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Costa FG, Mills KB, Crosby HA, Horswill AR. The Staphylococcus aureus regulatory program in a human skin-like environment. mBio 2024; 15:e0045324. [PMID: 38546267 PMCID: PMC11077960 DOI: 10.1128/mbio.00453-24] [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: 02/16/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024] Open
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.
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Affiliation(s)
- Flavia G. Costa
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Heidi A. Crosby
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Veterans Affairs, Eastern Colorado Healthcare System, Aurora, Colorado, USA
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2
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Dietrich M, Besser M, Stuermer EK. Characterization of the Human Plasma Biofilm Model (hpBIOM) to Identify Potential Therapeutic Targets for Wound Management of Chronic Infections. Microorganisms 2024; 12:269. [PMID: 38399673 PMCID: PMC10892339 DOI: 10.3390/microorganisms12020269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/18/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The treatment of chronic wounds still represents a major challenge in wound management. Recent estimates suggest that 60-80% of chronic wounds are colonized by pathogenic microorganisms, which are strongly considered to have a major inhibiting influence on the healing process. By means of an innovative biofilm model based on human plasma, the time-dependent behavior of various bacterial strains under wound-milieu-like conditions were investigated, and the growth habits of different cocci species were compared. Undescribed fusion events between colonies of MRSA as well as of Staphylococcus epidermidis were detected, which were associated with the remodeling and reorganization of the glycocalyx of the wound tissue. After reaching a maximum colony size, the spreading of individual bacteria was observed. Interestingly, the combination of different cocci species with Pseudomonas aeruginosa in the human plasma biofilm revealed partial synergistic effects in these multispecies organizations. RT-qPCR analyses gave a first impression of the relevant proteins involved in the formation and maturation of biofilms, especially the role of fibrinogen-binding proteins. Knowledge of the maturation and growth behavior of persistent biofilms investigated in a translational human biofilm model reflects a starting point for the development of novel tools for the treatment of chronic wounds.
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Affiliation(s)
- Michael Dietrich
- Institute of Virology and Microbiology, Centre for Biomedical Education and Research (ZBAF), Faculty of Health, Witten/Herdecke University, 58455 Witten, Germany
| | - Manuela Besser
- Institute of Virology and Microbiology, Centre for Biomedical Education and Research (ZBAF), Faculty of Health, Witten/Herdecke University, 58455 Witten, Germany
| | - Ewa Klara Stuermer
- Department of Vascular Medicine, University Heart and Vascular Center, University Medical Center Hamburg-Eppendorf (UKE), 20246 Hamburg, Germany
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3
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Bhattacharya M, Horswill AR. The role of human extracellular matrix proteins in defining Staphylococcus aureus biofilm infections. FEMS Microbiol Rev 2024; 48:fuae002. [PMID: 38337187 PMCID: PMC10873506 DOI: 10.1093/femsre/fuae002] [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: 07/19/2023] [Revised: 01/26/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
Twenty to forty one percent of the world's population is either transiently or permanently colonized by the Gram-positive bacterium, Staphylococcus aureus. In 2017, the CDC designated methicillin-resistant S. aureus (MRSA) as a serious threat, reporting ∼300 000 cases of MRSA-associated hospitalizations annually, resulting in over 19 000 deaths, surpassing that of HIV in the USA. S. aureus is a proficient biofilm-forming organism that rapidly acquires resistance to antibiotics, most commonly methicillin (MRSA). This review focuses on a large group of (>30) S. aureus adhesins, either surface-associated or secreted that are designed to specifically bind to 15 or more of the proteins that form key components of the human extracellular matrix (hECM). Importantly, this includes hECM proteins that are pivotal to the homeostasis of almost every tissue environment [collagen (skin), proteoglycans (lung), hemoglobin (blood), elastin, laminin, fibrinogen, fibronectin, and fibrin (multiple organs)]. These adhesins offer S. aureus the potential to establish an infection in every sterile tissue niche. These infections often endure repeated immune onslaught, developing into chronic, biofilm-associated conditions that are tolerant to ∼1000 times the clinically prescribed dose of antibiotics. Depending on the infection and the immune response, this allows S. aureus to seamlessly transition from colonizer to pathogen by subtly manipulating the host against itself while providing the time and stealth that it requires to establish and persist as a biofilm. This is a comprehensive discussion of the interaction between S. aureus biofilms and the hECM. We provide particular focus on the role of these interactions in pathogenesis and, consequently, the clinical implications for the prevention and treatment of S. aureus biofilm infections.
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Affiliation(s)
- Mohini Bhattacharya
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Alexander R Horswill
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO 80045, United States
- Department of Veterans Affairs, Eastern Colorado Health Care System, Aurora, CO 80045, United States
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4
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Brangulis K, Akopjana I, Bogans J, Kazaks A, Tars K. Structural studies of chromosomally encoded outer surface lipoprotein BB0158 from Borrelia burgdorferi sensu stricto. Ticks Tick Borne Dis 2024; 15:102287. [PMID: 38016210 DOI: 10.1016/j.ttbdis.2023.102287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 11/30/2023]
Abstract
Lyme disease, or also known as Lyme borreliosis, is caused by the spirochetes belonging to the Borrelia burgdorferi sensu lato complex, which can enter the human body following the bite of an infected tick. Many membrane lipid-bound proteins, also known as lipoproteins, are located on the surface of B. burgdorferi sensu lato and play a crucial role in the spirochete to interact with its environment, whether in ticks or mammals. Since the spirochete needs to perform various tasks, such as resisting the host's immune system or spreading throughout the organism, it is not surprising that numerous surface proteins have been found to be essential for B. burgdorferi sensu lato complex bacteria in causing Lyme disease. In this study, we have determined (at 2.4 Å resolution) and characterized the 3D structure of BB0158, one of the few chromosomally encoded outer surface proteins from B. burgdorferi sensu stricto. BB0158 belongs to the paralogous gene family 44 (PFam44), consisting of four other members (BB0159, BBA04, BBE09 and BBK52). The characterization of BB0158, which appears to form a domain-swapped dimer, in conjunction with the characterization of the corresponding PFam44 members, certainly contribute to our understanding of B. burgdorferi sensu stricto proteins.
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Affiliation(s)
- Kalvis Brangulis
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga LV-1067, Latvia.
| | - Inara Akopjana
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga LV-1067, Latvia
| | - Janis Bogans
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga LV-1067, Latvia
| | - Andris Kazaks
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga LV-1067, Latvia
| | - Kaspars Tars
- Latvian Biomedical Research and Study Centre, Ratsupites 1 k-1, Riga LV-1067, Latvia
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5
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Sabbih GO, Wijesinghe KM, Algama C, Dhakal S, Danquah MK. Computational generation and characterization of IsdA-binding aptamers with single-molecule FRET analysis. Biotechnol J 2023; 18:e2300076. [PMID: 37593983 DOI: 10.1002/biot.202300076] [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: 02/16/2023] [Revised: 08/09/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023]
Abstract
Staphylococcus aureus is a major foodborne bacterial pathogen. Early detection of S. aureus is crucial to prevent infections and ensure food quality. The iron-regulated surface determinant protein A (IsdA) of S. aureus is a unique surface protein necessary for sourcing vital iron from host cells for the survival and colonization of the bacteria. The function, structure, and location of the IsdA protein make it an important protein for biosensing applications relating to the pathogen. Here, we report an in-silico approach to develop and validate high-affinity binding aptamers for the IsdA protein detection using custom-designed in-silico tools and single-molecule Fluorescence Resonance Energy Transfer (smFRET) measurements. We utilized in-silico oligonucleotide screening methods and metadynamics-based methods to generate 10 aptamer candidates and characterized them based on the Dissociation Free Energy (DFE) of the IsdA-aptamer complexes. Three of the aptamer candidates were shortlisted for smFRET experimental analysis of binding properties. Limits of detection in the low picomolar range were observed for the aptamers, and the results correlated well with the DFE calculations, indicating the potential of the in-silico approach to support aptamer discovery. This study showcases a computational SELEX method in combination with single-molecule binding studies deciphering effective aptamers against S. aureus IsdA, protein. The established approach demonstrates the ability to expedite aptamer discovery that has the potential to cut costs and predict binding efficacy. The application can be extended to designing aptamers for various protein targets, enhancing molecular recognition, and facilitating the development of high-affinity aptamers for multiple uses.
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Affiliation(s)
| | | | - Chamika Algama
- Virginia Commonwealth University, Richmond, Virginia, USA
| | - Soma Dhakal
- Virginia Commonwealth University, Richmond, Virginia, USA
| | - Michael K Danquah
- University of Tennessee, Chattanooga, Tennessee, USA
- University of Tennessee, Knoxville, Tennessee, USA
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6
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Francis D, Veeramanickathadathil Hari G, Koonthanmala Subash A, Bhairaddy A, Joy A. The biofilm proteome of Staphylococcus aureus and its implications for therapeutic interventions to biofilm-associated infections. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 138:327-400. [PMID: 38220430 DOI: 10.1016/bs.apcsb.2023.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Staphylococcus aureus is a major healthcare concern due to its ability to inflict life-threatening infections and evolve antibiotic resistance at an alarming pace. It is frequently associated with hospital-acquired infections, especially device-associated infections. Systemic infections due to S. aureus are difficult to treat and are associated with significant mortality and morbidity. The situation is worsened by the ability of S. aureus to form social associations called biofilms. Biofilms embed a community of cells with the ability to communicate with each other and share resources within a polysaccharide or protein matrix. S. aureus establish biofilms on tissues and conditioned abiotic surfaces. Biofilms are hyper-tolerant to antibiotics and help evade host immune responses. Biofilms exacerbate the severity and recalcitrance of device-associated infections. The development of a biofilm involves various biomolecules, such as polysaccharides, proteins and nucleic acids, contributing to different structural and functional roles. Interconnected signaling pathways and regulatory molecules modulate the expression of these molecules. A comprehensive understanding of the molecular biology of biofilm development would help to devise effective anti-biofilm therapeutics. Although bactericidal agents, antimicrobial peptides, bacteriophages and nano-conjugated anti-biofilm agents have been employed with varying levels of success, there is still a requirement for effective and clinically viable anti-biofilm therapeutics. Proteins that are expressed and utilized during biofilm formation, constituting the biofilm proteome, are a particularly attractive target for anti-biofilm strategies. The proteome can be explored to identify potential anti-biofilm drug targets and utilized for rational drug discovery. With the aim of uncovering the biofilm proteome, this chapter explores the mechanism of biofilm formation and its regulation. Furthermore, it explores the antibiofilm therapeutics targeted against the biofilm proteome.
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Affiliation(s)
- Dileep Francis
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India.
| | | | | | - Anusha Bhairaddy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
| | - Atheene Joy
- Department of Life Sciences, Kristu Jayanti College (Autonomous), Bengaluru, India
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7
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Goncheva MI, Gibson RM, Shouldice AC, Dikeakos JD, Heinrichs DE. The Staphylococcus aureus protein IsdA increases SARS CoV-2 replication by modulating JAK-STAT signaling. iScience 2023; 26:105975. [PMID: 36687318 PMCID: PMC9838083 DOI: 10.1016/j.isci.2023.105975] [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: 07/15/2022] [Revised: 11/28/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (CoV-2) pandemic has affected millions globally. A significant complication of CoV-2 infection is secondary bacterial co-infection, as seen in approximately 25% of severe cases. The most common organism isolated during co-infection is Staphylococcus aureus. Here, we describe the development of an in vitro co-infection model where both viral and bacterial replication kinetics may be examined. We demonstrate CoV-2 infection does not alter bacterial interactions with host epithelial cells. In contrast, S. aureus enhances CoV-2 replication by 10- to 15-fold. We identify this pro-viral activity is due to the S. aureus iron-regulated surface determinant A (IsdA) protein and demonstrate IsdA modifies host transcription. We find that IsdA alters Janus Kinase - Signal Transducer and Activator of Transcription (JAK-STAT) signaling, by affecting JAK2-STAT3 levels, ultimately leading to increased viral replication. These findings provide key insight into the molecular interactions between host cells, CoV-2 and S. aureus during co-infection.
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Affiliation(s)
- Mariya I. Goncheva
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada,Corresponding author
| | - Richard M. Gibson
- ImPaKT Laboratory, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Ainslie C. Shouldice
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Jimmy D. Dikeakos
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - David E. Heinrichs
- Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada,Corresponding author
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8
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Torres G, Sánchez-Jiménez M, Reyes-Vélez J, Bach H, Olivera-Angel M. Evaluation of three Staphylococcus aureus proteins involved in the adhesion process as antigens for the detection of bovine intramammary infections. J Med Microbiol 2022; 71. [PMID: 36748695 DOI: 10.1099/jmm.0.001613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Introduction. Fast and accurate diagnosis is one of the key strategies in the successful control of intramammary infections caused by Staphylococcus aureus. Immunoassays are one of the diagnostic tools that have been proposed for the detection of S. aureus infection because they offer an advantage in terms of cost and are fast and easy to use compared to other diagnostic tests.Gap statement. The main challenge of the immunoassays is to identify antigens or serological markers that allow accurate discrimination between infected and uninfected cows with S. aureus, since this bacterium can naturally colonize different areas of the animal body.Aim. To evaluate three S. aureus proteins (IsdA, ClfA, SdrD) involved in the adhesion process as antigens to detect indicator antibodies of bovine intramammary infections.Methodology. Ninety-six cows in lactation and not vaccinated against S. aureus were included. Forty-eight of these cows were infected with S. aureus, while the rest (n=48 cows) were uninfected. Blood and milk samples were collected from each animal to recover serum and whey. IgG titres against the three proteins individually and combined (Mix) were measured in each sample using an enzyme-linked immunosorbent assay (ELISA) test.Results. Significant differences in the IgG response against the proteins evaluated were observed, highlighting the antigenic potential of IsdA and demonstrating that some antigens can detect specific antibodies of infection better than others. According to receiver operating characteristic (ROC) curve analysis, the combined proteins showed the most remarkable capacity (sensitivity of 79 % and specificity of 77 %) to differentiate between infected and uninfected cows when blood samples were used. In addition, the combined proteins also showed the highest specificity (94 %) when using milk samples.Conclusion. Our findings provide information on the usefulness of three adhesion-associated S. aureus proteins in detecting serological markers of intramammary infections in bovines.
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Affiliation(s)
- Giovanny Torres
- Instituto Colombiano de Medicina Tropical, Universidad CES, Cra. 43A No. 52 sur-99 Sabaneta, Antioquia, Colombia.,Biogenesis Research Group, Faculty of Agricultural sciences, University of Antioquia, Cra. 75 No. 65-87, Medellín, Antioquia, Colombia
| | - Miryan Sánchez-Jiménez
- Instituto Colombiano de Medicina Tropical, Universidad CES, Cra. 43A No. 52 sur-99 Sabaneta, Antioquia, Colombia
| | - Julián Reyes-Vélez
- Instituto Colombiano de Medicina Tropical, Universidad CES, Cra. 43A No. 52 sur-99 Sabaneta, Antioquia, Colombia.,Biogenesis Research Group, Faculty of Agricultural sciences, University of Antioquia, Cra. 75 No. 65-87, Medellín, Antioquia, Colombia
| | - Horacio Bach
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, 410-2660 Oak Street, Vancouver, BC, Canada
| | - Martha Olivera-Angel
- Biogenesis Research Group, Faculty of Agricultural sciences, University of Antioquia, Cra. 75 No. 65-87, Medellín, Antioquia, Colombia
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9
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Berry KA, Verhoef MTA, Leonard AC, Cox G. Staphylococcus aureus adhesion to the host. Ann N Y Acad Sci 2022; 1515:75-96. [PMID: 35705378 DOI: 10.1111/nyas.14807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is a pathobiont capable of colonizing and infecting most tissues within the human body, resulting in a multitude of different clinical outcomes. Adhesion of S. aureus to the host is crucial for both host colonization and the establishment of infections. Underlying the pathogen's success is a complex and diverse arsenal of adhesins. In this review, we discuss the different classes of adhesins, including a consideration of the various adhesion sites throughout the body and the clinical outcomes of each infection type. The development of therapeutics targeting the S. aureus host-pathogen interaction is a relatively understudied area. Due to the increasing global threat of antimicrobial resistance, it is crucial that innovative and alternative approaches are considered. Neutralizing virulence factors, through the development of antivirulence agents, could reduce bacterial pathogenicity and the ever-increasing burden of S. aureus infections. This review provides insight into potentially efficacious adhesion-associated targets for the development of novel decolonizing and antivirulence strategies.
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Affiliation(s)
- Kirsten A Berry
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mackenzie T A Verhoef
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Allison C Leonard
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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10
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van Dijk MC, de Kruijff RM, Hagedoorn PL. The Role of Iron in Staphylococcus aureus Infection and Human Disease: A Metal Tug of War at the Host—Microbe Interface. Front Cell Dev Biol 2022; 10:857237. [PMID: 35399529 PMCID: PMC8986978 DOI: 10.3389/fcell.2022.857237] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/24/2022] [Indexed: 11/27/2022] Open
Abstract
Iron deficiency anemia can be treated with oral or intravenous Fe supplementation. Such supplementation has considerable effects on the human microbiome, and on opportunistic pathogenic micro-organisms. Molecular understanding of the control and regulation of Fe availability at the host-microbe interface is crucial to interpreting the side effects of Fe supplementation. Here, we provide a concise overview of the regulation of Fe by the opportunistic pathogen Staphylococcus aureus. Ferric uptake regulator (Fur) plays a central role in controlling Fe uptake, utilization and storage in order to maintain a required value. The micro-organism has a strong preference for heme iron as an Fe source, which is enabled by the Iron-regulated surface determinant (Isd) system. The strategies it employs to overcome Fe restriction imposed by the host include: hijacking host proteins, replacing metal cofactors, and replacing functions by non-metal dependent enzymes. We propose that integrated omics approaches, which include metalloproteomics, are necessary to provide a comprehensive understanding of the metal tug of war at the host-microbe interface down to the molecular level.
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Affiliation(s)
- Madeleine C. van Dijk
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
- Department of Radiation Science and Technology, Delft University of Technology, Delft, Netherlands
| | - Robin M. de Kruijff
- Department of Radiation Science and Technology, Delft University of Technology, Delft, Netherlands
- *Correspondence: Robin M. de Kruijff, ; Peter-Leon Hagedoorn,
| | - Peter-Leon Hagedoorn
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
- *Correspondence: Robin M. de Kruijff, ; Peter-Leon Hagedoorn,
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11
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Diversity and pathogenesis of Staphylococcus aureus from bovine mastitis: current understanding and future perspectives. BMC Vet Res 2022; 18:115. [PMID: 35331225 PMCID: PMC8944054 DOI: 10.1186/s12917-022-03197-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/03/2022] [Indexed: 11/10/2022] Open
Abstract
Staphylococcus aureus is a leading cause of bovine mastitis worldwide. Despite some improved understanding of disease pathogenesis, progress towards new methods for the control of intramammary infections (IMI) has been limited, particularly in the field of vaccination. Although herd management programs have helped to reduce the number of clinical cases, S. aureus mastitis remains a major disease burden. This review summarizes the past 16 years of research on bovine S. aureus population genetics, and molecular pathogenesis that have been conducted worldwide. We describe the diversity of S. aureus associated with bovine mastitis and the geographical distribution of S. aureus clones in different continents. We also describe studies investigating the evolution of bovine S. aureus and the importance of host-adaptation in its emergence as a mastitis pathogen. The available information on the prevalence of virulence determinants and their functional relevance during the pathogenesis of bovine mastitis are also discussed. Although traits such as biofilm formation and innate immune evasion are critical for the persistence of bacteria, the current understanding of the key host-pathogen interactions that determine the outcome of S. aureus IMI is very limited. We suggest that greater investment in research into the genetic and molecular basis of bovine S. aureus pathogenesis is essential for the identification of novel therapeutic and vaccine targets.
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12
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Bencardino D, Amagliani G, Brandi G. Carriage of Staphylococcus aureus among food handlers: An ongoing challenge in public health. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108362] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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13
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Alfeo MJ, Pagotto A, Barbieri G, Foster TJ, Vanhoorelbeke K, De Filippis V, Speziale P, Pietrocola G. Staphylococcus aureus iron-regulated surface determinant B (IsdB) protein interacts with von Willebrand factor and promotes adherence to endothelial cells. Sci Rep 2021; 11:22799. [PMID: 34815454 PMCID: PMC8611056 DOI: 10.1038/s41598-021-02065-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/01/2021] [Indexed: 12/27/2022] Open
Abstract
Staphylococcus aureus is the cause of a spectrum of diseases in humans and animals. The molecular basis of this pathogenicity lies in the expression of a variety of virulence factors, including proteins that mediate adherence to the host plasma and extracellular matrix proteins. In this study, we discovered that the iron-regulated surface determinant B (IsdB) protein, besides being involved in iron transport and vitronectin binding, interacts with von Willebrand Factor (vWF). IsdB-expressing bacteria bound to both soluble and immobilized vWF. The binding of recombinant IsdB to vWF was blocked by heparin and reduced at high ionic strength. Furthermore, treatment with ristocetin, an allosteric agent that promotes the exposure of the A1 domain of vWF, potentiates the binding of IsdB to vWF. Both near-iron transporter motifs NEAT1 and NEAT2 of IsdB individually bound recombinant A1 domain with KD values in the micromolar range. The binding of IsdB and adhesion of S. aureus expressing IsdB to monolayers of activated endothelial cells was significantly inhibited by a monoclonal antibody against the A1 domain and by IsdB reactive IgG from patients with staphylococcal endocarditis. This suggests the importance of IsdB in adherence of S. aureus to the endothelium colonization and as potential therapeutic target.
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Affiliation(s)
- Mariangela J Alfeo
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, Viale Taramelli 3/b, 27100, Pavia, Italy
| | - Anna Pagotto
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131, Padua, Italy
| | - Giulia Barbieri
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Ferrata 9, 27100, Pavia, Italy
| | - Timothy J Foster
- Microbiology Department, Trinity College Dublin, Dublin, Ireland
| | - Karen Vanhoorelbeke
- Laboratory for Thrombosis Research, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Vincenzo De Filippis
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, Via Marzolo 5, 35131, Padua, Italy
| | - Pietro Speziale
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, Viale Taramelli 3/b, 27100, Pavia, Italy
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Biochemistry Unit, University of Pavia, Viale Taramelli 3/b, 27100, Pavia, Italy.
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14
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Dong Y, Miao X, Zheng YD, Liu J, He QY, Ge R, Sun X. Ciprofloxacin-Resistant Staphylococcus aureus Displays Enhanced Resistance and Virulence in Iron-Restricted Conditions. J Proteome Res 2021; 20:2839-2850. [PMID: 33872026 DOI: 10.1021/acs.jproteome.1c00077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The unreasonable misuse of antibiotics has led to the emergence of large-scale drug-resistant bacteria, seriously threatening human health. Compared with drug-sensitive bacteria, resistant bacteria are difficult to clear by host immunity. To fully explore the adaptive mechanism of resistant bacteria to the iron-restricted environment, we performed data-independent acquisition-based quantitative proteomics on ciprofloxacin (CIP)-resistant (CIP-R) Staphylococcus aureus in the presence or absence of iron. On bioinformatics analysis, CIP-R bacteria showed stronger amino acid synthesis and energy storage ability. Notably, CIP-R bacteria increased virulence by upregulating the expression of many virulence-related proteins and enhancing the synthesis of virulence-related amino acids under iron-restricted stress. This study will help us to further explain the adaptive mechanisms that lead to bacterial resistance to antibiotics depending on the host environment and provide insights into the development of novel drugs for the treatment of drug-resistant bacterial infections.
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Affiliation(s)
- Yingshan Dong
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Xinyu Miao
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Yun-Dan Zheng
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Jiajia Liu
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Qing-Yu He
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
| | - Ruiguang Ge
- State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xuesong Sun
- MOE Key Laboratory of Tumor Molecular Biology and Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China
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15
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Ellis-Guardiola K, Mahoney BJ, Clubb RT. NEAr Transporter (NEAT) Domains: Unique Surface Displayed Heme Chaperones That Enable Gram-Positive Bacteria to Capture Heme-Iron From Hemoglobin. Front Microbiol 2021; 11:607679. [PMID: 33488548 PMCID: PMC7815599 DOI: 10.3389/fmicb.2020.607679] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 12/03/2020] [Indexed: 11/13/2022] Open
Abstract
Iron is an important micronutrient that is required by bacteria to proliferate and to cause disease. Many bacterial pathogens forage iron from human hemoglobin (Hb) during infections, which contains this metal within heme (iron-protoporphyrin IX). Several clinically important pathogenic species within the Firmicutes phylum scavenge heme using surface-displayed or secreted NEAr Transporter (NEAT) domains. In this review, we discuss how these versatile proteins function in the Staphylococcus aureus Iron-regulated surface determinant system that scavenges heme-iron from Hb. S. aureus NEAT domains function as either Hb receptors or as heme-binding chaperones. In vitro studies have shown that heme-binding NEAT domains can rapidly exchange heme amongst one another via transiently forming transfer complexes, leading to the interesting hypothesis that they may form a protein-wire within the peptidoglycan layer through which heme flows from the microbial surface to the membrane. In Hb receptors, recent studies have revealed how dedicated heme- and Hb-binding NEAT domains function synergistically to extract Hb's heme molecules, and how receptor binding to the Hb-haptoglobin complex may block its clearance by macrophages, prolonging microbial access to Hb's iron. The functions of NEAT domains in other Gram-positive bacteria are also reviewed.
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Affiliation(s)
- Ken Ellis-Guardiola
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
- UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, United States
| | - Brendan J. Mahoney
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
- UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, United States
| | - Robert T. Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, United States
- UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, CA, United States
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, United States
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16
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Mathelié-Guinlet M, Viela F, Pietrocola G, Speziale P, Dufrêne YF. Nanonewton forces between Staphylococcus aureus surface protein IsdB and vitronectin. NANOSCALE ADVANCES 2020; 2:5728-5736. [PMID: 36133863 PMCID: PMC9419033 DOI: 10.1039/d0na00636j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/16/2020] [Indexed: 06/16/2023]
Abstract
Single-molecule experiments have recently revealed that the interaction between staphylococcal surface proteins and their ligands can be extremely strong, equivalent to the strength of covalent bonds. Here, we report on the unusually high binding strength between Staphylococcus aureus iron-regulated surface determinant B (IsdB) and vitronectin (Vn), an essential human blood protein known to interact with bacterial pathogens. The IsdB-Vn interaction is dramatically strengthened by mechanical tension, with forces up to 2000 pN at a loading rate of 105 pN s-1. In line with this, flow experiments show that IsdB-mediated bacterial adhesion to Vn is enhanced by fluid shear stress. The stress-dependent binding of IsdB to Vn is likely to play a role in promoting bacterial adhesion to human cells under fluid shear stress conditions.
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Affiliation(s)
- Marion Mathelié-Guinlet
- Louvain Institute of Biomolecular Science and Technology, UCLouvain Croix du Sud, 4-5, bte L7.07.07 B-1348 Louvain-la-Neuve Belgium
| | - Felipe Viela
- Louvain Institute of Biomolecular Science and Technology, UCLouvain Croix du Sud, 4-5, bte L7.07.07 B-1348 Louvain-la-Neuve Belgium
| | - Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia Viale Taramelli 3/b 27100 Pavia Italy
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia Viale Taramelli 3/b 27100 Pavia Italy
| | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, UCLouvain Croix du Sud, 4-5, bte L7.07.07 B-1348 Louvain-la-Neuve Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO) B-1300 Wavre Belgium
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17
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Pietrocola G, Pellegrini A, Alfeo MJ, Marchese L, Foster TJ, Speziale P. The iron-regulated surface determinant B (IsdB) protein from Staphylococcus aureus acts as a receptor for the host protein vitronectin. J Biol Chem 2020; 295:10008-10022. [PMID: 32499371 DOI: 10.1074/jbc.ra120.013510] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/01/2020] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is an important bacterial pathogen that can cause a wide spectrum of diseases in humans and other animals. S. aureus expresses a variety of virulence factors that promote infection with this pathogen. These include cell-surface proteins that mediate adherence of the bacterial cells to host extracellular matrix components, such as fibronectin and fibrinogen. Here, using immunoblotting, ELISA, and surface plasmon resonance analysis, we report that the iron-regulated surface determinant B (IsdB) protein, besides being involved in heme transport, plays a novel role as a receptor for the plasma and extracellular matrix protein vitronectin (Vn). Vn-binding activity was expressed by staphylococcal strains grown under iron starvation conditions when Isd proteins are expressed. Recombinant IsdB bound Vn dose dependently and specifically. Both near-iron transporter motifs NEAT1 and NEAT2 of IsdB individually bound Vn in a saturable manner, with KD values in the range of 16-18 nm Binding of Vn to IsdB was specifically blocked by heparin and reduced at high ionic strength. Furthermore, IsdB-expressing bacterial cells bound significantly higher amounts of Vn from human plasma than did an isdB mutant. Adherence to and invasion of epithelial and endothelial cells by IsdB-expressing S. aureus cells was promoted by Vn, and an αvβ3 integrin-blocking mAb or cilengitide inhibited adherence and invasion by staphylococci, suggesting that Vn acts as a bridge between IsdB and host αvβ3 integrin.
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Affiliation(s)
- Giampiero Pietrocola
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Angelica Pellegrini
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Mariangela J Alfeo
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Loredana Marchese
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
| | - Timothy J Foster
- Department of Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Pietro Speziale
- Department of Molecular Medicine, Unit of Biochemistry, University of Pavia, Pavia, Italy
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18
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Marchetti M, De Bei O, Bettati S, Campanini B, Kovachka S, Gianquinto E, Spyrakis F, Ronda L. Iron Metabolism at the Interface between Host and Pathogen: From Nutritional Immunity to Antibacterial Development. Int J Mol Sci 2020; 21:E2145. [PMID: 32245010 PMCID: PMC7139808 DOI: 10.3390/ijms21062145] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 02/08/2023] Open
Abstract
Nutritional immunity is a form of innate immunity widespread in both vertebrates and invertebrates. The term refers to a rich repertoire of mechanisms set up by the host to inhibit bacterial proliferation by sequestering trace minerals (mainly iron, but also zinc and manganese). This strategy, selected by evolution, represents an effective front-line defense against pathogens and has thus inspired the exploitation of iron restriction in the development of innovative antimicrobials or enhancers of antimicrobial therapy. This review focuses on the mechanisms of nutritional immunity, the strategies adopted by opportunistic human pathogen Staphylococcus aureus to circumvent it, and the impact of deletion mutants on the fitness, infectivity, and persistence inside the host. This information finally converges in an overview of the current development of inhibitors targeting the different stages of iron uptake, an as-yet unexploited target in the field of antistaphylococcal drug discovery.
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Affiliation(s)
- Marialaura Marchetti
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
| | - Omar De Bei
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Stefano Bettati
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
- National Institute of Biostructures and Biosystems, 00136 Rome, Italy
| | - Barbara Campanini
- Department of Food and Drug, University of Parma, 43124 Parma, Italy; (O.D.B.); (B.C.)
| | - Sandra Kovachka
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Eleonora Gianquinto
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Francesca Spyrakis
- Department of Drug Science and Technology, University of Turin, 10125 Turin, Italy; (S.K.); (E.G.); (F.S.)
| | - Luca Ronda
- Interdepartmental Center Biopharmanet-TEC, University of Parma, 43124 Parma, Italy; (M.M.); (S.B.)
- Department of Medicine and Surgery, University of Parma, 43126 Parma, Italy
- Institute of Biophysics, National Research Council, 56124 Pisa, Italy
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19
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Leonard AC, Petrie LE, Cox G. Bacterial Anti-adhesives: Inhibition of Staphylococcus aureus Nasal Colonization. ACS Infect Dis 2019; 5:1668-1681. [PMID: 31374164 DOI: 10.1021/acsinfecdis.9b00193] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bacterial adhesion to the skin and mucosa is often a fundamental and early step in host colonization, the establishment of bacterial infections, and pathology. This process is facilitated by adhesins on the surface of the bacterial cell that recognize host cell molecules. Interfering with bacterial host cell adhesion, so-called anti-adhesive therapeutics, offers promise for the development of novel approaches to control bacterial infections. In this review, we focus on the discovery of anti-adhesives targeting the high priority pathogen Staphylococcus aureus. This organism remains a major clinical burden, and S. aureus nasal colonization is associated with poor clinical outcomes. We describe the molecular basis of nasal colonization and highlight potentially efficacious targets for the development of novel nasal decolonization strategies.
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Affiliation(s)
- Allison C. Leonard
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Laurenne E. Petrie
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
| | - Georgina Cox
- College of Biological Sciences, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Rd E, Guelph, Ontario N1G 2W1, Canada
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20
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Macdonald R, Mahoney BJ, Ellis-Guardiola K, Maresso A, Clubb RT. NMR experiments redefine the hemoglobin binding properties of bacterial NEAr-iron Transporter domains. Protein Sci 2019; 28:1513-1523. [PMID: 31120610 DOI: 10.1002/pro.3662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 05/14/2019] [Indexed: 01/02/2023]
Abstract
Iron is a versatile metal cofactor that is used in a wide range of essential cellular processes. During infections, many bacterial pathogens acquire iron from human hemoglobin (Hb), which contains the majority of the body's total iron content in the form of heme (iron protoporphyrin IX). Clinically important Gram-positive bacterial pathogens scavenge heme using an array of secreted and cell-wall-associated receptors that contain NEAr-iron Transporter (NEAT) domains. Experimentally defining the Hb binding properties of NEAT domains has been challenging, limiting our understanding of their function in heme uptake. Here we show that solution-state NMR spectroscopy is a powerful tool to define the Hb binding properties of NEAT domains. The utility of this method is demonstrated using the NEAT domains from Bacillus anthracis and Listeria monocytogenes. Our results are compatible with the existence of at least two types of NEAT domains that are capable of interacting with either Hb or heme. These binding properties can be predicted from their primary sequences, with Hb- and heme-binding NEAT domains being distinguished by the presence of (F/Y)YH(Y/F) and S/YXXXY motifs, respectively. The results of this work should enable the functions of a wide range of NEAT domain containing proteins in pathogenic bacteria to be reliably predicted.
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Affiliation(s)
- Ramsay Macdonald
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, 90095.,UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, 90095
| | - Brendan J Mahoney
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, 90095.,UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, 90095
| | - Ken Ellis-Guardiola
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, 90095.,UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, 90095
| | - Anthony Maresso
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, 77030
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, 90095.,UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, 90095.,Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, 90095
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21
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Foster TJ. Surface Proteins of Staphylococcus aureus. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0046-2018. [PMID: 31267926 PMCID: PMC10957221 DOI: 10.1128/microbiolspec.gpp3-0046-2018] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 12/20/2022] Open
Abstract
The surface of Staphylococcus aureus is decorated with over 20 proteins that are covalently anchored to peptidoglycan by the action of sortase A. These cell wall-anchored (CWA) proteins can be classified into several structural and functional groups. The largest is the MSCRAMM family, which is characterized by tandemly repeated IgG-like folded domains that bind peptide ligands by the dock lock latch mechanism or the collagen triple helix by the collagen hug. Several CWA proteins comprise modules that have different functions, and some individual domains can bind different ligands, sometimes by different mechanisms. For example, the N-terminus of the fibronectin binding proteins comprises an MSCRAMM domain which binds several ligands, while the C-terminus is composed of tandem fibronectin binding repeats. Surface proteins promote adhesion to host cells and tissue, including components of the extracellular matrix, contribute to biofilm formation by stimulating attachment to the host or indwelling medical devices followed by cell-cell accumulation via homophilic interactions between proteins on neighboring cells, help bacteria evade host innate immune responses, participate in iron acquisition from host hemoglobin, and trigger invasion of bacteria into cells that are not normally phagocytic. The study of genetically manipulated strains using animal infection models has shown that many CWA proteins contribute to pathogenesis. Fragments of CWA proteins have the potential to be used in multicomponent vaccines to prevent S. aureus infections.
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22
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Sakr A, Brégeon F, Mège JL, Rolain JM, Blin O. Staphylococcus aureus Nasal Colonization: An Update on Mechanisms, Epidemiology, Risk Factors, and Subsequent Infections. Front Microbiol 2018; 9:2419. [PMID: 30349525 PMCID: PMC6186810 DOI: 10.3389/fmicb.2018.02419] [Citation(s) in RCA: 250] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 09/21/2018] [Indexed: 02/02/2023] Open
Abstract
Up to 30% of the human population are asymptomatically and permanently colonized with nasal Staphylococcus aureus. To successfully colonize human nares, S. aureus needs to establish solid interactions with human nasal epithelial cells and overcome host defense mechanisms. However, some factors like bacterial interactions in the human nose can influence S. aureus colonization and sometimes prevent colonization. On the other hand, certain host characteristics and environmental factors can predispose to colonization. Nasal colonization can cause opportunistic and sometimes life-threatening infections such as surgical site infections or other infections in non-surgical patients that increase morbidity, mortality as well as healthcare costs.
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Affiliation(s)
- Adèle Sakr
- Faculté de Médecine et de Pharmacie, IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France.,Service de Pharmacologie Clinique et Pharmacovigilance, AP-HM, Pharmacologie Intégrée et Interface Clinique et Industriel, Institut des Neurosciences Timone - UMR AMU-INSERM 1106, Aix-Marseille Université, Marseille, France
| | - Fabienne Brégeon
- Faculté de Médecine et de Pharmacie, IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
| | - Jean-Louis Mège
- Faculté de Médecine et de Pharmacie, IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
| | - Jean-Marc Rolain
- Faculté de Médecine et de Pharmacie, IRD, APHM, MEPHI, IHU Méditerranée Infection, Aix-Marseille Université, Marseille, France
| | - Olivier Blin
- Service de Pharmacologie Clinique et Pharmacovigilance, AP-HM, Pharmacologie Intégrée et Interface Clinique et Industriel, Institut des Neurosciences Timone - UMR AMU-INSERM 1106, Aix-Marseille Université, Marseille, France
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23
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Totté JEE, Pardo LM, Fieten KB, de Wit J, de Boer DV, van Wamel WJ, Pasmans SGMA. IgG response against Staphylococcus aureus is associated with severe atopic dermatitis in children. Br J Dermatol 2018; 179:118-126. [PMID: 29194572 DOI: 10.1111/bjd.16153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2017] [Indexed: 01/19/2023]
Abstract
BACKGROUND An altered immune response against Staphylococcus aureus might contribute to inflammation and barrier damage in atopic dermatitis (AD). OBJECTIVES To profile IgG antibodies against 55 S. aureus antigens in sera of children with mild-to-severe AD and to evaluate the association between IgG levels and disease severity. METHODS In this cross-sectional study, we included children with AD from two interventional study cohorts, the Shared Medical Appointment (SMA) cohort (n = 131) and the older DAVOS cohort (n = 76). AD severity was assessed using the Self-Administered Eczema Area and Severity Index (SA-EASI) and levels of thymus and activation-regulated chemokine (TARC) in serum. IgG antibody levels against 55 S. aureus antigens were quantified simultaneously using a Luminex assay. Pair-wise correlations were calculated between the 55 IgG levels using the Spearman rank correlation test. Linear regression analysis was performed to test for associations between 55 IgG levels and SA-EASI and TARC, adjusting for age, sex and S. aureus colonization. RESULTS In the SMA cohort, 16 antigens were associated with SA-EASI and 12 with TARC (10 overlapping antigens; P-values 0·001-0·044). The associated IgG antibodies targeted mainly secreted proteins with immunomodulatory functions. In the DAVOS study, IgG levels against only four and one S. aureus antigen(s) were associated with SA-EASI and TARC, respectively (no overlap). CONCLUSIONS In young children, severity of AD is associated with an IgG response directed against S. aureus antigens with mainly immunomodulatory functions. These findings encourage further evaluation of the role of S. aureus in the pathogenesis of AD.
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Affiliation(s)
- J E E Totté
- Department of Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - L M Pardo
- Department of Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - K B Fieten
- Department of Dermatology and Allergology, University Medical Centre Utrecht, Utrecht, The Netherlands.,Swiss Institute of Allergy and Asthma Research (SIAF), University of Zürich, Davos, Switzerland
| | - J de Wit
- Department of Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - D V de Boer
- Department of Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - W J van Wamel
- Department of Medical Microbiology and Infectious Diseases, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - S G M A Pasmans
- Department of Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands.,Department of Paediatric Dermatology, Sophia Children's Hospital, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
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24
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Misra N, Wines TF, Knopp CL, Hermann R, Bond L, Mitchell B, McGuire MA, Tinker JK. Immunogenicity of a Staphylococcus aureus-cholera toxin A 2/B vaccine for bovine mastitis. Vaccine 2018; 36:3513-3521. [PMID: 29739718 DOI: 10.1016/j.vaccine.2018.04.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 04/09/2018] [Accepted: 04/22/2018] [Indexed: 01/10/2023]
Abstract
Staphylococcus aureus causes a chronic, contagious disease of the udder, or mastitis, in dairy cows. This infection is often refractory to antibiotic treatment, and has a significant economic impact on milk production worldwide. An effective vaccine to prevent S. aureus mastitis would improve animal health, reduce antibiotic dependence and inform human vaccine approaches. The iron-regulated surface determinant A (IsdA) and clumping factor A (ClfA) are conserved S. aureus extracellular-matrix adhesins and target vaccine antigens. Here we report the results of two bovine immunogenicity trials using purified IsdA and ClfA-cholera toxin A2/B chimeras (IsdA-CTA2/B and ClfA-CTA2/B). Cows were intranasally inoculated with IsdA-CTA2/B + ClfA-CTA2/B at dry off and followed for 70 days. Trial 1 utilized three groups with one or two booster doses at a total concentration of 600 or 900 μg. Trial 2 utilized two groups with one booster at a total concentration of 1200 μg. Humoral immune responses in serum and milk were examined by ELISA. Responses in serum were significant between groups and provide evidence of antigen-specific IgG induction after vaccination in both trials. Cellular proliferation was detected by flow cytometry using antigen-stimulated PBMCs from day 60 of Trial 2 and revealed an increase in CD4+ T cells from vaccinated cows. IsdA and ClfA stimulation induced IL-4 expression, but not IFN-γ or IL-17, in PBMCs from day 60 as determined by cytokine expression analysis. Opsonophagocytosis of S. aureus confirmed the functional in vitro activity of anti-IsdA antibodies from Trial 2 serum and milk. The vaccine was well tolerated and safe, and results support the potential of mucosally-delivered CTA2/B chimeras to protect cows from mastitis caused by S. aureus.
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Affiliation(s)
- N Misra
- Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA
| | - T F Wines
- Department of Biological Sciences, Boise State University, Boise, ID, USA
| | - C L Knopp
- Department of Biological Sciences, Boise State University, Boise, ID, USA
| | - R Hermann
- Department of Biological Sciences, Boise State University, Boise, ID, USA; Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA
| | - L Bond
- Biomolecular Research Center, Boise State University, Boise, ID, USA
| | - B Mitchell
- DairyTeam Nutrition and Veterinary Consulting, Boise, ID, USA
| | - M A McGuire
- Department of Animal and Veterinary Science, University of Idaho, Moscow, ID, USA
| | - J K Tinker
- Department of Biological Sciences, Boise State University, Boise, ID, USA; Biomolecular Ph.D. Program, Boise State University, Boise, ID, USA.
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25
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Misra N, Pu X, Holt DN, McGuire MA, Tinker JK. Immunoproteomics to identify Staphylococcus aureus antigens expressed in bovine milk during mastitis. J Dairy Sci 2018; 101:6296-6309. [PMID: 29729920 DOI: 10.3168/jds.2017-14040] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/18/2018] [Indexed: 12/31/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen affecting both human and animal species. An effective vaccine to prevent S. aureus bovine disease and transmission would have positive effects on animal well-being, food production, and human health. The objective of this study was to identify multiple antigens that are immunoreactive during udder colonization and disease for exploration as vaccine antigens to prevent bovine mastitis. Staphylococcus aureus produces several cell wall-anchored and surface-associated virulence factors that play key roles in the pathogenesis of mastitis. Many of these proteins are conserved between different strains of S. aureus and represent promising vaccine candidates. We used an immunoproteomics approach to identify antigenic proteins from the surface of S. aureus. The expression of cell wall and surface proteins from S. aureus was induced under low iron conditions, followed by trypsin extraction and separation by 2-dimensional electrophoresis. The separated proteins were blotted with antibodies from mastitic bovine milk and identified by liquid chromatography-mass spectrometry. Thirty-eight unique proteins were identified, of which 8 were predicted to be surface exposed and involved in S. aureus virulence. Two surface proteins, iron-regulated surface determinant protein C (IsdC) and ESAT-6 secretion system extracellular protein (EsxA), were cloned, expressed, and purified from Escherichia coli for confirmation of immune reactivity by ELISA. A PCR of 37 bovine S. aureus isolates indicated that the presence of esxA and isdC is conserved, and amino acid alignments revealed that IsdC and EsxA sequences are highly conserved. The immunoproteomics technique used in this study generated reproducible results and identified surface exposed and reactive antigens for further characterization.
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Affiliation(s)
- N Misra
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725
| | - X Pu
- Biomolecular Research Center, Boise State University, Boise, ID 83725
| | - D N Holt
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725
| | - M A McGuire
- Department of Animal and Veterinary Science, University of Idaho, Moscow 83844
| | - J K Tinker
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725; Department of Biological Sciences, Boise State University, Boise, ID 83725.
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Staphylococcal Protein A Contributes to Persistent Colonization of Mice with Staphylococcus aureus. J Bacteriol 2018; 200:JB.00735-17. [PMID: 29440258 DOI: 10.1128/jb.00735-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/09/2018] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus persistently colonizes the nasopharynx in humans, which increases the risk for invasive diseases, such as skin infection and bacteremia. Nasal colonization triggers IgG responses against staphylococcal surface antigens; however, these antibodies cannot prevent subsequent colonization or disease. Here, we describe S. aureus WU1, a multilocus sequence type 88 (ST88) isolate that persistently colonizes the nasopharynx in mice. We report that staphylococcal protein A (SpA) is required for persistence of S. aureus WU1 in the nasopharynx. Compared to animals colonized by wild-type S. aureus, mice colonized with the Δspa variant mount increased IgG responses against staphylococcal colonization determinants. Immunization of mice with a nontoxigenic SpA variant, which cannot cross-link B cell receptors and divert antibody responses, elicits protein A-neutralizing antibodies that promote IgG responses against colonizing S. aureus and diminish pathogen persistence.IMPORTANCE Staphylococcus aureus persistently colonizes the nasopharynx in about one-third of the human population, thereby promoting community- and hospital-acquired infections. Antibiotics are currently used for decolonization of individuals at increased risk of infection. However, the efficacy of antibiotics is limited by recolonization and selection for drug-resistant strains. Here, we propose a model of how staphylococcal protein A (SpA), a B cell superantigen, modifies host immune responses during colonization to support continued persistence of S. aureus in the nasopharynx. We show that this mechanism can be thwarted by vaccine-induced anti-SpA antibodies that promote IgG responses against staphylococcal antigens and diminish colonization.
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Misra N, Wines TF, Knopp CL, McGuire MA, Tinker JK. Expression, immunogenicity and variation of iron-regulated surface protein A from bovine isolates of Staphylococcus aureus. FEMS Microbiol Lett 2017; 364:3739792. [PMID: 28430959 DOI: 10.1093/femsle/fnx082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 04/18/2017] [Indexed: 01/24/2023] Open
Abstract
Staphylococcus aureus iron-regulated surface protein A (IsdA) is a fibrinogen and fibronectin adhesin that also contributes to iron sequestration and resistance to innate immunity. IsdA is conserved in human isolates and has been investigated as a human vaccine candidate. Here we report the expression of isdA, the efficacy of anti-IsdA responses and the existence of IsdA sequence variants from bovine Staphylococcus. Clinical staphylococci were obtained from US dairy farms and assayed by PCR for the presence and expression of isdA. isdA-positive species from bovines included S. aureus, S. haemolyticus and S. chromogenes. Immunoassays on bovine milk and serum confirmed the induction and opsonophagocytic activity of anti-IsdA humoral responses. The variable region of isdA was sequenced and protein alignments predicted the presence of two main variants consistent with those from human S. aureus. Mouse antibodies against one IsdA variant reduced staphylococcal binding to fibronectin in vitro in an isotype-dependent manner. Purified IsdA variants bound distinctly to fibronectin and fibrinogen. Our findings demonstrate that variability within the C-terminus of this adhesin affects immune reactivity and binding specificity, but are consistent with the significance of IsdA in bovine disease and relevant for vaccine development.
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Affiliation(s)
- Neha Misra
- Biomolecular Ph.D. Program, Boise State University, Boise, ID 83725, USA
| | - Tyler F Wines
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Colton L Knopp
- Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
| | - Mark A McGuire
- Department of Animal and Veterinary Science, University of Idaho, Moscow, ID 83844, USA
| | - Juliette K Tinker
- Biomolecular Ph.D. Program, Boise State University, Boise, ID 83725, USA.,Department of Biological Sciences, Boise State University, Boise, ID 83725, USA
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O'Gara JP. Into the storm: Chasing the opportunistic pathogen Staphylococcus aureus from skin colonisation to life-threatening infections. Environ Microbiol 2017. [PMID: 28631399 DOI: 10.1111/1462-2920.13833] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Colonisation of the human skin by Staphylococcus aureus is a precursor for a variety of infections ranging from boils to sepsis and pneumonia. The rapid emergence of methicillin-resistant S. aureus following the clinical introduction of this antimicrobial drug and reports of resistance to all currently used anti-staphylococcal drugs has added to its formidable reputation. S. aureus survival on the skin and in vivo virulence is underpinned by a remarkable environmental adaptability, made possible by highly orchestrated regulation of gene expression and a capacity to undertake genome remodelling. Depending on the ecological or infection niche, controlled expression of a variety of adhesins can be initiated to facilitate adherence to extracellular matrix proteins, survival against desiccation or biofilm accumulation on implanted medical devices and host tissue. These adherence mechanisms complement toxin and enzyme production, immune evasion strategies, and antibiotic resistance and tolerance to collectively thwart efforts to develop reliable antimicrobial drug regimens and an effective S. aureus vaccine.
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Affiliation(s)
- James P O'Gara
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
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Abstract
The staphylococci comprise a diverse genus of Gram-positive, nonmotile commensal organisms that inhabit the skin and mucous membranes of humans and other mammals. In general, staphylococci are benign members of the natural flora, but many species have the capacity to be opportunistic pathogens, mainly infecting individuals who have medical device implants or are otherwise immunocompromised. Staphylococcus aureus and Staphylococcus epidermidis are major sources of hospital-acquired infections and are the most common causes of surgical site infections and medical device-associated bloodstream infections. The ability of staphylococci to form biofilms in vivo makes them highly resistant to chemotherapeutics and leads to chronic diseases. These biofilm infections include osteomyelitis, endocarditis, medical device infections, and persistence in the cystic fibrosis lung. Here, we provide a comprehensive analysis of our current understanding of staphylococcal biofilm formation, with an emphasis on adhesins and regulation, while also addressing how staphylococcal biofilms interact with the immune system. On the whole, this review will provide a thorough picture of biofilm formation of the staphylococcus genus and how this mode of growth impacts the host.
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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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Libberton B, Horsburgh MJ, Brockhurst MA. The effects of spatial structure, frequency dependence and resistance evolution on the dynamics of toxin-mediated microbial invasions. Evol Appl 2015; 8:738-50. [PMID: 26240609 PMCID: PMC4516424 DOI: 10.1111/eva.12284] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 06/01/2015] [Indexed: 12/02/2022] Open
Abstract
Recent evidence suggests that interference competition between bacteria shapes the distribution of the opportunistic pathogen Staphylococcus aureus in the lower nasal airway of humans, either by preventing colonization or by driving displacement. This competition within the nasal microbial community would add to known host factors that affect colonization. We tested the role of toxin-mediated interference competition in both structured and unstructured environments, by culturing S. aureus with toxin-producing or nonproducing Staphylococcus epidermidis nasal isolates. Toxin-producing S. epidermidis invaded S. aureus populations more successfully than nonproducers, and invasion was promoted by spatial structure. Complete displacement of S. aureus was prevented by the evolution of toxin resistance. Conversely, toxin-producing S. epidermidis restricted S. aureus invasion. Invasion of toxin-producing S. epidermidis populations by S. aureus resulted from the evolution of toxin resistance, which was favoured by high initial frequency and low spatial structure. Enhanced toxin production also evolved in some invading populations of S. epidermidis. Toxin production therefore promoted invasion by, and constrained invasion into, populations of producers. Spatial structure enhanced both of these invasion effects. Our findings suggest that manipulation of the nasal microbial community could be used to limit colonization by S. aureus, which might limit transmission and infection rates.
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Affiliation(s)
- Ben Libberton
- Department of Integrative Biology, University of Liverpool Liverpool, UK ; Karolinska Institute SE-171 77, Stockholm, Sweden
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Sjodt M, Macdonald R, Spirig T, Chan AH, Dickson CF, Fabian M, Olson JS, Gell DA, Clubb RT. The PRE-Derived NMR Model of the 38.8-kDa Tri-Domain IsdH Protein from Staphylococcus aureus Suggests That It Adaptively Recognizes Human Hemoglobin. J Mol Biol 2015; 428:1107-1129. [PMID: 25687963 DOI: 10.1016/j.jmb.2015.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 01/31/2015] [Accepted: 02/07/2015] [Indexed: 01/11/2023]
Abstract
Staphylococcus aureus is a medically important bacterial pathogen that, during infections, acquires iron from human hemoglobin (Hb). It uses two closely related iron-regulated surface determinant (Isd) proteins to capture and extract the oxidized form of heme (hemin) from Hb, IsdH and IsdB. Both receptors rapidly extract hemin using a conserved tri-domain unit consisting of two NEAT (near iron transporter) domains connected by a helical linker domain. To gain insight into the mechanism of extraction, we used NMR to investigate the structure and dynamics of the 38.8-kDa tri-domain IsdH protein (IsdH(N2N3), A326-D660 with a Y642A mutation that prevents hemin binding). The structure was modeled using long-range paramagnetic relaxation enhancement (PRE) distance restraints, dihedral angle, small-angle X-ray scattering, residual dipolar coupling and inter-domain NOE nuclear Overhauser effect data. The receptor adopts an extended conformation wherein the linker and N3 domains pack against each other via a hydrophobic interface. In contrast, the N2 domain contacts the linker domain via a hydrophilic interface and, based on NMR relaxation data, undergoes inter-domain motions enabling it to reorient with respect to the body of the protein. Ensemble calculations were used to estimate the range of N2 domain positions compatible with the PRE data. A comparison of the Hb-free and Hb-bound forms reveals that Hb binding alters the positioning of the N2 domain. We propose that binding occurs through a combination of conformational selection and induced-fit mechanisms that may promote hemin release from Hb by altering the position of its F helix.
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Affiliation(s)
- Megan Sjodt
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; University of California, Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA
| | - Ramsay Macdonald
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; University of California, Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA
| | - Thomas Spirig
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA
| | - Albert H Chan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; University of California, Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA
| | - Claire F Dickson
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Marian Fabian
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251, USA
| | - John S Olson
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251, USA
| | - David A Gell
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Robert T Clubb
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; University of California, Los Angeles-Department of Energy Institute of Genomics and Proteomics, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, 611 Charles Young Drive East, Los Angeles, CA 90095, USA.
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Cell Wall-Anchored Surface Proteins of Staphylococcus aureus: Many Proteins, Multiple Functions. Curr Top Microbiol Immunol 2015; 409:95-120. [PMID: 26667044 DOI: 10.1007/82_2015_5002] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Staphylococcus aureus persistently colonizes about 20 % of the population and is intermittently associated with the remainder. The organism can cause superficial skin infections and life-threatening invasive diseases. The surface of the bacterial cell displays a variety of proteins that are covalently anchored to peptidoglycan. They perform many functions including adhesion to host cells and tissues, invasion of non-phagocytic cells, and evasion of innate immune responses. The proteins have been categorized into distinct classes based on structural and functional analysis. Many surface proteins are multifunctional. Cell wall-anchored proteins perform essential functions supporting survival and proliferation during the commensal state and during invasive infections. The ability of cell wall-anchored proteins to bind to desquamated epithelial cells is important during colonization, and the binding to fibrinogen is of particular significance in pathogenesis.
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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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The effect of skin fatty acids on Staphylococcus aureus. Arch Microbiol 2014; 197:245-67. [PMID: 25325933 PMCID: PMC4326651 DOI: 10.1007/s00203-014-1048-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 09/19/2014] [Accepted: 10/06/2014] [Indexed: 12/14/2022]
Abstract
Staphylococcus aureus is a commensal of the human nose and skin. Human skin fatty acids, in particular cis-6-hexadecenoic acid (C-6-H), have high antistaphylococcal activity and can inhibit virulence determinant production. Here, we show that sub-MIC levels of C-6-H result in induction of increased resistance. The mechanism(s) of C-6-H activity was investigated by combined transcriptome and proteome analyses. Proteome analysis demonstrated a pleiotropic effect of C-6-H on virulence determinant production. In response to C-6-H, transcriptomics revealed altered expression of over 500 genes, involved in many aspects of virulence and cellular physiology. The expression of toxins (hla, hlb, hlgBC) was reduced, whereas that of host defence evasion components (cap, sspAB, katA) was increased. In particular, members of the SaeRS regulon had highly reduced expression, and the use of specific mutants revealed that the effect on toxin production is likely mediated via SaeRS.
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Jaglic Z, Desvaux M, Weiss A, Nesse LL, Meyer RL, Demnerova K, Schmidt H, Giaouris E, Sipailiene A, Teixeira P, Kačániová M, Riedel CU, Knøchel S. Surface adhesins and exopolymers of selected foodborne pathogens. MICROBIOLOGY-SGM 2014; 160:2561-2582. [PMID: 25217529 DOI: 10.1099/mic.0.075887-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The ability of bacteria to bind different compounds and to adhere to biotic and abiotic surfaces provides them with a range of advantages, such as colonization of various tissues, internalization, avoidance of an immune response, and survival and persistence in the environment. A variety of bacterial surface structures are involved in this process and these promote bacterial adhesion in a more or less specific manner. In this review, we will focus on those surface adhesins and exopolymers in selected foodborne pathogens that are involved mainly in primary adhesion. Their role in biofilm development will also be considered when appropriate. Both the clinical impact and the implications for food safety of such adhesion will be discussed.
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Affiliation(s)
- Zoran Jaglic
- Veterinary Research Institute, Brno, Czech Republic
| | - Mickaël Desvaux
- INRA, UR454 Microbiologie, F-63122 Saint-Genès Champanelle, France
| | - Agnes Weiss
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | | | - Rikke L Meyer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Katerina Demnerova
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
| | - Herbert Schmidt
- Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Efstathios Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, 81400 Myrina, Lemnos Island, Greece
| | | | - Pilar Teixeira
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
| | | | - Christian U Riedel
- Institute of Microbiology and Biotechnology, University of Ulm, Ulm, Germany
| | - Susanne Knøchel
- Department of Food Science, University of Copenhagen, Rolighedsvej 30, Frederiksberg C 1958, Denmark
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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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Solis N, Parker BL, Kwong SM, Robinson G, Firth N, Cordwell SJ. Staphylococcus aureus surface proteins involved in adaptation to oxacillin identified using a novel cell shaving approach. J Proteome Res 2014; 13:2954-72. [PMID: 24708102 DOI: 10.1021/pr500107p] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Staphylococcus aureus is a Gram-positive pathogen responsible for a variety of infections, and some strains are resistant to virtually all classes of antibiotics. Cell shaving proteomics using a novel probability scoring algorithm to compare the surfaceomes of the methicillin-resistant, laboratory-adapted S. aureus COL strain with a COL strain in vitro adapted to high levels of oxacillin (APT). APT displayed altered cell morphology compared with COL and increased aggregation in biofilm assays. Increased resistance to β-lactam antibiotics was observed, but adaptation to oxacillin did not confer multidrug resistance. Analysis of the S. aureus COL and APT surfaceomes identified 150 proteins at a threshold determined by the scoring algorithm. Proteins unique to APT included the LytR-CpsA-Psr (LCP) domain-containing MsrR and SACOL2302. Quantitative RT-PCR showed increased expression of sacol2302 in APT grown with oxacillin (>6-fold compared with COL). Overexpression of sacol2302 in COL to levels consistent with APT (+ oxacillin) did not influence biofilm formation or β-lactam resistance. Proteomics using iTRAQ and LC-MS/MS identified 1323 proteins (∼50% of the theoretical S. aureus proteome), and cluster analysis demonstrated elevated APT abundances of LCP proteins, capsule and peptidoglycan biosynthesis proteins, and proteins involved in wall remodelling. Adaptation to oxacillin also induced urease proteins, which maintained culture pH compared to COL. These results show that S. aureus modifies surface architecture in response to antibiotic adaptation.
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Affiliation(s)
- Nestor Solis
- School of Molecular Bioscience, ‡Discipline of Pathology, School of Medical Sciences, and §School of Biological Sciences, The University of Sydney , New South Wales 2006, Australia
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A nasal epithelial receptor for Staphylococcus aureus WTA governs adhesion to epithelial cells and modulates nasal colonization. PLoS Pathog 2014; 10:e1004089. [PMID: 24788600 PMCID: PMC4006915 DOI: 10.1371/journal.ppat.1004089] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 03/10/2014] [Indexed: 02/02/2023] Open
Abstract
Nasal colonization is a major risk factor for S. aureus infections. The mechanisms responsible for colonization are still not well understood and involve several factors on the host and the bacterial side. One key factor is the cell wall teichoic acid (WTA) of S. aureus, which governs direct interactions with nasal epithelial surfaces. We report here the first receptor for the cell wall glycopolymer WTA on nasal epithelial cells. In several assay systems this type F-scavenger receptor, termed SREC-I, bound WTA in a charge dependent manner and mediated adhesion to nasal epithelial cells in vitro. The impact of WTA and SREC-I interaction on epithelial adhesion was especially pronounced under shear stress, which resembles the conditions found in the nasal cavity. Most importantly, we demonstrate here a key role of the WTA-receptor interaction in a cotton rat model of nasal colonization. When we inhibited WTA mediated adhesion with a SREC-I antibody, nasal colonization in the animal model was strongly reduced at the early onset of colonization. More importantly, colonization stayed low over an extended period of 6 days. Therefore we propose targeting of this glycopolymer-receptor interaction as a novel strategy to prevent or control S. aureus nasal colonization. About 20% of the human population is colonized by Staphylococcus aureus. The reservoir of S. aureus is mainly the human nose. Usually, colonization does not lead to infection and is therefore without symptoms. However, when hospitalized patients exhibit a suppressed immune system, they are at risk of getting infected by their own nasal S. aureus strain. Therefore, it is important to understand the events and mechanisms underlying colonization. Until now S. aureus nasal colonization is only partially understood. One bacterial key factor is a sugar polymer of S. aureus, termed cell wall teichoic acid (WTA), which is involved in S. aureus adhesion to cellular surfaces in the inner part of the nasal cavity. We show here that a receptor-protein, which is expressed on such cells, binds WTA and is thereby involved in adhesion of S. aureus to nasal cells. This mechanism has a strong impact on nasal colonization in an animal model that resembles the situation in the human nose. Most importantly, inhibition of WTA mediated adhesion strongly reduces nasal colonization in the animal model. Therefore we propose that targeting of this glycopolymer-receptor interaction could serve as a novel strategy to control S. aureus nasal colonization.
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Foster TJ, Geoghegan JA, Ganesh VK, Höök M. Adhesion, invasion and evasion: the many functions of the surface proteins of Staphylococcus aureus. Nat Rev Microbiol 2014; 12:49-62. [PMID: 24336184 DOI: 10.1038/nrmicro3161] [Citation(s) in RCA: 960] [Impact Index Per Article: 96.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is an important opportunistic pathogen and persistently colonizes about 20% of the human population. Its surface is 'decorated' with proteins that are covalently anchored to the cell wall peptidoglycan. Structural and functional analysis has identified four distinct classes of surface proteins, of which microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) are the largest class. These surface proteins have numerous functions, including adhesion to and invasion of host cells and tissues, evasion of immune responses and biofilm formation. Thus, cell wall-anchored proteins are essential virulence factors for the survival of S. aureus in the commensal state and during invasive infections, and targeting them with vaccines could combat S. aureus infections.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Joan A Geoghegan
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Vannakambadi K Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
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Krismer B, Liebeke M, Janek D, Nega M, Rautenberg M, Hornig G, Unger C, Weidenmaier C, Lalk M, Peschel A. Nutrient limitation governs Staphylococcus aureus metabolism and niche adaptation in the human nose. PLoS Pathog 2014; 10:e1003862. [PMID: 24453967 PMCID: PMC3894218 DOI: 10.1371/journal.ppat.1003862] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 11/18/2013] [Indexed: 01/23/2023] Open
Abstract
Colonization of the human nose by Staphylococcus aureus in one-third of the population represents a major risk factor for invasive infections. The basis for adaptation of S. aureus to this specific habitat and reasons for the human predisposition to become colonized have remained largely unknown. Human nasal secretions were analyzed by metabolomics and found to contain potential nutrients in rather low amounts. No significant differences were found between S. aureus carriers and non-carriers, indicating that carriage is not associated with individual differences in nutrient supply. A synthetic nasal medium (SNM3) was composed based on the metabolomics data that permits consistent growth of S. aureus isolates. Key genes were expressed in SNM3 in a similar way as in the human nose, indicating that SNM3 represents a suitable surrogate environment for in vitro simulation studies. While the majority of S. aureus strains grew well in SNM3, most of the tested coagulase-negative staphylococci (CoNS) had major problems to multiply in SNM3 supporting the notion that CoNS are less well adapted to the nose and colonize preferentially the human skin. Global gene expression analysis revealed that, during growth in SNM3, S. aureus depends heavily on de novo synthesis of methionine. Accordingly, the methionine-biosynthesis enzyme cysteine-γ-synthase (MetI) was indispensable for growth in SNM3, and the MetI inhibitor DL-propargylglycine inhibited S. aureus growth in SNM3 but not in the presence of methionine. Of note, metI was strongly up-regulated by S. aureus in human noses, and metI mutants were strongly abrogated in their capacity to colonize the noses of cotton rats. These findings indicate that the methionine biosynthetic pathway may include promising antimicrobial targets that have previously remained unrecognized. Hence, exploring the environmental conditions facultative pathogens are exposed to during colonization can be useful for understanding niche adaptation and identifying targets for new antimicrobial strategies.
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Affiliation(s)
- Bernhard Krismer
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
- * E-mail:
| | - Manuel Liebeke
- Institute of Pharmacy, Ernst-Moritz-Arndt University of Greifswald, Greifswald, Germany
| | - Daniela Janek
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Mulugeta Nega
- Interfaculty Institute of Microbiology and Infection Medicine, Microbial Genetics, Eberhard-Karls-University Tübingen, Tübingen, Germany
| | - Maren Rautenberg
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Gabriele Hornig
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Clemens Unger
- Institute for Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Christopher Weidenmaier
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
| | - Michael Lalk
- Institute of Pharmacy, Ernst-Moritz-Arndt University of Greifswald, Greifswald, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, Cellular and Molecular Microbiology, Eberhard-Karls-University Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, Tübingen, Germany
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Sollid J, Furberg A, Hanssen A, Johannessen M. Staphylococcus aureus: Determinants of human carriage. INFECTION GENETICS AND EVOLUTION 2014; 21:531-41. [DOI: 10.1016/j.meegid.2013.03.020] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/15/2013] [Accepted: 03/16/2013] [Indexed: 02/02/2023]
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Ouattara M, Pennati A, Devlin DJ, Huang YS, Gadda G, Eichenbaum Z. Kinetics of heme transfer by the Shr NEAT domains of Group A Streptococcus. Arch Biochem Biophys 2013; 538:71-9. [PMID: 23993953 DOI: 10.1016/j.abb.2013.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 08/06/2013] [Accepted: 08/14/2013] [Indexed: 01/07/2023]
Abstract
The hemolytic Group A Streptococcus (GAS) is a notorious human pathogen. Shr protein of GAS participates in iron acquisition by obtaining heme from host hemoglobin and delivering it to the adjacent receptor on the surface, Shp. Heme is then conveyed to the SiaABC proteins for transport across the membrane. Using rapid kinetic studies, we investigated the role of the two heme binding NEAT modules of Shr. Stopped-flow analysis showed that holoNEAT1 quickly delivered heme to apoShp. HoloNEAT2 did not exhibit such activity; only little and slow transfer of heme from NEAT2 to apoShp was seen, suggesting that Shr NEAT domains have distinctive roles in heme transport. HoloNEAT1 also provided heme to apoNEAT2, by a fast and reversible process. To the best of our knowledge this is the first transfer observed between isolated NEAT domains of the same receptor. Sequence alignment revealed that Shr NEAT domains belong to two families of NEAT domains that are conserved in Shr orthologs from several species. Based on the heme transfer kinetics, we propose that Shr proteins modulate heme uptake according to heme availability by a mechanism where NEAT1 facilitates fast heme delivery to Shp, whereas NEAT2 serves as a temporary storage for heme on the bacterial surface.
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Affiliation(s)
- Mahamoudou Ouattara
- Department of Biology, College of Arts and Sciences, Georgia State University, Atlanta, GA 30303, USA
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Analysis of novel iron-regulated, surface-anchored hemin-binding proteins in Corynebacterium diphtheriae. J Bacteriol 2013; 195:2852-63. [PMID: 23585541 DOI: 10.1128/jb.00244-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Corynebacterium diphtheriae utilizes hemin and hemoglobin (Hb) as iron sources during growth in iron-depleted environments, and recent studies have shown that the surface-exposed HtaA protein binds both hemin and Hb and also contributes to the utilization of hemin iron. Conserved (CR) domains within HtaA and in the associated hemin-binding protein, HtaB, are required for the ability to bind hemin and Hb. In this study, we identified and characterized two novel genetic loci in C. diphtheriae that encode factors that bind hemin and Hb. Both genetic systems contain two-gene operons that are transcriptionally regulated by DtxR and iron. The gene products of these operons are ChtA-ChtB and ChtC-CirA (previously DIP0522-DIP0523). The chtA and chtB genes are carried on a putative composite transposon associated with C. diphtheriae isolates that dominated the diphtheria outbreak in the former Soviet Union in the 1990s. ChtA and ChtC each contain a single N-terminal CR domain and exhibit significant sequence similarity to each other but only limited similarity with HtaA. The chtB and htaB gene products exhibited a high level of sequence similarity throughout their sequences, and both proteins contain a single CR domain. Whole-cell binding studies as well as protease analysis indicated that all four of the proteins encoded by these two operons are surface exposed, which is consistent with the presence of a transmembrane segment in their C-terminal regions. ChtA, ChtB, and ChtC are able to bind hemin and Hb, with ChtA showing the highest affinity. Site-directed mutagenesis showed that specific tyrosine residues within the ChtA CR domain were critical for hemin and Hb binding. Hemin iron utilization assays using various C. diphtheriae mutants indicate that deletion of the chtA-chtB region and the chtC gene has no affect on the ability of C. diphtheriae to use hemin or Hb as iron sources; however, a chtB htaB double mutant exhibits a significant decrease in hemin iron use, indicating a role in hemin transport for HtaB and ChtB.
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Sugimoto S, Iwamoto T, Takada K, Okuda KI, Tajima A, Iwase T, Mizunoe Y. Staphylococcus epidermidis Esp degrades specific proteins associated with Staphylococcus aureus biofilm formation and host-pathogen interaction. J Bacteriol 2013; 195:1645-55. [PMID: 23316041 PMCID: PMC3624567 DOI: 10.1128/jb.01672-12] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 01/07/2013] [Indexed: 12/27/2022] Open
Abstract
Staphylococcus aureus exhibits a strong capacity to attach to abiotic or biotic surfaces and form biofilms, which lead to chronic infections. We have recently shown that Esp, a serine protease secreted by commensal Staphylococcus epidermidis, disassembles preformed biofilms of S. aureus and inhibits its colonization. Esp was expected to degrade protein determinants of the adhesive and cohesive strength of S. aureus biofilms. The aim of this study was to elucidate the substrate specificity and target proteins of Esp and thereby determine the mechanism by which Esp disassembles S. aureus biofilms. We used a mutant Esp protein (Esp(S235A)) with defective proteolytic activity; this protein did not disassemble the biofilm formed by a clinically isolated methicillin-resistant S. aureus (MRSA) strain, thereby indicating that the proteolytic activity of Esp is essential for biofilm disassembly. Esp degraded specific proteins in the biofilm matrix and cell wall fractions, in contrast to proteinase K, which is frequently used for testing biofilm robustness and showed no preference for proteolysis. Proteomic and immunological analyses showed that Esp degrades at least 75 proteins, including 11 biofilm formation- and colonization-associated proteins, such as the extracellular adherence protein, the extracellular matrix protein-binding protein, fibronectin-binding protein A, and protein A. In addition, Esp selectively degraded several human receptor proteins of S. aureus (e.g., fibronectin, fibrinogen, and vitronectin) that are involved in its colonization or infection. These results suggest that Esp inhibits S. aureus colonization and biofilm formation by degrading specific proteins that are crucial for biofilm construction and host-pathogen interaction.
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Affiliation(s)
| | | | - Koji Takada
- Department of Biochemistry, The Jikei University School of Medicine, Tokyo, Japan
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Zapotoczna M, Jevnikar Z, Miajlovic H, Kos J, Foster TJ. Iron-regulated surface determinant B (IsdB) promotes Staphylococcus aureus adherence to and internalization by non-phagocytic human cells. Cell Microbiol 2013; 15:1026-41. [PMID: 23279065 DOI: 10.1111/cmi.12097] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 11/28/2012] [Accepted: 12/13/2012] [Indexed: 01/22/2023]
Abstract
Staphylococcus aureus is a human pathogen that causes invasive and recurring infections. The ability to internalize into and persist within host cells is thought to contribute to infection. Here we report a novel role for the well-characterized iron-regulated surface determinant B (IsdB) protein which we have shown can promote adhesion of 293T, HeLa cells and platelets to immobilized bacteria independently of its ability to bind haemoglobin. IsdB bound to the active form of the platelet integrin αIIb β3 , both on platelets and when the integrin was expressed ectopically in CHO cells. IsdB also promoted bacterial invasion into human cells. This was clearly demonstrated with bacteria lacking fibronectin-binding proteins (FnBPs), which are known to promote invasion in the presence of fibronectin. However, IsdB also contributed significantly to invasion by cells expressing FnBPs in the presence of serum. Thus IsdB appears to be able to interact with the broader family of integrins that bind ligands with the RGD motif and to act as a back up mechanism to promote interactions with mammalian cells.
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Affiliation(s)
- Marta Zapotoczna
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland
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Eichenbaum Z. The streptococcal hemoprotein receptor: a moonlighting protein or a virulence factor? Virulence 2012; 3:553-5. [PMID: 23154285 DOI: 10.4161/viru.22440] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The β-hemolytic group A streptococcus (GAS) is a major pathogen that readily uses hemoglobin to satisfy its requirements for iron. The streptococcal hemoprotein receptor in GAS plays a central role in heme utilization and binds fibronectin and laminin in vitro. Shr inactivation attenuates the virulent M1T1 GAS strain in two murine infection models and reduces bacterial growth in blood and binding to laminin. Shr impact on the globally disseminated M1T1 strain underscores the importance of heme uptake in GAS pathogenesis and raises the possibility of targeting heme-uptake proteins in the development of new methods to combat GAS infections.
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Spirig T, Malmirchegini GR, Zhang J, Robson SA, Sjodt M, Liu M, Krishna Kumar K, Dickson CF, Gell DA, Lei B, Loo JA, Clubb RT. Staphylococcus aureus uses a novel multidomain receptor to break apart human hemoglobin and steal its heme. J Biol Chem 2012; 288:1065-78. [PMID: 23132864 DOI: 10.1074/jbc.m112.419119] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Staphylococcus aureus is a leading cause of life-threatening infections in the United States. It requires iron to grow, which must be actively procured from its host to successfully mount an infection. Heme-iron within hemoglobin (Hb) is the most abundant source of iron in the human body and is captured by S. aureus using two closely related receptors, IsdH and IsdB. Here we demonstrate that each receptor captures heme using two conserved near iron transporter (NEAT) domains that function synergistically. NMR studies of the 39-kDa conserved unit from IsdH (IsdH(N2N3), Ala(326)-Asp(660)) reveals that it adopts an elongated dumbbell-shaped structure in which its NEAT domains are properly positioned by a helical linker domain, whose three-dimensional structure is determined here in detail. Electrospray ionization mass spectrometry and heme transfer measurements indicate that IsdH(N2N3) extracts heme from Hb via an ordered process in which the receptor promotes heme release by inducing steric strain that dissociates the Hb tetramer. Other clinically significant Gram-positive pathogens capture Hb using receptors that contain multiple NEAT domains, suggesting that they use a conserved mechanism.
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Affiliation(s)
- Thomas Spirig
- Department of Chemistry and Biochemistry and the UCLA-Department of Energy Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095, USA
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Tiedemann MT, Heinrichs DE, Stillman MJ. Multiprotein Heme Shuttle Pathway in Staphylococcus aureus: Iron-Regulated Surface Determinant Cog-Wheel Kinetics. J Am Chem Soc 2012; 134:16578-85. [DOI: 10.1021/ja305115y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Michael T. Tiedemann
- Department of Chemistry, The University of Western Ontario, London, Ontario,
Canada, N6A 5B7
| | - David E. Heinrichs
- Department
of Microbiology and
Immunology, The University of Western Ontario, London, Ontario, Canada, N6A 5C1
| | - Martin J. Stillman
- Department of Chemistry, The University of Western Ontario, London, Ontario,
Canada, N6A 5B7
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Iron-regulated surface determinant (Isd) proteins of Staphylococcus lugdunensis. J Bacteriol 2012; 194:6453-67. [PMID: 23002220 DOI: 10.1128/jb.01195-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus lugdunensis is the only coagulase-negative Staphylococcus species with a locus encoding iron-regulated surface determinant (Isd) proteins. In Staphylococcus aureus, the Isd proteins capture heme from hemoglobin and transfer it across the wall to a membrane-bound transporter, which delivers it into the cytoplasm, where heme oxygenases release iron. The Isd proteins of S. lugdunensis are expressed under iron-restricted conditions. We propose that S. lugdunensis IsdB and IsdC proteins perform the same functions as those of S. aureus. S. lugdunensis IsdB is the only hemoglobin receptor within the isd locus. It specifically binds human hemoglobin with a dissociation constant (K(d)) of 23 nM and transfers heme on IsdC. IsdB expression promotes bacterial growth in an iron-limited medium containing human hemoglobin but not mouse hemoglobin. This correlates with weak binding of IsdB to mouse hemoglobin in vitro. Unlike IsdB and IsdC, the proteins IsdJ and IsdK are not sorted to the cell wall in S. lugdunensis. In contrast, IsdJ expressed in S. aureus and Lactococcus lactis is anchored to peptidoglycan, suggesting that S. lugdunensis sortases may differ in signal recognition or could be defective. IsdJ and IsdK are present in the culture supernatant, suggesting that they could acquire heme from the external milieu. The IsdA protein of S. aureus protects bacteria from bactericidal lipids due to its hydrophilic C-terminal domain. IsdJ has a similar region and protected S. aureus and L. lactis as efficiently as IsdA but, possibly due to its location, was less effective in its natural host.
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