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Li P, Schulte J, Wurpts G, Hornef MW, Wolz C, Yazdi AS, Burian M. Transcriptional Profiling of Staphylococcus aureus during the Transition from Asymptomatic Nasal Colonization to Skin Colonization/Infection in Patients with Atopic Dermatitis. Int J Mol Sci 2024; 25:9165. [PMID: 39273114 PMCID: PMC11394835 DOI: 10.3390/ijms25179165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2024] [Revised: 08/18/2024] [Accepted: 08/19/2024] [Indexed: 09/15/2024] Open
Abstract
Staphylococcus aureus acts both as a colonizing commensal bacterium and invasive pathogen. Nasal colonization is associated with an increased risk of infection caused by the identical strain. In patients with atopic dermatitis (AD), the degree of S. aureus colonization is associated with the severity of the disease. Here, we comparatively analyzed the in vivo transcriptional profile of S. aureus colonizing the nose and non-diseased skin (non-lesional skin) as opposed to the diseased skin (lesional skin-defined here as infection) of 12 patients with AD. The transcriptional profile during the asymptomatic colonization of the nose closely resembled that of the lesional skin samples for many of the genes studied, with an elevated expression of the genes encoding adhesion-related proteins and proteases. In addition, the genes that modify and remodel the cell wall and encode proteins that facilitate immune evasion showed increased transcriptional activity. Notably, in a subgroup of patients, the global virulence regulator Agr (accessory gene regulator) and downstream target genes were inactive during nasal colonization but upregulated in the lesional and non-lesional skin samples. Taken together, our results demonstrate a colonization-like transcriptional profile on diseased skin and suggest a role for the peptide quorum sensing system Agr during the transition from asymptomatic nasal colonization to skin colonization/infection.
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Affiliation(s)
- Peijuan Li
- Department of Dermatology and Allergology, RWTH University Hospital Aachen, D-5207 Aachen, Germany
| | - Julia Schulte
- Department of Dermatology and Allergology, RWTH University Hospital Aachen, D-5207 Aachen, Germany
| | - Gerda Wurpts
- Department of Dermatology and Allergology, RWTH University Hospital Aachen, D-5207 Aachen, Germany
| | - Mathias W Hornef
- Institute of Medical Microbiology, RWTH University Hospital Aachen, D-52074 Aachen, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tuebingen, D-72076 Tuebingen, Germany
- Cluster of Excellence EXC 2124 "Controlling Microbes to Fight Infections", University of Tuebingen, D-72076 Tuebingen, Germany
| | - Amir S Yazdi
- Department of Dermatology and Allergology, RWTH University Hospital Aachen, D-5207 Aachen, Germany
| | - Marc Burian
- Department of Dermatology and Allergology, RWTH University Hospital Aachen, D-5207 Aachen, Germany
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2
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Kline SN, Saito Y, Archer NK. Staphylococcus aureus Proteases: Orchestrators of Skin Inflammation. DNA Cell Biol 2024. [PMID: 38957987 DOI: 10.1089/dna.2024.0134] [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] [Indexed: 07/04/2024] Open
Abstract
Skin homeostasis relies on a delicate balance between host proteases and protease inhibitors along with those secreted from microbial communities, as disruption to this harmony contributes to the pathogenesis of inflammatory skin disorders, including atopic dermatitis and Netherton's syndrome. In addition to being a prominent cause of skin and soft tissue infections, the gram-positive bacterium Staphylococcus aureus is a key player in inflammatory skin conditions due to its array of 10 secreted proteases. Herein we review how S. aureus proteases augment the development of inflammation in skin disorders. These mechanisms include degradation of skin barrier integrity, immune dysregulation and pruritis, and impairment of host defenses. Delineating the diverse roles of S. aureus proteases has the potential to reveal novel therapeutic strategies, such as inhibitors of proteases or their cognate target, as well as neutralizing vaccines to alleviate the burden of inflammatory skin disorders in patients.
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Affiliation(s)
- Sabrina N Kline
- Department of Dermatology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Yoshine Saito
- School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Nathan K Archer
- Department of Dermatology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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3
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Jackson JK, Kennedy SJ, Felton EA, Cella E, Lima A, Becker D, Silbert S, Kim K, Azarian T, Shaw LN. Draft genome sequence of a highly proteolytic Staphylococcus aureus USA300 isolate from human urine. Microbiol Resour Announc 2023; 12:e0067923. [PMID: 37933968 PMCID: PMC10720404 DOI: 10.1128/mra.00679-23] [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: 08/07/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
The secreted proteases of Staphylococcus aureus have been shown to be critical during infection. Here, we present the draft genome sequence of S. aureus TGH337, a hyper-proteolytic USA300 strain isolated from human urine.
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Affiliation(s)
- Jessica K. Jackson
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Sarah J. Kennedy
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Emily A. Felton
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
| | - Eleonora Cella
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, USA
| | - Amorce Lima
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Deanna Becker
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Suzane Silbert
- Esoteric Testing/R&D Laboratory, Tampa General Hospital, Tampa, Florida, USA
| | - Kami Kim
- Division of Infectious Disease and Internal Medicine, University of South Florida, Tampa, Florida, USA
- Center for Global Health Infectious Diseases Research, University of South Florida, Tampa, Florida, USA
- Global Emerging Diseases Institute, Tampa General Hospital, Tampa, Florida, USA
| | - Taj Azarian
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, USA
| | - Lindsey N. Shaw
- Department of Molecular Biosciences, University of South Florida, Tampa, Florida, USA
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4
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Hsieh RC, Liu R, Burgin DJ, Otto M. Understanding mechanisms of virulence in MRSA: implications for antivirulence treatment strategies. Expert Rev Anti Infect Ther 2023; 21:911-928. [PMID: 37501364 DOI: 10.1080/14787210.2023.2242585] [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: 05/15/2023] [Accepted: 07/26/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION Methicillin-resistant Staphylococcus aureus (MRSA) is a widespread pathogen, often causing recurrent and deadly infections in the hospital and community. Many S. aureus virulence factors have been suggested as potential targets for antivirulence therapy to decrease the threat of diminishing antibiotic availability. Antivirulence methods hold promise due to their adjunctive and prophylactic potential and decreased risk for selective pressure. AREAS COVERED This review describes the dominant virulence mechanisms exerted by MRSA and antivirulence therapeutics that are currently undergoing testing in clinical or preclinical stages. We also discuss the advantages and downsides of several investigational antivirulence approaches, including the targeting of bacterial transporters, host-directed therapy, and quorum-sensing inhibitors. For this review, a systematic search of literature on PubMed, Google Scholar, and Web of Science for relevant search terms was performed in April and May 2023. EXPERT OPINION Vaccine and antibody strategies have failed in clinical trials and could benefit from more basic science-informed approaches. Antivirulence-targeting approaches need to be set up better to meet the requirements of drug development, rather than only providing limited results to provide 'proof-of-principle' translational value of pathogenesis research. Nevertheless, there is great potential of such strategies and potential particular promise for novel probiotic approaches.
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Affiliation(s)
- Roger C Hsieh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Ryan Liu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Dylan J Burgin
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), U.S. National Institutes of Health (NIH), Bethesda, Maryland, USA
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Francis D, Bhairaddy A, Joy A, Hari GV, Francis A. Secretory proteins in the orchestration of microbial virulence: The curious case of Staphylococcus aureus. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:271-350. [PMID: 36707204 DOI: 10.1016/bs.apcsb.2022.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Microbial virulence showcases an excellent model for adaptive changes that enable an organism to survive and proliferate in a hostile environment and exploit host resources to its own benefit. In Staphylococcus aureus, an opportunistic pathogen of the human host, known for the diversity of the disease conditions it inflicts and the rapid evolution of antibiotic resistance, virulence is a consequence of having a highly plastic genome that is amenable to quick reprogramming and the ability to express a diverse arsenal of virulence factors. Virulence factors that are secreted to the host milieu effectively manipulate the host conditions to favor bacterial survival and growth. They assist in colonization, nutrient acquisition, immune evasion, and systemic spread. The structural and functional characteristics of the secreted virulence proteins have been shaped to assist S. aureus in thriving and disseminating effectively within the host environment and exploiting the host resources to its best benefit. With the aim of highlighting the importance of secreted virulence proteins in bacterial virulence, the present chapter provides a comprehensive account of the role of the major secreted proteins of S. aureus in orchestrating its virulence in the human host.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India.
| | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College, Autonomous, Bengaluru, Karnataka, India
| | | | - Ashik Francis
- Rajiv Gandhi Centre for Biotechnology, Trivandrum, Kerala, India
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Exploration of Dual Ionic Cross-Linked Alginate Hydrogels Via Cations of Varying Valences towards Wound Healing. Polymers (Basel) 2022; 14:polym14235192. [PMID: 36501587 PMCID: PMC9738749 DOI: 10.3390/polym14235192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
This study explored the synergistic effects of simultaneously using calcium and gallium cations in the cross-linking of alginate, detailing its effects on the characteristics of alginate compared to its single cation counterparts. The primary goal is to determine if there are any synergistic effects associated with the utilisation of multiple multivalent cations in polymer cross-linking and whether or not it could therefore be used in pharmaceutical applications such as wound healing. Given the fact divalent and trivalent cations have never been utilised together for cross-linking, an explanation for the mode of binding that occurs between the alginate and the cations during the cross-linking process and how it may affect the future applications of the polymer has been investigated. The calcium gallium alginate polymers were able to retain the antibacterial effects of gallium within the confines of the polymer matrix, possessing superior rheological properties, 6 times that of pure calcium and pure gallium, coupled with an improved swelling capacity that is 4 times higher than that of gallium alginate.
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Rodrigues Lopes I, Alcantara LM, Silva RJ, Josse J, Vega EP, Cabrerizo AM, Bonhomme M, Lopez D, Laurent F, Vandenesch F, Mano M, Eulalio A. Microscopy-based phenotypic profiling of infection by Staphylococcus aureus clinical isolates reveals intracellular lifestyle as a prevalent feature. Nat Commun 2022; 13:7174. [PMID: 36418309 PMCID: PMC9684519 DOI: 10.1038/s41467-022-34790-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/08/2022] [Indexed: 11/24/2022] Open
Abstract
Staphylococcus aureus is increasingly recognized as a facultative intracellular pathogen, although the significance and pervasiveness of its intracellular lifestyle remain controversial. Here, we applied fluorescence microscopy-based infection assays and automated image analysis to profile the interaction of 191 S. aureus isolates from patients with bone/joint infections, bacteremia, and infective endocarditis, with four host cell types, at five times post-infection. This multiparametric analysis revealed that almost all isolates are internalized and that a large fraction replicate and persist within host cells, presenting distinct infection profiles in non-professional vs. professional phagocytes. Phenotypic clustering highlighted interesting sub-groups, including one comprising isolates exhibiting high intracellular replication and inducing delayed host death in vitro and in vivo. These isolates are deficient for the cysteine protease staphopain A. This study establishes S. aureus intracellular lifestyle as a prevalent feature of infection, with potential implications for the effective treatment of staphylococcal infections.
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Affiliation(s)
- Ines Rodrigues Lopes
- grid.8051.c0000 0000 9511 4342RNA & Infection Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Functional Genomics and RNA-based Therapeutics Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Laura Maria Alcantara
- grid.8051.c0000 0000 9511 4342RNA & Infection Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Ricardo Jorge Silva
- grid.8051.c0000 0000 9511 4342Functional Genomics and RNA-based Therapeutics Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Jerome Josse
- grid.15140.310000 0001 2175 9188Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France
| | - Elena Pedrero Vega
- grid.4711.30000 0001 2183 4846National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, Spain
| | - Ana Marina Cabrerizo
- grid.4711.30000 0001 2183 4846National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, Spain
| | - Melanie Bonhomme
- grid.15140.310000 0001 2175 9188Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France
| | - Daniel Lopez
- grid.4711.30000 0001 2183 4846National Centre for Biotechnology, Spanish National Research Council (CNB-CSIC), Madrid, Spain
| | - Frederic Laurent
- grid.15140.310000 0001 2175 9188Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France ,grid.413852.90000 0001 2163 3825Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
| | - Francois Vandenesch
- grid.15140.310000 0001 2175 9188Centre International de Recherche en Infectiologie (CIRI), Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, ENS de Lyon, Lyon, France ,grid.413852.90000 0001 2163 3825Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
| | - Miguel Mano
- grid.8051.c0000 0000 9511 4342Functional Genomics and RNA-based Therapeutics Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal ,grid.8051.c0000 0000 9511 4342Department of Life Sciences, University of Coimbra, Coimbra, Portugal ,grid.13097.3c0000 0001 2322 6764British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, King’s College London, London, United Kingdom
| | - Ana Eulalio
- grid.8051.c0000 0000 9511 4342RNA & Infection Laboratory, Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal ,grid.7311.40000000123236065Institute of Biomedicine (iBiMED), Department of Medical Sciences, University of Aveiro, Aveiro, Portugal ,grid.7445.20000 0001 2113 8111Department of Life Sciences, Imperial College London, London, United Kingdom
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8
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Activation of Human Platelets by Staphylococcus aureus Secreted Protease Staphopain A. Pathogens 2022; 11:pathogens11111237. [DOI: 10.3390/pathogens11111237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 10/19/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
Infection by Staphylococcus aureus is the leading cause of infective endocarditis (IE). Activation of platelets by this pathogen results in their aggregation and thrombus formation which are considered to be important steps in the development and pathogenesis of IE. Here, we show that a secreted cysteine protease, staphopain A, activates human platelets and induces their aggregation. The culture supernatant of a scpA mutant deficient in staphopain A production was reduced in its ability to trigger platelet aggregation. The platelet agonist activity of purified staphopain A was inhibited by staphostatin A, a specific inhibitor, thus implicating its protease activity in the agonism. In whole blood, using concentrations of staphopain A that were otherwise insufficient to induce platelet aggregation, increased binding to collagen and thrombus formation was observed. Using antagonists specific to protease-activated receptors 1 and 4, we demonstrate their role in mediating staphopain A induced platelet activation.
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9
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Staphylococcus aureus increases platelet reactivity in patients with infective endocarditis. Sci Rep 2022; 12:12933. [PMID: 35902612 PMCID: PMC9334290 DOI: 10.1038/s41598-022-16681-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/13/2022] [Indexed: 01/30/2023] Open
Abstract
Thromboembolism is frequent in infective endocarditis (IE). However, the optimal antithrombotic regimen in IE is unknown. Staphylococcus aureus (SA) is the leading cause of IE. First studies emphasize increased platelet reactivity by SA. In this pilot study, we hypothesized that platelet reactivity is increased in patients with SA− IE, which could be abrogated by antiplatelet medication. We conducted a prospective, observatory, single-center cohort study in 114 patients with IE, with four cohorts: (1) SA coagulase positive IE without aspirin (ASA) medication, (2) coagulase negative IE without ASA, (3) SA coagulase positive IE with ASA, (4) coagulase negative IE with ASA. Platelet function was measured by Multiplate electrode aggregometry, blood clotting by ROTEM thromboelastometry. Bleeding events were assessed according to TIMI classification. In ASA-naïve patients, aggregation with ADP was increased with coag. pos. IE (coagulase negative: 39.47 ± 4.13 AUC vs. coagulase positive: 59.46 ± 8.19 AUC, p = 0.0219). This was abrogated with ASA medication (coagulase negative: 42.4 ± 4.67 AUC vs. coagulase positive: 45.11 ± 6.063 AUC p = 0.7824). Aspirin did not increase bleeding in SA positive patients. However, in SA negative patients with aspirin, red blood cell transfusions were enhanced. SA coagulase positive IE is associated with increased platelet reactivity. This could be abrogated by aspirin without increased bleeding risk. The results of this pilot study suggest that ASA might be beneficial in SA coagulase positive IE. This needs to be confirmed in clinical trials.
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Abstract
The human skin is our outermost layer and serves as a protective barrier against external insults. Advances in next generation sequencing have enabled the discoveries of a rich and diverse community of microbes - bacteria, fungi and viruses that are residents of this surface. The genomes of these microbes also revealed the presence of many secretory enzymes. In particular, proteases which are hydrolytic enzymes capable of protein cleavage and degradation are of special interest in the skin environment which is enriched in proteins and lipids. In this minireview, we will focus on the roles of these skin-relevant microbial secreted proteases, both in terms of their widely studied roles as pathogenic agents in tissue invasion and host immune inactivation, and their recently discovered roles in inter-microbial interactions and modulation of virulence factors. From these studies, it has become apparent that while microbial proteases are capable of a wide range of functions, their expression is tightly regulated and highly responsive to the environments the microbes are in. With the introduction of new biochemical and bioinformatics tools to study protease functions, it will be important to understand the roles played by skin microbial secretory proteases in cutaneous health, especially the less studied commensal microbes with an emphasis on contextual relevance.
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11
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Intracellular Staphylococcus aureus employs the cysteine protease staphopain A to induce host cell death in epithelial cells. PLoS Pathog 2021; 17:e1009874. [PMID: 34473800 PMCID: PMC8443034 DOI: 10.1371/journal.ppat.1009874] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 09/15/2021] [Accepted: 08/07/2021] [Indexed: 11/19/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen, which can invade and survive in non-professional and professional phagocytes. Uptake by host cells is thought to contribute to pathogenicity and persistence of the bacterium. Upon internalization by epithelial cells, cytotoxic S. aureus strains can escape from the phagosome, replicate in the cytosol and induce host cell death. Here, we identified a staphylococcal cysteine protease to induce cell death after translocation of intracellular S. aureus into the host cell cytoplasm. We demonstrated that loss of staphopain A function leads to delayed onset of host cell death and prolonged intracellular replication of S. aureus in epithelial cells. Overexpression of staphopain A in a non-cytotoxic strain facilitated intracellular killing of the host cell even in the absence of detectable intracellular replication. Moreover, staphopain A contributed to efficient colonization of the lung in a mouse pneumonia model. In phagocytic cells, where intracellular S. aureus is exclusively localized in the phagosome, staphopain A did not contribute to cytotoxicity. Our study suggests that staphopain A is utilized by S. aureus to exit the epithelial host cell and thus contributes to tissue destruction and dissemination of infection. Staphylococcus aureus is an antibiotic-resistant pathogen that emerges in hospital and community settings and can cause a variety of diseases ranging from skin abscesses to lung inflammation and blood poisoning. The bacterium can asymptomatically colonize the upper respiratory tract and skin of humans and take advantage of opportune conditions, like immunodeficiency or breached barriers, to cause infection. Although S. aureus was not regarded as intracellular bacterium, it can be internalized by human cells and subsequently exit the host cells by induction of cell death, which is considered to cause tissue destruction and spread of infection. The bacterial virulence factors and underlying molecular mechanisms involved in the intracellular lifestyle of S. aureus remain largely unknown. We identified a bacterial cysteine protease to contribute to host cell death of epithelial cells mediated by intracellular S. aureus. Staphopain A induced killing of the host cell after translocation of the pathogen into the cell cytosol, while bacterial proliferation was not required. Further, the protease enhanced survival of the pathogen during lung infection. These findings reveal a novel, intracellular role for the bacterial protease staphopain A.
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Nishida T, Sugioka K, Fukuda K, Murakami J. Pivotal Role of Corneal Fibroblasts in Progression to Corneal Ulcer in Bacterial Keratitis. Int J Mol Sci 2021; 22:ijms22168979. [PMID: 34445684 PMCID: PMC8396668 DOI: 10.3390/ijms22168979] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 01/05/2023] Open
Abstract
The shape and transparency of the cornea are essential for clear vision. However, its location at the ocular surface renders the cornea vulnerable to pathogenic microorganisms in the external environment. Pseudomonas aeruginosa and Staphylococcus aureus are two such microorganisms and are responsible for most cases of bacterial keratitis. The development of antimicrobial agents has allowed the successful treatment of bacterial keratitis if the infection is diagnosed promptly. However, no effective medical treatment is available after progression to corneal ulcer, which is characterized by excessive degradation of collagen in the corneal stroma and can lead to corneal perforation and corneal blindness. This collagen degradation is mediated by both infecting bacteria and corneal fibroblasts themselves, with a urokinase-type plasminogen activator (uPA)-plasmin-matrix metalloproteinase (MMP) cascade playing a central role in collagen destruction by the host cells. Bacterial factors stimulate the production by corneal fibroblasts of both uPA and pro-MMPs, released uPA mediates the conversion of plasminogen in the extracellular environment to plasmin, and plasmin mediates the conversion of secreted pro-MMPs to the active form of these enzymes, which then degrade stromal collagen. Bacterial factors also stimulate expression by corneal fibroblasts of the chemokine interleukin-8 and the adhesion molecule ICAM-1, both of which contribute to recruitment and activation of polymorphonuclear neutrophils, and these cells then further stimulate corneal fibroblasts via the secretion of interleukin-1. At this stage of the disease, bacteria are no longer necessary for collagen degradation. In this review, we discuss the pivotal role of corneal fibroblasts in corneal ulcer associated with infection by P. aeruginosa or S. aureus as well as the development of potential new modes of treatment for this condition.
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Affiliation(s)
- Teruo Nishida
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi 755-8505, Japan;
- Division of Cornea and Ocular Surface, Ohshima Eye Hospital, Fukuoka 812-0036, Japan
| | - Koji Sugioka
- Department of Ophthalmology, Kindai University Nara Hospital, Ikoma, Nara 630-0293, Japan;
| | - Ken Fukuda
- Department of Ophthalmology and Visual Science, Kochi Medical School, Kochi University, Nankoku, Kochi 783-8505, Japan
- Correspondence:
| | - Junko Murakami
- Division of Ophthalmology, Sakibana Hospital, Izumi, Osaka 594-1105, Japan;
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Hammers D, Carothers K, Lee S. The Role of Bacterial Proteases in Microbe and Host-microbe Interactions. Curr Drug Targets 2021; 23:222-239. [PMID: 34370632 DOI: 10.2174/1389450122666210809094100] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Secreted proteases are an important class of factors used by bacterial to modulate their extracellular environment through the cleavage of peptides and proteins. These proteases can range from broad, general proteolytic activity to high degrees of substrate specificity. They are often involved in interactions between bacteria and other species, even across kingdoms, allowing bacteria to survive and compete within their niche. As a result, many bacterial proteases are of clinical importance. The immune system is a common target for these enzymes, and bacteria have evolved ways to use these proteases to alter immune responses for their benefit. In addition to the wide variety of human proteins that can be targeted by bacterial proteases, bacteria also use these secreted factors to disrupt competing microbes, ranging from outright antimicrobial activity to disrupting processes like biofilm formation. OBJECTIVE In this review, we address how bacterial proteases modulate host mechanisms of protection from infection and injury, including immune factors and cell barriers. We also discuss the contributions of bacterial proteases to microbe-microbe interactions, including antimicrobial and anti-biofilm dynamics. CONCLUSION Bacterial secreted proteases represent an incredibly diverse group of factors that bacteria use to shape and thrive in their microenvironment. Due to the range of activities and targets of these proteases, some have been noted for having potential as therapeutics. The vast array of bacterial proteases and their targets remains an expanding field of research, and this field has many important implications for human health.
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Affiliation(s)
- Daniel Hammers
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
| | - Katelyn Carothers
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
| | - Shaun Lee
- Department of Biological Sciences, University of Notre Dame, Galvin Hall, Notre Dame, IN 46556, United States
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14
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Donovan C, Koudouna E, Margo CE, Avila MY, Espana EM. Genipin Delays Corneal Stromal Enzymatic Digestion. Transl Vis Sci Technol 2021; 10:25. [PMID: 34424287 PMCID: PMC8394563 DOI: 10.1167/tvst.10.9.25] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the use of genipin in delaying enzymatic digestion of corneal stroma. Methods Human corneal stromal tissue was treated with genipin, a known chemical crosslinker, and then along with control tissue was subjected to enzymatic digestion with collagenase. The effects of genipin treatment in retarding stromal digestion were analyzed with phase contrast microscopy, a protein quantification assay, second harmonic generation imaging, and transmission electron microscopy. Results Genipin increased stromal resistance to enzymatic digestion when compared with untreated stroma. A morphologic analysis and protein quantification showed increased stromal resistance to enzymatic digestion once stromal tissue was treated with genipin. Second harmonic generation imaging revealed persistent fibrillar collagen signaling in genipin-treated tissue in contrast with untreated tissue suggesting that genipin retards collagenolysis. Conclusions Genipin increases stromal resistance to enzymatic digestion in controlled experiments as demonstrated by protein quantification studies and through morphologic imaging. Translational Relevance This study explores the novel use of genipin in delaying enzymatic stromal digestion. Delaying stromal melting in the setting of corneal infectious or autoimmune keratitis can potentially decrease clinical morbidity.
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Affiliation(s)
- Christopher Donovan
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Elena Koudouna
- Department of Ophthalmology, School of Medicine, Universidad Nacional de Colombia, Hospital Universitario Nacional, Bogota, Colombia.,Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK
| | - Curtis E Margo
- Department of Pathology and Cell Biology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Marcel Y Avila
- Department of Ophthalmology, School of Medicine, Universidad Nacional de Colombia, Hospital Universitario Nacional, Bogota, Colombia
| | - Edgar M Espana
- Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
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Wang X, Koffi PF, English OF, Lee JC. Staphylococcus aureus Extracellular Vesicles: A Story of Toxicity and the Stress of 2020. Toxins (Basel) 2021; 13:toxins13020075. [PMID: 33498438 PMCID: PMC7909408 DOI: 10.3390/toxins13020075] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/15/2021] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus generates and releases extracellular vesicles (EVs) that package cytosolic, cell-wall associated, and membrane proteins, as well as glycopolymers and exoproteins, including alpha hemolysin, leukocidins, phenol-soluble modulins, superantigens, and enzymes. S. aureus EVs, but not EVs from pore-forming toxin-deficient strains, were cytolytic for a variety of mammalian cell types, but EV internalization was not essential for cytotoxicity. Because S. aureus is subject to various environmental stresses during its encounters with the host during infection, we assessed how these exposures affected EV production in vitro. Staphylococci grown at 37 °C or 40 °C did not differ in EV production, but cultures incubated at 30 °C yielded more EVs when grown to the same optical density. S. aureus cultivated in the presence of oxidative stress, in iron-limited media, or with subinhibitory concentrations of ethanol, showed greater EV production as determined by protein yield and quantitative immunoblots. In contrast, hyperosmotic stress or subinhibitory concentrations of erythromycin reduced S. aureus EV yield. EVs represent a novel S. aureus secretory system that is affected by a variety of stress responses and allows the delivery of biologically active pore-forming toxins and other virulence determinants to host cells.
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Staphylococcus aureus Fatty Acid Kinase FakA Modulates Pathogenesis during Skin Infection via Proteases. Infect Immun 2020; 88:IAI.00163-20. [PMID: 32513856 DOI: 10.1128/iai.00163-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 05/23/2020] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus fatty acid kinase FakA is necessary for the incorporation of exogenous fatty acids into the lipid membrane. We previously demonstrated that the inactivation of fakA leads to decreased α-hemolysin (Hla) production but increased expression of the proteases SspAB and aureolysin in vitro, and that the ΔfakA mutant causes larger lesions than the wild type (WT) during murine skin infection. As expected, necrosis is Hla dependent in the presence or absence of FakA, as both hla and hla ΔfakA mutants are unable to cause necrosis of the skin. At day 4 postinfection, while the ΔfakA mutant maintains larger and more necrotic abscesses, bacterial numbers are similar to those of the WT, indicating the enhanced tissue damage of mice infected with the ΔfakA mutant is not due to an increase in bacterial burden. At this early stage of infection, skin infected with the ΔfakA mutant has decreased levels of proinflammatory cytokines, such as interleukin-17A (IL-17A) and IL-1α, compared to those of WT-infected skin. At a later stage of infection (day 7), abscess resolution and bacterial clearance are hindered in ΔfakA mutant-infected mice. The paradoxical findings of decreased Hla in vitro but increased necrosis in vivo led us to investigate the role of the proteases regulated by FakA. Utilizing Δaur and ΔsspAB mutants in both the WT and fakA mutant backgrounds, we found that the absence of these proteases in a fakA mutant reduced dermonecrosis to levels similar to those of the WT strain. These studies suggest that the overproduction of proteases is one factor contributing to the enhanced pathogenesis of the ΔfakA mutant during skin infection.
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Çankirili NK, Kart D, Çelebi-Saltik B. Evaluation of the biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa on human umbilical cord CD146+ stem cells and stem cell-based decellularized matrix. Cell Tissue Bank 2020; 21:215-231. [PMID: 32020424 DOI: 10.1007/s10561-020-09815-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/30/2020] [Indexed: 02/06/2023]
Abstract
This study aims to evaluate the CD146+ stem cells obtained from the human umbilical cord and their extracellular matrix proteins on in vitro Pseudomonas aeruginosa and Staphylococcus aureus biofilms to understand their possible antimicrobial activity. CD146+ stem cells were determined according to cell surface markers and differentiation capacity. Characterization of the decellularized matrix was done with DAPI, Masson's Trichrome staining and proteome analysis. Cell viability/proliferation of cells in co-cultures was evaluated by WST-1 and crystal-violet staining. The effects of cells and decellularized matrix proteins on biofilms were investigated on a drip flow biofilm reactor and their effects on gene expression were determined by RT-qPCR. We observed that CD146/105+ stem cells could differentiate adipogenically and decellularized matrix showed negative DAPI and positive collagen staining with Masson' s Trichrome. Proteome analysis of the decellularized matrix revealed some matrix components and growth factors. Although the decellularized matrix significantly reduced the cell counts of P. aeruginosa, no significant difference was observed for S. aureus cells in both groups. Supporting data was obtained from the gene expression results of P. aeruginosa with the significant down-regulation of rhlR and lasR. For S. aureus, icaADBC genes were significantly up-regulated when grown on the decellularized matrix.
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Affiliation(s)
- Nur Kübra Çankirili
- Department of Stem Cell Sciences, Hacettepe University Graduate School of Health Sciences, 06100, Sihhiye, Ankara, Turkey
- Center for Stem Cell Research and Development, Hacettepe University, 06100, Sihhiye, Ankara, Turkey
| | - Didem Kart
- Department of Pharmaceutical Microbiology, Hacettepe University Faculty of Pharmacy, 06100, Sihhiye, Ankara, Turkey
| | - Betül Çelebi-Saltik
- Department of Stem Cell Sciences, Hacettepe University Graduate School of Health Sciences, 06100, Sihhiye, Ankara, Turkey.
- Center for Stem Cell Research and Development, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.
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Man E, Hoskins C. Towards advanced wound regeneration. Eur J Pharm Sci 2020; 149:105360. [PMID: 32361177 DOI: 10.1016/j.ejps.2020.105360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/22/2020] [Accepted: 04/22/2020] [Indexed: 12/12/2022]
Abstract
Wound management is a major contributor towards the economic burden placed upon the national health service (NHS), serving as an important target for the development of advanced therapeutic interventions. The economic expenditure of wound care for the NHS exceeds £5 billion per annum, thus presenting a significant opportunity for the introduction of alternative treatments in regards to their approach in tackling the ever increasing prevalence of wound management associated problems. As most wounds typically fall under the acute or chronic category, it is therefore necessary to design a therapeutic intervention capable of effectively resolving the pathologies associated with each problem. Such an intervention should be of increased economic viability and therapeutic effectiveness when compared to standardized treatments, thus helping to alleviate the financial burden imposed upon the NHS. The purpose of this review is to critically analyse the various aspects associated with wound management, detailing the fundamental concepts of dermal regeneration, whilst also providing an evaluation of the different materials and methods that can be utilised to achieve maximal wound regeneration. The primary aspects of this review revolve around the three concepts of antibacterial methodology, enhancement of dermal regeneration and the utilisation of a carrier medium to facilitate the regenerative process. Each aspect is explored, conveying its justifications as a target for dermal regeneration, whilst offering various solutions towards the fulfilment of a therapeutic design that is both effective and financially feasible.
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Affiliation(s)
- Ernest Man
- Department of Pure and Applied Chemistry, Faculty of Science, University of Strathclyde, Glasgow, Scotland, G1 1RD, United Kingdom
| | - Clare Hoskins
- Department of Pure and Applied Chemistry, Faculty of Science, University of Strathclyde, Glasgow, Scotland, G1 1RD, United Kingdom.
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Early-Stage Staphylococcus aureus Bloodstream Infection Causes Changes in the Concentrations of Lipoproteins and Acute-Phase Proteins and Is Associated with Low Antibody Titers against Bacterial Virulence Factors. mSystems 2020; 5:5/1/e00632-19. [PMID: 31964768 PMCID: PMC6977072 DOI: 10.1128/msystems.00632-19] [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] [Indexed: 02/06/2023] Open
Abstract
S. aureus sepsis has a high complication and mortality rate. Given the limited therapeutic possibilities, effective prevention strategies, e.g., a vaccine, or the early identification of high-risk patients would be important but are not available. Our study showed an acute-phase response in patients with S. aureus bloodstream infection and evidence that lipoproteins are downregulated in plasma. Using immunoproteomics, stratification of patients appears to be achievable, since at the early stages of systemic S. aureus infection patients had low preexisting anti-S. aureus antibody levels. This strengthens the notion that a robust immune memory for S. aureus protects against infections with the pathogen. Systemic and quantitative investigations of human plasma proteins (proteomics) and Staphylococcus aureus-specific antibodies (immunoproteomics) provide complementary information and hold promise for the discovery of biomarkers in Staphylococcus aureus bloodstream infection (SABSI). Usually, data-dependent acquisition (DDA) is used for proteome analysis of serum or plasma, but data-independent acquisition (DIA) is more comprehensive and reproducible. In this prospective cohort study, we aimed to identify biomarkers associated with the early stages of SABSI using a serum DIA proteomic and immunoproteomic approach. Sera from 49 SABSI patients and 43 noninfected controls were analyzed. In total, 608 human serum proteins were identified with DIA. A total of 386 proteins could be quantified, of which 9 proteins, mainly belonging to acute-phase proteins, were significantly increased, while 7 high-density lipoproteins were lower in SABSI. In SABSI, total anti-S. aureus serum IgG was reduced compared with controls as shown by immunoproteomic quantification of IgG binding to 143 S. aureus antigens. IgG binding to 48 of these anti-S. aureus proteins was significantly lower in SABSI, while anti-Ecb IgG was the only one increased in SABSI. Serum IgG binding to autoinducing peptide MsrB, FadB, EsxA, Pbp2, FadB, SspB, or SodA was very low in SABSI. This marker panel discriminated early SABSI from controls with 95% sensitivity and 100% specificity according to random forest prediction. This holds promise for patient stratification according to their risk of S. aureus infection, underlines the protective function of the adaptive immune system, and encourages further efforts in the development of a vaccine against S. aureus. IMPORTANCES. aureus sepsis has a high complication and mortality rate. Given the limited therapeutic possibilities, effective prevention strategies, e.g., a vaccine, or the early identification of high-risk patients would be important but are not available. Our study showed an acute-phase response in patients with S. aureus bloodstream infection and evidence that lipoproteins are downregulated in plasma. Using immunoproteomics, stratification of patients appears to be achievable, since at the early stages of systemic S. aureus infection patients had low preexisting anti-S. aureus antibody levels. This strengthens the notion that a robust immune memory for S. aureus protects against infections with the pathogen.
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Abstract
The complex regulatory role of the proteases necessitates very tight coordination and control of their expression. While this process has been well studied, a major oversight has been the consideration of proteases as a single entity rather than as 10 enzymes produced from four different promoters. As such, in this study, we comprehensively characterized the regulation of each protease promoter, discovering vast differences in the way each protease operon is controlled. Additionally, we broaden the picture of protease regulation using a global screen to identify novel loci controlling protease activity, uncovering a cadre of new effectors of protease expression. The impact of these elements on the activity of proteases and known regulators was characterized by producing a comprehensive regulatory circuit that emphasizes the complexity of protease regulation in Staphylococcus aureus. A primary function of the extracellular proteases of Staphylococcus aureus is to control the progression of infection by selectively modulating the stability of virulence factors. Consequently, a regulatory network exists to titrate protease abundance/activity to influence the accumulation, or lack thereof, of individual virulence factors. Herein, we comprehensively map this system, exploring the regulation of the four protease loci by known and novel factors. In so doing, we determined that seven major elements (SarS, SarR, Rot, MgrA, CodY, SaeR, and SarA) form the primary network of control, with the latter three being the most powerful. We note that expression of aureolysin is largely repressed by these factors, while the spl operon is subject to the strongest upregulation of any protease loci, particularly by SarR and SaeR. Furthermore, when exploring scpA expression, we find it to be profoundly influenced in opposing fashions by SarA (repressor) and SarR (activator). We also present the screening of >100 regulator mutants of S. aureus, identifying 7 additional factors (ArgR2, AtlR, MntR, Rex, XdrA, Rbf, and SarU) that form a secondary circuit of protease control. Primarily, these elements serve as activators, although we reveal XdrA as a new repressor of protease expression. With the exception or ArgR2, each of the new effectors appears to work through the primary network of regulation to influence protease production. Collectively, we present a comprehensive regulatory circuit that emphasizes the complexity of protease regulation and suggest that its existence speaks to the importance of these enzymes to S. aureus physiology and pathogenic potential. IMPORTANCE The complex regulatory role of the proteases necessitates very tight coordination and control of their expression. While this process has been well studied, a major oversight has been the consideration of proteases as a single entity rather than as 10 enzymes produced from four different promoters. As such, in this study, we comprehensively characterized the regulation of each protease promoter, discovering vast differences in the way each protease operon is controlled. Additionally, we broaden the picture of protease regulation using a global screen to identify novel loci controlling protease activity, uncovering a cadre of new effectors of protease expression. The impact of these elements on the activity of proteases and known regulators was characterized by producing a comprehensive regulatory circuit that emphasizes the complexity of protease regulation in Staphylococcus aureus.
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21
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The Role of Streptococcal and Staphylococcal Exotoxins and Proteases in Human Necrotizing Soft Tissue Infections. Toxins (Basel) 2019; 11:toxins11060332. [PMID: 31212697 PMCID: PMC6628391 DOI: 10.3390/toxins11060332] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 06/04/2019] [Accepted: 06/10/2019] [Indexed: 12/31/2022] Open
Abstract
Necrotizing soft tissue infections (NSTIs) are critical clinical conditions characterized by extensive necrosis of any layer of the soft tissue and systemic toxicity. Group A streptococci (GAS) and Staphylococcus aureus are two major pathogens associated with monomicrobial NSTIs. In the tissue environment, both Gram-positive bacteria secrete a variety of molecules, including pore-forming exotoxins, superantigens, and proteases with cytolytic and immunomodulatory functions. The present review summarizes the current knowledge about streptococcal and staphylococcal toxins in NSTIs with a special focus on their contribution to disease progression, tissue pathology, and immune evasion strategies.
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22
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Contribution of YjbIH to Virulence Factor Expression and Host Colonization in Staphylococcus aureus. Infect Immun 2019; 87:IAI.00155-19. [PMID: 30885928 DOI: 10.1128/iai.00155-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 03/10/2019] [Indexed: 12/17/2022] Open
Abstract
To persist within the host and cause disease, Staphylococcus aureus relies on its ability to precisely fine-tune virulence factor expression in response to rapidly changing environments. During an unbiased transposon mutant screen, we observed that disruption of a two-gene operon, yjbIH, resulted in decreased levels of pigmentation and aureolysin (Aur) activity relative to the wild-type strain. Further analyses revealed that YjbH, a predicted thioredoxin-like oxidoreductase, is predominantly responsible for the observed yjbIH mutant phenotypes, though a minor role exists for the putative truncated hemoglobin YjbI. These differences were due to significantly decreased expression of crtOPQMN and aur Previous studies found that YjbH targets the disulfide- and oxidative stress-responsive regulator Spx for degradation by ClpXP. The absence of yjbH or yjbI resulted in altered sensitivities to nitrosative and oxidative stress and iron deprivation. Additionally, aconitase activity was altered in the yjbH and yjbI mutant strains. Decreased levels of pigmentation and aureolysin (Aur) activity in the yjbH mutant were found to be Spx dependent. Lastly, we used a murine sepsis model to determine the effect of the yjbIH deletion on pathogenesis and found that the mutant was better able to colonize the kidneys and spleens during an acute infection than the wild-type strain. These studies identified changes in pigmentation and protease activity in response to YjbIH and are the first to have shown a role for these proteins during infection.
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Abstract
Staphylococcus aureus has the ability to cause infections in a variety of niches, suggesting a robust metabolic capacity facilitating proliferation under various nutrient conditions. The mature skin abscess is glucose depleted, indicating that peptides and free amino acids are important sources of nutrients for S. aureus. Our studies have found that mutations in both pyruvate carboxykinase and glutamate dehydrogenase, enzymes that function in essential gluconeogenesis reactions when amino acids serve as the major carbon source, reduce bacterial burden in a murine skin abscess model. Moreover, peptides liberated from collagen by host protease MMP-9 as well as the staphylococcal protease aureolysin support S. aureus growth in an Opp3-dependent manner under nutrient-limited conditions. Additionally, the presence of peptides induces aureolysin expression. Overall, these studies define one pathway by which S. aureus senses a nutrient-limiting environment and induces factors that function to acquire and utilize carbon from host-derived sources. Staphylococcus aureus has the ability to cause infections in multiple organ systems, suggesting an ability to rapidly adapt to changing carbon and nitrogen sources. Although there is little information about the nutrients available at specific sites of infection, a mature skin abscess has been characterized as glucose depleted, indicating that peptides and free amino acids are an important source of nutrients for the bacteria. Our studies have found that mutations in enzymes necessary for growth on amino acids, including pyruvate carboxykinase (ΔpckA) and glutamate dehydrogenase (ΔgudB), reduced the ability of the bacteria to proliferate within a skin abscess, suggesting that peptides and free amino acids are important for S. aureus growth. Furthermore, we found that collagen, an abundant host protein that is present throughout a skin abscess, serves as a reservoir of peptides. To liberate peptides from the collagen, we identified that the host protease, MMP-9, as well as the staphylococcal proteases aureolysin and staphopain B function to cleave collagen into peptide fragments that can support S. aureus growth under nutrient-limited conditions. Moreover, the oligopeptide transporter Opp3 is the primary staphylococcal transporter responsible for peptide acquisition. Lastly, we observed that the presence of peptides (3-mer to 7-mer) induces the expression of aureolysin, suggesting that S. aureus has the ability to detect peptides in the environment.
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Yoon DJ, Fregoso DR, Nguyen D, Chen V, Strbo N, Fuentes JJ, Tomic-Canic M, Crawford R, Pastar I, Isseroff RR. A tractable, simplified ex vivo human skin model of wound infection. Wound Repair Regen 2019; 27:421-425. [PMID: 30825247 DOI: 10.1111/wrr.12712] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/31/2019] [Accepted: 02/07/2019] [Indexed: 12/13/2022]
Abstract
The prevalence of infection in chronic wounds is well documented in the literature but not optimally studied due to the drawbacks of current methodologies. Here, we describe a tractable and simplified ex vivo human skin model of infection that addresses the critical drawbacks of high costs and limited translatability. Wounds were generated from excised abdominal skin from cosmetic procedures and cultured, inoculated with Staphylococcus aureus strain UAMS-1, or under aseptic conditions. After three days, the infected wounds exhibited biofilm formation and significantly impaired reepithelialization compared to the control. Additionally, promigratory and proreparative genes were significantly downregulated, while proinflammatory genes were significantly upregulated, demonstrating molecular characterizations of impaired healing as in chronic wounds. This model allows for a simplified and versatile tool for the study of wound infection and subsequent development of novel therapies.
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Affiliation(s)
- Daniel J Yoon
- Department of Dermatology, University of California, Davis, Sacramento, California
| | - Daniel R Fregoso
- Department of Dermatology, University of California, Davis, Sacramento, California
| | - Duc Nguyen
- Department of Dermatology, University of California, Davis, Sacramento, California
| | - Vivien Chen
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida
| | - Natasa Strbo
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, Florida
| | - Jaime J Fuentes
- Department of Biological Sciences, California State University Sacramento, Sacramento, California
| | - Marjana Tomic-Canic
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida
| | - Robert Crawford
- Department of Biological Sciences, California State University Sacramento, Sacramento, California
| | - Irena Pastar
- Dr. Phillip Frost Department of Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida
| | - R Rivkah Isseroff
- Department of Dermatology, University of California, Davis, Sacramento, California
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Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 197] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
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Singh V, Phukan UJ. Interaction of host and Staphylococcus aureus protease-system regulates virulence and pathogenicity. Med Microbiol Immunol 2018; 208:585-607. [PMID: 30483863 DOI: 10.1007/s00430-018-0573-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 11/22/2018] [Indexed: 02/06/2023]
Abstract
Staphylococcus aureus causes various health care- and community-associated infections as well as certain chronic TH2 driven inflammatory diseases. It is a potent pathogen with serious virulence and associated high morbidity. Severe pathogenicity is accredited to the S. aureus secreted virulence factors such as proteases and host protease modulators. These virulence factors promote adhesion and invasion of bacteria through damage of tight junction barrier and keratinocytes. They inhibit activation and transmigration of various immune cells such as neutrophils (and neutrophil proteases) to evade opsono-phagocytosis and intracellular bacterial killing. Additionally, they protect the bacteria from extracellular killing by disrupting integrity of extracellular matrix. Platelet activation and agglutination is also impaired by these factors. They also block the classical as well as alternative pathways of complement activation and assist in spread of infection through blood and tissue. As these factors are exquisite factors of S. aureus mediated disease development, we have focused on review of diversification of various protease-system associated virulence factors, their structural building, diverse role in disease development and available therapeutic counter measures. This review summarises the role of protease-associated virulence factors during invasion and progression of disease.
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Affiliation(s)
- Vigyasa Singh
- Molecular Bioprospection Department, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, 226015, India
| | - Ujjal Jyoti Phukan
- School of Life Science, Jawaharlal Nehru University, New Delhi, 110067, India.
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Guanine Limitation Results in CodY-Dependent and -Independent Alteration of Staphylococcus aureus Physiology and Gene Expression. J Bacteriol 2018; 200:JB.00136-18. [PMID: 29712876 DOI: 10.1128/jb.00136-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/25/2018] [Indexed: 02/03/2023] Open
Abstract
In Staphylococcus aureus, the global transcriptional regulator CodY modulates the expression of hundreds of genes in response to the availability of GTP and the branched-chain amino acids isoleucine, leucine, and valine (ILV). CodY DNA-binding activity is high when GTP and ILV are abundant. When GTP and ILV are limited, CodY's affinity for DNA drops, altering expression of CodY-regulated targets. In this work, we investigated the impact of guanine nucleotides (GNs) on S. aureus physiology and CodY activity by constructing a guaA null mutant (ΔguaA strain). De novo biosynthesis of guanine monophosphate is abolished due to the guaA mutation; thus, the mutant cells require exogenous guanosine for growth. We also found that CodY activity was reduced when we knocked out guaA, activating the Agr two-component system and increasing secreted protease activity. Notably, in a rich, complex medium, we detected an increase in alternative sigma factor B activity in the ΔguaA mutant, which results in a 5-fold increase in production of the antioxidant pigment staphyloxanthin. Under biologically relevant flow conditions, ΔguaA cells failed to form robust biofilms when limited for guanine or guanosine. Transcriptome sequencing (RNA-Seq) analysis of the S. aureus transcriptome during growth in guanosine-limited chemostats revealed substantial CodY-dependent and -independent alterations of gene expression profiles. Importantly, these changes increase production of proteases and δ-toxin, suggesting that S. aureus exhibits a more invasive lifestyle when limited for guanosine. Further, gene products upregulated under GN limitation, including those necessary for lipoic acid biosynthesis and sugar transport, may prove to be useful drug targets for treating Gram-positive infections.IMPORTANCE Staphylococcus aureus infections impose a serious economic burden on health care facilities and patients because of the emergence of strains resistant to last-line antibiotics. Understanding the physiological processes governing fitness and virulence of S. aureus in response to environmental cues is critical for developing efficient diagnostics and treatments. De novo purine biosynthesis is essential for both fitness and virulence in S. aureus since inhibiting production cripples S. aureus's ability to cause infection. Here, we corroborate these findings and show that blocking guanine nucleotide synthesis severely affects S. aureus fitness by altering metabolic and virulence gene expression. Characterizing pathways and gene products upregulated in response to guanine limitation can aid in the development of novel adjuvant strategies to combat S. aureus infections.
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Kavanagh N, O’Brien FJ, Kerrigan SW. Staphylococcus aureus protein A causes osteoblasts to hyper-mineralise in a 3D extra-cellular matrix environment. PLoS One 2018; 13:e0198837. [PMID: 29927956 PMCID: PMC6013232 DOI: 10.1371/journal.pone.0198837] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/25/2018] [Indexed: 01/18/2023] Open
Abstract
Osteomyelitis is an inflammatory bone infection that is caused most commonly by the opportunistic pathogen Staphylococcus aureus. Research into staphylococcal induced bone infection is typically conducted using traditional 2D in vitro culture settings, which is not fully representative of the dynamic in vivo environment. In this study we utilised a collagen glycosaminoglycan scaffold, previously developed for bone tissue engineering, as a representative 3D model of infection. The scaffold resisted degradation and retained its pore structure, which is important for cellular function and survival, when seeded with both cells and bacteria. Using this model, we showed that in the presence of S. aureus, osteoblast proliferation was reduced over 21 days. Interestingly however these cells were more metabolically active compared to the uninfected cells and demonstrated increased mineralisation. Protein A (SpA) is a virulence factor found on the surface of S. aureus and has been shown to interact with osteoblasts. When SpA was removed from the surface of S. aureus, the osteoblasts show comparable activity with the uninfected cells-demonstrating the importance of SpA in the interaction between bone cells and S. aureus. Our results suggest that infected osteoblasts are capable of over-compensating for bone loss and bone destruction by increasing mineralisation in a 3D environment, key elements required for ensuring bone strength. It also reinforces our previously established result that S. aureus SpA is a critical mediator in osteomyelitis and might be a potential novel drug target to treat osteomyelitis by preventing the interaction between S. aureus and osteoblasts.
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Affiliation(s)
- Nicola Kavanagh
- Cardiovascular Infection Research Group, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
- Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Fergal J. O’Brien
- Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
- Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland and Trinity College Dublin, Dublin, Ireland
| | - Steve W. Kerrigan
- Cardiovascular Infection Research Group, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
- Tissue Engineering Research Group, Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland
- School of Pharmacy and Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
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Imamura T, Murakami Y, Nitta H. Aeromonas sobria serine protease (ASP): a subtilisin family endopeptidase with multiple virulence activities. Biol Chem 2017; 398:1055-1068. [PMID: 28432839 DOI: 10.1515/hsz-2016-0344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 04/07/2017] [Indexed: 11/15/2022]
Abstract
Aeromonas sobria serine protease (ASP) is secreted from Aeromonas sobria, a pathogen causing gastroenteritis and sepsis. ASP resembles Saccharomyces cerevisiae Kex2, a member of the subtilisin family, and preferentially cleaves peptide bonds at the C-terminal side of paired basic amino acid residues; also accepting unpaired arginine at the P1 site. Unlike Kex2, however, ASP lacks an intramolecular chaperone N-terminal propeptide, instead utilizes the external chaperone ORF2 for proper folding, therefore, ASP and its homologues constitute a new subfamily in the subtilisin family. Through activation of the kallikrein/kinin system, ASP induces vascular leakage, and presumably causes edema and septic shock. ASP accelerates plasma clotting by α-thrombin generation from prothrombin, whereas it impairs plasma clottability by fibrinogen degradation, together bringing about blood coagulation disorder that occurs in disseminated intravascular coagulation, a major complication of sepsis. From complement C5 ASP liberates C5a that induces neutrophil recruitment and superoxide release, and mast cell degranulation, which are associated with pus formation, tissue injury and diarrhea, respectively. Nicked two-chain ASP also secreted from A. sobria is more resistant to inactivation by α2-macroglobulin than single-chain ASP, thereby raising virulence activities. Thus, ASP is a potent virulence factor and may participate in the pathogenesis of A. sobria infection.
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Troger J, Theurl M, Kirchmair R, Pasqua T, Tota B, Angelone T, Cerra MC, Nowosielski Y, Mätzler R, Troger J, Gayen JR, Trudeau V, Corti A, Helle KB. Granin-derived peptides. Prog Neurobiol 2017; 154:37-61. [PMID: 28442394 DOI: 10.1016/j.pneurobio.2017.04.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 04/10/2017] [Accepted: 04/16/2017] [Indexed: 12/14/2022]
Abstract
The granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromogranin A (CgA), chromogranin B (CgB) and secretogranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main granins, e.g. to the chromogranin A derived vasostatins, betagranins, pancreastatin and catestatins, the chromogranin B-derived secretolytin and the secretogranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromogranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed.
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Affiliation(s)
- Josef Troger
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Markus Theurl
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Rudolf Kirchmair
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Teresa Pasqua
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Bruno Tota
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Tommaso Angelone
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Maria C Cerra
- Department of Biology, Ecology and Earth Sciences, University of Calabria, Arcavacata di Rende, Italy
| | - Yvonne Nowosielski
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | - Raphaela Mätzler
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | - Jasmin Troger
- Department of Ophthalmology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Vance Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Angelo Corti
- Vita-Salute San Raffaele University and Division of Experimental Oncology, San Raffaele Scientific Institute, Milan, Italy
| | - Karen B Helle
- Department of Biomedicine, University of Bergen, Norway
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Amino Acid Catabolism in Staphylococcus aureus and the Function of Carbon Catabolite Repression. mBio 2017; 8:mBio.01434-16. [PMID: 28196956 PMCID: PMC5312079 DOI: 10.1128/mbio.01434-16] [Citation(s) in RCA: 122] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting that S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids, including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in the gudB gene, coding for glutamate dehydrogenase, which generates 2-oxoglutarate from glutamate, significantly reduced growth in CDM, suggesting that glutamate and those amino acids generating glutamate, particularly proline, serve as the major carbon source in this medium. Nuclear magnetic resonance (NMR) studies confirmed this supposition. Furthermore, a mutation in the ackA gene, coding for acetate kinase, also abrogated growth of JE2 in CDM, suggesting that ATP production from pyruvate-producing amino acids is also critical for growth. In addition, although a functional respiratory chain was absolutely required for growth, the oxygen consumption rate and intracellular ATP concentration were significantly lower during growth in CDM than during growth in glucose-containing media. Finally, transcriptional analyses demonstrated that expression levels of genes coding for the enzymes that synthesize glutamate from proline, arginine, and histidine are repressed by CcpA and carbon catabolite repression. These data show that pathways important for glutamate catabolism or ATP generation via Pta/AckA are important for growth in niches where glucose is not abundant, such as abscesses within skin and soft tissue infections. S. aureus is a significant cause of both morbidity and mortality worldwide. This bacterium causes infections in a wide variety of organ systems, the most common being skin and soft tissue. Within a staphylococcal abscess, levels of glucose, a preferred carbon source, are limited due to the host immune response. Therefore, S. aureus must utilize other available carbon sources such as amino acids or peptides to proliferate. Our results show that glutamate and amino acids that serve as substrates for glutamate synthesis, particularly proline, function as major carbon sources during growth, whereas other amino acids that generate pyruvate are important for ATP synthesis via substrate-level phosphorylation in the Pta-AckA pathway. Our data support a model whereby certain amino acid catabolic pathways, and acquisition of those particular amino acids, are crucial for growth in niches where glucose is not abundant.
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Abstract
Bovine mastitis is the most costly disease for dairy farmers, hence, control measures to prevent it are crucial for dairy farm sustainability. Staphylococcus aureus is considered a major mastitis pathogen because of its impact on milk quality and low cure rates. Prevention of S. aureus mastitis includes segregation of infected animals, whilst treatment of such animals should be performed for a longer time to improve cure rates. This makes identification of S. aureus infected quarters and animals of significant importance. The experiments reported in this research paper aimed to develop and validate a sensitive method for magnetic detection of S. aureus and of the Staphylococcus genus in raw milk samples. Mastitic milk samples were collected aseptically from 47 cows with subclinical mastitis, from 12 Portuguese dairy farms. Forty nine quarter milk samples were selected based on bacteriological results. All samples were submitted to PCR analysis. In parallel, these milk samples were mixed with a solution combining specific antibodies and magnetic nanoparticles, to be analysed using a lab-on-a-chip magnetoresistive cytometer, with microfluidic sample handling. The antibodies used in this work were a rabbit polyclonal IgG anti-S. aureus ScpA protein and a mouse monoclonal IgM anti-S. aureus ATCC 29740. This paper describes the methodology used for magnetic detection of bacteria, including analysis of false positive/negative results. This immunological recognition was able to detect bacterial presence above 100 cfu/ml, independently of antibody and targeted bacteria used in this work. Comparison with PCR results showed sensitivities of 57·1 and 79·3%, specificity values of 75 and 50%, and PPV values of 40 and 95·8% for magnetic identification of Staphylococci species with an anti-S. aureus antibody and an anti-Staphylococcus spp. antibody, respectively. Some constraints are described as well as the method's limitations in bacterial quantification. Sensitivities and specificities require to be improved, nevertheless, the methodology described may form the basis for a means of identifying S. aureus infected cows at the point of care.
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The Spl Serine Proteases Modulate Staphylococcus aureus Protein Production and Virulence in a Rabbit Model of Pneumonia. mSphere 2016; 1:mSphere00208-16. [PMID: 27747296 PMCID: PMC5061998 DOI: 10.1128/msphere.00208-16] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/23/2016] [Indexed: 01/09/2023] Open
Abstract
Staphylococcus aureus is a versatile human pathogen that produces an array of virulence factors, including several proteases. Of these, six proteases called the Spls are the least characterized. Previous evidence suggests that the Spls are expressed during human infection; however, their function is unknown. Our study shows that the Spls are required for S. aureus to cause disseminated lung damage during pneumonia. Further, we present the first example of a human protein cut by an Spl protease. Although the Spls were predicted not to cut staphylococcal proteins, we also show that an spl mutant has altered abundance of both secreted and surface-associated proteins. This work provides novel insight into the function of Spls during infection and their potential ability to degrade both staphylococcal and human proteins. The Spl proteases are a group of six serine proteases that are encoded on the νSaβ pathogenicity island and are unique to Staphylococcus aureus. Despite their interesting biochemistry, their biological substrates and functions in virulence have been difficult to elucidate. We found that an spl operon mutant of the community-associated methicillin-resistant S. aureus USA300 strain LAC induced localized lung damage in a rabbit model of pneumonia, characterized by bronchopneumonia observed histologically. Disease in the mutant-infected rabbits was restricted in distribution compared to that in wild-type USA300-infected rabbits. We also found that SplA is able to cleave the mucin 16 glycoprotein from the surface of the CalU-3 lung cell line, suggesting a possible mechanism for wild-type USA300 spreading pneumonia to both lungs. Investigation of the secreted and surface proteomes of wild-type USA300 and the spl mutant revealed multiple alterations in metabolic proteins and virulence factors. This study demonstrates that the Spls modulate S. aureus physiology and virulence, identifies a human target of SplA, and suggests potential S. aureus targets of the Spl proteases. IMPORTANCEStaphylococcus aureus is a versatile human pathogen that produces an array of virulence factors, including several proteases. Of these, six proteases called the Spls are the least characterized. Previous evidence suggests that the Spls are expressed during human infection; however, their function is unknown. Our study shows that the Spls are required for S. aureus to cause disseminated lung damage during pneumonia. Further, we present the first example of a human protein cut by an Spl protease. Although the Spls were predicted not to cut staphylococcal proteins, we also show that an spl mutant has altered abundance of both secreted and surface-associated proteins. This work provides novel insight into the function of Spls during infection and their potential ability to degrade both staphylococcal and human proteins.
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34
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Bonar E, Wojcik I, Jankowska U, Kedracka-Krok S, Bukowski M, Polakowska K, Lis MW, Kosecka-Strojek M, Sabat AJ, Dubin G, Friedrich AW, Miedzobrodzki J, Dubin A, Wladyka B. Identification of Secreted Exoproteome Fingerprints of Highly-Virulent and Non-Virulent Staphylococcus aureus Strains. Front Cell Infect Microbiol 2016; 6:51. [PMID: 27242969 PMCID: PMC4874363 DOI: 10.3389/fcimb.2016.00051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 04/19/2016] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus is a commensal inhabitant of skin and mucous membranes in nose vestibule but also an important opportunistic pathogen of humans and livestock. The extracellular proteome as a whole constitutes its major virulence determinant; however, the involvement of particular proteins is still relatively poorly understood. In this study, we compared the extracellular proteomes of poultry-derived S. aureus strains exhibiting a virulent (VIR) and non-virulent (NVIR) phenotype in a chicken embryo experimental infection model with the aim to identify proteomic signatures associated with the particular phenotypes. Despite significant heterogeneity within the analyzed proteomes, we identified alpha-haemolysin and bifunctional autolysin as indicators of virulence, whereas glutamylendopeptidase production was characteristic for non-virulent strains. Staphopain C (StpC) was identified in both the VIR and NVIR proteomes and the latter fact contradicted previous findings suggesting its involvement in virulence. By supplementing NVIR, StpC-negative strains with StpC, and comparing the virulence of parental and supplemented strains, we demonstrated that staphopain C alone does not affect staphylococcal virulence in a chicken embryo model.
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Affiliation(s)
- Emilia Bonar
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Iwona Wojcik
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Urszula Jankowska
- Malopolska Centre of Biotechnology, Jagiellonian University Krakow, Poland
| | - Sylwia Kedracka-Krok
- Malopolska Centre of Biotechnology, Jagiellonian UniversityKrakow, Poland; Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Michal Bukowski
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Klaudia Polakowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Marcin W Lis
- Department of Veterinary and Animal Reproduction and Welfare, Faculty of Animal Welfare, University of Agriculture in Krakow Krakow, Poland
| | - Maja Kosecka-Strojek
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Artur J Sabat
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen Groningen, Netherlands
| | - Grzegorz Dubin
- Malopolska Centre of Biotechnology, Jagiellonian UniversityKrakow, Poland; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Alexander W Friedrich
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen Groningen, Netherlands
| | - Jacek Miedzobrodzki
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Adam Dubin
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
| | - Benedykt Wladyka
- Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University Krakow, Poland
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35
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Microbial inhibitors of cysteine proteases. Med Microbiol Immunol 2016; 205:275-96. [DOI: 10.1007/s00430-016-0454-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 03/24/2016] [Indexed: 01/06/2023]
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36
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Methamphetamine Alters the Antimicrobial Efficacy of Phagocytic Cells during Methicillin-Resistant Staphylococcus aureus Skin Infection. mBio 2015; 6:e01622-15. [PMID: 26507236 PMCID: PMC4626859 DOI: 10.1128/mbio.01622-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Methamphetamine (METH) is a major drug of abuse in the United States and worldwide. Furthermore, Staphylococcus aureus infections and METH use are coemerging public health problems. S. aureus is the single most important bacterial pathogen in infections among injection drug users, with skin and soft tissue infections (SSTI) being extremely common. Notably, the incidence of SSTI, especially in drug users, is difficult to estimate because such infections are often self-treated. Although there is substantial information on the behavioral and cognitive defects caused by METH in drug users, there is a dearth of knowledge regarding its impact on bacterial infections and immunity. Therefore, we hypothesized that METH exacerbates S. aureus skin infection. Using a murine model of METH administration and wound infection, we demonstrated that METH reduces wound healing and facilitates host-mediated collagen degradation by increased expression and production of matrix metalloproteinase-2 (MMP-2). Additionally, we found that METH induces S. aureus biofilm formation and leads to detrimental effects on the functions of human and murine phagocytic cells, enhancing susceptibility to S. aureus infection. Our findings provide empirical evidence of the adverse impact of METH use on the antimicrobial efficacy of the cells that comprise innate immunity, the initial host response to combat microbial infection. METH is an extremely addictive central nervous system stimulant that is frequently administered by injection. SSTI, common problems among injection drug users, result in serious morbidity for patients and costly hospitalizations for treatment of superficial wounds and incision and drainage of abscesses; however, there has been little etiologic or preventive epidemiological research on this problem. In addition, the evasive nature of injection drug users toward medical care complicates our ability to accurately predict the prevalence of these infections. Hence, this study investigated the impact of METH use on S. aureus skin infection. Our findings demonstrate that this drug of abuse promotes biofilm formation and negatively impacts the wound healing process and innate immune function, exacerbating susceptibility to S. aureus infection. The findings may translate into new knowledge and development of therapeutic and public health strategies to deal with the devastating complications of METH abuse.
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37
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Richter ME, Neugebauer S, Engelmann F, Hagel S, Ludewig K, La Rosée P, Sayer HG, Hochhaus A, von Lilienfeld-Toal M, Bretschneider T, Pausch C, Engel C, Brunkhorst FM, Kiehntopf M. Biomarker candidates for the detection of an infectious etiology of febrile neutropenia. Infection 2015; 44:175-86. [PMID: 26275448 DOI: 10.1007/s15010-015-0830-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/31/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE Infections and subsequent septicemia are major complications in neutropenic patients with hematological malignancies. Here, we identify biomarker candidates for the early detection of an infectious origin, and monitoring of febrile neutropenia (FN). METHODS Proteome, metabolome, and conventional biomarkers from 20 patients with febrile neutropenia without proven infection (FNPI) were compared to 28 patients with proven infection, including 17 patients with bacteremia. RESULTS Three peptides (mass to charge ratio 1017.4-1057.3; p-values 0.011-0.024), six proteins (mass to charge ratio 6881-17,215; p-values 0.002-0.004), and six phosphatidylcholines (p-values 0.007-0.037) were identified that differed in FNPI patients compared to patients with infection or bacteremia. Seven of these marker candidates discriminated FNPI from infection at fever onset with higher sensitivity and specificity (ROC-AUC 0.688-0.824) than conventional biomarkers i.e., procalcitonin, C-reactive protein, or interleukin-6 (ROC-AUC 0.535-0.672). In a post hoc analysis, monitoring the time course of four lysophosphatidylcholines, threonine, and tryptophan allowed for discrimination of patients with or without resolution of FN (ROC-AUC 0.648-0.919) with higher accuracy compared to conventional markers (ROC-AUC 0.514-0.871). CONCLUSIONS Twenty-one promising biomarker candidates for the early detection of an infectious origin or for monitoring the course of FN were found which might overcome known shortcomings of conventional markers.
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Affiliation(s)
- Martin E Richter
- Institut für Klinische Chemie und Laboratoriumsdiagnostik, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Sophie Neugebauer
- Institut für Klinische Chemie und Laboratoriumsdiagnostik, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Falco Engelmann
- Institut für Klinische Chemie und Laboratoriumsdiagnostik, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Stefan Hagel
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Zentrum für Infektionsmedizin und Krankenhaushygiene, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Klinik für Innere Medizin IV (Gastroenterologie, Hepatologie, Infektiologie), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Katrin Ludewig
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Paul La Rosée
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Klinik für Innere Medizin II, Abt. Hämatologie und Intern. Onkologie, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Herbert G Sayer
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Klinik für Innere Medizin II, Abt. Hämatologie und Intern. Onkologie, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,4. Medizinische Klinik (Hämatologie und internistische Onkologie, Hämostaseologie), HELIOS Klinikum Erfurt, Nordhäuser Straße 74, 99089, Erfurt, Germany
| | - Andreas Hochhaus
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Klinik für Innere Medizin II, Abt. Hämatologie und Intern. Onkologie, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Marie von Lilienfeld-Toal
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Klinik für Innere Medizin II, Abt. Hämatologie und Intern. Onkologie, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany
| | - Tom Bretschneider
- Leibniz Institut für Naturstoff-Forschung und Infektionsbiologie, Hans-Knöll-Institut, Adolf-Reichwein-Straße 23, 07745, Jena, Germany
| | - Christine Pausch
- Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.,Institut für Medizinische Informatik, Statistik und Epidemiologie, Universität Leipzig, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Christoph Engel
- Institut für Medizinische Informatik, Statistik und Epidemiologie, Universität Leipzig, Härtelstraße 16-18, 04107, Leipzig, Germany
| | - Frank M Brunkhorst
- Zentrum für Klinische Studien, Universitätsklinikum Jena, Salvador-Allende-Platz 27, 07747, Jena, Germany
| | - Michael Kiehntopf
- Institut für Klinische Chemie und Laboratoriumsdiagnostik, Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany. .,Integriertes Forschungs- und Behandlungszentrum Sepsis und Sepsisfolgen (CSCC), Universitätsklinikum Jena, Erlanger Allee 101, 07747, Jena, Germany.
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38
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Hall JW, Yang J, Guo H, Ji Y. The AirSR two-component system contributes to Staphylococcus aureus survival in human blood and transcriptionally regulates sspABC operon. Front Microbiol 2015; 6:682. [PMID: 26191060 PMCID: PMC4490255 DOI: 10.3389/fmicb.2015.00682] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022] Open
Abstract
To date, genes identified and transcriptionally regulated by the AirSR TCS have been involved in energy production and cellular homeostasis of the staphylococcal cell. It is well accepted that the state of cellular metabolism impacts the expression of virulence factors in Staphylococcus aureus. For this reason, we conducted experiments to determine if the AirSR TCS contributes to the pathogenesis of S. aureus using an antisense RNA interference technology, an inducible overexpression system, and gene deletions. Depletion of AirSR by antisense RNA expression or deletion of the genes, results in significant decrease in bacterial survival in human blood. Conversely, overexpression of AirR significantly promotes survival of S. aureus in blood. AirR promotes the secretion of virulence factors that inhibits opsonin-based phagocytosis. This enhanced survival is partially linked to the transcriptional regulation of the sspABC operon, encoding V8 protease (SspA), staphopain B (SspB) and staphostatin B (SspC). SspA and SspB are known virulence factors which proteolytically digest opsonins and inhibit killing of S. aureus by professional phagocytes. This is the first evidence linking the AirSR TCS to pathogenesis of S. aureus.
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Affiliation(s)
- Jeffrey W Hall
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN USA
| | - Junshu Yang
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN USA
| | - Haiyong Guo
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN USA
| | - Yinduo Ji
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN USA
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Tulinski P, Duim B, Wittink FR, Jonker MJ, Breit TM, van Putten JP, Wagenaar JA, Fluit AC. Staphylococcus aureus ST398 gene expression profiling during ex vivo colonization of porcine nasal epithelium. BMC Genomics 2014; 15:915. [PMID: 25331735 PMCID: PMC4210494 DOI: 10.1186/1471-2164-15-915] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/13/2014] [Indexed: 11/10/2022] Open
Abstract
Background Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Results We report the analysis of changes in the transcription of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes may represent metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of the main virulence associated genes or known human colonization factors. Here, we documented regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vWbp, encoded on SaPIbov5). Colonization with isogenic-deletion strains (Δvwbp and ΔscpA) did not alter the ex vivo nasal S. aureus colonization compared to wild type. Conclusions Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-915) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Birgitta Duim
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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Staphopains in Staphylococcus aureus bacteremia: Virulence activities related to the onset of septic shock, coagulation disorders, and infectious endocarditis. J Oral Biosci 2014. [DOI: 10.1016/j.job.2014.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Coates R, Moran J, Horsburgh MJ. Staphylococci: colonizers and pathogens of human skin. Future Microbiol 2014; 9:75-91. [PMID: 24328382 DOI: 10.2217/fmb.13.145] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Staphylococci are abundant bacteria of the human skin microbiome. Several species, particularly Staphylococcus aureus and Staphylococcus epidermidis, are opportunistic pathogens and cause significant disease. The human skin serves many functions and here we review its role as an antimicrobial barrier and the staphylococcal mechanisms to colonize and counteract the various stresses present in this niche. Successful colonization is achieved using a diversity of adhesins, surface proteins and secreted enzymes to counteract the antimicrobial peptides, enzymes and lipid matrix components present in the acid mantle. Further mechanisms enable these bacteria to overcome osmotic and acid stresses and desiccation in order to survive the exacting demands of an ever-changing landscape.
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Affiliation(s)
- Rosanna Coates
- Microbiology Research Group, Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, L69 7ZB, UK
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42
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Purification and biochemical characterization of halophilic, alkalithermophilic protease AbCP from Alkalibacillus sp. NM-Fa4. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2014.03.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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43
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Kopitar-Jerala N. The role of cysteine proteinases and their inhibitors in the host-pathogen cross talk. Curr Protein Pept Sci 2013; 13:767-75. [PMID: 23305363 PMCID: PMC3594739 DOI: 10.2174/138920312804871102] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/17/2012] [Accepted: 07/25/2012] [Indexed: 01/12/2023]
Abstract
Proteinases and their inhibitors play essential functional roles in basic biological processes in both hosts and pathogens. Endo/lysosomal cathepsins participate in immune response in pathogen recognition and elimination. They are essential for both antigen processing and presentation (host adaptive immune response) and activation of endosomal Toll like receptors (innate immune response). Pathogens can produce proteases and also natural inhibitors to subvert the host immune response. Several pathogens are sensed through the intracellular pathogen recognition receptors, but only some of them use the host proteolytic system to escape into the cytosol. In this review, I provide an update on the most recent developments regarding the role of proteinases and their inhibitors in the initiation and regulation of immune responses.
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Affiliation(s)
- Natasa Kopitar-Jerala
- Department of Biochemistry, Molecular and Structural Biology, ›Jozef Stefan‹ Institute, Jamova 39, 1000 Ljubljana, Slovenia.
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Aslam R, Marban C, Corazzol C, Jehl F, Delalande F, Van Dorsselaer A, Prévost G, Haïkel Y, Taddei C, Schneider F, Metz-Boutigue MH. Cateslytin, a chromogranin A derived peptide is active against Staphylococcus aureus and resistant to degradation by its proteases. PLoS One 2013; 8:e68993. [PMID: 23894389 PMCID: PMC3722296 DOI: 10.1371/journal.pone.0068993] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 06/03/2013] [Indexed: 12/24/2022] Open
Abstract
Innate immunity involving antimicrobial peptides represents an integrated and highly effective system of molecular and cellular mechanisms that protects host against infections. One of the most frequent hospital-acquired pathogens, Staphylococcus aureus, capable of producing proteolytic enzymes, which can degrade the host defence agents and tissue components. Numerous antimicrobial peptides derived from chromogranins, are secreted by nervous, endocrine and immune cells during stress conditions. These kill microorganisms by their lytic effect at micromolar range, using a pore-forming mechanism against Gram-positive bacteria, filamentous fungi and yeasts. In this study, we tested antimicrobial activity of chromogranin A-derived peptides (catestatin and cateslytin) against S. aureus and analysed S. aureus-mediated proteolysis of these peptides using HPLC, sequencing and MALDI-TOF mass spectrometry. Interestingly, this study is the first to demonstrate that cateslytin, the active domain of catestatin, is active against S. aureus and is interestingly resistant to degradation by S. aureus proteases.
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Affiliation(s)
- Rizwan Aslam
- Inserm UMR-1121, Université de Strasbourg, Strasbourg, France
| | - Céline Marban
- Inserm UMR-1121, Université de Strasbourg, Strasbourg, France
| | - Christian Corazzol
- EA-7290, Virulence bactérienne précoce, Fédération de Médecine Translationnelle de Strasbourg, Institut de Bactériologie, Université de Strasbourg – CHRU Strasbourg, Strasbourg, France
| | - François Jehl
- EA-7290, Virulence bactérienne précoce, Fédération de Médecine Translationnelle de Strasbourg, Institut de Bactériologie, Université de Strasbourg – CHRU Strasbourg, Strasbourg, France
| | - François Delalande
- CNRS UMR-7178, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Alain Van Dorsselaer
- CNRS UMR-7178, Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Strasbourg, France
| | - Gilles Prévost
- EA-7290, Virulence bactérienne précoce, Fédération de Médecine Translationnelle de Strasbourg, Institut de Bactériologie, Université de Strasbourg – CHRU Strasbourg, Strasbourg, France
| | - Youssef Haïkel
- Inserm UMR-1121, Université de Strasbourg, Strasbourg, France
- Faculté de chirurgie dentaire, Université de Strasbourg, Strasbourg, France
| | - Corinne Taddei
- Faculté de chirurgie dentaire, Université de Strasbourg, Strasbourg, France
| | - Francis Schneider
- Service de Réanimation Médicale, Hôpital de Hautepierre, Université de Strasbourg, Strasbourg, France
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Jusko M, Potempa J, Kantyka T, Bielecka E, Miller HK, Kalinska M, Dubin G, Garred P, Shaw LN, Blom AM. Staphylococcal proteases aid in evasion of the human complement system. J Innate Immun 2013; 6:31-46. [PMID: 23838186 DOI: 10.1159/000351458] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 04/15/2013] [Indexed: 01/01/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that presents severe health care concerns due to the prevalence of multiple antibiotic-resistant strains. New treatment strategies are urgently needed, which requires an understanding of disease causation mechanisms. Complement is one of the first lines of defense against bacterial pathogens, and S. aureus expresses several specific complement inhibitors. The effect of extracellular proteases from this bacterium on complement, however, has been the subject of limited investigation, except for a recent report regarding cleavage of the C3 component by aureolysin (Aur). We demonstrate here that four major extracellular proteases of S. aureus are potent complement inhibitors. Incubation of human serum with the cysteine proteases staphopain A and staphopain B, the serine protease V8 and the metalloproteinase Aur resulted in a drastic decrease in the hemolytic activity of serum, whereas two staphylococcal serine proteases D and E, had no effect. These four proteases were found to inhibit all pathways of complement due to the efficient degradation of several crucial components. Furthermore, S. aureus mutants lacking proteolytic enzymes were found to be more efficiently killed in human blood. Taken together, the major proteases of S. aureus appear to be important for pathogen-mediated evasion of the human complement system.
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Affiliation(s)
- Monika Jusko
- Section of Medical Protein Chemistry, Department of Laboratory Medicine, Skåne University Hospital, Lund University, Malmö, Sweden
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Abstract
Staphylococcus aureus is a known cause of chronic biofilm infections that can reside on medical implants or host tissue. Recent studies have demonstrated an important role for proteinaceous material in the biofilm structure. The S. aureus genome encodes many secreted proteases, and there is growing evidence that these enzymes have self-cleavage properties that alter biofilm integrity. However, the specific contribution of each protease and mechanism of biofilm modulation is not clear. To address this issue, we utilized a sigma factor B (ΔsigB) mutant where protease activity results in a biofilm-negative phenotype, thereby creating a condition where the protease(s) responsible for the phenotype could be identified. Using a plasma-coated microtiter assay, biofilm formation was restored to the ΔsigB mutant through the addition of the cysteine protease inhibitor E-64 or by using Staphostatin inhibitors that specifically target the extracellular cysteine proteases SspB and ScpA (called Staphopains). Through construction of gene deletion mutants, we determined that an sspB scpA double mutant restored ΔsigB biofilm formation, and this recovery could be replicated in plasma-coated flow cell biofilms. Staphopain levels were also found to be decreased under biofilm-forming conditions, possibly allowing biofilm establishment. The treatment of S. aureus biofilms with purified SspB or ScpA enzyme inhibited their formation, and ScpA was also able to disperse an established biofilm. The antibiofilm properties of ScpA were conserved across S. aureus strain lineages. These findings suggest an underappreciated role of the SspB and ScpA cysteine proteases in modulating S. aureus biofilm architecture.
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Inactivation of the serine proteinase operon (proMCD) of Staphylococcus warneri M: serine proteinase and cysteine proteases are involved in the autolysis. Gene 2013; 512:240-6. [PMID: 23107764 DOI: 10.1016/j.gene.2012.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 10/16/2012] [Indexed: 01/28/2023]
Abstract
Unlike other members of coagulase negative staphylococci (CNS), strain warneri has proMCD operon, a homologue of sspABC proteinase operon of S. aureus. The proM and proC encode serine glutamyl endopeptidase and cysteine protease respectively, whereas proD directs homologue of SspC, putative cytoplasmic inhibitor which protects the host bacterium from premature activation of SspB. We determined whole nucleotide sequence of proMCD operon of S. warneri M, succeeded in expression of these genes, and investigated their functions by gene inactivation and complementation experiments. In gelatin zymography of the culture supernatant, a 20-kDa band corresponding to PROC cysteine protease was detected. By Western blotting, PROD was also confirmed in the cytoplasmic protein fraction. PROC and PROD showed significant similarity to SspB and SspC of S. aureus (73% and 58%, respectively). Inactivation mutants of proMCD, proCD and proD genes were established, separately. In the proMCD mutant, degradation/processing of extracellular proteins was drastically reduced, suggesting that PROM was responsible for the cleavage of extracellular proteins. By the proD mutation, the growth profile was not affected, and secretion of PROC was retained. Extracellular protein profiles of the proCD and proD mutants were not so different each other, but autolysin profiles were slightly dissimilar, around 39-48 kDa and 20kDa bands in zymogram. Experiments in buffer systems showed that autolysis was significantly diminished in proMCD mutant, and was promoted by addition of purified PROM. The proC gene was cloned into a multicopy plasmid, and introduced into the proMCD mutant. Compared with the wild type, autolysis of the proC-complemented strain was definitely enhanced by addition of purified PROM. These results suggested that PROM and PROC affected the coccal autolysis, through processing of the autolysin.
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Abstract
Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated with the proteases either encoded within the same polypeptide or on separate subunits. In contrast, substrate recognition by extracellular proteases is less selective and therefore these enzymes are generally expressed as zymogens to prevent premature proteolytic activity that would be detrimental to the cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host.
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Affiliation(s)
- Dorte Frees
- Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Stigbøjlen 4, Frederiksberg, C 1870, Denmark
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Kantyka T, Pyrc K, Gruca M, Smagur J, Plaza K, Guzik K, Zeglen S, Ochman M, Potempa J. Staphylococcus aureus proteases degrade lung surfactant protein A potentially impairing innate immunity of the lung. J Innate Immun 2012; 5:251-60. [PMID: 23235402 DOI: 10.1159/000345417] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 10/23/2012] [Indexed: 11/19/2022] Open
Abstract
The pulmonary surfactant is a complex mixture of lipids and proteins that is important for respiratory lung functions, which also provides the first line of innate immune defense. Pulmonary surfactant protein-A (SP-A) is a major surfactant component with immune functions with importance during Staphylococcus aureus infections that has been demonstrated in numerous studies. The current study showed that S. aureus can efficiently cleave the SP-A protein using its arsenal of proteolytic enzymes. This degradation appears to be mediated by cysteine proteases, in particular staphopain A (ScpA). The staphopain-mediated proteolysis of SP-A resulted in a decrease or complete abolishment of SP-A biological activity, including the promotion of S. aureus phagocytosis by neutrophils, aggregation of Gram-negative bacteria and bacterial cell adherence to epithelium. Significantly, ScpA has also efficiently degraded SP-A in complete bronchi-alveolar lavage fluid from human lungs. This indicates that staphopain activity in the lungs is resistant to protease inhibitors, thus suggesting that SP-A can be cleaved in vivo. Collectively, this study showed that the S. aureus protease ScpA is an important virulence factor that may impair innate immunity of the lungs.
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Affiliation(s)
- Tomasz Kantyka
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
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Nuxoll AS, Halouska SM, Sadykov MR, Hanke ML, Bayles KW, Kielian T, Powers R, Fey PD. CcpA regulates arginine biosynthesis in Staphylococcus aureus through repression of proline catabolism. PLoS Pathog 2012; 8:e1003033. [PMID: 23209408 PMCID: PMC3510247 DOI: 10.1371/journal.ppat.1003033] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 10/01/2012] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, arcB1, argG and argH abolished the ability of S. aureus JE2 ccpA::tetL to grow in the absence of arginine, whereas an interruption in argJBCF, arcB2, or proC had no effect. Furthermore, nuclear magnetic resonance demonstrated that JE2 ccpA::ermB produced 13C5 labeled arginine when grown with 13C5 proline. Taken together, these data support the conclusion that S. aureus synthesizes arginine from proline during growth on secondary carbon sources. Furthermore, although highly conserved in all sequenced S. aureus genomes, the arginine anabolic pathway (ArgJBCDFGH) is not functional under in vitro growth conditions. Finally, a mutation in argH attenuated virulence in a mouse kidney abscess model in comparison to wild type JE2 demonstrating the importance of arginine biosynthesis in vivo via the urea cycle. However, mutations in argB, argF, and putA did not attenuate virulence suggesting both the glutamate and proline pathways are active and they, or their pathway intermediates, can complement each other in vivo. Although Staphylococcus aureus encodes the highly conserved arginine biosynthesis pathway via glutamate, arginine is an essential amino acid. We found that a mutation in ccpA, a gene encoding a protein facilitating carbon catabolite repression, mediates arginine biosynthesis under in vitro growth conditions. However, both genetic and biochemical evidence suggested that a S. aureus ccpA mutant synthesizes arginine via proline and the urea cycle, a pathway not demonstrated in bacteria before. Furthermore, an animal model of S. aureus infection demonstrated the importance of arginine biosynthesis in vivo. This new pathway sheds light on important host-pathogen interactions and suggests S. aureus has evolved to address arginine depletion in the host by synthesizing arginine from a readily available substrate such as proline.
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Affiliation(s)
- Austin S. Nuxoll
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Steven M. Halouska
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Marat R. Sadykov
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Mark L. Hanke
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Kenneth W. Bayles
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Tammy Kielian
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Robert Powers
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America
| | - Paul D. Fey
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail:
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