - Alejandro M. Armas
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Viviana Escudero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - César Poza-Carrión
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Luis M. Rubio
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
| | - Manuel González-Guerrero
- Centro de Biotecnología y Genómica de Plantas (UPM-INIA/CSIC), Campus de Montegancedo UPM, Crta. M-40 km 38, 28223 Madrid, Spain; (E.R.-N.); (C.E.-E.); (A.M.A.); (C.P.-C.); (L.M.R.)
- Escuela Técnica de Ingeniería Agraria, Alimentaria, y de Biosistemas, Universidad Politécnica de Madrid, Avda. Puerta de Hierro, 2, 28040 Madrid, Spain
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11
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Kurihara K, Umezawa K, Donnelly AE, Sperling B, Liao G, Hecht MH, Arai R. Crystal structure and activity of a de novo enzyme, ferric enterobactin esterase Syn-F4. Proc Natl Acad Sci U S A 2023; 120:e2218281120. [PMID: 37695900 PMCID: PMC10515146 DOI: 10.1073/pnas.2218281120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 08/07/2023] [Indexed: 09/13/2023] Open
Abstract
Producing novel enzymes that are catalytically active in vitro and biologically functional in vivo is a key goal of synthetic biology. Previously, we reported Syn-F4, the first de novo protein that meets both criteria. Syn-F4 hydrolyzed the siderophore ferric enterobactin, and expression of Syn-F4 allowed an inviable strain of Escherichia coli (Δfes) to grow in iron-limited medium. Here, we describe the crystal structure of Syn-F4. Syn-F4 forms a dimeric 4-helix bundle. Each monomer comprises two long α-helices, and the loops of the Syn-F4 dimer are on the same end of the bundle (syn topology). Interestingly, there is a penetrated hole in the central region of the Syn-F4 structure. Extensive mutagenesis experiments in a previous study showed that five residues (Glu26, His74, Arg77, Lys78, and Arg85) were essential for enzymatic activity in vivo. All these residues are located around the hole in the central region of the Syn-F4 structure, suggesting a putative active site with a catalytic dyad (Glu26-His74). The complete inactivity of purified proteins with mutations at the five residues supports the putative active site and reaction mechanism. Molecular dynamics and docking simulations of the ferric enterobactin siderophore binding to the Syn-F4 structure demonstrate the dynamic property of the putative active site. The structure and active site of Syn-F4 are completely different from native enterobactin esterase enzymes, thereby demonstrating that proteins designed de novo can provide life-sustaining catalytic activities using structures and mechanisms dramatically different from those that arose in nature.
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Affiliation(s)
- Kodai Kurihara
- Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano386-8567, Japan
| | - Koji Umezawa
- Department of Agricultural and Life Sciences, Faculty of Agriculture, Shinshu University, Minami-minowa, Kami-ina, Nagano399-4598, Japan
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto, Nagano390-8621, Japan
| | - Ann E. Donnelly
- Department of Chemistry, Princeton University, Princeton, NJ08544
| | - Brendan Sperling
- Department of Chemistry, Princeton University, Princeton, NJ08544
| | - Guanyu Liao
- Department of Chemistry, Princeton University, Princeton, NJ08544
| | - Michael H. Hecht
- Department of Chemistry, Princeton University, Princeton, NJ08544
| | - Ryoichi Arai
- Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano386-8567, Japan
- Department of Biomolecular Innovation, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto, Nagano390-8621, Japan
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12
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Ma Y, Fei Y, Ding S, Jiang H, Fang J, Liu G. Trace metal elements: a bridge between host and intestinal microorganisms. SCIENCE CHINA. LIFE SCIENCES 2023; 66:1976-1993. [PMID: 37528296 DOI: 10.1007/s11427-022-2359-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/23/2023] [Indexed: 08/03/2023]
Abstract
Trace metal elements, such as iron, copper, manganese, and zinc, are essential nutrients for biological processes. Although their intake demand is low, they play a crucial role in cell homeostasis as the cofactors of various enzymes. Symbiotic intestinal microorganisms compete with their host for the use of trace metal elements. Moreover, the metabolic processes of trace metal elements in the host and microorganisms affect the organism's health. Supplementation or the lack of trace metal elements in the host can change the intestinal microbial community structure and function. Functional changes in symbiotic microorganisms can affect the host's metabolism of trace metal elements. In this review, we discuss the absorption and transport processes of trace metal elements in the host and symbiotic microorganisms and the effects of dynamic changes in the levels of trace metal elements on the intestinal microbial community structure. We also highlight the participation of trace metal elements as enzyme cofactors in the host immune process. Our findings indicate that the host uses metal nutrition immunity or metal poisoning to resist pathogens and improve immunity.
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Affiliation(s)
- Yong Ma
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China
| | - Yanquan Fei
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China
| | - Sujuan Ding
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China
| | - Hongmei Jiang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China
| | - Jun Fang
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China.
| | - Gang Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, 410128, China
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13
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Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550588. [PMID: 37546885 PMCID: PMC10402112 DOI: 10.1101/2023.07.25.550588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Uropathogenic E. coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here we find the siderophore enterobactin and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined enterobactin biosynthesis and import mutants, we identify lower molecular weight, dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-enterobactin complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed enterobactin, we find that enterobactin and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
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Affiliation(s)
- Zongsen Zou
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - John I. Robinson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lindsey K. Steinberg
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jeffrey P. Henderson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
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14
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Zhang Y, Liu L, Tu B, Cui B, Guo J, Zhao X, Wang J, Yan Y. An artificial synapse based on molecular junctions. Nat Commun 2023; 14:247. [PMID: 36646674 PMCID: PMC9842743 DOI: 10.1038/s41467-023-35817-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 01/03/2023] [Indexed: 01/18/2023] Open
Abstract
Shrinking the size of the electronic synapse to molecular length-scale, for example, an artificial synapse directly fabricated by using individual or monolayer molecules, is important for maximizing the integration density, reducing the energy consumption, and enabling functionalities not easily achieved by other synaptic materials. Here, we show that the conductance of the self-assembled peptide molecule monolayer could be dynamically modulated by placing electrical biases, enabling us to implement basic synaptic functions. Both short-term plasticity (e.g., paired-pulse facilitation) and long-term plasticity (e.g., spike-timing-dependent plasticity) are demonstrated in a single molecular synapse. The dynamic current response is due to a combination of both chemical gating and coordination effects between Ag+ and hosting groups within peptides which adjusts the electron hopping rate through the molecular junction. In the end, based on the nonlinearity and short-term synaptic characteristics, the molecular synapses are utilized as reservoirs for waveform recognition with 100% accuracy at a small mask length.
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Affiliation(s)
- Yuchun Zhang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Lin Liu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bin Tu
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Bin Cui
- School of Physics, Shandong University, Jinan, 250100, China
| | - Jiahui Guo
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xing Zhao
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jingyu Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yong Yan
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Department of Chemistry, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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15
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Almeida MC, da Costa PM, Sousa E, Resende DISP. Emerging Target-Directed Approaches for the Treatment and Diagnosis of Microbial Infections. J Med Chem 2023; 66:32-70. [PMID: 36586133 DOI: 10.1021/acs.jmedchem.2c01212] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
With the rising levels of drug resistance, developing efficient antimicrobial therapies has become a priority. A promising strategy is the conjugation of antibiotics with relevant moieties that can potentiate their activity by target-directing. The conjugation of siderophores with antibiotics allows them to act as Trojan horses by hijacking the microorganisms' highly developed iron transport systems and using them to carry the antibiotic into the cell. Through the analysis of relevant examples of the past decade, this Perspective aims to reveal the potential of siderophore-antibiotic Trojan horses for the treatment of infections and the role of siderophores in diagnostic techniques. Other conjugated molecules will be the subject of discussion, namely those involving vitamin B12, carbohydrates, and amino acids, as well as conjugated compounds targeting protein degradation and β-lactamase activated prodrugs.
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Affiliation(s)
- Mariana C Almeida
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Paulo M da Costa
- CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal.,ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
| | - Emília Sousa
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
| | - Diana I S P Resende
- Laboratório de Química Orgânica e Farmacêutica, Departamento de Ciências Químicas, FFUP - Faculdade de Farmácia, Universidade do Porto, Rua de Jorge de Viterbo Ferreira 228, 4050-313 Porto, Portugal.,CIIMAR- Centro Interdisciplinar de Investigação Marinha e Ambiental, Terminal de Cruzeiros do Porto de Leixões, 4450-208 Matosinhos, Portugal
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16
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The LysR-Type Transcription Regulator YhjC Promotes the Systemic Infection of Salmonella Typhimurium in Mice. Int J Mol Sci 2023; 24:ijms24021302. [PMID: 36674819 PMCID: PMC9867438 DOI: 10.3390/ijms24021302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/07/2023] [Accepted: 01/08/2023] [Indexed: 01/11/2023] Open
Abstract
Salmonella Typhimurium is a Gram-negative intestinal pathogen that can infect humans and a variety of animals, causing gastroenteritis or serious systemic infection. Replication within host macrophages is essential for S. Typhimurium to cause systemic infection. By analyzing transcriptome data, the expression of yhjC gene, which encodes a putative regulator in S. Typhimurium, was found to be significantly up-regulated after the internalization of Salmonella by macrophages. Whether yhjC gene is involved in S. Typhimurium systemic infection and the related mechanisms were investigated in this study. The deletion of yhjC reduced the replication ability of S. Typhimurium in macrophages and decreased the colonization of S. Typhimurium in mouse systemic organs (liver and spleen), while increasing the survival rate of the infected mice, suggesting that YhjC protein promotes systemic infection by S. Typhimurium. Furthermore, by using transcriptome sequencing and RT-qPCR assay, the transcription of several virulence genes, including spvD, iroCDE and zraP, was found to be down-regulated after the deletion of yhjC. Electrophoretic mobility shift assay showed that YhjC protein can directly bind to the promoter region of spvD and zraP to promote their transcription. These findings suggest that YhjC contributes to the systemic virulence of S. Typhimurium via the regulation of multiple virulence genes and YhjC could represent a promising target to control S. Typhimurium infection.
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17
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Gehrer CM, Hoffmann A, Hilbe R, Grubwieser P, Mitterstiller AM, Talasz H, Fang FC, Meyron-Holtz EG, Atkinson SH, Weiss G, Nairz M. Availability of Ferritin-Bound Iron to Enterobacteriaceae. Int J Mol Sci 2022; 23:13087. [PMID: 36361875 PMCID: PMC9657528 DOI: 10.3390/ijms232113087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/18/2022] [Accepted: 10/20/2022] [Indexed: 11/10/2023] Open
Abstract
The sequestration of iron in case of infection, termed nutritional immunity, is an established strategy of host defense. However, the interaction between pathogens and the mammalian iron storage protein ferritin is hitherto not completely understood. To better characterize the function of ferritin in Gram-negative infections, we incubated iron-starved cultures of Salmonella Typhimurium and knockout mutant strains defective for major iron uptake pathways or Escherichia coli with horse spleen ferritin or ionic iron as the sole iron source. Additionally, we added bovine superoxide dismutase and protease inhibitors to the growth medium to assess the effect of superoxide and bacterial proteases, respectively, on Salmonella proliferation and reductive iron release. Compared to free ionic iron, ferritin-bound iron was less available to Salmonella, but was still sufficient to significantly enhance the growth of the bacteria. In the absence of various iron acquisition genes, the availability of ferritin iron further decreased. Supplementation with superoxide dismutase significantly reduced the growth of the ΔentC knockout strain with holoferritin as the sole iron source in comparison with ionic ferrous iron. In contrast, this difference was not observed in the wildtype strain, suggesting that superoxide dismutase undermines bacterial iron uptake from ferritin by siderophore-independent mechanisms. Ferritin seems to diminish iron availability for bacteria in comparison to ionic iron, and its iron sequestering effect could possibly be enhanced by host superoxide dismutase activity.
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Affiliation(s)
- Clemens M. Gehrer
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Alexander Hoffmann
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Richard Hilbe
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Philipp Grubwieser
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Mitterstiller
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Heribert Talasz
- Biocenter, Institute of Medical Biochemistry, Medical Universitiy of Innsbruck, 6020 Innsbruck, Austria
| | - Ferric C. Fang
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA 98195-7110, USA
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195-7735, USA
| | - Esther G. Meyron-Holtz
- Laboratory of Molecular Nutrition, Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Sarah H. Atkinson
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine Research Coast, KEMRI-Wellcome Trust Research Programme, Kilifi 80108, Kenya
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7LG, UK
- Department of Paediatrics, University of Oxford, Oxford OX3 9DU, UK
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
- Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria
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18
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Yang J, Wencewicz TA. In Vitro Reconstitution of Fimsbactin Biosynthesis from Acinetobacter baumannii. ACS Chem Biol 2022; 17:2923-2935. [PMID: 36122366 DOI: 10.1021/acschembio.2c00573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Siderophores produced via nonribosomal peptide synthetase (NRPS) pathways serve as critical virulence factors for many pathogenic bacteria. Improved knowledge of siderophore biosynthesis guides the development of inhibitors, vaccines, and other therapeutic strategies. Fimsbactin A is a mixed ligand siderophore derived from human pathogenic Acinetobacter baumannii that contains phenolate-oxazoline, catechol, and hydroxamate metal chelating groups branching from a central l-Ser tetrahedral unit via amide and ester linkages. Fimsbactin A is derived from two molecules of l-Ser, two molecules of 2,3-dihydroxybenzoic acid (DHB), and one molecule of l-Orn and is a product of the fbs biosynthetic operon. Here, we report the complete in vitro reconstitution of fimsbactin A biosynthesis in a cell-free system using purified enzymes. We demonstrate the conversion of l-Orn to N1-acetyl-N1-hydroxy-putrescine (ahPutr) via ordered action of FbsJ (decarboxylase), FbsI (flavin N-monooxygenase), and FbsK (N-acetyltransferase). We achieve conversion of l-Ser, DHB, and l-Orn to fimsbactin A using FbsIJK in combination with the NRPS modules FbsEFGH. We also demonstrate chemoenzymatic conversion of synthetic ahPutr to fimsbactin A using FbsEFGH and establish the substrate selectivity for the NRPS adenylation domains in FbsH (DHB) and FbsF (l-Ser). We assign a role for the type II thioesterase FbsM in producing the shunt metabolite 2-(2,3-dihydroxyphenyl)-4,5-dihydrooxazole-4-carboxylic acid (DHB-oxa) via cleavage of the corresponding thioester intermediate that is tethered to NRPS peptidyl carrier domains during biosynthetic assembly. We propose a mechanism for branching NRPS-derived peptides via amide and ester linkages via the dynamic equilibration of N-DHB-Ser and O-DHB-Ser thioester intermediates via hydrolysis of DHB-oxa thioester intermediates. We also propose a genetic signature for NRPS "branching" in the presence of a terminating C-T-C motif (FbsG).
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Affiliation(s)
- Jinping Yang
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Timothy A Wencewicz
- Department of Chemistry, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, United States
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19
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The Key Element Role of Metallophores in the Pathogenicity and Virulence of Staphylococcus aureus: A Review. BIOLOGY 2022; 11:biology11101525. [PMID: 36290427 PMCID: PMC9598555 DOI: 10.3390/biology11101525] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/17/2022] [Accepted: 10/14/2022] [Indexed: 11/05/2022]
Abstract
The ubiquitous bacterium Staphylococcus aureus causes many diseases that sometimes can be fatal due to its high pathogenicity. The latter is caused by the ability of this pathogen to secrete secondary metabolites, enabling it to colonize inside the host causing infection through various processes. Metallophores are secondary metabolites that enable bacteria to sequester metal ions from the surrounding environment since the availability of metal ions is crucial for bacterial metabolism and virulence. The uptake of iron and other metal ions such as nickel and zinc is one of these essential mechanisms that gives this germ its virulence properties and allow it to overcome the host immune system. Additionally, extensive interactions occur between this pathogen and other bacteria as they compete for resources. Staphylococcus aureus has high-affinity metal import pathways including metal ions acquisition, recruitment and metal-chelate complex import. These characteristics give this bacterium the ability to intake metallophores synthesized by other bacteria, thus enabling it to compete with other microorganisms for the limited nutrients. In scarce host conditions, free metal ions are extremely low because they are confined to storage and metabolic molecules, so metal ions are sequestered by metallophores produced by this bacterium. Both siderophores (iron chelating molecules) and staphylopine (wide- spectrum metallophore) are secreted by Staphylococcus aureus giving it infectious properties. The genetic regulation of the synthesis and export together with the import of metal loaded metallophores are well established and are all covered in this review.
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20
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Cui Y, Wang H, Guo F, Cao X, Wang X, Zeng X, Cui G, Lin J, Xu F. Monoclonal antibody-based indirect competitive ELISA for quantitative detection of Enterobacteriaceae siderophore enterobactin. Food Chem 2022; 391:133241. [PMID: 35598389 DOI: 10.1016/j.foodchem.2022.133241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/18/2022] [Accepted: 05/15/2022] [Indexed: 12/16/2022]
Abstract
Enterobactin (Ent) is a promising indicator to monitor intestinal level of Enterobacteriaceae for assessment of gut inflammation. In this study, we developed a monoclonal antibody (mAb)-based ELISA for Ent quantification. We immunized mice with an Ent conjugate vaccine. An mAb named 2E4, with the highest anti-Ent antibody titer, was selected for developing indirect competitive ELISA (ic-ELISA). The purified mAb 2E4 showed high affinity (3.1 × 10-10 M) and specificity to Ent. The limit of detection of ic-ELISA was 0.39 μg/mL. The intra- and inter-assay recovery rates of standard curve were up to 94.6% with the coefficients of variation between 4.0% and 12.3%, indicating high accuracy, repeatability, and reproducibility of the ic-ELISA. In addition, the ic-ELISA was able to quantitatively detect Ent produced in different bacterial cultures. Collectively, this study developed an ic-ELISA with excellent performance in Ent quantification, laying a solid foundation for Ent-based diagnostics of gut health.
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Affiliation(s)
- Yifang Cui
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Huiwen Wang
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Fangfang Guo
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Xiaoya Cao
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Xue Wang
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996, USA
| | - Guolin Cui
- College of Life Sciences and Food Engineering, Hebei University of Engineering, Handan 056038, China
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996, USA.
| | - Fuzhou Xu
- Beijing Key Laboratory for Prevention and Control of Infectious Diseases in Livestock and Poultry, Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
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21
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Moynié L, Hoegy F, Milenkovic S, Munier M, Paulen A, Gasser V, Faucon AL, Zill N, Naismith JH, Ceccarelli M, Schalk IJ, Mislin GLA. Hijacking of the Enterobactin Pathway by a Synthetic Catechol Vector Designed for Oxazolidinone Antibiotic Delivery in Pseudomonas aeruginosa. ACS Infect Dis 2022; 8:1894-1904. [PMID: 35881068 DOI: 10.1021/acsinfecdis.2c00202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Enterobactin (ENT) is a tris-catechol siderophore used to acquire iron by multiple bacterial species. These ENT-dependent iron uptake systems have often been considered as potential gates in the bacterial envelope through which one can shuttle antibiotics (Trojan horse strategy). In practice, siderophore analogues containing catechol moieties have shown promise as vectors to which antibiotics may be attached. Bis- and tris-catechol vectors (BCVs and TCVs, respectively) were shown using structural biology and molecular modeling to mimic ENT binding to the outer membrane transporter PfeA in Pseudomonas aeruginosa. TCV but not BCV appears to cross the outer membrane via PfeA when linked to an antibiotic (linezolid). TCV is therefore a promising vector for Trojan horse strategies against P. aeruginosa, confirming the ENT-dependent iron uptake system as a gate to transport antibiotics into P. aeruginosa cells.
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Affiliation(s)
- Lucile Moynié
- The Rosalind Franklin Institute, Harwell Campus, Oxfordshire OX11 0QS, U.K
| | - Françoise Hoegy
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Stefan Milenkovic
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy
| | - Mathilde Munier
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Aurélie Paulen
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Véronique Gasser
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Aline L Faucon
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Nicolas Zill
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - James H Naismith
- The Rosalind Franklin Institute, Harwell Campus, Oxfordshire OX11 0QS, U.K.,Division of Structural Biology, Wellcome Trust Centre of Human Genomics, 7 Roosevelt Drive, Oxford OX3 7BN, U.K
| | - Matteo Ceccarelli
- Department of Physics, University of Cagliari, 09042 Monserrato, Italy.,IOM/CNR, Sezione di Cagliari, University of Cagliari, 09042 Monserrato, Italy
| | - Isabelle J Schalk
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
| | - Gaëtan L A Mislin
- CNRS, UMR7242 Biotechnologie et Signalisation Cellulaire, 300 Boulevard Sébastien Brant, F-67412 Illkirch, France.,Université de Strasbourg, Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), 300 Boulevard Sébastien Brant, F-67412 Illkirch, France
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22
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Guo C, Nolan EM. Heavy-Metal Trojan Horse: Enterobactin-Directed Delivery of Platinum(IV) Prodrugs to Escherichia coli. J Am Chem Soc 2022; 144:12756-12768. [PMID: 35803281 DOI: 10.1021/jacs.2c03324] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The global crisis of untreatable microbial infections necessitates the design of new antibiotics. Drug repurposing is a promising strategy for expanding the antibiotic repertoire. In this study, we repurpose the clinically approved anticancer agent cisplatin into a targeted antibiotic by conjugating its Pt(IV) prodrug to enterobactin (Ent), a triscatecholate siderophore employed by Enterobacteriaceae for iron (Fe) acquisition. The l-Ent-Pt(IV) conjugate (l-EP) exhibits antibacterial activity against Escherichia coli K12 and the uropathogenic isolate E. coli CFT073. Similar to cisplatin, l-EP causes a filamentous morphology in E. coli and initiates lysis in lysogenic bacteria. Studies with E. coli mutants defective in Ent transport proteins show that Ent mediates the delivery of l-EP into the E. coli cytoplasm, where reduction of the Pt(IV) prodrug releases the cisplatin warhead, causing growth inhibition and filamentation of E. coli. Substitution of Ent with its enantiomer affords the d-Ent-Pt(IV) conjugate (d-EP), which displays enhanced antibacterial activity, presumably because d-Ent cannot be hydrolyzed by Ent esterases and thus Fe cannot be released from this conjugate. E. coli treated with l/d-EP accumulate ≥10-fold more Pt as compared to cisplatin treatment. By contrast, human embryonic kidney cells (HEK293T) accumulate cisplatin but show negligible Pt uptake after treatment with either conjugate. Overall, this work demonstrates that the attachment of a siderophore repurposes a Pt anticancer agent into a targeted antibiotic that is recognized and transported by siderophore uptake machinery, providing a design strategy for drug repurposing by siderophore modification and heavy-metal "trojan-horse" antibiotics.
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Affiliation(s)
- Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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23
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Liu L, Wang W, Wu S, Gao H. Recent Advances in the Siderophore Biology of Shewanella. Front Microbiol 2022; 13:823758. [PMID: 35250939 PMCID: PMC8891985 DOI: 10.3389/fmicb.2022.823758] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 01/12/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the abundance of iron in nature, iron acquisition is a challenge for life in general because the element mostly exists in the extremely insoluble ferric (Fe3+) form in oxic environments. To overcome this, microbes have evolved multiple iron uptake strategies, a common one of which is through the secretion of siderophores, which are iron-chelating metabolites generated endogenously. Siderophore-mediated iron transport, a standby when default iron transport routes are abolished under iron rich conditions, is essential under iron starvation conditions. While there has been a wealth of knowledge about the molecular basis of siderophore synthesis, uptake and regulation in model bacteria, we still know surprisingly little about siderophore biology in diverse environmental microbes. Shewanella represent a group of γ-proteobacteria capable of respiring a variety of organic and inorganic substrates, including iron ores. This respiratory process relies on a large number of iron proteins, c-type cytochromes in particular. Thus, iron plays an essential and special role in physiology of Shewanella. In addition, these bacteria use a single siderophore biosynthetic system to produce an array of macrocyclic dihydroxamate siderophores, some of which show particular biological activities. In this review, we first outline current understanding of siderophore synthesis, uptake and regulation in model bacteria, and subsequently discuss the siderophore biology in Shewanella.
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Affiliation(s)
- Lulu Liu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wei Wang
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shihua Wu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Haichun Gao
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
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24
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Abstract
Iron is an essential element for Escherichia, Salmonella, and Shigella species. The acquisition of sufficient amounts of iron is difficult in many environments, including the intestinal tract, where these bacteria usually reside. Members of these genera have multiple iron transport systems to transport both ferrous and ferric iron. These include transporters for free ferrous iron, ferric iron associated with chelators, and heme. The numbers and types of transport systems in any species reflect the diversity of niches that it can inhabit. Many of the iron transport genes are found on mobile genetic elements or pathogenicity islands, and there is evidence of the spread of the genes among different species and pathotypes. This is notable among the pathogenic members of the genera in which iron transport systems acquired by horizontal gene transfer allow the bacteria to overcome host innate defenses that act to restrict the availability of iron to the pathogen. The need for iron is balanced by the need to avoid iron overload since excess iron is toxic to the cell. Genes for iron transport and metabolism are tightly regulated and respond to environmental cues, including iron availability, oxygen, and temperature. Master regulators, the iron sensor Fur and the Fur-regulated small RNA (sRNA) RyhB, coordinate the expression of iron transport and cellular metabolism genes in response to the availability of iron.
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25
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Oliveira F, Rohde H, Vilanova M, Cerca N. Fighting Staphylococcus epidermidis Biofilm-Associated Infections: Can Iron Be the Key to Success? Front Cell Infect Microbiol 2021; 11:798563. [PMID: 34917520 PMCID: PMC8670311 DOI: 10.3389/fcimb.2021.798563] [Citation(s) in RCA: 3] [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: 10/20/2021] [Accepted: 11/11/2021] [Indexed: 12/29/2022] Open
Abstract
Staphylococcus epidermidis is one of the most important commensal microorganisms of human skin and mucosae. However, this bacterial species is also the cause of severe infections in immunocompromised patients, specially associated with the utilization of indwelling medical devices, that often serve as a scaffold for biofilm formation. S. epidermidis strains are often multidrug resistant and its association with biofilm formation makes these infections hard to treat. Their remarkable ability to form biofilms is widely regarded as its major pathogenic determinant. Although a significant amount of knowledge on its biofilm formation mechanisms has been achieved, we still do not understand how the species survives when exposed to the host harsh environment during invasion. A previous RNA-seq study highlighted that iron-metabolism associated genes were the most up-regulated bacterial genes upon contact with human blood, which suggested that iron acquisition plays an important role in S. epidermidis biofilm development and escape from the host innate immune system. In this perspective article, we review the available literature on the role of iron metabolism on S. epidermidis pathogenesis and propose that exploiting its dependence on iron could be pursued as a viable therapeutic alternative.
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Affiliation(s)
- Fernando Oliveira
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel Vilanova
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto (ICBAS-UP), Porto, Portugal
| | - Nuno Cerca
- Centre of Biological Engineering, Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal
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26
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Sora VM, Meroni G, Martino PA, Soggiu A, Bonizzi L, Zecconi A. Extraintestinal Pathogenic Escherichia coli: Virulence Factors and Antibiotic Resistance. Pathogens 2021; 10:pathogens10111355. [PMID: 34832511 PMCID: PMC8618662 DOI: 10.3390/pathogens10111355] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/05/2021] [Accepted: 10/18/2021] [Indexed: 12/29/2022] Open
Abstract
The One Health approach emphasizes the importance of antimicrobial resistance (AMR) as a major concern both in public health and in food animal production systems. As a general classification, E. coli can be distinguished based on the ability to cause infection of the gastrointestinal system (IPEC) or outside of it (ExPEC). Among the different pathogens, E. coli are becoming of great importance, and it has been suggested that ExPEC may harbor resistance genes that may be transferred to pathogenic or opportunistic bacteria. ExPEC strains are versatile bacteria that can cause urinary tract, bloodstream, prostate, and other infections at non-intestinal sites. In this context of rapidly increasing multidrug-resistance worldwide and a diminishingly effective antimicrobial arsenal to tackle resistant strains. ExPEC infections are now a serious public health threat worldwide. However, the clinical and economic impact of these infections and their optimal management are challenging, and consequently, there is an increasing awareness of the importance of ExPECs amongst healthcare professionals and the general public alike. This review aims to describe pathotype characteristics of ExPEC to increase our knowledge of these bacteria and, consequently, to increase our chances to control them and reduce the risk for AMR, following a One Health approach.
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27
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Jones CV, Jarboe BG, Majer HM, Ma AT, Beld J. Escherichia coli Nissle 1917 secondary metabolism: aryl polyene biosynthesis and phosphopantetheinyl transferase crosstalk. Appl Microbiol Biotechnol 2021; 105:7785-7799. [PMID: 34546406 DOI: 10.1007/s00253-021-11546-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 10/20/2022]
Abstract
Escherichia coli Nissle 1917 (EcN) is a Gram-negative bacterium that is used to treat inflammatory bowel diseases. The probiotic character of EcN is not well-understood, but its ability to produce secondary metabolites plays an important role in its activity. The EcN genome encodes for an aryl polyene (APE) biosynthetic gene cluster (BGC), and APE products have a role in biofilm formation. We show here that this unusual polyketide assembly line synthase produces four APE molecules which are likely cis/trans isomers. Within the APE BGC, two acyl carrier proteins are involved in biosynthesis. Acyl carrier proteins require activation by post-translational modification with a phosphopantetheinyl transferase (PPTase). Through analysis of single, double, and triple mutants of three PPTases, the PPTase-BGC crosstalk relationship in EcN was characterized. Understanding PPTase-BGC crosstalk is important for the engineering of secondary metabolite production hosts and for targeting of PPTases with new antibiotics. KEY POINTS: • Escherichia coli Nissle 1917 biosynthesizes four aryl polyene isoforms. • Phosphopantetheinyl transferase crosstalk is important for biosynthesis.
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Affiliation(s)
- Courtney V Jones
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing and Center for Genomics Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
| | - Brianna G Jarboe
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing and Center for Genomics Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
| | - Haley M Majer
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing and Center for Genomics Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
| | - Amy T Ma
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing and Center for Genomics Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA
| | - Joris Beld
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing and Center for Genomics Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, PA, 19102, USA.
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28
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Peukert C, Langer LNB, Wegener SM, Tutov A, Bankstahl JP, Karge B, Bengel FM, Ross TL, Brönstrup M. Optimization of Artificial Siderophores as 68Ga-Complexed PET Tracers for In Vivo Imaging of Bacterial Infections. J Med Chem 2021; 64:12359-12378. [PMID: 34370949 DOI: 10.1021/acs.jmedchem.1c01054] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The diagnosis of bacterial infections at deep body sites benefits from noninvasive imaging of molecular probes that can be traced by positron emission tomography (PET). We specifically labeled bacteria by targeting their iron transport system with artificial siderophores. The cyclen-based probes contain different binding sites for iron and the PET nuclide gallium-68. A panel of 11 siderophores with different iron coordination numbers and geometries was synthesized in up to 8 steps, and candidates with the best siderophore potential were selected by a growth recovery assay. The probes [68Ga]7 and [68Ga]15 were found to be suitable for PET imaging based on their radiochemical yield, radiochemical purity, and complex stability in vitro and in vivo. Both showed significant uptake in mice infected with Escherichia coli and were able to discern infection from lipopolysaccharide-triggered, sterile inflammation. The study qualifies cyclen-based artificial siderophores as readily accessible scaffolds for the in vivo imaging of bacteria.
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Affiliation(s)
- Carsten Peukert
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany
| | - Laura N B Langer
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Sophie M Wegener
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Anna Tutov
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Bianka Karge
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany
| | - Frank M Bengel
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Tobias L Ross
- Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstraße 7, 38124 Braunschweig, Germany
- German Center for Infection Research (DZIF), Site Hannover-Braunschweig, 38124 Braunschweig, Germany
- Center for Biomolecular Drug Research (BMWZ), Schneiderberg 38, 30167 Hannover, Germany
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29
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Structural insights into a novel family of integral membrane siderophore reductases. Proc Natl Acad Sci U S A 2021; 118:2101952118. [PMID: 34417315 DOI: 10.1073/pnas.2101952118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gram-negative bacteria take up the essential ion Fe3+ as ferric-siderophore complexes through their outer membrane using TonB-dependent transporters. However, the subsequent route through the inner membrane differs across many bacterial species and siderophore chemistries and is not understood in detail. Here, we report the crystal structure of the inner membrane protein FoxB (from Pseudomonas aeruginosa) that is involved in Fe-siderophore uptake. The structure revealed a fold with two tightly bound heme molecules. In combination with in vitro reduction assays and in vivo iron uptake studies, these results establish FoxB as an inner membrane reductase involved in the release of iron from ferrioxamine during Fe-siderophore uptake.
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30
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Cunrath O, Palmer JD. An overview of Salmonella enterica metal homeostasis pathways during infection. ACTA ACUST UNITED AC 2021; 2:uqab001. [PMID: 34250489 PMCID: PMC8264917 DOI: 10.1093/femsml/uqab001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/19/2021] [Indexed: 12/14/2022]
Abstract
Nutritional immunity is a powerful strategy at the core of the battlefield between host survival and pathogen proliferation. A host can prevent pathogens from accessing biological metals such as Mg, Fe, Zn, Mn, Cu, Co or Ni, or actively intoxicate them with metal overload. While the importance of metal homeostasis for the enteric pathogen Salmonella enterica Typhimurium was demonstrated many decades ago, inconsistent results across various mouse models, diverse Salmonella genotypes, and differing infection routes challenge aspects of our understanding of this phenomenon. With expanding access to CRISPR-Cas9 for host genome manipulation, it is now pertinent to re-visit past results in the context of specific mouse models, identify gaps and incongruities in current knowledge landscape of Salmonella homeostasis, and recommend a straight path forward towards a more universal understanding of this historic host-microbe relationship.
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Affiliation(s)
- Olivier Cunrath
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Rd, Oxford, UK OX1 3SZ
| | - Jacob D Palmer
- Department of Zoology, University of Oxford, Zoology Research and Administration Building, 11a Mansfield Rd, Oxford, UK OX1 3SZ
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31
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Legros J, Jan S, Bonnassie S, Gautier M, Croguennec T, Pezennec S, Cochet MF, Nau F, Andrews SC, Baron F. The Role of Ovotransferrin in Egg-White Antimicrobial Activity: A Review. Foods 2021; 10:823. [PMID: 33920211 PMCID: PMC8070150 DOI: 10.3390/foods10040823] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 12/17/2022] Open
Abstract
Eggs are a whole food which affordably support human nutritional requirements worldwide. Eggs strongly resist bacterial infection due to an arsenal of defensive systems, many of which reside in the egg white. However, despite improved control of egg production and distribution, eggs remain a vehicle for foodborne transmission of Salmonella enterica serovar Enteritidis, which continues to represent a major public health challenge. It is generally accepted that iron deficiency, mediated by the iron-chelating properties of the egg-white protein ovotransferrin, has a key role in inhibiting infection of eggs by Salmonella. Ovotransferrin has an additional antibacterial activity beyond iron-chelation, which appears to depend on direct interaction with the bacterial cell surface, resulting in membrane perturbation. Current understanding of the antibacterial role of ovotransferrin is limited by a failure to fully consider its activity within the natural context of the egg white, where a series relevant environmental factors (such as alkalinity, high viscosity, ionic composition, and egg white protein interactions) may exert significant influence on ovotransferrin activity. This review provides an overview of what is known and what remains to be determined regarding the antimicrobial activity of ovotransferrin in egg white, and thus enhances understanding of egg safety through improved insight of this key antimicrobial component of eggs.
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Affiliation(s)
- Julie Legros
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
- School of Biological Sciences, Health and Life Sciences Building, University of Reading, Reading RG6 6AX, UK;
| | - Sophie Jan
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Sylvie Bonnassie
- UFR Sciences de la vie et de L’environnement, Université de Rennes 1, 35000 Rennes, France;
| | - Michel Gautier
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Thomas Croguennec
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Stéphane Pezennec
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Marie-Françoise Cochet
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Françoise Nau
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
| | - Simon C. Andrews
- School of Biological Sciences, Health and Life Sciences Building, University of Reading, Reading RG6 6AX, UK;
| | - Florence Baron
- STLO, INRAE, Institut Agro, 35042 Rennes, France; (J.L.); (S.J.); (M.G.); (T.C.); (S.P.); (M.-F.C.); (F.N.)
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32
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Zhu J, Wang T, Chen L, Du H. Virulence Factors in Hypervirulent Klebsiella pneumoniae. Front Microbiol 2021; 12:642484. [PMID: 33897652 PMCID: PMC8060575 DOI: 10.3389/fmicb.2021.642484] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/11/2021] [Indexed: 12/25/2022] Open
Abstract
Hypervirulent Klebsiella pneumoniae (hvKP) has spread globally since first described in the Asian Pacific Rim. It is an invasive variant that differs from the classical K. pneumoniae (cKP), with hypermucoviscosity and hypervirulence, causing community-acquired infections, including pyogenic liver abscess, pneumonia, meningitis, and endophthalmitis. It utilizes a battery of virulence factors for survival and pathogenesis, such as capsule, siderophores, lipopolysaccharide, fimbriae, outer membrane proteins, and type 6 secretion system, of which the former two are dominant. This review summarizes these hvKP-associated virulence factors in order to understand its molecular pathogenesis and shed light on new strategies to improve the prevention, diagnosis, and treatment of hvKP-causing infection.
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Affiliation(s)
- Jie Zhu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Tao Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Liang Chen
- Hackensack Meridian Health Center for Discovery and Innovation, Nutley, NJ, United States.,Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, United States
| | - Hong Du
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
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33
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Zeng X, Wang H, Huang C, Logue CM, Barbieri NL, Nolan LK, Lin J. Evaluation of the Immunogenic Response of a Novel Enterobactin Conjugate Vaccine in Chickens for the Production of Enterobactin-Specific Egg Yolk Antibodies. Front Immunol 2021; 12:629480. [PMID: 33868248 PMCID: PMC8050339 DOI: 10.3389/fimmu.2021.629480] [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] [Received: 11/14/2020] [Accepted: 03/01/2021] [Indexed: 12/12/2022] Open
Abstract
Passive immunization with specific egg yolk antibodies (immunoglobulin Y, IgY) is emerging as a promising alternative to antibiotics to control bacterial infections. Recently, we developed a novel conjugate vaccine that could trigger a strong immune response in rabbits directed against enterobactin (Ent), a highly conserved siderophore molecule utilized by different Gram-negative pathogens. However, induction of Ent-specific antibodies appeared to be affected by the choice of animal host and vaccination regimen. It is still unknown if the Ent conjugate vaccine can trigger a specific immune response in layers for the purpose of production of anti-Ent egg yolk IgY. In this study, three chicken vaccination trials with different regimens were performed to determine conditions for efficient production of anti-Ent egg yolk IgY. Purified Ent was conjugated to three carrier proteins, keyhole limpet hemocyanin (KLH), bovine serum albumin (BSA) and CmeC (a subunit vaccine candidate), respectively. Intramuscular immunization of Barred Rock layers with KLH-Ent conjugate four times induced strong immune response against whole conjugate vaccine but the titer of Ent-specific IgY did not change in yolk with only a 4 fold increase detected in serum. In the second trial, three different Ent conjugate vaccines were evaluated in Rhode Island Red pullets with four subcutaneous injections. The KLH-Ent or CmeC-Ent conjugate consistently induced high level of Ent-specific IgY in both serum (up to 2,048 fold) and yolk (up to 1,024 fold) in each individual chicken. However, the Ent-specific immune response was only temporarily and moderately induced using a BSA-Ent vaccination. In the third trial, ten White Leghorn layers were subcutaneously immunized three times with KLH-Ent, leading to consistent and strong immune response against both whole conjugate and the Ent molecule in each chicken; the mean titer of Ent-specific IgY increased approximately 32 and 256 fold in serum and yolk, respectively. Consistent with its potent binding to various Ent derivatives, the Ent-specific egg yolk IgY also inhibited in vitro growth of a representative Escherichia coli strain. Together, this study demonstrated that the novel Ent conjugate vaccine could induce strong, specific, and robust immune response in chickens. The Ent-specific hyperimmune egg yolk IgY has potential for passive immune intervention against Gram-negative infections.
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Affiliation(s)
- Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN, United States
| | - Huiwen Wang
- Department of Animal Science, The University of Tennessee, Knoxville, TN, United States
| | - Canghai Huang
- Department of Animal Science, The University of Tennessee, Knoxville, TN, United States.,College of Fisheries, Jimei University, Xiamen, China
| | - Catherine M Logue
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Nicolle L Barbieri
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Lisa K Nolan
- College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN, United States
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34
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Gasser V, Kuhn L, Hubert T, Aussel L, Hammann P, Schalk IJ. The Esterase PfeE, the Achilles' Heel in the Battle for Iron between Pseudomonas aeruginosa and Escherichia coli. Int J Mol Sci 2021; 22:ijms22062814. [PMID: 33802163 PMCID: PMC8001512 DOI: 10.3390/ijms22062814] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/23/2021] [Accepted: 03/02/2021] [Indexed: 11/16/2022] Open
Abstract
Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen Pseudomonas aeruginosa produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by Escherichia coli. ENT-Fe complexes are imported across the outer membrane of P. aeruginosa by the two outer membrane transporters PfeA and PirA. Iron is released from ENT in the P. aeruginosa periplasm by hydrolysis of ENT by the esterase PfeE. We show here that pfeE gene deletion renders P. aeruginosa unable to grow in the presence of ENT because it is unable to access iron via this siderophore. Two-species co-cultures under iron-restricted conditions show that P. aeruginosa strongly represses the growth of E. coli as long it is able to produce its own siderophores. Both strains are present in similar proportions in the culture as long as the siderophore-deficient P. aeruginosa strain is able to use ENT produced by E. coli to access iron. If pfeE is deleted, E. coli has the upper hand in the culture and P. aeruginosa growth is repressed. Overall, these data show that PfeE is the Achilles' heel of P. aeruginosa in communities with bacteria producing ENT.
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Affiliation(s)
- Véronique Gasser
- InnoVec, UMR7242, Université de Strasbourg, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France; (V.G.); (T.H.)
- UMR7242, CNRS, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France
| | - Laurianne Kuhn
- Plateforme Proteomique Strasbourg-Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS, FR1589, 15 rue Descartes, F-67084 Strasbourg CEDEX, France; (L.K.); (P.H.)
| | - Thibaut Hubert
- InnoVec, UMR7242, Université de Strasbourg, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France; (V.G.); (T.H.)
- UMR7242, CNRS, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France
| | - Laurent Aussel
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, Aix-Marseille University, CNRS, 13 900 Marseille, France;
| | - Philippe Hammann
- Plateforme Proteomique Strasbourg-Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS, FR1589, 15 rue Descartes, F-67084 Strasbourg CEDEX, France; (L.K.); (P.H.)
| | - Isabelle J. Schalk
- InnoVec, UMR7242, Université de Strasbourg, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France; (V.G.); (T.H.)
- UMR7242, CNRS, ESBS, Bld Sébastien Brant, F-67413 Illkirch, France
- Correspondence:
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35
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Fan D, Fang Q. Siderophores for medical applications: Imaging, sensors, and therapeutics. Int J Pharm 2021; 597:120306. [PMID: 33540031 DOI: 10.1016/j.ijpharm.2021.120306] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 01/07/2023]
Abstract
Siderophores are low-molecular-weight chelators produced by microorganisms to scavenge iron from the environment and deliver it to cells via specific receptors. Tremendous researches on the molecular basis of siderophore regulation, synthesis, secretion, and uptake have inspired their diverse applications in the medical field. Replacing iron with radionuclides in siderophores, such as the most prominent Ga-68 for positron emission tomography (PET), carves out ways for targeted imaging of infectious diseases and cancers. Additionally, the high affinity of siderophores for metal ions or microorganisms makes them a potent detecting moiety in sensors that can be used for diagnosis. As for therapeutics, the notable Trojan horse-inspired siderophore-antibiotic conjugates demonstrate enhanced toxicity against multi-drug resistant (MDR) pathogens. Besides, siderophores can tackle iron overload diseases and, when combined with moieties such as hydrogels and nanoparticles, a wide spectrum of iron-induced diseases and even cancers. In this review, we briefly outline the related mechanisms, before summarizing the siderophore-based applications in imaging, sensors, and therapeutics.
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Affiliation(s)
- Di Fan
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China
| | - Qiaojun Fang
- Laboratory of Theoretical and Computational Nanoscience, CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Ambient Particles Health Effects and Prevention Techniques, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, PR China; Sino-Danish Center for Education and Research, Beijing 101408, PR China.
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Nodwell MB, Britton R. Enterobactin on a Bead: Parallel, Solid Phase Siderophore Synthesis Reveals Structure-Activity Relationships for Iron Uptake in Bacteria. ACS Infect Dis 2021; 7:153-161. [PMID: 33290047 DOI: 10.1021/acsinfecdis.0c00687] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A solid-phase platform for the precise and sequential synthesis of enterobactin analogues is described. This chemistry unites the power of solid-phase peptide synthesis with the unique opportunities and applications offered by siderophore chemistry. Here, a series of hybrid enterobactin hydroxamate/catecholate (HEHC) analogues were synthesized using both catechols and amino acid derived hydroxmate chelators. The HEHC analogues were evaluated for their ability to bind free iron and to promote growth in siderophore-auxotrophic mutant bacteria. We find that, in contrast to S. aureus or E. coli, a number of HEHC analogues promote growth in P. aeruginosa and structure-activity relationships (SARs) exist for the growth promotion via HEHC analogues in this organism.
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Affiliation(s)
- Matthew B. Nodwell
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S2, Canada
| | - Robert Britton
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V5A 1S2, Canada
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Southwell JW, Black CM, Duhme-Klair AK. Experimental Methods for Evaluating the Bacterial Uptake of Trojan Horse Antibacterials. ChemMedChem 2020; 16:1063-1076. [PMID: 33238066 DOI: 10.1002/cmdc.202000806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Indexed: 01/10/2023]
Abstract
The field of antibacterial siderophore conjugates, referred to as Trojan Horse antibacterials, has received increasing attention in recent years, driven by the rise of antimicrobial resistance. Trojan Horse antibacterials offer an opportunity to exploit the specific pathways present in bacteria for active iron uptake, potentially allowing the drugs to bypass membrane-associated resistance mechanisms. Hence, the Trojan Horse approach might enable the redesigning of old antibiotics and the development of antibacterials that target specific pathogens. Critical parts of evaluating such Trojan Horse antibacterials and improving their design are the quantification of their bacterial uptake and the identification of the pathways by which this occurs. In this minireview, we highlight a selection of the biological and chemical methods used to study the uptake of Trojan Horse antibacterials, exemplified with case studies, some of which have led to drug candidates in clinical development or approved antibiotics.
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Affiliation(s)
- James W Southwell
- Department of Chemistry, University of York, Heslington, North Yorkshire, YO10 5DD, UK
| | - Conor M Black
- Department of Chemistry, University of York, Heslington, North Yorkshire, YO10 5DD, UK
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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39
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Wellawa DH, Allan B, White AP, Köster W. Iron-Uptake Systems of Chicken-Associated Salmonella Serovars and Their Role in Colonizing the Avian Host. Microorganisms 2020; 8:E1203. [PMID: 32784620 PMCID: PMC7465098 DOI: 10.3390/microorganisms8081203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 07/30/2020] [Accepted: 07/31/2020] [Indexed: 01/09/2023] Open
Abstract
Iron is an essential micronutrient for most bacteria. Salmonella enterica strains, representing human and animal pathogens, have adopted several mechanisms to sequester iron from the environment depending on availability and source. Chickens act as a major reservoir for Salmonella enterica strains which can lead to outbreaks of human salmonellosis. In this review article we summarize the current understanding of the contribution of iron-uptake systems to the virulence of non-typhoidal S. enterica strains in colonizing chickens. We aim to address the gap in knowledge in this field, to help understand and define the interactions between S. enterica and these important hosts, in comparison to mammalian models.
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Affiliation(s)
- Dinesh H. Wellawa
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Brenda Allan
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
| | - Aaron P. White
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
| | - Wolfgang Köster
- Vaccine & Infectious Disease Organization-International Vaccine Centre, University of Saskatchewan, 120 Veterinary Rd., Saskatoon, SK S7N 5E3, Canada; (D.H.W.); (B.A.); (A.P.W.)
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada
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Zhang Y, Sen S, Giedroc DP. Iron Acquisition by Bacterial Pathogens: Beyond Tris-Catecholate Complexes. Chembiochem 2020; 21:1955-1967. [PMID: 32180318 PMCID: PMC7367709 DOI: 10.1002/cbic.201900778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/06/2020] [Indexed: 12/11/2022]
Abstract
Sequestration of the essential nutrient iron from bacterial invaders that colonize the vertebrate host is a central feature of nutritional immunity and the "fight over transition metals" at the host-pathogen interface. The iron quota for many bacterial pathogens is large, as iron enzymes often make up a significant share of the metalloproteome. Iron enzymes play critical roles in respiration, energy metabolism, and other cellular processes by catalyzing a wide range of oxidation-reduction, electron transfer, and oxygen activation reactions. In this Concept article, we discuss recent insights into the diverse ways that bacterial pathogens acquire this essential nutrient, beyond the well-characterized tris-catecholate FeIII complexes, in competition and cooperation with significant host efforts to cripple these processes. We also discuss pathogen strategies to adapt their metabolism to less-than-optimal iron concentrations, and briefly speculate on what might be an integrated adaptive response to the concurrent limitation of both iron and zinc in the infected host.
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Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
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Whole-Genome Comparative and Pathogenicity Analysis of Salmonella enterica subsp. enterica Serovar Rissen. G3-GENES GENOMES GENETICS 2020; 10:2159-2170. [PMID: 32358017 PMCID: PMC7341144 DOI: 10.1534/g3.120.401201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Salmonella are a type of bacteria known to cause food-borne illness. Their host range varies widely, and their susceptibility to the host determines its pathogenicity. Salmonella enterica serovar Rissen (S. Rissen) is a widely distributed serotype; however, its virulence and pathogenicity are poorly understood. In this study, the pathogenicity and antibiotic resistance of a representative S. Rissen isolate were investigated. The cell model results showed that S. Rissen preferred to replicate in human macrophage cells U937 compared to murine macrophage cells RAW264.7, suggesting that it has a level of host adaptability. Genome sequencing and comparison analysis revealed that the distribution and nonsynonymous single nucleotide polymorphisms of virulence factors in S. Rissen were similar to those in S. Typhi rather than to those in S. Typhimurium. Taken together, our results suggest that although S. Rissen is a common serotype distributed in swine herds, pork and chicken products, it has strong ability to infect humans.
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42
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Guo C, Steinberg LK, Cheng M, Song JH, Henderson JP, Gross ML. Site-Specific Siderocalin Binding to Ferric and Ferric-Free Enterobactin As Revealed by Mass Spectrometry. ACS Chem Biol 2020; 15:1154-1160. [PMID: 31869199 PMCID: PMC7236765 DOI: 10.1021/acschembio.9b00741] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/23/2019] [Indexed: 11/29/2022]
Abstract
Both host and pathogen competitively manipulate coordination environments during bacterial infections. Human cells release the innate immune protein siderocalin (Scn, also known as lipocalin-2/Lcn2, neutrophil gelatinase-associated lipocalin/NGAL) that can inhibit bacterial growth by sequestering iron in a ferric complex with enterobactin (Ent), the ubiquitous Escherichia coli siderophore. Pathogenic E. coli use the virulence-associated esterase IroE to linearize the Ent cyclic trilactone to linear enterobactin (lin-Ent). We characterized lin-Ent interactions with Scn by using native mass spectrometry (MS) with hydrogen-deuterium exchange (HDX) and Lys/Arg specific covalent footprinting. These approaches support 1:1 binding of both Fe(III)-lin-Ent to Scn and iron-free lin-Ent to Scn. Both ferric and nonferric lin-Ent localize to all three pockets of the Scn calyx, consistent with Scn capture of lin-Ent both before and after Fe(III) chelation. These findings raise the possibility that Scn neutralizes both siderophores and siderophore-bound iron during infections. This integrated, MS-based approach circumvents the limitations that frustrate traditional structural approaches to examining Scn interactions with enterobactin-based ligands.
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Affiliation(s)
- Chunyang Guo
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Lindsey K. Steinberg
- Division
of Infectious Diseases, Department of Medicine, the Center for Women’s
Infectious Disease Research, Washington
University School of Medicine, St. Louis, Missouri 63110, United States
| | - Ming Cheng
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Jong Hee Song
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
| | - Jeffrey P. Henderson
- Division
of Infectious Diseases, Department of Medicine, the Center for Women’s
Infectious Disease Research, Washington
University School of Medicine, St. Louis, Missouri 63110, United States
| | - Michael L. Gross
- Department
of Chemistry, Washington University, St. Louis, Missouri 63130, United States
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Linearized Siderophore Products Secreted via MacAB Efflux Pump Protect Salmonella enterica Serovar Typhimurium from Oxidative Stress. mBio 2020; 11:mBio.00528-20. [PMID: 32371597 PMCID: PMC7403778 DOI: 10.1128/mbio.00528-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Nontyphoidal Salmonella bacteria induce a classic inflammatory diarrhea by eliciting a large influx of neutrophils, producing a robust oxidative burst. Despite substantial progress understanding the benefits to the host of the inflammatory response to Salmonella, little is known regarding how Salmonella can simultaneously resist the damaging effects of the oxidative burst. The multidrug efflux pump MacAB is important for survival of oxidative stress both in vitro and during infection. We describe a new pathway used by Salmonella Typhimurium to detoxify extracellular reactive oxygen species using a multidrug efflux pump (MacAB) to secrete a linear siderophore, a metabolite of enterobactin. The natural substrates of many multidrug efflux pumps are unknown, and functional roles of the linear metabolites of enterobactin are unknown. We bring two novel discoveries together to highlight an important mechanism used by Salmonella to survive under the oxidative stress conditions that this organism encounters during the classic inflammatory diarrhea that it also induces. Nontyphoidal salmonellae (NTS) are exposed to reactive oxygen species (ROS) during their residency in the gut. To survive oxidative stress encountered during infection, salmonellae employ several mechanisms. One of these mechanisms involves the multidrug efflux pump MacAB, although the natural substrate of this pump has not been identified. MacAB homologs in pseudomonads secrete products of nonribosomal peptide synthesis (NRPS). In Salmonella enterica serovar Typhimurium, the siderophore enterobactin is produced by NRPS in response to iron starvation and this molecule can be processed into salmochelin and several linear metabolites. We found that Salmonella mutants lacking the key NRPS enzyme EntF are sensitive to peroxide mediated killing and cannot detoxify extracellular H2O2. Moreover, EntF and MacAB function in a common pathway to promote survival of Salmonella during oxidative stress. We further demonstrated that S. Typhimurium secretes siderophores in iron-rich media when peroxide is present and that these MacAB-secreted metabolites participate in protection of bacteria against H2O2. We showed that secretion of anti-H2O2 molecules is independent of the presence of the known siderophore efflux pumps EntS and IroC, well-described efflux systems involved in secretion of enterobactin and salmochelin. Both salmochelin and enterobactin are dispensable for S. Typhimurium protection against ROS; however, linear metabolites of enterobactin produced by esterases IroE and Fes are needed for bacterial survival in peroxide-containing media. We determined that linearized enterobactin trimer protects S. Typhimurium against peroxide-mediated killing in a MacAB-dependent fashion. Thus, we suggest that linearized enterobactin trimer is a natural substrate of MacAB and that its purpose is to detoxify extracellular reactive oxygen species.
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Palmer JD, Mortzfeld BM, Piattelli E, Silby MW, McCormick BA, Bucci V. Microcin H47: A Class IIb Microcin with Potent Activity Against Multidrug Resistant Enterobacteriaceae. ACS Infect Dis 2020; 6:672-679. [PMID: 32096972 DOI: 10.1021/acsinfecdis.9b00302] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microcin H47 (MccH47) is an antimicrobial peptide produced by some strains of Escherichia coli that has demonstrated inhibitory activity against enteric pathogens in vivo and has been heterologously overexpressed in proof-of-concept engineered probiotic applications. While most studies clearly demonstrate inhibitory activity against E. coli isolates, there are conflicting results on the qualitative capacity for MccH47 to inhibit strains of Salmonella. Here, we rectify these inconsistencies via the overexpression and purification of a form of MccH47, termed MccH47-monoglycosylated enterobactin (MccH47-MGE). We then use purified MccH47 to estimate minimum inhibitory concentrations (MICs) against a number of medically relevant Enterobacteriaceae, including Salmonella and numerous multidrug resistant (MDR) strains. While previous reports suggested that the spectrum of activity for MccH47 is quite narrow and restricted to activity against E. coli, our data demonstrate that MccH47 has broad and potent activity within the Enterobacteriaceae family, suggesting it as a candidate for further development toward treating MDR enteric infections.
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Affiliation(s)
- Jacob D. Palmer
- Department of Bioengineering, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
| | - Benedikt M. Mortzfeld
- Department of Bioengineering, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, Massachusetts 01605, United States
| | - Emma Piattelli
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
| | - Mark W. Silby
- Department of Biology, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
| | - Beth A. McCormick
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, Massachusetts 01605, United States
- Center for Microbiome Research, University of Massachusetts Medical School, 368 Plantation Street, Worcester, Massachusetts 01605, United States
| | - Vanni Bucci
- Department of Bioengineering, University of Massachusetts Dartmouth, 285 Old Westport Road, N. Dartmouth, Massachusetts 02747-2300, United States
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street, Worcester, Massachusetts 01605, United States
- Center for Microbiome Research, University of Massachusetts Medical School, 368 Plantation Street, Worcester, Massachusetts 01605, United States
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Marchetti M, De Bei O, Bettati S, Campanini B, Kovachka S, Gianquinto E, Spyrakis F, Ronda L. Iron Metabolism at the Interface between Host and Pathogen: From Nutritional Immunity to Antibacterial Development. Int J Mol Sci 2020; 21:E2145. [PMID: 32245010 PMCID: PMC7139808 DOI: 10.3390/ijms21062145] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/08/2023] Open
Abstract
Nutritional immunity is a form of innate immunity widespread in both vertebrates and invertebrates. The term refers to a rich repertoire of mechanisms set up by the host to inhibit bacterial proliferation by sequestering trace minerals (mainly iron, but also zinc and manganese). This strategy, selected by evolution, represents an effective front-line defense against pathogens and has thus inspired the exploitation of iron restriction in the development of innovative antimicrobials or enhancers of antimicrobial therapy. This review focuses on the mechanisms of nutritional immunity, the strategies adopted by opportunistic human pathogen Staphylococcus aureus to circumvent it, and the impact of deletion mutants on the fitness, infectivity, and persistence inside the host. This information finally converges in an overview of the current development of inhibitors targeting the different stages of iron uptake, an as-yet unexploited target in the field of antistaphylococcal drug discovery.
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Affiliation(s)
- Marialaura Marchetti
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
| | - Omar De Bei
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Stefano Bettati
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
- National Institute of Biostructures and Biosystems, 00136 Rome, Italy
| | - Barbara Campanini
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Sandra Kovachka
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Eleonora Gianquinto
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Luca Ronda
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
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46
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Kramer J, Özkaya Ö, Kümmerli R. Bacterial siderophores in community and host interactions. Nat Rev Microbiol 2020; 18:152-163. [PMID: 31748738 PMCID: PMC7116523 DOI: 10.1038/s41579-019-0284-4] [Citation(s) in RCA: 407] [Impact Index Per Article: 101.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2019] [Indexed: 01/06/2023]
Abstract
Iron is an essential trace element for most organisms. A common way for bacteria to acquire this nutrient is through the secretion of siderophores, which are secondary metabolites that scavenge iron from environmental stocks and deliver it to cells via specific receptors. While there has been tremendous interest in understanding the molecular basis of siderophore synthesis, uptake and regulation, questions about the ecological and evolutionary consequences of siderophore secretion have only recently received increasing attention. In this Review, we outline how eco-evolutionary questions can complement the mechanistic perspective and help to obtain a more integrated view of siderophores. In particular, we explain how secreted diffusible siderophores can affect other community members, leading to cooperative, exploitative and competitive interactions between individuals. These social interactions in turn can spur co-evolutionary arms races between strains and species, lead to ecological dependencies between them and potentially contribute to the formation of stable communities. In brief, this Review shows that siderophores are much more than just iron carriers: they are important mediators of interactions between members of microbial assemblies and the eukaryotic hosts they inhabit.
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Affiliation(s)
- Jos Kramer
- Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
| | - Özhan Özkaya
- Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland
| | - Rolf Kümmerli
- Department of Quantitative Biomedicine, University of Zurich, Zurich, Switzerland.
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47
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Massip C, Branchu P, Bossuet-Greif N, Chagneau CV, Gaillard D, Martin P, Boury M, Sécher T, Dubois D, Nougayrède JP, Oswald E. Deciphering the interplay between the genotoxic and probiotic activities of Escherichia coli Nissle 1917. PLoS Pathog 2019; 15:e1008029. [PMID: 31545853 PMCID: PMC6776366 DOI: 10.1371/journal.ppat.1008029] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 10/03/2019] [Accepted: 08/14/2019] [Indexed: 12/28/2022] Open
Abstract
Although Escherichia coli Nissle 1917 (EcN) has been used therapeutically for over a century, the determinants of its probiotic properties remain elusive. EcN produces two siderophore-microcins (Mcc) responsible for an antagonistic activity against other Enterobacteriaceae. EcN also synthesizes the genotoxin colibactin encoded by the pks island. Colibactin is a virulence factor and a putative pro-carcinogenic compound. Therefore, we aimed to decouple the antagonistic activity of EcN from its genotoxic activity. We demonstrated that the pks-encoded ClbP, the peptidase that activates colibactin, is required for the antagonistic activity of EcN. The analysis of a series of ClbP mutants revealed that this activity is linked to the transmembrane helices of ClbP and not the periplasmic peptidase domain, indicating the transmembrane domain is involved in some aspect of Mcc biosynthesis or secretion. A single amino acid substitution in ClbP inactivates the genotoxic activity but maintains the antagonistic activity. In an in vivo salmonellosis model, this point mutant reduced the clinical signs and the fecal shedding of Salmonella similarly to the wild type strain, whereas the clbP deletion mutant could neither protect nor outcompete the pathogen. The ClbP-dependent antibacterial effect was also observed in vitro with other E. coli strains that carry both a truncated form of the Mcc gene cluster and the pks island. In such strains, siderophore-Mcc synthesis also required the glucosyltransferase IroB involved in salmochelin production. This interplay between colibactin, salmochelin, and siderophore-Mcc biosynthetic pathways suggests that these genomic islands were co-selected and played a role in the evolution of E. coli from phylogroup B2. This co-evolution observed in EcN illustrates the fine margin between pathogenicity and probiotic activity, and the need to address both the effectiveness and safety of probiotics. Decoupling the antagonistic from the genotoxic activity by specifically inactivating ClbP peptidase domain opens the way to the safe use of EcN.
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Affiliation(s)
- Clémence Massip
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
| | - Priscilla Branchu
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | | | | | - Déborah Gaillard
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Patricia Martin
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Michèle Boury
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Thomas Sécher
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
| | - Damien Dubois
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
| | | | - Eric Oswald
- IRSD, Université de Toulouse, INSERM, INRA, ENVT, UPS, Toulouse, France
- CHU Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse, France
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48
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Kong H, Cheng W, Wei H, Yuan Y, Yang Z, Zhang X. An overview of recent progress in siderophore-antibiotic conjugates. Eur J Med Chem 2019; 182:111615. [PMID: 31434038 DOI: 10.1016/j.ejmech.2019.111615] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/01/2019] [Accepted: 08/09/2019] [Indexed: 01/09/2023]
Abstract
Multi-drug resistant infections caused by Gram-negative bacteria have become one of the most important reasons for the failure of clinical anti-infective treatment. Siderophore-antibiotic conjugates, which were designed based on a "Trojan horse" strategy wherein features enabled active uptake to bypass the Gram-negative cell wall, have been expected to be a weapon for anti-infective treatment in the clinic. Herein, we review antibiotic drug design strategies based on mimics of nature siderophores reported in recent years, we also focus our attention on the relationship between the type of linker and the corresponding antibacterial activity.
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Affiliation(s)
- Huimin Kong
- Department of Pediatrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Weiyan Cheng
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Han Wei
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Yongliang Yuan
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Zhiheng Yang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
| | - Xiaojian Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
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49
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Identification of a novel esterase from the thermophilic bacterium Geobacillus thermodenitrificans NG80-2. Extremophiles 2019; 23:407-419. [DOI: 10.1007/s00792-019-01093-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 04/16/2019] [Indexed: 12/14/2022]
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50
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Enterobactin-Specific Antibodies Induced by a Novel Enterobactin Conjugate Vaccine. Appl Environ Microbiol 2019; 85:AEM.00358-19. [PMID: 30877122 DOI: 10.1128/aem.00358-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 03/12/2019] [Indexed: 01/01/2023] Open
Abstract
Enterobactin (Ent)-mediated high-affinity iron acquisition is critical for Gram-negative bacteria to survive in the host. Given the bacteriostatic effect of lipocalin resulting from its potent Ent-binding ability, immune intervention directly targeting Ent is promising for iron-dependent pathogen control. Recently, an Ent conjugate vaccine was reported, but it still has several significant weaknesses. In this study, we sought to develop an innovative Ent conjugate vaccine that can induce a high level of antibodies directed against Ent and to provide solid evidence demonstrating siderophore-binding capacity of Ent-specific antibodies. Using a simple method, we successfully conjugated purified Ent to different carriers, including keyhole limpet hemocyanin (KLH), bovine serum albumin, and CmeC, a vaccine candidate for Campylobacter control. Subcutaneous immunization of rabbits with the KLH-Ent conjugate triggered a strong systemic IgG immune response with an up to 16,384-fold increase in IgG titer directed against whole conjugate and an up to 4,096-fold increase in the level of specific anti-Ent IgG. To evaluate the ability of Ent-specific IgG to bind to the Ent derivatives present in vivo, various Ent derivatives were chemically synthesized and a unique enzyme-linked immunosorbent assay method was developed. The Ent-specific IgG also displayed exceptional reactivity to ferric Ent, a linear trimer of Ent, and different salmochelins. Growth assays further demonstrated that the Ent-specific antibodies significantly inhibited Ent-dependent growth of Campylobacter spp. and Escherichia coli Collectively, this study reports an efficient method to prepare a new type of Ent conjugate vaccines for inducing a high level of Ent-specific antibodies, which can bind to various Ent derivatives and display lipocalin-like bacteriostatic features.IMPORTANCE Ent-mediated high-affinity iron acquisition is a universal and critical contributor for Gram-negative pathogens to survive and infect hosts. Published information has supported an innovative immune intervention strategy that directly targets Ent to starve pathogens by limiting the availability of iron to be utilized. Compared to a recently published Ent conjugate, there are three advantages of the vaccine described in this study: ease of preparation, induction of high titer of anti-Ent IgG, and the ability of Ent-specific antibodies to bind various Ent derivatives, including the salmochelins that help enteric pathogens evade sequestration of siderophores by host lipocalins. In addition, the Ent-specific antibodies were demonstrated to function similarly to lipocalin to interfere with the Ent-dependent growth of Campylobacter and E. coli under iron-restricted conditions. This study has significant potential for broader applications to prevent and control various Gram-negative infections in humans and animals.
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