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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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Ganske A, Busch LM, Hentschker C, Reder A, Michalik S, Surmann K, Völker U, Mäder U. Exploring the targetome of IsrR, an iron-regulated sRNA controlling the synthesis of iron-containing proteins in Staphylococcus aureus. Front Microbiol 2024; 15:1439352. [PMID: 39035440 PMCID: PMC11257911 DOI: 10.3389/fmicb.2024.1439352] [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: 05/27/2024] [Accepted: 06/25/2024] [Indexed: 07/23/2024] Open
Abstract
Staphylococcus aureus is a common colonizer of the skin and nares of healthy individuals, but also a major cause of severe human infections. During interaction with the host, pathogenic bacteria must adapt to a variety of adverse conditions including nutrient deprivation. In particular, they encounter severe iron limitation in the mammalian host through iron sequestration by haptoglobin and iron-binding proteins, a phenomenon called "nutritional immunity." In most bacteria, including S. aureus, the ferric uptake regulator (Fur) is the key regulator of iron homeostasis, which primarily acts as a transcriptional repressor of genes encoding iron acquisition systems. Moreover, Fur can control the expression of trans-acting small regulatory RNAs that play an important role in the cellular iron-sparing response involving major changes in cellular metabolism under iron-limiting conditions. In S. aureus, the sRNA IsrR is controlled by Fur, and most of its predicted targets are iron-containing proteins and other proteins related to iron metabolism and iron-dependent pathways. To characterize the IsrR targetome on a genome-wide scale, we combined proteomics-based identification of potential IsrR targets using S. aureus strains either lacking or constitutively expressing IsrR with an in silico target prediction approach, thereby suggesting 21 IsrR targets, of which 19 were negatively affected by IsrR based on the observed protein patterns. These included several Fe-S cluster- and heme-containing proteins, such as TCA cycle enzymes and catalase encoded by katA. IsrR affects multiple metabolic pathways connected to the TCA cycle as well as the oxidative stress response of S. aureus and links the iron limitation response to metabolic remodeling. In contrast to the majority of target mRNAs, the IsrR-katA mRNA interaction is predicted upstream of the ribosome binding site, and further experiments including mRNA half-life measurements demonstrated that IsrR, in addition to inhibiting translation initiation, can downregulate target protein levels by affecting mRNA stability.
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Affiliation(s)
| | | | | | | | | | | | | | - Ulrike Mäder
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
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Sosa-Fajardo A, Díaz-Muñoz C, Van der Veken D, Pradal I, Verce M, Weckx S, Leroy F. Genomic exploration of the fermented meat isolate Staphylococcus shinii IMDO-S216 with a focus on competitiveness-enhancing secondary metabolites. BMC Genomics 2024; 25:575. [PMID: 38849728 PMCID: PMC11161930 DOI: 10.1186/s12864-024-10490-0] [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: 09/01/2023] [Accepted: 06/03/2024] [Indexed: 06/09/2024] Open
Abstract
BACKGROUND Staphylococcus shinii appears as an umbrella species encompassing several strains of Staphylococcus pseudoxylosus and Staphylococcus xylosus. Given its phylogenetic closeness to S. xylosus, S. shinii can be found in similar ecological niches, including the microbiota of fermented meats where the species may contribute to colour and flavour development. In addition to these conventional functionalities, a biopreservation potential based on the production of antagonistic compounds may be available. Such potential, however, remains largely unexplored in contrast to the large body of research that is available on the biopreservative properties of lactic acid bacteria. The present study outlines the exploration of the genetic basis of competitiveness and antimicrobial activity of a fermented meat isolate, S. shinii IMDO-S216. To this end, its genome was sequenced, de novo assembled, and annotated. RESULTS The genome contained a single circular chromosome and eight plasmid replicons. Focus of the genomic exploration was on secondary metabolite biosynthetic gene clusters coding for ribosomally synthesized and posttranslationally modified peptides. One complete cluster was coding for a bacteriocin, namely lactococcin 972; the genes coding for the pre-bacteriocin, the ATP-binding cassette transporter, and the immunity protein were also identified. Five other complete clusters were identified, possibly functioning as competitiveness factors. These clusters were found to be involved in various responses such as membrane fluidity, iron intake from the medium, a quorum sensing system, and decreased sensitivity to antimicrobial peptides and competing microorganisms. The presence of these clusters was equally studied among a selection of multiple Staphylococcus species to assess their prevalence in closely-related organisms. CONCLUSIONS Such factors possibly translate in an improved adaptation and competitiveness of S. shinii IMDO-S216 which are, in turn, likely to improve its fitness in a fermented meat matrix.
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Affiliation(s)
- Ana Sosa-Fajardo
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Cristian Díaz-Muñoz
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - David Van der Veken
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Inés Pradal
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marko Verce
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Stefan Weckx
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Frédéric Leroy
- Research Group of Industrial Microbiology and Food Biotechnology (IMDO), Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
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Narh Mensah DL, Wingfield BD, Coetzee MPA. Two distinct non-ribosomal peptide synthetase-independent siderophore synthetase gene clusters identified in Armillaria and other species in the Physalacriaceae. G3 (BETHESDA, MD.) 2023; 13:jkad205. [PMID: 37843963 PMCID: PMC10700112 DOI: 10.1093/g3journal/jkad205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 08/28/2023] [Indexed: 10/18/2023]
Abstract
Siderophores are important for ferric iron solubilization, sequestration, transportation, and storage, especially under iron-limiting conditions such as aerobic conditions at high pH. Siderophores are mainly produced by non-ribosomal peptide synthetase-dependent siderophore pathway, non-ribosomal peptide synthetase-independent siderophore synthetase pathway, or the hybrid non-ribosomal peptide synthetases/non-ribosomal peptide synthetases-independent siderophore pathway. Outcompeting or inhibition of plant pathogens, alteration of host defense mechanisms, and alteration of plant-fungal interactions have been associated with fungal siderophores. To understand these mechanisms in fungi, studies have been conducted on siderophore biosynthesis by ascomycetes with limited focus on the basidiomycetes. Armillaria includes several species that are pathogens of woody plants and trees important to agriculture, horticulture, and forestry. The aim of this study was to investigate the presence of non-ribosomal peptide synthetases-independent siderophore synthetase gene cluster(s) in genomes of Armillaria species using a comparative genomics approach. Iron-dependent growth and siderophore biosynthesis in strains of selected Armillaria spp. were also evaluated in vitro. Two distinct non-ribosomal peptide synthetases-independent siderophore synthetase gene clusters were identified in all the genomes. All non-ribosomal peptide synthetases-independent siderophore synthetase genes identified putatively encode Type A' non-ribosomal peptide synthetases-independent siderophore synthetases, most of which have IucA_IucC and FhuF-like transporter domains at their N- and C-terminals, respectively. The effect of iron on culture growth varied among the strains studied. Bioassays using the CAS assay on selected Armillaria spp. revealed in vitro siderophore biosynthesis by all strains irrespective of added FeCl3 concentration. This study highlights some of the tools that Armillaria species allocate to iron homeostasis. The information generated from this study may in future aid in developing molecular based methods to control these phytopathogens.
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Affiliation(s)
- Deborah L Narh Mensah
- Departments of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa
- CSIR—Food Research Institute, Microbiology and Mushroom Research Division, P. O. Box, M20, Accra, Ghana
| | - Brenda D Wingfield
- Departments of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa
| | - Martin P A Coetzee
- Departments of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria 0002, South Africa
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Blanco Nouche C, Paris C, Dhalleine T, Oger P, Turpault MP, Uroz S. The non-ribosomal peptide synthetase-independent siderophore (NIS) rhizobactin produced by Caballeronia mineralivorans PML1(12) confers the ability to weather minerals. Appl Environ Microbiol 2023; 89:e0045323. [PMID: 37800940 PMCID: PMC10617554 DOI: 10.1128/aem.00453-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 07/16/2023] [Indexed: 10/07/2023] Open
Abstract
To mobilize nutrients entrapped into minerals and rocks, heterotrophic bacteria living in nutrient-poor environments have developed different mechanisms based mainly on acidolysis and chelation. However, the genetic bases of these mechanisms remain unidentified. To fill this gap, we considered the model strain Caballeronia mineralivorans PML1(12) known to be effective at weathering. Based on its transcriptomics and proteomics responses in Fe-depleted conditions, we pointed a cluster of genes differentially expressed and putatively involved in the production of siderophores. In this study, we report the characterization of this gene region coding for the production of a non-ribosomal peptide synthetase-independent siderophore (NIS). Targeted mutagenesis associated with functional assays and liquid chromatography coupled to high-resolution tandem mass spectrometry demonstrated the production of a single siderophore, identified as rhizobactin. This siderophore represents the first NIS containing malic acid in its structure. The evidence for the implication of rhizobactin in mineral weathering was demonstrated during a hematite dissolution assay. This study provides the first demonstration of the synthesis of a NIS in the genus Caballeronia and its involvement in mineral weathering. Our conclusions reinforce the idea that strain PML1(12) is particularly well adapted to nutrient-poor environments. IMPORTANCE This work deciphers the molecular and genetic bases used by strain PML1(12) of Caballeronia mineralivorans to mobilize iron and weather minerals. Through the combination of bioinformatics, chemical, and phylogenetic analyses, we characterized the siderophore produced by strain PML1(12) and the related genes. This siderophore was identified as rhizobactin and classified as a non-ribosomal peptide synthetase-independent siderophore (NIS). Contrary to the previously identified NIS synthetases that form siderophores containing citric acid, α-ketoglutarate, or succinic acid, our analyses revealed that rhizobactin contains malic acid in its structure, representing, therefore, the first identified NIS with such an acid and probably a new NIS category. Last, this work demonstrates for the first time the effectiveness at weathering minerals of a siderophore of the NIS family. Our findings offer relevant information for different fields of research, such as environmental genomics, microbiology, chemistry, and soil sciences.
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Affiliation(s)
- Cintia Blanco Nouche
- Université de Lorraine, INRAE, UMR1136 Interactions Arbres-Microorganismes, Nancy, France
- INRAE, UR1138 Biogéochimie des Ecosystèmes Forestiers, Champenoux, France
| | - Cédric Paris
- Université de Lorraine, EA 4367 Laboratoire d’Ingénierie des Biomolécules, Ecole Nationale Supérieure d’Agronomie et des Industries Alimentaires (ENSAIA), Vandœuvre-lès-Nancy, France
| | - Tiphaine Dhalleine
- Université de Lorraine, INRAE, UMR1136 Interactions Arbres-Microorganismes, Nancy, France
| | - Philippe Oger
- INSA Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5240, Villeurbanne, France
| | | | - Stéphane Uroz
- Université de Lorraine, INRAE, UMR1136 Interactions Arbres-Microorganismes, Nancy, France
- INRAE, UR1138 Biogéochimie des Ecosystèmes Forestiers, Champenoux, France
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Battaglia M, Garrett-Sinha LA. Staphylococcus xylosus and Staphylococcus aureus as commensals and pathogens on murine skin. Lab Anim Res 2023; 39:18. [PMID: 37533118 PMCID: PMC10394794 DOI: 10.1186/s42826-023-00169-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 08/04/2023] Open
Abstract
Skin ulcers, skin dermatitis and skin infections are common phenomena in colonies of laboratory mice and are often found at increased prevalence in certain immunocompromised strains. While in many cases these skin conditions are mild, in other cases they can be severe and lead to animal morbidity. Furthermore, the presence of skin infections and ulcerations can complicate the interpretation of experimental protocols, including those examining immune cell activation. Bacterial species in the genus Staphylococcus are the most common pathogens recovered from skin lesions in mice. In particular, Staphylococcus aureus and Staphylococcus xylosus have both been implicated as pathogens on murine skin. Staphylococcus aureus is a well-known pathogen of human skin, but S. xylosus skin infections in humans have not been described, indicating that there is a species-specific difference in the ability of S. xylosus to serve as a skin pathogen. The aim of this review is to summarize studies that link S. aureus and S. xylosus to skin infections of mice and to describe factors involved in their adherence to tissue and their virulence. We discuss potential differences in mouse and human skin that might underlie the ability of S. xylosus to act as a pathogen on murine skin, but not human skin. Finally, we also describe mouse mutants that have shown increased susceptibility to skin infections with staphylococcal bacteria. These mutants point to pathways that are important in the control of commensal staphylococcal bacteria. The information here may be useful to researchers who are working with mouse strains that are prone to skin infections with staphylococcal bacteria.
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Affiliation(s)
- Michael Battaglia
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Lee Ann Garrett-Sinha
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
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Patil RH, Luptáková D, Havlíček V. Infection metallomics for critical care in the post-COVID era. MASS SPECTROMETRY REVIEWS 2023; 42:1221-1243. [PMID: 34854486 DOI: 10.1002/mas.21755] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 06/07/2023]
Abstract
Infection metallomics is a mass spectrometry (MS) platform we established based on the central concept that microbial metallophores are specific, sensitive, noninvasive, and promising biomarkers of invasive infectious diseases. Here we review the in vitro, in vivo, and clinical applications of metallophores from historical and functional perspectives, and identify under-studied and emerging application areas with high diagnostic potential for the post-COVID era. MS with isotope data filtering is fundamental to infection metallomics; it has been used to study the interplay between "frenemies" in hosts and to monitor the dynamic response of the microbiome to antibiotic and antimycotic therapies. During infection in critically ill patients, the hostile environment of the host's body activates secondary bacterial, mycobacterial, and fungal metabolism, leading to the production of metallophores that increase the pathogen's chance of survival in the host. MS can reveal the structures, stability, and threshold concentrations of these metal-containing microbial biomarkers of infection in humans and model organisms, and can discriminate invasive disease from benign colonization based on well-defined thresholds distinguishing proliferation from the colonization steady state.
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Affiliation(s)
- Rutuja H Patil
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Dominika Luptáková
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
- Department of Analytical Chemistry, Faculty of Science, Palacký University, Olomouc, Czechia
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Puja H, Mislin GLA, Rigouin C. Engineering Siderophore Biosynthesis and Regulation Pathways to Increase Diversity and Availability. Biomolecules 2023; 13:959. [PMID: 37371539 PMCID: PMC10296737 DOI: 10.3390/biom13060959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 05/23/2023] [Accepted: 06/01/2023] [Indexed: 06/29/2023] Open
Abstract
Siderophores are small metal chelators synthesized by numerous organisms to access iron. These secondary metabolites are ubiquitously present on Earth, and because their production represents the main strategy to assimilate iron, they play an important role in both positive and negative interactions between organisms. In addition, siderophores are used in biotechnology for diverse applications in medicine, agriculture and the environment. The generation of non-natural siderophore analogs provides a new opportunity to create new-to-nature chelating biomolecules that can offer new properties to expand applications. This review summarizes the main strategies of combinatorial biosynthesis that have been used to generate siderophore analogs. We first provide a brief overview of siderophore biosynthesis, followed by a description of the strategies, namely, precursor-directed biosynthesis, the design of synthetic or heterologous pathways and enzyme engineering, used in siderophore biosynthetic pathways to create diversity. In addition, this review highlights the engineering strategies that have been used to improve the production of siderophores by cells to facilitate their downstream utilization.
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Affiliation(s)
- Hélène Puja
- CNRS-UMR7242, Biotechnologie et Signalisation Cellulaire, 300 Bld Sébastien Brant, 67412 Illkirch, France (G.L.A.M.)
- Institut de Recherche de l’Ecole de Biotechnologie de Strasbourg (IREBS), Université de Strasbourg, 300 Bld Sébastien Brant, 67412 Illkirch, France
| | - Gaëtan L. A. Mislin
- CNRS-UMR7242, Biotechnologie et Signalisation Cellulaire, 300 Bld Sébastien Brant, 67412 Illkirch, France (G.L.A.M.)
- Institut de Recherche de l’Ecole de Biotechnologie de Strasbourg (IREBS), Université de Strasbourg, 300 Bld Sébastien Brant, 67412 Illkirch, France
| | - Coraline Rigouin
- CNRS-UMR7242, Biotechnologie et Signalisation Cellulaire, 300 Bld Sébastien Brant, 67412 Illkirch, France (G.L.A.M.)
- Institut de Recherche de l’Ecole de Biotechnologie de Strasbourg (IREBS), Université de Strasbourg, 300 Bld Sébastien Brant, 67412 Illkirch, France
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Yee DA, Niwa K, Perlatti B, Chen M, Li Y, Tang Y. Genome mining for unknown-unknown natural products. Nat Chem Biol 2023; 19:633-640. [PMID: 36702957 PMCID: PMC10159913 DOI: 10.1038/s41589-022-01246-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 12/20/2022] [Indexed: 01/27/2023]
Abstract
Genome mining of biosynthetic pathways with no identifiable core enzymes can lead to discovery of the so-called unknown (biosynthetic route)-unknown (molecular structure) natural products. Here we focused on a conserved fungal biosynthetic pathway that lacks a canonical core enzyme and used heterologous expression to identify the associated natural product, a highly modified cyclo-arginine-tyrosine dipeptide. Biochemical characterization of the pathway led to identification of a new arginine-containing cyclodipeptide synthase (RCDPS), which was previously annotated as a hypothetical protein and has no sequence homology to non-ribosomal peptide synthetase or bacterial cyclodipeptide synthase. RCDPS homologs are widely encoded in fungal genomes; other members of this family can synthesize diverse cyclo-arginine-Xaa dipeptides, and characterization of a cyclo-arginine-tryptophan RCDPS showed that the enzyme is aminoacyl-tRNA dependent. Further characterization of the biosynthetic pathway led to discovery of new compounds whose structures would not have been predicted without knowledge of RCDPS function.
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Affiliation(s)
- Danielle A Yee
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA
- Hexagon Bio, Menlo Park, CA, USA
| | - Kanji Niwa
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Bruno Perlatti
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
- Hexagon Bio, Menlo Park, CA, USA
| | - Mengbin Chen
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Process Research and Development, Merck & Co., Inc., Rahway, NJ, USA
| | - Yuqing Li
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yi Tang
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA.
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Characterization of Multidrug-Resistant Staphylococcus aureus Isolates and Comparison of Methods of Susceptibility to Vancomycin. Curr Microbiol 2022; 79:374. [DOI: 10.1007/s00284-022-03070-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/29/2022] [Indexed: 11/03/2022]
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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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12
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Siderophores Produced by the Fish Pathogen Flavobacterium columnare Strain MS-FC-4 Are Not Essential for Its Virulence. Appl Environ Microbiol 2022; 88:e0094822. [PMID: 35969053 PMCID: PMC9469716 DOI: 10.1128/aem.00948-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish. F. columnare virulence mechanisms are not well understood, and current methods to control columnaris disease are inadequate. Iron acquisition from the host is important for the pathogenicity and virulence of many bacterial pathogens. F. columnare iron acquisition has not been studied in detail. We identified genes predicted to function in siderophore production for ferric iron uptake. Genes predicted to encode the proteins needed for siderophore synthesis, export, uptake, and regulation were deleted from F. columnare strain MS-FC-4. The mutants were examined for defects in siderophore production, for growth defects in iron-limited conditions, and for virulence against zebrafish and rainbow trout. Mutants lacking all siderophore activity were obtained. These mutants displayed growth defects when cultured under iron-limited conditions, but they retained virulence against zebrafish and rainbow trout similar to that exhibited by the wild type, indicating that the F. columnare MS-FC-4 siderophores are not required for virulence under the conditions tested. IMPORTANCE Columnaris disease, which is caused by Flavobacterium columnare, is a major problem for freshwater aquaculture. Little is known regarding F. columnare virulence factors, and control measures are limited. Iron acquisition mechanisms such as siderophores are important for virulence of other pathogens. We identified F. columnare siderophore biosynthesis, export, and uptake genes. Deletion of these genes eliminated siderophore production and resulted in growth defects under iron-limited conditions but did not alter virulence in rainbow trout or zebrafish. The results indicate that the F. columnare strain MS-FC-4 siderophores are not critical virulence factors under the conditions tested but may be important for survival under iron-limited conditions in natural aquatic environments or aquaculture systems.
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In vivo growth of Staphylococcus lugdunensis is facilitated by the concerted function of heme and non-heme iron acquisition mechanisms. J Biol Chem 2022; 298:101823. [PMID: 35283192 PMCID: PMC9052147 DOI: 10.1016/j.jbc.2022.101823] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 03/04/2022] [Accepted: 03/07/2022] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus lugdunensis has increasingly been recognized as a pathogen that can cause serious infection indicating this bacterium overcomes host nutritional immunity. Despite this, there exists a significant knowledge gap regarding the iron acquisition mechanisms employed by S. lugdunensis, especially during infection of the mammalian host. Here we show that S. lugdunensis can usurp hydroxamate siderophores and staphyloferrin A and B from Staphylococcus aureus. These transport activities all required a functional FhuC ATPase. Moreover, we show that the acquisition of catechol siderophores and catecholamine stress hormones by S. lugdunensis required the presence of the sst-1 transporter-encoding locus, but not the sst-2 locus. Iron-dependent growth in acidic culture conditions necessitated the ferrous iron transport system encoded by feoAB. Heme iron was acquired via expression of the iron-regulated surface determinant (isd) locus. During systemic infection of mice, we demonstrated that while S. lugdunensis does not cause overt illness, it does colonize and proliferate to high numbers in the kidneys. By combining mutations in the various iron acquisition loci (isd, fhuC, sst-1, and feo), we demonstrate that only a strain deficient for all of these systems was attenuated in its ability to proliferate to high numbers in the murine kidney. We propose the concerted action of heme and non-heme iron acquisition systems also enable S. lugdunensis to cause human infection.
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14
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Oliveira F, Lima T, Correia A, Silva AM, Soares C, Morais S, Weißelberg S, Vilanova M, Rohde H, Cerca N. Involvement of the Iron-Regulated Loci hts and fhuC in Biofilm Formation and Survival of Staphylococcus epidermidis within the Host. Microbiol Spectr 2022; 10:e0216821. [PMID: 35019768 PMCID: PMC8754135 DOI: 10.1128/spectrum.02168-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/05/2021] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus epidermidis is a major nosocomial pathogen with a remarkable ability to persist on indwelling medical devices through biofilm formation. Nevertheless, it remains intriguing how this process is efficiently achieved under the host's harsh conditions, where the availability of nutrients, such as essential metals, is scarce. Following our previous identification of two iron-regulated loci putatively involved in iron transport, hts and fhuC, we assessed here their individual contribution to both bacterial physiology and interaction with host immune cells. Single deletions of the hts and fhuC loci led to marked changes in the cell iron content, which were partly detrimental for planktonic growth and strongly affected biofilm formation under iron-restricted conditions. Deletion of each of these two loci did not lead to major changes in S. epidermidis survival within human macrophages or in an ex vivo human blood model of bloodstream infection. However, the lack of either hts or fhuC loci significantly impaired bacterial survival in vivo in a murine model of bacteremia. Collectively, this study establishes, for the first time, the pivotal role of the iron-regulated loci hts and fhuC in S. epidermidis biofilm formation and survival within the host, providing relevant information for the development of new targeted therapeutics against this pathogen. IMPORTANCE Staphylococcus epidermidis is one of the most important nosocomial pathogens and a major cause of central line-associated bloodstream infections. Once in the bloodstream, this bacterium must surpass severe iron restriction in order to survive and establish infection. Surprisingly, very little is known about the iron acquisition mechanisms in this species. This study represents the first report on the involvement of the S. epidermidis iron-regulated loci hts and fhuC in biofilm formation under host relevant conditions and, most importantly, in survival within the host. Ultimately, these findings highlight iron acquisition and these loci in particular, as potential targets for future therapeutic strategies against biofilm-associated S. epidermidis infections.
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Affiliation(s)
- Fernando Oliveira
- Centre of Biological Engineering, LIBRO – Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Tânia Lima
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Alexandra Correia
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Ana Margarida Silva
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Cristina Soares
- REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal
| | - Simone Morais
- REQUIMTE-LAQV, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Porto, Portugal
| | - Samira Weißelberg
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Manuel Vilanova
- i3S – Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- IBMC, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS-UP, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Nuno Cerca
- Centre of Biological Engineering, LIBRO – Laboratory of Research in Biofilms Rosário Oliveira, University of Minho, Braga, Portugal
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15
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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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16
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Le Masters T, Johnson S, Jeraldo PR, Greenwood-Quaintance KE, Cunningham SA, Abdel MP, Chia N, Patel R. Comparative Transcriptomic Analysis of Staphylococcus aureus Associated with Periprosthetic Joint Infection under in Vivo and in Vitro Conditions. J Mol Diagn 2021; 23:986-999. [PMID: 34098085 PMCID: PMC8351120 DOI: 10.1016/j.jmoldx.2021.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 02/25/2021] [Accepted: 05/06/2021] [Indexed: 11/15/2022] Open
Abstract
Transcriptomic analysis can provide insight as to how Staphylococcus aureus adapts to the environmental niche of periprosthetic joint infection (PJI), a challenging clinical infection. Here, in vivo RNA expression of eight S. aureus PJIs was compared with expression of the corresponding isolates in planktonic culture using a total RNA-sequencing approach. Expression varied among isolates, with a common trend showing increased expression of several ica-independent biofilm formation genes, including sdr, fnb, ebpS, and aaa; genes encoding enzymes and toxins, including coa, nuc, hlb, and hlgA/B/C; and genes facilitating acquisition of iron via the iron-binding molecule siderophore B (snb) and heme consumption protein (isd) pathways in PJI. Several antimicrobial resistance determinants were detected; although their presence correlated with phenotypic susceptibility of the associated isolates, no difference in expression between in vivo and in vitro conditions was identified.
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Affiliation(s)
- Thao Le Masters
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Stephen Johnson
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota
| | - Patricio R Jeraldo
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota; Department of Surgery, Mayo Clinic, Rochester, Minnesota
| | - Kerryl E Greenwood-Quaintance
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Scott A Cunningham
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Matthew P Abdel
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
| | - Nicholas Chia
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota; Department of Surgery, Mayo Clinic, Rochester, Minnesota
| | - Robin Patel
- Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota; Division of Infectious Diseases, Department of Medicine, Mayo Clinic, Rochester, Minnesota.
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17
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Torres Salazar BO, Heilbronner S, Peschel A, Krismer B. Secondary Metabolites Governing Microbiome Interaction of Staphylococcal Pathogens and Commensals. Microb Physiol 2021; 31:198-216. [PMID: 34325424 DOI: 10.1159/000517082] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/03/2021] [Indexed: 11/19/2022]
Abstract
Various Staphylococcus species colonize skin and upper airways of warm-blooded animals. They compete successfully with many other microorganisms under the hostile and nutrient-poor conditions of these habitats using mechanisms that we are only beginning to appreciate. Small-molecule mediators, whose biosynthesis requires complex enzymatic cascades, so-called secondary metabolites, have emerged as crucial components of staphylococcal microbiome interactions. Such mediators belong to a large variety of compound classes and several of them have attractive properties for future drug development. They include, for instance, bacteriocins such as lanthipeptides, thiopeptides, and fibupeptides that inhibit bacterial competitor species; signaling molecules such as thiolactone peptides that induce or inhibit sensory cascades in other bacteria; or metallophores such as staphyloferrins and staphylopine that scavenge scant transition metal ions. For some secondary metabolites such as the aureusimines, the exact function remains to be elucidated. How secondary metabolites shape the fitness of Staphylococcus species in the complex context of other microbial and host defense factors remains a challenging field of future research. A detailed understanding will help to harness staphylococcal secondary metabolites for excluding the pathogenic species Staphylococcus aureus from the nasal microbiomes of at-risk patients, and it will be instrumental for the development of advanced anti-infective interventions.
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Affiliation(s)
- Benjamin O Torres Salazar
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Simon Heilbronner
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Andreas Peschel
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Bernhard Krismer
- Department of Infection Biology, Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Tübingen, Germany.,German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
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18
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Barber CC, Zhang W. Small molecule natural products in human nasal/oral microbiota. J Ind Microbiol Biotechnol 2021; 48:6129854. [PMID: 33945611 PMCID: PMC8210680 DOI: 10.1093/jimb/kuab010] [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: 10/06/2020] [Accepted: 12/07/2020] [Indexed: 12/26/2022]
Abstract
Small molecule natural products are a chemically diverse class of biomolecules that fulfill myriad biological functions, including autoregulation, communication with microbial neighbors and the host, interference competition, nutrient acquisition, and resistance to oxidative stress. Human commensal bacteria are increasingly recognized as a potential source of new natural products, which may provide insight into the molecular ecology of many different human body sites as well as novel scaffolds for therapeutic development. Here, we review the scientific literature on natural products derived from residents of the human nasal/oral cavity, discuss their discovery, biosynthesis, and ecological roles, and identify key questions in the study of these compounds.
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Affiliation(s)
- Colin Charles Barber
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley 94720, USA
| | - Wenjun Zhang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley 94720, USA.,Chan-Zuckerberg Biohub, San Francisco 94158, USA
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19
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Li B, Deng X, Kim SH, Buhrow L, Tomchick DR, Phillips MA, Michael AJ. Alternative pathways utilize or circumvent putrescine for biosynthesis of putrescine-containing rhizoferrin. J Biol Chem 2020; 296:100146. [PMID: 33277357 PMCID: PMC7857480 DOI: 10.1074/jbc.ra120.016738] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 11/23/2022] Open
Abstract
The siderophore rhizoferrin (N1,N4-dicitrylputrescine) is produced in fungi and bacteria to scavenge iron. Putrescine-producing bacterium Ralstonia pickettii synthesizes rhizoferrin and encodes a single nonribosomal peptide synthetase-independent siderophore (NIS) synthetase. From biosynthetic logic, we hypothesized that this single enzyme is sufficient for rhizoferrin biosynthesis. We confirmed this by expression of R. pickettii NIS synthetase in Escherichia coli, resulting in rhizoferrin production. This was further confirmed in vitro using the recombinant NIS synthetase, synthesizing rhizoferrin from putrescine and citrate. Heterologous expression of homologous lbtA from Legionella pneumophila, required for rhizoferrin biosynthesis in that species, produced siderophore activity in E. coli. Rhizoferrin is also synthesized by Francisella tularensis and Francisella novicida, but unlike R. pickettii or L. pneumophila, Francisella species lack putrescine biosynthetic pathways because of genomic decay. Francisella encodes a NIS synthetase FslA/FigA and an ornithine decarboxylase homolog FslC/FigC, required for rhizoferrin biosynthesis. Ornithine decarboxylase produces putrescine from ornithine, but we show here in vitro that FigA synthesizes N-citrylornithine, and FigC is an N-citrylornithine decarboxylase that together synthesize rhizoferrin without using putrescine. We co-expressed F. novicida figA and figC in E. coli and produced rhizoferrin. A 2.1 Å X-ray crystal structure of the FigC N-citrylornithine decarboxylase reveals how the larger substrate is accommodated and how active site residues have changed to recognize N-citrylornithine. FigC belongs to a new subfamily of alanine racemase-fold PLP-dependent decarboxylases that are not involved in polyamine biosynthesis. These data reveal a natural product biosynthetic workaround that evolved to bypass a missing precursor and re-establish it in the final structure.
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Affiliation(s)
- Bin Li
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Xiaoyi Deng
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Sok Ho Kim
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Leann Buhrow
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Diana R Tomchick
- Department of Biophysics, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Margaret A Phillips
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Anthony J Michael
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, Texas, USA.
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20
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How Severe Anaemia Might Influence the Risk of Invasive Bacterial Infections in African Children. Int J Mol Sci 2020; 21:ijms21186976. [PMID: 32972031 PMCID: PMC7555399 DOI: 10.3390/ijms21186976] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 09/04/2020] [Accepted: 09/15/2020] [Indexed: 12/21/2022] Open
Abstract
Severe anaemia and invasive bacterial infections are common causes of childhood sickness and death in sub-Saharan Africa. Accumulating evidence suggests that severely anaemic African children may have a higher risk of invasive bacterial infections. However, the mechanisms underlying this association remain poorly described. Severe anaemia is characterized by increased haemolysis, erythropoietic drive, gut permeability, and disruption of immune regulatory systems. These pathways are associated with dysregulation of iron homeostasis, including the downregulation of the hepatic hormone hepcidin. Increased haemolysis and low hepcidin levels potentially increase plasma, tissue and intracellular iron levels. Pathogenic bacteria require iron and/or haem to proliferate and have evolved numerous strategies to acquire labile and protein-bound iron/haem. In this review, we discuss how severe anaemia may mediate the risk of invasive bacterial infections through dysregulation of hepcidin and/or iron homeostasis, and potential studies that could be conducted to test this hypothesis.
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21
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Raue S, Fan SH, Rosenstein R, Zabel S, Luqman A, Nieselt K, Götz F. The Genome of Staphylococcus epidermidis O47. Front Microbiol 2020; 11:2061. [PMID: 32983045 PMCID: PMC7477909 DOI: 10.3389/fmicb.2020.02061] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/05/2020] [Indexed: 12/21/2022] Open
Abstract
The skin colonizing coagulase-negative Staphylococcus epidermidis causes nosocomial infections and is an important opportunistic and highly adaptable pathogen. To gain more insight into this species, we sequenced the genome of the biofilm positive, methicillin susceptible S. epidermidis O47 strain (hereafter O47). This strain belongs to the most frequently isolated sequence type 2. In comparison to the RP62A strain, O47 can be transformed, which makes it a preferred strain for molecular studies. S. epidermidis O47’s genome has a single chromosome of about 2.5 million base pairs and no plasmid. Its oriC sequence has the same directionality as S. epidermidis RP62A, S. carnosus, S. haemolyticus, S. saprophyticus and is inverted in comparison to Staphylococcus aureus and S. epidermidis ATCC 12228. A phylogenetic analysis based on all S. epidermidis genomes currently available at GenBank revealed that O47 is closest related to DAR1907. The genome of O47 contains genes for the typical global regulatory systems known in staphylococci. In addition, it contains most of the genes encoding for the typical virulence factors for S. epidermidis but not for S. aureus with the exception of a putative hemolysin III. O47 has the typical S. epidermidis genetic islands and several mobile genetic elements, which include staphylococcal cassette chromosome (SCC) of about 54 kb length and two prophages φO47A and φO47B. However, its genome has no transposons and the smallest number of insertion sequence (IS) elements compared to the other known S. epidermidis genomes. By sequencing and analyzing the genome of O47, we provide the basis for its utilization in genetic and molecular studies of biofilm formation.
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Affiliation(s)
- Stefan Raue
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany.,Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Sook-Ha Fan
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Ralf Rosenstein
- Infection Biology, Interfaculty Institute for Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
| | - Susanne Zabel
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Arif Luqman
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany.,Biology Department, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
| | - Kay Nieselt
- Institute for Bioinformatics and Medical Informatics, University of Tübingen, Tübingen, Germany
| | - Friedrich Götz
- Microbial Genetics, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), University of Tübingen, Tübingen, Germany
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22
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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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23
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Ramakrishnan G, Pérez NM, Carroll C, Moore MM, Nakamoto RK, Fox TE. Citryl Ornithine Is an Intermediate in a Three-Step Biosynthetic Pathway for Rhizoferrin in Francisella. ACS Chem Biol 2019; 14:1760-1766. [PMID: 31260252 DOI: 10.1021/acschembio.9b00297] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The Gram-negative bacterium Francisella tularensis secretes the siderophore rhizoferrin to scavenge necessary iron from the environment. Rhizoferrin, also produced by a variety of fungi and bacteria, comprises two citrate molecules linked by amide bonds to a central putrescine (diaminobutane) moiety. Genetic analysis has determined that rhizoferrin production in F. tularensis requires two enzymes: FslA, a siderophore synthetase of the nonribosomal peptide synthetase-independent siderophore synthetase (NIS) family, and FslC, a pyridoxal-phosphate-dependent decarboxylase. To discern the steps in the biosynthetic pathway, we tested F. tularensis strain LVS and its ΔfslA and ΔfslC mutants for the ability to incorporate potential precursors into rhizoferrin. Unlike putrescine supplementation, supplementation with ornithine greatly enhanced siderophore production by LVS. Radioactivity from L-[U-14C] ornithine, but not from L-[1-14C] ornithine, was efficiently incorporated into rhizoferrin by LVS. Although neither the ΔfslA nor the ΔfslC mutant produced rhizoferrin, a putative siderophore intermediate labeled by both [U-14C] ornithine and [1-14C] ornithine was secreted by the ΔfslC mutant. Rhizoferrin was identified by liquid chromatography and mass spectrometry in LVS culture supernatants, while citryl-ornithine was detected as the siderophore intermediate in the culture supernatant of the ΔfslC mutant. Our findings support a three-step pathway for rhizoferrin production in Francisella; unlike the fungus Rhizopus delemar, where putrescine functions as a primary precursor for rhizoferrin, biosynthesis in Francisella preferentially starts with ornithine as the substrate for FslA-mediated condensation with citrate. Decarboxylation of this citryl ornithine intermediate by FslC is necessary for a second condensation reaction with citrate to produce rhizoferrin.
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Affiliation(s)
| | | | - Cassandra Carroll
- Department of Biological Sciences, Simon Fraser University, Burnaby V5A 1S6, Canada
| | - Margo M. Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby V5A 1S6, Canada
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24
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Abstract
Staphylococcus aureus is clearly the most pathogenic member of the Staphylococcaceae. This is in large part due to the acquisition of an impressive arsenal of virulence factors that are coordinately regulated by a series of dedicated transcription factors. What is becoming more and more appreciated in the field is the influence of the metabolic state of S. aureus on the activity of these virulence regulators and their roles in modulating metabolic gene expression. Here I highlight recent advances in S. aureus metabolism as it pertains to virulence. Specifically, mechanisms of nutrient acquisition are outlined including carbohydrate and non-carbohydrate carbon/energy sources as well as micronutrient (Fe, Mn, Zn and S) acquisition. Additionally, energy producing strategies (respiration versus fermentation) are discussed and put in the context of pathogenesis. Finally, transcriptional regulators that coordinate metabolic gene expression are outlined, particularly those that affect the activities of major virulence factor regulators. This chapter essentially connects many recent observations that link the metabolism of S. aureus to its overall pathogenesis and hints that the mere presence of a plethora of virulence factors may not entirely explain the extraordinary pathogenic potential of S. aureus.
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Competition among Nasal Bacteria Suggests a Role for Siderophore-Mediated Interactions in Shaping the Human Nasal Microbiota. Appl Environ Microbiol 2019; 85:AEM.02406-18. [PMID: 30578265 DOI: 10.1128/aem.02406-18] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 12/14/2018] [Indexed: 12/26/2022] Open
Abstract
Resources available in the human nasal cavity are limited. Therefore, to successfully colonize the nasal cavity, bacteria must compete for scarce nutrients. Competition may occur directly through interference (e.g., antibiotics) or indirectly by nutrient sequestration. To investigate the nature of nasal bacterial competition, we performed coculture inhibition assays between nasal Actinobacteria and Staphylococcus spp. We found that isolates of coagulase-negative staphylococci (CoNS) were sensitive to growth inhibition by Actinobacteria but that Staphylococcus aureus isolates were resistant to inhibition. Among Actinobacteria, we observed that Corynebacterium spp. were variable in their ability to inhibit CoNS. We sequenced the genomes of 10 Corynebacterium species isolates, including 3 Corynebacterium propinquum isolates that strongly inhibited CoNS and 7 other Corynebacterium species isolates that only weakly inhibited CoNS. Using a comparative genomics approach, we found that the C. propinquum genomes were enriched in genes for iron acquisition and harbored a biosynthetic gene cluster (BGC) for siderophore production, absent in the noninhibitory Corynebacterium species genomes. Using a chrome azurol S assay, we confirmed that C. propinquum produced siderophores. We demonstrated that iron supplementation rescued CoNS from inhibition by C. propinquum, suggesting that inhibition was due to iron restriction through siderophore production. Through comparative metabolomics and molecular networking, we identified the siderophore produced by C. propinquum as dehydroxynocardamine. Finally, we confirmed that the dehydroxynocardamine BGC is expressed in vivo by analyzing human nasal metatranscriptomes from the NIH Human Microbiome Project. Together, our results suggest that bacteria produce siderophores to compete for limited available iron in the nasal cavity and improve their fitness.IMPORTANCE Within the nasal cavity, interference competition through antimicrobial production is prevalent. For instance, nasal Staphylococcus species strains can inhibit the growth of other bacteria through the production of nonribosomal peptides and ribosomally synthesized and posttranslationally modified peptides. In contrast, bacteria engaging in exploitation competition modify the external environment to prevent competitors from growing, usually by hindering access to or depleting essential nutrients. As the nasal cavity is a nutrient-limited environment, we hypothesized that exploitation competition occurs in this system. We determined that Corynebacterium propinquum produces an iron-chelating siderophore, and this iron-sequestering molecule correlates with the ability to inhibit the growth of coagulase-negative staphylococci. Furthermore, we found that the genes required for siderophore production are expressed in vivo Thus, although siderophore production by bacteria is often considered a virulence trait, our work indicates that bacteria may produce siderophores to compete for limited iron in the human nasal cavity.
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Conroy BS, Grigg JC, Kolesnikov M, Morales LD, Murphy MEP. Staphylococcus aureus heme and siderophore-iron acquisition pathways. Biometals 2019; 32:409-424. [PMID: 30911924 DOI: 10.1007/s10534-019-00188-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/18/2019] [Indexed: 11/24/2022]
Abstract
Staphylococcus aureus is a versatile opportunistic human pathogen. Infection by this bacterium requires uptake of iron from the human host, but iron is highly restricted in this environment. Staphylococcus aureus iron sufficiency is achieved primarily through uptake of heme and high-affinity iron chelators, known as siderophores. Two siderophores (staphyloferrins) are produced and secreted by S. aureus into the extracellular environment to capture iron. Staphylococcus aureus expresses specific uptake systems for staphyloferrins and more general uptake systems for siderophores produced by other microorganisms. The S. aureus heme uptake system uses highly-specific cell surface receptors to extract heme from hemoglobin and hemoglobin-haptoglobin complexes for transport into the cytoplasm where it is degraded to liberate iron. Initially thought to be independent systems, recent findings indicate that these iron uptake pathways intersect. IruO is a reductase that releases iron from heme and some ferric-siderophores. Moreover, multifunctional SbnI produces a precursor for staphyloferrin B biosynthesis, and also binds heme to regulate expression of the staphyloferrin B biosynthesis pathway. Intersection of the S. aureus iron uptake pathways is hypothesized to be important for rapid adaptation to available iron sources. Components of the heme and siderophore uptake systems are currently being targeted in the development of therapeutics against S. aureus.
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Affiliation(s)
- Brigid S Conroy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Maxim Kolesnikov
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - L Daniela Morales
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada
| | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, V6T 1Z3, Canada.
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Seif Y, Monk JM, Mih N, Tsunemoto H, Poudel S, Zuniga C, Broddrick J, Zengler K, Palsson BO. A computational knowledge-base elucidates the response of Staphylococcus aureus to different media types. PLoS Comput Biol 2019; 15:e1006644. [PMID: 30625152 PMCID: PMC6326480 DOI: 10.1371/journal.pcbi.1006644] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 11/14/2018] [Indexed: 12/15/2022] Open
Abstract
S. aureus is classified as a serious threat pathogen and is a priority that guides the discovery and development of new antibiotics. Despite growing knowledge of S. aureus metabolic capabilities, our understanding of its systems-level responses to different media types remains incomplete. Here, we develop a manually reconstructed genome-scale model (GEM-PRO) of metabolism with 3D protein structures for S. aureus USA300 str. JE2 containing 854 genes, 1,440 reactions, 1,327 metabolites and 673 3-dimensional protein structures. Computations were in 85% agreement with gene essentiality data from random barcode transposon site sequencing (RB-TnSeq) and 68% agreement with experimental physiological data. Comparisons of computational predictions with experimental observations highlight: 1) cases of non-essential biomass precursors; 2) metabolic genes subject to transcriptional regulation involved in Staphyloxanthin biosynthesis; 3) the essentiality of purine and amino acid biosynthesis in synthetic physiological media; and 4) a switch to aerobic fermentation upon exposure to extracellular glucose elucidated as a result of integrating time-course of quantitative exo-metabolomics data. An up-to-date GEM-PRO thus serves as a knowledge-based platform to elucidate S. aureus’ metabolic response to its environment. Environmental perturbations (e.g., antibiotic stress, nutrient starvation, oxidative stress) induce systems-level perturbations of bacterial cells that vary depending on the growth environment. The generation of omics data is aimed at capturing a complete view of the organism’s response under different conditions. Genome-scale models (GEMs) of metabolism represent a knowledge-based platform for the contextualization and integration of multi-omic measurements and can serve to offer valuable insights of system-level responses. This work provides the most up to date reconstruction effort integrating recent advances in the knowledge of S. aureus molecular biology with previous annotations resulting in the first quantitatively and qualitatively validated S. aureus GEM. GEM guided predictions obtained from model analysis provided insights into the effects of medium composition on metabolic flux distribution and gene essentiality. The model can also serve as a platform to guide network reconstructions for other Staphylococci as well as direct hypothesis generation following the integration of omics data sets, including transcriptomics, proteomics, metabolomics, and multi-strain genomic data.
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Affiliation(s)
- Yara Seif
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Jonathan M. Monk
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Nathan Mih
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Hannah Tsunemoto
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
| | - Saugat Poudel
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Cristal Zuniga
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Jared Broddrick
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
| | - Karsten Zengler
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States of America
| | - Bernhard O. Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, United States of America
- Division of Biological Sciences, University of California San Diego, La Jolla, CA, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States of America
- * E-mail:
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Carroll CS, Moore MM. Ironing out siderophore biosynthesis: a review of non-ribosomal peptide synthetase (NRPS)-independent siderophore synthetases. Crit Rev Biochem Mol Biol 2018; 53:356-381. [DOI: 10.1080/10409238.2018.1476449] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
| | - Margo M. Moore
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
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Ackerman DL, Craft KM, Doster RS, Weitkamp JH, Aronoff DM, Gaddy JA, Townsend SD. Antimicrobial and Antibiofilm Activity of Human Milk Oligosaccharides against Streptococcus agalactiae, Staphylococcus aureus, and Acinetobacter baumannii. ACS Infect Dis 2018; 4:315-324. [PMID: 29198102 DOI: 10.1021/acsinfecdis.7b00183] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In a previous study, we reported that human milk oligosaccharides (HMOs) isolated from five donor milk samples possessed antimicrobial and antibiofilm activity against Streptococcus agalactiae, also known as Group B Streptococcus or GBS. Herein, we present a broader evaluation of the antimicrobial and antibiofilm activity by screening HMOs from 14 new donors against three strains of GBS and two of the ESKAPE pathogens of particular interest to child health, Staphylococcus aureus and Acinetobacter baumannii. Growth and biofilm assays showed that HMOs from these new donors possessed antimicrobial and antibiofilm activity against all three strains of GBS, antibiofilm activity against methicillin-resistant S. aureus strain USA300, and antimicrobial activity against A. baumannii strain ATCC 19606.
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Affiliation(s)
- Dorothy L. Ackerman
- Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Nashville, Tennessee 37235, United States
| | - Kelly M. Craft
- Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Nashville, Tennessee 37235, United States
| | - Ryan S. Doster
- Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, D-3100 Medical Center North, Nashville, Tennessee 37232, United States
| | - Jörn-Hendrik Weitkamp
- Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, D-3100 Medical Center North, Nashville, Tennessee 37232, United States
- Department of Pediatrics, Monroe Carell Jr. Children’s Hospital at Vanderbilt, 2200 Children’s Way, Suite 2404, Nashville, Tennessee 37232, United States
| | - David M. Aronoff
- Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, D-3100 Medical Center North, Nashville, Tennessee 37232, United States
| | - Jennifer A. Gaddy
- Department of Medicine, Vanderbilt University Medical Center, 1161 21st Avenue South, D-3100 Medical Center North, Nashville, Tennessee 37232, United States
- Tennessee Valley Healthcare Systems, Department of Veterans Affairs, 1310 24th Avenue South, Nashville, Tennessee 37212, United States
| | - Steven D. Townsend
- Department of Chemistry, Vanderbilt University, 7330 Stevenson Center, Nashville, Tennessee 37235, United States
- Institute of Chemical Biology, Vanderbilt University, 896 Preston Research Building, Nashville, Tennessee 37232-6304, United States
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Verstraete MM, Perez-Borrajero C, Brown KL, Heinrichs DE, Murphy MEP. SbnI is a free serine kinase that generates O -phospho-l-serine for staphyloferrin B biosynthesis in Staphylococcus aureus. J Biol Chem 2018; 293:6147-6160. [PMID: 29483190 DOI: 10.1074/jbc.ra118.001875] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/15/2018] [Indexed: 12/22/2022] Open
Abstract
Staphyloferrin B (SB) is an iron-chelating siderophore produced by Staphylococcus aureus in invasive infections. Proteins for SB biosynthesis and export are encoded by the sbnABCDEFGHI gene cluster, in which SbnI, a member of the ParB/Srx superfamily, acts as a heme-dependent transcriptional regulator of the sbn locus. However, no structural or functional information about SbnI is available. Here, a crystal structure of SbnI revealed striking structural similarity to an ADP-dependent free serine kinase, SerK, from the archaea Thermococcus kodakarensis We found that features of the active sites are conserved, and biochemical assays and 31P NMR and HPLC analyses indicated that SbnI is also a free serine kinase but uses ATP rather than ADP as phosphate donor to generate the SB precursor O-phospho-l-serine (OPS). SbnI consists of two domains, and elevated B-factors in domain II were consistent with the open-close reaction mechanism previously reported for SerK. Mutagenesis of Glu20 and Asp58 in SbnI disclosed that they are required for kinase activity. The only known OPS source in bacteria is through the phosphoserine aminotransferase activity of SerC within the serine biosynthesis pathway, and we demonstrate that an S. aureus serC mutant is a serine auxotroph, consistent with a function in l-serine biosynthesis. However, the serC mutant strain could produce SB when provided l-serine, suggesting that SbnI produces OPS for SB biosynthesis in vivo These findings indicate that besides transcriptionally regulating the sbn locus, SbnI also has an enzymatic role in the SB biosynthetic pathway.
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Affiliation(s)
| | - Cecilia Perez-Borrajero
- the Genome Sciences and Technology Program Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
| | | | - David E Heinrichs
- the Department of Microbiology and Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada
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31
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Carroll CS, Grieve CL, Murugathasan I, Bennet AJ, Czekster CM, Liu H, Naismith J, Moore MM. The rhizoferrin biosynthetic gene in the fungal pathogen Rhizopus delemar is a novel member of the NIS gene family. Int J Biochem Cell Biol 2017; 89:136-146. [DOI: 10.1016/j.biocel.2017.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/30/2017] [Accepted: 06/03/2017] [Indexed: 11/29/2022]
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32
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An overview of siderophores for iron acquisition in microorganisms living in the extreme. Biometals 2016; 29:551-71. [PMID: 27457587 DOI: 10.1007/s10534-016-9949-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/08/2016] [Indexed: 12/11/2022]
Abstract
Siderophores are iron-chelating molecules produced by microbes when intracellular iron concentrations are low. Low iron triggers a cascade of gene activation, allowing the cell to survive due to the synthesis of important proteins involved in siderophore synthesis and transport. Generally, siderophores are classified by their functional groups as catecholates, hydroxamates and hydroxycarboxylates. Although other chemical structural modifications and functional groups can be found. The functional groups participate in the iron-chelating process when the ferri-siderophore complex is formed. Classified as acidophiles, alkaliphiles, halophiles, thermophiles, psychrophiles, piezophiles, extremophiles have particular iron requirements depending on the environmental conditions in where they grow. Most of the work done in siderophore production by extremophiles is based in siderophore concentration and/or genomic studies determining the presence of siderophore synthesis and transport genes. Siderophores produced by extremophiles are not well known and more work needs to be done to elucidate chemical structures and their role in microorganism survival and metal cycling in extreme environments.
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Kobylarz MJ, Grigg JC, Liu Y, Lee MSF, Heinrichs DE, Murphy MEP. Deciphering the Substrate Specificity of SbnA, the Enzyme Catalyzing the First Step in Staphyloferrin B Biosynthesis. Biochemistry 2016; 55:927-39. [PMID: 26794841 PMCID: PMC5084695 DOI: 10.1021/acs.biochem.5b01045] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Staphylococcus aureus assembles the siderophore,
staphyloferrin B, from l-2,3-diaminopropionic acid (l-Dap), α-ketoglutarate, and citrate. Recently, SbnA and SbnB
were shown to produce l-Dap and α-ketoglutarate from O-phospho-l-serine (OPS) and l-glutamate.
SbnA is a pyridoxal 5′-phosphate (PLP)-dependent enzyme with
homology to O-acetyl-l-serine sulfhydrylases;
however, SbnA utilizes OPS instead of O-acetyl-l-serine (OAS), and l-glutamate serves as a nitrogen
donor instead of a sulfide. In this work, we examined how SbnA dictates
substrate specificity for OPS and l-glutamate using a combination
of X-ray crystallography, enzyme kinetics, and site-directed mutagenesis.
Analysis of SbnA crystals incubated with OPS revealed the structure
of the PLP-α-aminoacrylate intermediate. Formation of the intermediate
induced closure of the active site pocket by narrowing the channel
leading to the active site and forming a second substrate binding
pocket that likely binds l-glutamate. Three active site residues
were identified: Arg132, Tyr152, Ser185 that were essential for OPS
recognition and turnover. The Y152F/S185G SbnA double mutant was completely
inactive, and its crystal structure revealed that the mutations induced
a closed form of the enzyme in the absence of the α-aminoacrylate
intermediate. Lastly, l-cysteine was shown to be a competitive
inhibitor of SbnA by forming a nonproductive external aldimine with
the PLP cofactor. These results suggest a regulatory link between
siderophore and l-cysteine biosynthesis, revealing a potential
mechanism to reduce iron uptake under oxidative stress.
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Affiliation(s)
- Marek J Kobylarz
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Yunan Liu
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | - Mathew S F Lee
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
| | | | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z3
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References. Antibiotics (Basel) 2015. [DOI: 10.1128/9781555819316.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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35
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Laakso HA, Marolda CL, Pinter TB, Stillman MJ, Heinrichs DE. A Heme-responsive Regulator Controls Synthesis of Staphyloferrin B in Staphylococcus aureus. J Biol Chem 2015; 291:29-40. [PMID: 26534960 DOI: 10.1074/jbc.m115.696625] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 11/06/2022] Open
Abstract
Staphylococcus aureus possesses a multitude of mechanisms by which it can obtain iron during growth under iron starvation conditions. It expresses an effective heme acquisition system (the iron-regulated surface determinant system), it produces two carboxylate-type siderophores staphyloferrin A and staphyloferrin B (SB), and it expresses transporters for many other siderophores that it does not synthesize. The ferric uptake regulator protein regulates expression of genes encoding all of these systems. Mechanisms of fine-tuning expression of iron-regulated genes, beyond simple iron regulation via ferric uptake regulator, have not been uncovered in this organism. Here, we identify the ninth gene of the sbn operon, sbnI, as encoding a ParB/Spo0J-like protein that is required for expression of genes in the sbn operon from sbnD onward. Expression of sbnD-I is drastically decreased in an sbnI mutant, and the mutant does not synthesize detectable SB during early phases of growth. Thus, SB-mediated iron acquisition is impaired in an sbnI mutant strain. We show that the protein forms dimers and tetramers in solution and binds to DNA within the sbnC coding region. Moreover, we show that SbnI binds heme and that heme-bound SbnI does not bind DNA. Finally, we show that providing exogenous heme to S. aureus growing in an iron-free medium results in delayed synthesis of SB. This is the first study in S. aureus that identifies a DNA-binding regulatory protein that senses heme to control gene expression for siderophore synthesis.
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Affiliation(s)
| | | | | | | | - David E Heinrichs
- From the Departments of Microbiology and Immunology and Centre for Human Immunology, University of Western Ontario, London, Ontario N6A 5C1, Canada
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36
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Louzao I, Sui C, Winzer K, Fernandez-Trillo F, Alexander C. Cationic polymer mediated bacterial clustering: Cell-adhesive properties of homo- and copolymers. Eur J Pharm Biopharm 2015; 95:47-62. [DOI: 10.1016/j.ejpb.2015.05.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 05/15/2015] [Accepted: 05/26/2015] [Indexed: 11/16/2022]
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Hannauer M, Arifin AJ, Heinrichs DE. Involvement of reductases IruO and NtrA in iron acquisition byStaphylococcus aureus. Mol Microbiol 2015; 96:1192-210. [DOI: 10.1111/mmi.13000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Mélissa Hannauer
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
| | - Andrew J. Arifin
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
| | - David E. Heinrichs
- Department of Microbiology and Immunology; University of Western Ontario; London ON Canada N6A 5C1
- Centre for Human Immunology; University of Western Ontario; London ON Canada N6A 5C1
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38
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Sheldon JR, Heinrichs DE. Recent developments in understanding the iron acquisition strategies of gram positive pathogens. FEMS Microbiol Rev 2015; 39:592-630. [DOI: 10.1093/femsre/fuv009] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2015] [Indexed: 12/26/2022] Open
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39
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Involvement of major facilitator superfamily proteins SfaA and SbnD in staphyloferrin secretion in Staphylococcus aureus. FEBS Lett 2015; 589:730-7. [PMID: 25680529 DOI: 10.1016/j.febslet.2015.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 01/31/2015] [Accepted: 02/02/2015] [Indexed: 12/11/2022]
Abstract
A paucity of information exists concerning the mechanism(s) by which bacteria secrete siderophores into the extracellular compartment. We investigated the role of SfaA and SbnD, two major facilitator superfamily (MFS)-type efflux proteins, in the secretion of the Staphylococcus aureus siderophores staphyloferrin A (SA) and staphyloferrin B (SB), respectively. Deletion of sfaA resulted in a drastic reduction of SA secreted into the supernatant with a corresponding accumulation of SA in the cytoplasm and a significant growth defect in cells devoid of SB synthesis. In contrast, sbnD mutants showed transiently lowered levels of secreted SB, suggesting the involvement of additional efflux mechanisms.
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Kobylarz MJ, Grigg JC, Sheldon JR, Heinrichs DE, Murphy MEP. SbnG, a citrate synthase in Staphylococcus aureus: a new fold on an old enzyme. J Biol Chem 2014; 289:33797-807. [PMID: 25336653 DOI: 10.1074/jbc.m114.603175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.
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Affiliation(s)
- Marek J Kobylarz
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
| | - Jason C Grigg
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
| | | | - David E Heinrichs
- the Department of Microbiology and Immunology and the Centre for Human Immunology University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Michael E P Murphy
- From the Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and
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41
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Cooper JD, Hannauer M, Marolda CL, Briere LAK, Heinrichs DE. Identification of a Positively Charged Platform in Staphylococcus aureus HtsA That Is Essential for Ferric Staphyloferrin A Transport. Biochemistry 2014; 53:5060-9. [DOI: 10.1021/bi500729h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- John D. Cooper
- Department
of Microbiology and Immunology, ‡Centre for Human Immunology,
and §Department of
Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Mélissa Hannauer
- Department
of Microbiology and Immunology, ‡Centre for Human Immunology,
and §Department of
Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Cristina L. Marolda
- Department
of Microbiology and Immunology, ‡Centre for Human Immunology,
and §Department of
Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - Lee-Ann K. Briere
- Department
of Microbiology and Immunology, ‡Centre for Human Immunology,
and §Department of
Biochemistry, University of Western Ontario, London, Ontario, Canada
| | - David E. Heinrichs
- Department
of Microbiology and Immunology, ‡Centre for Human Immunology,
and §Department of
Biochemistry, University of Western Ontario, London, Ontario, Canada
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42
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Sheldon JR, Marolda CL, Heinrichs DE. TCA cycle activity in Staphylococcus aureus is essential for iron-regulated synthesis of staphyloferrin A, but not staphyloferrin B: the benefit of a second citrate synthase. Mol Microbiol 2014; 92:824-39. [PMID: 24666349 DOI: 10.1111/mmi.12593] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2014] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus elaborates two citrate-containing siderophores, staphyloferrin A (SA) and staphyloferrin B (SB), that enhance growth under iron-restriction, yet, paradoxically, expression of the TCA cycle citrate synthase, CitZ, is downregulated during iron starvation. Iron starvation does, however, result in expression of SbnG, recently identified as a novel citrate synthase that is encoded from within the iron-regulated SB biosynthetic locus, suggesting an important role for SbnG in staphyloferrin production. We demonstrate that during growth of S. aureus in iron-restricted media containing glucose, SB is produced but, in contrast, SA production is severely repressed; accordingly, SB-deficient mutants grow poorly in these media. Hypothesizing that reduced TCA cycle activity hinders SA production, we show that a citZ mutant is capable of SB synthesis, but not SA synthesis, providing evidence that SbnG does not generate citrate for incorporation into SA. A citZ sbnG mutant synthesizes neither staphyloferrin, is severely compromised for growth in iron-restricted media, and is significantly more impaired for virulence than either of the single-deletion mutants. We propose that SB is the more important of the two siderophores for S. aureus insofar as it is synthesized, and supports iron-restricted growth, without need of TCA cycle activity.
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Affiliation(s)
- Jessica R Sheldon
- Department of Microbiology and Immunology, University of Western Ontario, London, ON, Canada
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43
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Role of the siderophore transporter SirABC in the Staphylococcus aureus resistance to oxidative stress. Curr Microbiol 2014; 69:164-8. [PMID: 24682218 DOI: 10.1007/s00284-014-0567-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/30/2014] [Indexed: 10/25/2022]
Abstract
In Staphylococcus aureus, the intracellular siderophore staphyloferrin B, which has been shown to chelate iron-bound to serum transferrin, is transported into cells by the SirABC system. In this work, we have analysed the role of the Sir transporter under stress conditions that resemble those imposed by the mammalian innate immune system. We show that exposure of S. aureus to oxidative and nitrosative stress generated by hydrogen peroxide and S-nitrosoglutathione, respectively, induced the expression of the sirA gene. The disruption of the sir operon led to a strain with lower viability and decreased resistance to oxidative stress. S. aureus sir null mutant was also analysed during infection of murine macrophages and shown to contribute to S. aureus survival inside macrophages. Altogether, our results indicate that the Sir transport system confers protection against reactive oxygen species, therefore, contributing to the virulence of S. aureus.
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44
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Brozyna JR, Sheldon JR, Heinrichs DE. Growth promotion of the opportunistic human pathogen, Staphylococcus lugdunensis, by heme, hemoglobin, and coculture with Staphylococcus aureus. Microbiologyopen 2014; 3:182-95. [PMID: 24515974 PMCID: PMC3996567 DOI: 10.1002/mbo3.162] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 12/24/2013] [Accepted: 12/30/2013] [Indexed: 02/02/2023] Open
Abstract
Staphylococcus lugdunensis is both a commensal of humans and an opportunistic pathogen. Little is currently known about the molecular mechanisms underpinning the virulence of this bacterium. Here, we demonstrate that in contrast to S. aureus,S. lugdunensis makes neither staphyloferrin A (SA) nor staphyloferrin B (SB) in response to iron deprivation, owing to the absence of the SB gene cluster, and a large deletion in the SA biosynthetic gene cluster. As a result, the species grows poorly in serum-containing media, and this defect was complemented by introduction of the S. aureusSA gene cluster into S. lugdunensis. S. lugdunensis expresses the HtsABC and SirABC transporters for SA and SB, respectively; the latter gene set is found within the isd (heme acquisition) gene cluster. An isd deletion strain was significantly debilitated for iron acquisition from both heme and hemoglobin, and was also incapable of utilizing ferric-SB as an iron source, while an hts mutant could not grow on ferric-SA as an iron source. In iron-restricted coculture experiments, S. aureus significantly enhanced the growth of S. lugdunensis, in a manner dependent on staphyloferrin production by S. aureus, and the expression of the cognate transporters by S. lugdunensis.
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Affiliation(s)
- Jeremy R Brozyna
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada, N6A 5C1
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45
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Kobylarz MJ, Grigg JC, Takayama SIJ, Rai DK, Heinrichs DE, Murphy MEP. Synthesis of L-2,3-diaminopropionic acid, a siderophore and antibiotic precursor. ACTA ACUST UNITED AC 2014; 21:379-88. [PMID: 24485762 DOI: 10.1016/j.chembiol.2013.12.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/03/2013] [Accepted: 12/07/2013] [Indexed: 11/29/2022]
Abstract
L-2,3-diaminopropionic acid (L-Dap) is an amino acid that is a precursor of antibiotics and staphyloferrin B a siderophore produced by Staphylococcus aureus. SbnA and SbnB are encoded by the staphyloferrin B biosynthetic gene cluster and are implicated in L-Dap biosynthesis. We demonstrate here that SbnA uses PLP and substrates O-phospho-L-serine and L-glutamate to produce a metabolite N-(1-amino-1-carboxyl-2-ethyl)-glutamic acid (ACEGA). SbnB is shown to use NAD(+) to oxidatively hydrolyze ACEGA to yield α-ketoglutarate and L-Dap. Also, we describe crystal structures of SbnB in complex with NADH and ACEGA as well as with NAD(+) and α-ketoglutarate to reveal the residues required for substrate binding, oxidation, and hydrolysis. SbnA and SbnB contribute to the iron sparing response of S. aureus that enables staphyloferrin B biosynthesis in the absence of an active tricarboxylic acid cycle.
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Affiliation(s)
- Marek J Kobylarz
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Jason C Grigg
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Shin-ichi J Takayama
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Dushyant K Rai
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - David E Heinrichs
- Department of Microbiology and Immunology, The Centre for Human Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Michael E P Murphy
- Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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46
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Pandey RK, Jarvis GG, Low PS. Chemical synthesis of staphyloferrin A and its application for Staphylococcus aureus detection. Org Biomol Chem 2014; 12:1707-10. [PMID: 24500249 DOI: 10.1039/c3ob41230j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chemical synthesis of staphyloferrin A, a siderophore used by Staphylococcus bacteria for ferric iron retrieval, has been achieved with 79% yield via solid phase peptide synthesis (SPPS).
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Affiliation(s)
| | | | - Philip S. Low
- Department of Chemistry
- Purdue University
- West Lafayette, USA
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47
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Sørensen JL, Knudsen M, Hansen FT, Olesen C, Fuertes PR, Lee TV, Sondergaard TE, Pedersen CNS, Brodersen DE, Giese H. Fungal NRPS-Dependent Siderophores: From Function to Prediction. Fungal Biol 2014. [DOI: 10.1007/978-1-4939-1191-2_15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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48
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Loutet SA, Kobylarz MJ, Chau CHT, Murphy MEP. IruO is a reductase for heme degradation by IsdI and IsdG proteins in Staphylococcus aureus. J Biol Chem 2013; 288:25749-25759. [PMID: 23893407 DOI: 10.1074/jbc.m113.470518] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus is a common hospital- and community-acquired bacterium that can cause devastating infections and is often multidrug-resistant. Iron acquisition is required by S. aureus during an infection, and iron acquisition pathways are potential targets for therapies. The gene NWMN2274 in S. aureus strain Newman is annotated as an oxidoreductase of the diverse pyridine nucleotide-disulfide oxidoreductase (PNDO) family. We show that NWMN2274 is an electron donor to IsdG and IsdI catalyzing the degradation of heme, and we have renamed this protein IruO. Recombinant IruO is a FAD-containing NADPH-dependent reductase. In the presence of NADPH and IruO, either IsdI or IsdG degraded bound heme 10-fold more rapidly than with the chemical reductant ascorbic acid. Varying IsdI-heme substrate and monitoring loss of the heme Soret band gave a K(m) of 15 ± 4 μM, a k(cat) of 5.2 ± 0.7 min(-1), and a k(cat)/K(m) of 5.8 × 10(3) M(-1) s(-1). From HPLC and electronic spectra, the major heme degradation products are 5-oxo-δ-bilirubin and 15-oxo-β-bilirubin (staphylobilins), as observed with ascorbic acid. Although heme degradation by IsdI or IsdG can occur in the presence of H2O2, the addition of catalase and superoxide dismutase did not disrupt NADPH/IruO heme degradation reactions. The degree of electron coupling between IruO and IsdI or IsdG remains to be determined. Homologs of IruO were identified by sequence similarity in the genomes of Gram-positive bacteria that possess IsdG-family heme oxygenases. A phylogeny of these homologs identifies a distinct clade of pyridine nucleotide-disulfide oxidoreductases likely involved in iron uptake systems. IruO is the likely in vivo reductant required for heme degradation by S. aureus.
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Affiliation(s)
- Slade A Loutet
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Marek J Kobylarz
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Crystal H T Chau
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael E P Murphy
- From the Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
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49
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Abstract
The proliferative capability of many invasive pathogens is limited by the bioavailability of iron. Pathogens have thus developed strategies to obtain iron from their host organisms. In turn, host defense strategies have evolved to sequester iron from invasive pathogens. This review explores the mechanisms employed by bacterial pathogens to gain access to host iron sources, the role of iron in bacterial virulence, and iron-related genes required for the establishment or maintenance of infection. Host defenses to limit iron availability for bacterial growth during the acute-phase response and the consequences of iron overload conditions on susceptibility to bacterial infection are also examined. The evidence summarized herein demonstrates the importance of iron bioavailability in influencing the risk of infection and the ability of the host to clear the pathogen.
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50
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Discovery of an Iron-Regulated Citrate Synthase in Staphylococcus aureus. ACTA ACUST UNITED AC 2012; 19:1568-78. [DOI: 10.1016/j.chembiol.2012.10.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 09/06/2012] [Accepted: 10/03/2012] [Indexed: 11/21/2022]
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