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Jo J, Upadhyay T, Woods EC, Park KW, Pedowitz NJ, Jaworek-Korjakowska J, Wang S, Valdez TA, Fellner M, Bogyo M. Development of Oxadiazolone Activity-Based Probes Targeting FphE for Specific Detection of Staphylococcus aureus Infections. J Am Chem Soc 2024; 146:6880-6892. [PMID: 38411555 DOI: 10.1021/jacs.3c13974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Staphylococcus aureus (S. aureus) is a major human pathogen that is responsible for a wide range of systemic infections. Since its propensity to form biofilms in vivo poses formidable challenges for both detection and treatment, tools that can be used to specifically image S. aureus biofilms are highly valuable for clinical management. Here, we describe the development of oxadiazolone-based activity-based probes to target the S. aureus-specific serine hydrolase FphE. Because this enzyme lacks homologues in other bacteria, it is an ideal target for selective imaging of S. aureus infections. Using X-ray crystallography, direct cell labeling, and mouse models of infection, we demonstrate that oxadiazolone-based probes enable specific labeling of S. aureus bacteria through the direct covalent modification of the FphE active site serine. These results demonstrate the utility of the oxadizolone electrophile for activity-based probes and validate FphE as a target for the development of imaging contrast agents for the rapid detection of S. aureus infections.
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Affiliation(s)
- Jeyun Jo
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Tulsi Upadhyay
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Emily C Woods
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Ki Wan Park
- Department of Otolaryngology-Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Nichole J Pedowitz
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | | | - Sijie Wang
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Tulio A Valdez
- Department of Otolaryngology-Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, California 94305, United States
| | - Matthias Fellner
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Matthew Bogyo
- Department of Pathology, Stanford University School of Medicine, Stanford, California 94305, United States
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, United States
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2
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Jo J, Upadhyay T, Woods EC, Park KW, Pedowitz NJ, Jaworek-Korjakowska J, Wang S, Valdez TA, Fellner M, Bogyo M. Development of Oxadiazolone Activity-Based Probes Targeting FphE for Specific Detection of S. aureus Infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.11.571116. [PMID: 38168396 PMCID: PMC10760020 DOI: 10.1101/2023.12.11.571116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Staphylococcus aureus is a major human pathogen responsible for a wide range of systemic infections. Since its propensity to form biofilms in vivo poses formidable challenges for both detection and treatment, tools that can be used to specifically image S. aureus biofilms are highly valuable for clinical management. Here we describe the development of oxadiazolonebased activity-based probes to target the S. aureus-specific serine hydrolase FphE. Because this enzyme lacks homologs in other bacteria, it is an ideal target for selective imaging of S. aureus infections. Using X-ray crystallography, direct cell labeling and mouse models of infection we demonstrate that oxadiazolone-based probes enable specific labeling of S. aureus bacteria through the direct covalent modification of the FphE active site serine. These results demonstrate the utility of the oxadizolone electrophile for activity-based probes (ABPs) and validate FphE as a target for development of imaging contrast agents for the rapid detection of S. aureus infections.
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Affiliation(s)
- Jeyun Jo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tulsi Upadhyay
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Emily C. Woods
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ki Wan Park
- Department of Otolaryngology–Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nichole J. Pedowitz
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | | | - Sijie Wang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tulio A. Valdez
- Department of Otolaryngology–Head & Neck Surgery Divisions, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Matthias Fellner
- Biochemistry Department, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Matthew Bogyo
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
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Usié A, Leão C, Gaspar D, Monteiro H, Tábuas L, Bettencourt E, Caetano P, Padre L, Carolino N, Ramos AM, de Matos C, Branco S. A metagenomics approach to characterize the footrot microbiome in Merino sheep. Vet Microbiol 2023; 281:109745. [PMID: 37080086 DOI: 10.1016/j.vetmic.2023.109745] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/17/2023] [Accepted: 04/14/2023] [Indexed: 04/22/2023]
Abstract
In the Portuguese Alentejo region, Merino sheep breed is the most common breed, reared for the production of meat, dairy, and wool. Footrot is responsible for lameness, decreased animal welfare, and higher production losses, generating a negative economic impact. The disease is caused by Dichelobacter nodosus that interacts with the sheep foot microbiome, to date largely uncharacterized. In fact, Dichelobacter nodosus is not able to induce footrot by itself being required the presence of a second pathogen known as Fusobacterium necrophorum. To understand and characterize the footrot microbiome dynamics of different footrot lesion scores, a whole metagenome sequencing (WMGS) approach was used. Foot tissue samples were collected from 212 animals with different degrees of footrot lesion scores, ranging from 0 to 5. Distinct bacterial communities were associated with feet with different footrot scores identifying a total of 63 phyla and 504 families. As the severity of footrot infection increases the microorganisms' diversity decreases triggering a shift in the composition of the microbiome from a dominant gram-positive in mild stages to a dominant gram-negative in the severe stages. Several species previously associated with footrot and other polymicrobial diseases affecting the epidermis and provoking inflammatory responses such as Treponema spp., Staphylococcus spp., Streptococcus spp. and Campylobacter spp. were identified proliferating along with the lesions' severity. Although these bacteria are not able to initiate footrot, several evidences have been described supporting their association with the severity and incidence increase of footrot lesions caused by Dichelobacter nodosus and Fusobacterium necrophorum. Further investigation is required to establish the roles of particular taxa and identify which of them play a role in the disease process and which are opportunistic pathogens.
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Affiliation(s)
- Ana Usié
- Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo (CEBAL) / Instituto Politécnico de Beja (IPBeja), 7801-908 Beja, Portugal; MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, CEBAL - Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo, 7801-908 Beja, Portugal.
| | - Célia Leão
- Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo (CEBAL) / Instituto Politécnico de Beja (IPBeja), 7801-908 Beja, Portugal; MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, CEBAL - Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo, 7801-908 Beja, Portugal; Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV, I.P.), Avenida da República, Quinta do Marquês, 2780-157 Oeiras, Portugal
| | - Daniel Gaspar
- Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo (CEBAL) / Instituto Politécnico de Beja (IPBeja), 7801-908 Beja, Portugal; BIOPOIS-CIBIO-InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Portugal
| | - Helena Monteiro
- Associação de Agricultores do Sul (ACOS), Rua Cidade De São Paulo, Aptd. 294, Beja, Portugal
| | - Lino Tábuas
- Associação de Agricultores do Sul (ACOS), Rua Cidade De São Paulo, Aptd. 294, Beja, Portugal
| | - Elisa Bettencourt
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, University of Évora, Polo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Pedro Caetano
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, University of Évora, Polo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Ludovina Padre
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, University of Évora, Polo da Mitra, Ap. 94, 7006-554 Évora, Portugal
| | - Nuno Carolino
- Instituto Nacional de Investigação Agrária e Veterinária, I.P. (INIAV, I.P.), Avenida da República, Quinta do Marquês, 2780-157 Oeiras, Portugal
| | - António Marcos Ramos
- Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo (CEBAL) / Instituto Politécnico de Beja (IPBeja), 7801-908 Beja, Portugal; MED - Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, CEBAL - Centro de Biotecnologia Agrícola e Agro-Alimentar do Alentejo, 7801-908 Beja, Portugal
| | - Claudino de Matos
- Associação de Agricultores do Sul (ACOS), Rua Cidade De São Paulo, Aptd. 294, Beja, Portugal.
| | - Sandra Branco
- MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE - Global Change and Sustainability Institute, University of Évora, Polo da Mitra, Ap. 94, 7006-554 Évora, Portugal.
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Chong CE, Bengtsson RJ, Horsburgh MJ. Comparative genomics of Staphylococcus capitis reveals species determinants. Front Microbiol 2022; 13:1005949. [PMID: 36246238 PMCID: PMC9563023 DOI: 10.3389/fmicb.2022.1005949] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/05/2022] [Indexed: 11/27/2022] Open
Abstract
Staphylococcus capitis is primarily described as a human skin commensal but is now emergent as an opportunistic pathogen isolated from the bloodstream and prosthetic joint infections, and neonatal intensive care unit (NICU)-associated sepsis. We used comparative genomic analyses of S. capitis to provide new insights into commensal scalp isolates from varying skin states (healthy, dandruff lesional, and non-lesional), and to expand our current knowledge of the species populations (scalp isolates, n = 59; other skin isolates, n = 7; publicly available isolates, n = 120). A highly recombinogenic population structure was revealed, with genomes including the presence of a range of previously described staphylococcal virulence factors, cell wall-associated proteins, and two-component systems. Genomic differences between the two described S. capitis subspecies were explored, which revealed the determinants associated exclusively with each subspecies. The subspecies ureolyticus was distinguished from subspecies capitis based on the differences in antimicrobial resistance genes, β-lactam resistance genes, and β-class phenol soluble modulins and gene clusters linked to biofilm formation and survival on skin. This study will aid further research into the classification of S. capitis and virulence-linked phylogroups to monitor the spread and evolution of S. capitis.
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Nepal A, Ræder SB, Søgaard CK, Haugan MS, Otterlei M. Broad-Spectrum Antibacterial Peptide Kills Extracellular and Intracellular Bacteria Without Affecting Epithelialization. Front Microbiol 2021; 12:764451. [PMID: 34899646 PMCID: PMC8661032 DOI: 10.3389/fmicb.2021.764451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
New antibacterial drugs with novel modes of action are urgently needed as antibiotic resistance in bacteria is increasing and spreading throughout the world. In this study, we aimed to explore the possibility of using APIM-peptides targeting the bacterial β-clamp for treatment of skin infections. We selected a lead peptide, named betatide, from five APIM-peptide candidates based on their antibacterial and antimutagenic activities in both G+ and G- bacteria. Betatide was further tested in minimal inhibitory concentration (MIC) assays in ESKAPE pathogens, in in vitro infection models, and in a resistance development assay. We found that betatide is a broad-range antibacterial which obliterated extracellular bacterial growth of methicillin-resistant Staphylococcus epidermidis (MRSE) in cell co-cultures without affecting the epithelialization of HaCaT keratinocytes. Betatide also reduced the number of intracellular Staphylococcus aureus in infected HaCaT cells. Furthermore, long-time exposure to betatide at sub-MICs induced minimal or no increase in resistance development compared to ciprofloxacin and gentamicin or ampicillin in S. aureus and Escherichia coli. These properties support the potential of betatide for the treatment of topical skin infections.
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Affiliation(s)
- Anala Nepal
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Synnøve Brandt Ræder
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Caroline Krogh Søgaard
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Maria Schei Haugan
- Department of Medical Microbiology, St. Olav's University Hospital, Trondheim, Norway
| | - Marit Otterlei
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.,Department of Medical Microbiology, St. Olav's University Hospital, Trondheim, Norway
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Etter D, Schelin J, Schuppler M, Johler S. Staphylococcal Enterotoxin C-An Update on SEC Variants, Their Structure and Properties, and Their Role in Foodborne Intoxications. Toxins (Basel) 2020; 12:E584. [PMID: 32927913 PMCID: PMC7551944 DOI: 10.3390/toxins12090584] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
Staphylococcal enterotoxins are the most common cause of foodborne intoxications (staphylococcal food poisoning) and cause a wide range of diseases. With at least six variants staphylococcal enterotoxin C (SEC) stands out as particularly diverse amongst the 25 known staphylococcal enterotoxins. Some variants present unique and even host-specific features. Here, we review the role of SEC in human and animal health with a particular focus on its role as a causative agent for foodborne intoxications. We highlight structural features unique to SEC and its variants, particularly, the emetic and superantigen activity, as well as the roles of SEC in mastitis and in dairy products. Information about the genetic organization as well as regulatory mechanisms including the accessory gene regulator and food-related stressors are provided.
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Affiliation(s)
- Danai Etter
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Jenny Schelin
- Division of Applied Microbiology, Department of Chemistry, Lund University, 22100 Lund, Sweden;
| | - Markus Schuppler
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Sophia Johler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
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Keller LJ, Lentz CS, Chen YE, Metivier RJ, Weerapana E, Fischbach MA, Bogyo M. Characterization of Serine Hydrolases Across Clinical Isolates of Commensal Skin Bacteria Staphylococcus epidermidis Using Activity-Based Protein Profiling. ACS Infect Dis 2020; 6:930-938. [PMID: 32298574 DOI: 10.1021/acsinfecdis.0c00095] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The bacterial genus Staphylococcus comprises diverse species that colonize the skin as commensals but can also cause infection. Previous work identified a family of serine hydrolases termed fluorophoshonate-binding hydrolases (Fphs) in the pathogenic bacteria Staphylococcus aureus, one of which, FphB, functions as a virulence factor. Using a combination of bioinformatics and activity-based protein profiling (ABPP), we identify homologues of these enzymes in the related commensal bacteria Staphylococcus epidermidis. Two of the S. aureus Fph enzymes were not identified in S. epidermidis. Using ABPP, we identified several candidate hydrolases that were not previously identified in S. aureus that may be functionally related to the Fphs. Interestingly, the activity of the Fphs vary across clinical isolates of S. epidermidis. Biochemical characterization of the FphB homologue in S. epidermidis (SeFphB) suggests it is a functional homologue of FphB in S. aureus, but our preliminary studies suggest it may not have a role in colonization in vivo. This potential difference in biological function between the Fphs of closely related staphylococcal species may provide mechanisms for specific inhibition of S. aureus infection without perturbing commensal communities of related bacteria.
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Affiliation(s)
| | | | - Y. Erin Chen
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, California 94305, United States
- Dermatology Service, Veterans Affairs Medical Center, San Francisco, California 94121, United States
| | - Rebecca J. Metivier
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Eranthie Weerapana
- Department of Chemistry, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | - Michael A. Fischbach
- Department of Bioengineering and ChEM-H, Stanford University, Stanford, California 94305, United States
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8
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Luan Y, van der Mei HC, Dijk M, Geertsema-Doornbusch GI, Atema-Smit J, Ren Y, Chen H, Busscher HJ. Polarization of Macrophages, Cellular Adhesion, and Spreading on Bacterially Contaminated Gold Nanoparticle-Coatings in Vitro. ACS Biomater Sci Eng 2020; 6:933-945. [PMID: 33464836 DOI: 10.1021/acsbiomaterials.9b01518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biomaterial-associated infections often arise from contaminating bacteria adhering to an implant surface that are introduced during surgical implantation and not effectively eradicated by antibiotic treatment. Whether or not infection develops from contaminating bacteria depends on an interplay between bacteria contaminating the biomaterial surface and tissue cells trying to integrate the surface with the aid of immune cells. The biomaterial surface plays a crucial role in defining the outcome of this race for the surface. Tissue integration is considered the best protection of a biomaterial implant against infectious bacteria. This paper aims to determine whether and how macrophages aid osteoblasts and human mesenchymal stem cells to adhere and spread over gold nanoparticle (GNP)-coatings with different hydrophilicity and roughness in the absence or presence of contaminating, adhering bacteria. All GNP-coatings had identical chemical surface composition, and water contact angles decreased with increasing roughness. Upon increasing the roughness of the GNP-coatings, the presence of contaminating Staphylococcus epidermidis in biculture with cells gradually decreased surface coverage by adhering and spreading cells, as in the absence of staphylococci. More virulent Staphylococcus aureus fully impeded cellular adhesion and spreading on smooth gold- or GNP-coatings, while Escherichia coli allowed minor cellular interaction. Murine macrophages in monoculture tended toward their pro-inflammatory "fighting" M1-phenotype on all coatings to combat the biomaterial, but in bicultures with contaminating, adhering bacteria, macrophages demonstrated Ym1 expression, indicative of polarization toward their anti-inflammatory "fix-and-repair" M2-phenotype. Damage repair of cells by macrophages improved cellular interactions on intermediately hydrophilic/rough (water contact angle 30 deg/surface roughness 118 nm) GNP-coatings in the presence of contaminating, adhering Gram-positive staphylococci but provided little aid in the presence of Gram-negative E. coli. Thus, the merits on GNP-coatings to influence the race for the surface and prevent biomaterial-associated infection critically depend on their hydrophilicity/roughness and the bacterial strain involved in contaminating the biomaterial surface.
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Affiliation(s)
- Yafei Luan
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, Jiangsu, P. R. China.,University of Groningen, University Medical center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Henny C van der Mei
- University of Groningen, University Medical center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Melissa Dijk
- University of Groningen, University Medical center Groningen, Department of Orthodontics, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Gésinda I Geertsema-Doornbusch
- University of Groningen, University Medical center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Jelly Atema-Smit
- University of Groningen, University Medical center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Yijin Ren
- University of Groningen, University Medical center Groningen, Department of Orthodontics, Hanzeplein 1, 9713 GZ Groningen, The Netherlands
| | - Hong Chen
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Ren'ai Road, Suzhou 215123, Jiangsu, P. R. China
| | - Henk J Busscher
- University of Groningen, University Medical center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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9
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Haque S, Yadav DK, Bisht SC, Yadav N, Singh V, Dubey KK, Jawed A, Wahid M, Dar SA. Quorum sensing pathways in Gram-positive and -negative bacteria: potential of their interruption in abating drug resistance. J Chemother 2019; 31:161-187. [DOI: 10.1080/1120009x.2019.1599175] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Gene Expression Laboratory, Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India
| | - Dinesh K. Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Shekhar C. Bisht
- Department of Biotechnology, H.N.B Garhwal University, Srinagar, Uttarakhand, India
| | - Neelam Yadav
- Department of Botany, University of Allahabad, Allahabad, Uttar Pradesh, India
| | - Vineeta Singh
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India
| | - Kashyap Kumar Dubey
- Industrial Biotechnology Laboratory, University Institute of Engineering and Technology, M.D. University, Rohtak, Haryana, India
| | - Arshad Jawed
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
| | - Sajad Ahmad Dar
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, Saudi Arabia
- Departments of Microbiology, University College of Medical Sciences (University of Delhi), Delhi, India
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10
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Trübe P, Hertlein T, Mrochen DM, Schulz D, Jorde I, Krause B, Zeun J, Fischer S, Wolf SA, Walther B, Semmler T, Bröker BM, Ulrich RG, Ohlsen K, Holtfreter S. Bringing together what belongs together: Optimizing murine infection models by using mouse-adapted Staphylococcus aureus strains. Int J Med Microbiol 2018; 309:26-38. [PMID: 30391222 DOI: 10.1016/j.ijmm.2018.10.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 10/05/2018] [Accepted: 10/18/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus (S.) aureus is a leading cause of bacterial infection world-wide, and currently no vaccine is available for humans. Vaccine development relies heavily on clinically relevant infection models. However, the suitability of mice for S. aureus infection models has often been questioned, because experimental infection of mice with human-adapted S. aureus requires very high infection doses. Moreover, mice were not considered to be natural hosts of S. aureus. The latter has been disproven by our recent findings, showing that both laboratory mice, as well as wild small mammals including mice, voles, and shrews, are naturally colonized with S. aureus. Here, we investigated whether mouse-and vole-derived S. aureus strains show an enhanced virulence in mice as compared to the human-adapted strain Newman. Using a step-wise approach based on the bacterial genotype and in vitro assays for host adaptation, we selected the most promising candidates for murine infection models out of a total of 254 S. aureus isolates from laboratory mice as well as wild rodents and shrews. Four strains representing the clonal complexes (CC) 8, 49, and 88 (n = 2) were selected and compared to the human-adapted S. aureus strain Newman (CC8) in murine pneumonia and bacteremia models. Notably, a bank vole-derived CC49 strain, named DIP, was highly virulent in BALB/c mice in pneumonia and bacteremia models, whereas the other murine and vole strains showed virulence similar to or lower than that of Newman. At one tenth of the standard infection dose DIP induced disease severity, bacterial load and host cytokine and chemokine responses in the murine bacteremia model similar to that of Newman. In the pneumonia model, DIP was also more virulent than Newman but the effect was less pronounced. Whole genome sequencing data analysis identified a pore-forming toxin gene, lukF-PV(P83)/lukM, in DIP but not in the other tested S. aureus isolates. To conclude, the mouse-adapted S. aureus strain DIP allows a significant reduction of the inoculation dose in mice and is hence a promising tool to develop clinically more relevant infection models.
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Affiliation(s)
- Patricia Trübe
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Tobias Hertlein
- Institute for Molecular Infection Biology, University of Würzburg, Germany
| | - Daniel M Mrochen
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Daniel Schulz
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Ilka Jorde
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Bettina Krause
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Julia Zeun
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Stefan Fischer
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Silver A Wolf
- Microbial Genomics (NG1), Robert Koch Institute, Berlin, Germany
| | - Birgit Walther
- Advanced Light and Electron Microscopy, Robert Koch Institute, Berlin, Germany
| | - Torsten Semmler
- Microbial Genomics (NG1), Robert Koch Institute, Berlin, Germany
| | - Barbara M Bröker
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Rainer G Ulrich
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Knut Ohlsen
- Institute for Molecular Infection Biology, University of Würzburg, Germany
| | - Silva Holtfreter
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany.
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11
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Santos SS, Augusto DG, Alves PAC, Pereira JS, Duarte LMB, Melo PC, Gross E, Kaneto CM, Silva A, Santos JL. Trichoderma asperelloides ethanolic extracts efficiently inhibit Staphylococcus growth and biofilm formation. PLoS One 2018; 13:e0202828. [PMID: 30142222 PMCID: PMC6108504 DOI: 10.1371/journal.pone.0202828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 08/09/2018] [Indexed: 11/19/2022] Open
Abstract
Fungi from the widely distributed genus Trichoderma are of great biotechnological interest, being currently used in a vast range of applications. Here, we report that high-molecular weight fraction (HWF) derived from Trichoderma asperelloides ethanolic extract exhibits antibiotic activity against staphylococcal biofilms. The antibacterial and anti-biofilm properties of T. asperelloides extracts were evaluated by well-established assays in Staphylococcus aureus ATCC strains (29213 and 6538) and in one clinical isolate from bovine mastitis. The HWF from T. asperelloides eradicated S. aureus by causing substantial matrix de-structuring and biomass reduction (p < 10-5) at concentrations as low as 2.3 μg mL-1. Additionally, we present ultra-structure analysis by the use of scanning electron microscopy as well as transmission microscopy, which showed that T. asperelloides killed cells through cell wall and membrane disturbance. Remarkably, the HWF from T. asperelloides killed S. aureus and eradicated its biofilms in a greater performance than gentamicin (p < 10-5), a known potent antibiotic against S. aureus. Our results indicate that extract from T. asperelloides may represent a promising candidate for the development of new antibiotics against gram-positive bacteria.
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Affiliation(s)
- Simone S. Santos
- Laboratório de Imunobiologia, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Danillo G. Augusto
- Laboratório de Imunobiologia, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
- Laboratório de Genética Molecular Humana, Universidade Federal do Paraná, Curitiba, Brazil
| | - Patrícia A. Casaes Alves
- Centro de Microscopia Eletrônica, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Julia S. Pereira
- Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Engenharia de Materiais, Belo Horizonte, Brazil
| | - Larissa M. B. Duarte
- Centro Federal de Educação Tecnológica de Minas Gerais, Departamento de Engenharia de Materiais, Belo Horizonte, Brazil
| | - Poliana C. Melo
- Hospital Veterinário Departamento de Ciências Agrárias, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Eduardo Gross
- Centro de Microscopia Eletrônica, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Carla M. Kaneto
- Laboratório de Imunobiologia, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Aline Silva
- Laboratório de Microbiologia, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
| | - Jane L. Santos
- Laboratório de Imunobiologia, Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz, Ilhéus, Brazil
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12
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Vadakkan K, Choudhury AA, Gunasekaran R, Hemapriya J, Vijayanand S. Quorum sensing intervened bacterial signaling: Pursuit of its cognizance and repression. J Genet Eng Biotechnol 2018; 16:239-252. [PMID: 30733731 PMCID: PMC6353778 DOI: 10.1016/j.jgeb.2018.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 06/09/2018] [Accepted: 07/03/2018] [Indexed: 01/24/2023]
Abstract
Bacteria communicate within a system by means of a density dependent mechanism known as quorum sensing which regulate the metabolic and behavioral activities of a bacterial community. This sort of interaction occurs through a dialect of chemical signals called as autoinducers synthesized by bacteria. Bacterial quorum sensing occurs through various complex pathways depending upon specious diversity. Therefore the cognizance of quorum sensing mechanism will enable the regulation and thereby constrain bacterial communication. Inhibition strategies of quorum sensing are collectively called as quorum quenching; through which bacteria are incapacitated of its interaction with each other. Many virulence mechanism such as sporulation, biofilm formation, toxin production can be blocked by quorum quenching. Usually quorum quenching mechanisms can be broadly classified into enzymatic methods and non-enzymatic methods. Substantial understanding of bacterial communication and its inhibition enhances the development of novel antibacterial therapeutic drugs. In this review we have discussed the types and mechanisms of quorum sensing and various methods to inhibit and regulate density dependent bacterial communication.
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Affiliation(s)
- Kayeen Vadakkan
- Bioresource Technology Lab, Department of Biotechnology, Thiruvalluvar University, Vellore, TN 632115, India
| | - Abbas Alam Choudhury
- Bioresource Technology Lab, Department of Biotechnology, Thiruvalluvar University, Vellore, TN 632115, India
| | - Ramya Gunasekaran
- Bioresource Technology Lab, Department of Biotechnology, Thiruvalluvar University, Vellore, TN 632115, India
| | | | - Selvaraj Vijayanand
- Bioresource Technology Lab, Department of Biotechnology, Thiruvalluvar University, Vellore, TN 632115, India
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13
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Pereira VC, Pinheiro L, Oliveira A, Martins KB, Riboli DFM, da Cunha MDLRDS. Expression of superantigens and the agr system in Staphylococcus epidermidis. Microb Pathog 2017; 115:19-24. [PMID: 29233782 DOI: 10.1016/j.micpath.2017.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 11/09/2017] [Indexed: 10/18/2022]
Abstract
Infections with coagulase-negative staphylococci (CoNS) can involve the production of toxins such as superantigens, which contribute to tissue degradation and inflammatory immune responses. The accessory gene regulator (agr) quorum sensing system coordinates the expression of most S. aureus virulence factors. Therefore, the aim of this study was to investigate the expression of these superantigens and the presence of the agr locus in CoNS strains isolated from blood cultures. PCR was used to detect enterotoxin and agr genes and expression was analyzed by RT-PCR. Expression of the sea gene was observed in one S. epidermidis isolate andof sec-1 in two, seg and sei were expressed concomitantly in one isolate, and sei was expressed in another isolate. The agr group I was detected in S. epidermidis expressing the sea, seg and sei genes, whereas agr group II was detected in isolates expressing thesec-1 gene. The agr groups were only expressed in strains expressing thesec-1 gene. The results show that enterotoxin genes are highly frequent in CoNS isolated from clinical specimens and confirm the toxin-producing ability of these strains. The agr group II may be associated with enterotoxin C production by S. epidermidis, increasing the virulence of strains isolated from blood cultures and consequently the severity of sepsis caused by these organisms.
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Affiliation(s)
- Valéria Cataneli Pereira
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil; Universidade do Oeste Paulista, CEP 19050-920, Presidente Prudente, São Paulo, Brazil.
| | - Luiza Pinheiro
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil
| | - Adilson Oliveira
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil
| | - Katheryne Benini Martins
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil
| | - Danilo Flávio Moraes Riboli
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil
| | - Maria de Lourdes Ribeiro de Souza da Cunha
- Laboratory of Bacteriology, Department of Microbiology and Immunology, Institute of Biosciences, UNESP - Univ. Estadual Paulista, CEP 18618-970, Botucatu, São Paulo, Brazil
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14
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Abstract
The secretion of proteins that damage host tissue is well established as integral to the infectious processes of many bacterial pathogens. However, recent advances in our understanding of the activity of toxins suggest that the attributes we have assigned to them from early in vitro experimentation have misled us into thinking of them as merely destructive tools. Here, we will discuss the multifarious ways in which toxins contribute to the lifestyle of bacteria and, by considering their activity from an evolutionary perspective, demonstrate how this extends far beyond their ability to destroy host tissue.
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15
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Mononen T, Ruokolainen L. Spatial disease dynamics of free-living pathogens under pathogen predation. Sci Rep 2017; 7:7729. [PMID: 28798313 PMCID: PMC5552698 DOI: 10.1038/s41598-017-07983-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/03/2017] [Indexed: 11/09/2022] Open
Abstract
The epidemiological dynamics of potentially free-living pathogens are often studied with respect to a specific pathogen species (e.g., cholera) and most studies concentrate only on host-pathogen interactions. Here we show that metacommunity-level interactions can alter conventional spatial disease dynamics. We introduce a pathogen eating consumer species and investigate a deterministic epidemiological model of two habitat patches, where both patches can be occupied by hosts, pathogens, and consumers of free-living pathogens. An isolated habitat patch shows periodic disease outbreaks in the host population, arising from cyclic consumer-pathogen dynamics. On the other hand, consumer dispersal between the patches generate asymmetric disease prevalence, such that the host population in one patch stays disease-free, while disease outbreaks occur in the other patch. Such asymmetry can also arise with host dispersal, where infected hosts carry pathogens to the other patch. This indirect movement of pathogens causes also a counter-intuitive effect: decreasing morbidity in a focal patch under increasing pathogen immigration. Our results underline that community-level interactions influence disease dynamics and consistent spatial asymmetry can arise also in spatially homogeneous systems.
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Affiliation(s)
- Tommi Mononen
- University of Helsinki, Department of Biosciences, Helsinki, FI-00014, Finland.
| | - Lasse Ruokolainen
- University of Helsinki, Department of Biosciences, Helsinki, FI-00014, Finland
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16
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Hodille E, Cuerq C, Badiou C, Bienvenu F, Steghens JP, Cartier R, Bes M, Tristan A, Plesa A, Le VTM, Diep BA, Lina G, Dumitrescu O. Delta Hemolysin and Phenol-Soluble Modulins, but Not Alpha Hemolysin or Panton-Valentine Leukocidin, Induce Mast Cell Activation. Front Cell Infect Microbiol 2016; 6:180. [PMID: 28018862 PMCID: PMC5149515 DOI: 10.3389/fcimb.2016.00180] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/24/2016] [Indexed: 11/13/2022] Open
Abstract
Mast cells are located at host interfaces, such as the skin, and contribute to the first-line defense against pathogens by releasing soluble mediators, including those that induce itching and scratching behavior. Here, we show that delta-hemolysin (Hld) and phenol soluble modulins (PSMs) PSMα1 and PSMα3, but not alpha-hemolysin (Hla) or Panton-Valentine leukocidin (PVL), induce dose-dependent tryptase, and lactate dehydrogenase (LDH) release by the HMC-1 human mast cell line. Using supernatants from isogenic strains, we verified that tryptase and LDH release was Hld- and PSMα-dependent. PSMα1 and Hld production was detected in 65 and 17% of human Staphylococcus aureus-infected skin abscess specimens, respectively, but they were produced in vitro by all clinical isolates. The results suggest that Hld and PSM-α1 produced in vivo during S. aureus skin infections induce the release of mast cell mediators responsible for itching and scratching behavior, which may enhance skin to skin transmission of S. aureus via the hands. As Hld and PSMs are upregulated by accessory gene regulator (agr), their association may contribute to the elective transmission of S. aureus strains with a functional agr system.
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Affiliation(s)
- Elisabeth Hodille
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de LyonLyon, France; Hospices Civils de LyonLyon, France
| | - Charlotte Cuerq
- Hospices Civils de LyonLyon, France; Laboratoire de Biochimie, Centre de Biologie SudLyon, France
| | - Cédric Badiou
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de Lyon Lyon, France
| | - Françoise Bienvenu
- Hospices Civils de LyonLyon, France; Laboratoire d'Immunologie, Centre de Biologie SudLyon, France
| | - Jean-Paul Steghens
- Hospices Civils de LyonLyon, France; Laboratoire de Biochimie, Centre de Biologie SudLyon, France
| | - Régine Cartier
- Hospices Civils de LyonLyon, France; Laboratoire de Biochimie, Groupement Hospitalier EstLyon, France
| | - Michèle Bes
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de LyonLyon, France; Hospices Civils de LyonLyon, France; Centre National de Référence des StaphylocoquesBron, France
| | - Anne Tristan
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de LyonLyon, France; Hospices Civils de LyonLyon, France; Centre National de Référence des StaphylocoquesBron, France
| | - Adriana Plesa
- Hospices Civils de LyonLyon, France; Laboratoire d'hématologie, Centre de Biologie SudLyon, France
| | - Vien T M Le
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, University of California San Francisco, CA, USA
| | - Binh A Diep
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, University of California San Francisco, CA, USA
| | - Gérard Lina
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de LyonLyon, France; Hospices Civils de LyonLyon, France; Centre National de Référence des StaphylocoquesBron, France
| | - Oana Dumitrescu
- Centre International de Recherche en Infectiologie, Institut National de la Santé et de la Recherche Médicale U1111, Université Lyon 1, Centre National de la Recherche Scientifique UMR5308, Ecole Normale Supérieure de LyonLyon, France; Hospices Civils de LyonLyon, France; Centre National de Référence des StaphylocoquesBron, France
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17
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DNA microarray analysis of Staphylococcus aureus causing bloodstream infection: bacterial genes associated with mortality? Eur J Clin Microbiol Infect Dis 2016; 35:1285-95. [PMID: 27177754 DOI: 10.1007/s10096-016-2663-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/24/2016] [Indexed: 01/07/2023]
Abstract
Providing evidence for microbial genetic determinants' impact on outcome in Staphylococcus aureus bloodstream infections (SABSI) is challenging due to the complex and dynamic microbe-host interaction. Our recent population-based prospective study reported an association between the S. aureus clonal complex (CC) 30 genotype and mortality in SABSI patients. This follow-up investigation aimed to examine the genetic profiles of the SABSI isolates and test the hypothesis that specific genetic characteristics in S. aureus are associated with mortality. SABSI isolates (n = 305) and S. aureus CC30 isolates from asymptomatic nasal carriers (n = 38) were characterised by DNA microarray analysis and spa typing. Fisher's exact test, least absolute shrinkage and selection operator (LASSO) and elastic net regressions were performed to discern within four groups defined by patient outcome and characteristics. No specific S. aureus genetic determinants were found to be associated with mortality in SABSI patients. By applying LASSO and elastic net regressions, we found evidence suggesting that agrIII and cna were positively and setC (=selX) and seh were negatively associated with S. aureus CC30 versus non-CC30 isolates. The genes chp and sak, encoding immune evasion molecules, were found in higher frequencies in CC30 SABSI isolates compared to CC30 carrier isolates, indicating a higher virulence potential. In conclusion, no specific S. aureus genes were found to be associated with mortality by DNA microarray analysis and state-of-the-art statistical analyses. The next natural step is to test the hypothesis in larger samples with higher resolution methods, like whole genome sequencing.
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18
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Kaesler S, Skabytska Y, Chen KM, Kempf WE, Volz T, Köberle M, Wölbing F, Hein U, Hartung T, Kirschning C, Röcken M, Biedermann T. Staphylococcus aureus-derived lipoteichoic acid induces temporary T-cell paralysis independent of Toll-like receptor 2. J Allergy Clin Immunol 2016; 138:780-790.e6. [PMID: 26949056 DOI: 10.1016/j.jaci.2015.11.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 11/09/2015] [Accepted: 11/20/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND The interplay between microbes and surface organs, such as the skin, shapes a complex immune system with several checks and balances. The first-line defense is mediated by innate immune pathways leading to inflammation. In the second phase specific T cells invade the infected organ, amplifying inflammation and defense. Consecutively, termination of inflammation is crucial to avoid chronic inflammation triggered by microbes, such as in patients with atopic dermatitis. OBJECTIVE We aimed to elucidate how the Staphylococcus aureus-derived cell-wall component lipoteichoic acid (LTA) governs the second phase of immune responses when high concentrations of LTA access T cells directly through disrupted skin. METHODS We analyzed the direct exposure of T cells to LTA in vitro. For in vivo analyses, we used fluorescein isothiocyanate contact hypersensitivity and ovalbumin-induced dermatitis as models for TH2-mediated cutaneous inflammation. RESULTS We observed that LTA potently suppressed T-lymphocyte activation in a Toll-like receptor 2-independent manner. LTA-exposed T cells did not proliferate and did not produce cytokines. Importantly, these T cells remained completely viable and were responsive to consecutive activation signals on subsequent removal of LTA. Thus LTA exposure resulted in temporary functional T-cell paralysis. In vivo experiments revealed that T-cell cytokine production and cutaneous recall responses were significantly suppressed by LTA. CONCLUSION We identified a new mechanism through which bacterial compounds directly but temporarily modulate adaptive immune responses.
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Affiliation(s)
- Susanne Kaesler
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany
| | - Yuliya Skabytska
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany
| | - Ko-Ming Chen
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Derma Labor Düsseldorf, Dusseldorf, Germany
| | - Wolfgang E Kempf
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany
| | - Thomas Volz
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany
| | - Martin Köberle
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany
| | - Florian Wölbing
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany
| | - Ulrike Hein
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany
| | - Thomas Hartung
- Center for Alternatives to Animal Testing Europe, University of Konstanz, Konstanz, Germany; Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Md
| | - Carsten Kirschning
- Institute of Medical Microbiology, University of Duisburg-Essen, Essen, Germany
| | - Martin Röcken
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany
| | - Tilo Biedermann
- Department of Dermatology, Eberhard Karls University, Liebermeisterstr, Tubingen, Germany; Department of Dermatology and Allergology, Technische Universität München, Munich, Germany.
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19
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Liu PF, Cheng JS, Sy CL, Huang WC, Yang HC, Gallo RL, Huang CM, Shu CW. IsaB Inhibits Autophagic Flux to Promote Host Transmission of Methicillin-Resistant Staphylococcus aureus. J Invest Dermatol 2015; 135:2714-2722. [PMID: 26134948 PMCID: PMC4641007 DOI: 10.1038/jid.2015.254] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Accepted: 06/17/2015] [Indexed: 12/19/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major nosocomial pathogen that is widespread in both health-care facilities and in the community at large, as a result of direct host-to-host transmission. Several virulence factors are associated with pathogen transmission to naive hosts. Immunodominant surface antigen B (IsaB) is a virulence factor that helps Staphylococcus aureus to evade the host defense system. However, the mechanism of IsaB on host transmissibility remains unclear. We found that IsaB expression was elevated in transmissible MRSA. Wild-type isaB strains inhibited autophagic flux to promote bacterial survival and elicit inflammation in THP-1 cells and mouse skin. MRSA isolates with increased IsaB expression showed decreased autophagic flux, and the MRSA isolate with the lowest IsaB expression showed increased autophagic flux. In addition, recombinant IsaB rescued the virulence of the isaB deletion strain and increased the group A streptococcus (GAS) virulence in vivo. Together, these results reveal that IsaB diminishes autophagic flux, thereby allowing MRSA to evade host degradation. These findings suggest that IsaB is a suitable target for preventing or treating MRSA infection.
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Affiliation(s)
- Pei-Feng Liu
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
| | - Jin-Shiung Cheng
- Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Cheng-Len Sy
- Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Wei-Chun Huang
- Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, Kaohsiung City
- School of Medicine, National Yang-Ming University, Taipei City
| | - Hsiu-Chen Yang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Richard L. Gallo
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
- VA San Diego Healthcare Center, San Diego, USA
| | - Chun-Ming Huang
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
| | - Chih-Wen Shu
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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20
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Cameron DR, Jiang JH, Hassan KA, Elbourne LDH, Tuck KL, Paulsen IT, Peleg AY. Insights on virulence from the complete genome of Staphylococcus capitis. Front Microbiol 2015; 6:980. [PMID: 26441910 PMCID: PMC4585213 DOI: 10.3389/fmicb.2015.00980] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 09/03/2015] [Indexed: 12/28/2022] Open
Abstract
Staphylococcus capitis is an opportunistic pathogen of the coagulase negative staphylococci (CoNS). Functional genomic studies of S. capitis have thus far been limited by a lack of available complete genome sequences. Here, we determined the closed S. capitis genome and methylome using Single Molecule Real Time (SMRT) sequencing. The strain, AYP1020, harbors a single circular chromosome of 2.44 Mb encoding 2304 predicted proteins, which is the smallest of all complete staphylococcal genomes sequenced to date. AYP1020 harbors two large mobile genetic elements; a plasmid designated pAYP1020 (59.6 Kb) and a prophage, ΦAYP1020 (48.5 Kb). Methylome analysis identified significant adenine methylation across the genome involving two distinct methylation motifs (1972 putative 6-methyladenine (m6A) residues identified). Putative adenine methyltransferases were also identified. Comparative analysis of AYP1020 and the closely related CoNS, S. epidermidis RP62a, revealed a host of virulence factors that likely contribute to S. capitis pathogenicity, most notably genes important for biofilm formation and a suite of phenol soluble modulins (PSMs); the expression/production of these factors were corroborated by functional assays. The complete S. capitis genome will aid future studies on the evolution and pathogenesis of the coagulase negative staphylococci.
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Affiliation(s)
- David R Cameron
- Department of Microbiology, Monash University Melbourne, VIC, Australia
| | - Jhih-Hang Jiang
- Department of Microbiology, Monash University Melbourne, VIC, Australia
| | - Karl A Hassan
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia
| | - Liam D H Elbourne
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia
| | - Kellie L Tuck
- School of Chemistry, Monash University Melbourne, VIC, Australia
| | - Ian T Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University Sydney, NSW, Australia
| | - Anton Y Peleg
- Department of Microbiology, Monash University Melbourne, VIC, Australia ; Department of Infectious Diseases, Alfred Hospital Melbourne, VIC, Australia
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21
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Gastrointestinal dissemination and transmission of Staphylococcus aureus following bacteremia. Infect Immun 2014; 83:372-8. [PMID: 25385792 DOI: 10.1128/iai.02272-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mutations that alter virulence and antibiotic susceptibility arise and persist during Staphylococcus aureus bacteremia. However, an experimental system demonstrating transmission following bacteremia has been lacking, and thus implications of within-host adaptation for between-host transmission are unknown. We report that S. aureus disseminates to the gastrointestinal tract of mice following intravenous injection and readily transmits to cohoused naive mice. Both intestinal dissemination and transmission were linked to the production of virulence factors based on gene deletion studies of the sae and agr two-component systems. Furthermore, antimicrobial selection for antibiotic-resistant S. aureus displaced susceptible S. aureus from the intestine of infected hosts, which led to the preferential transmission and dominance of antibiotic-resistant bacteria among cohoused untreated mice. These findings establish an animal model to investigate gastrointestinal dissemination and transmission of S. aureus and suggest that adaptation during the course of systemic infection has implications beyond the level of a single host.
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Painter KL, Krishna A, Wigneshweraraj S, Edwards AM. What role does the quorum-sensing accessory gene regulator system play during Staphylococcus aureus bacteremia? Trends Microbiol 2014; 22:676-85. [PMID: 25300477 DOI: 10.1016/j.tim.2014.09.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/18/2022]
Abstract
Staphylococcus aureus is a major cause of bacteremia, which frequently results in serious secondary infections such as infective endocarditis, osteomyelitis, and septic arthritis. The ability of S. aureus to cause such a wide range of infections has been ascribed to its huge armoury of different virulence factors, many of which are under the control of the quorum-sensing accessory gene regulator (Agr) system. However, a significant fraction of S. aureus bacteremia cases are caused by agr-defective isolates, calling into question the role of Agr in invasive staphylococcal infections. This review draws on recent work to define the role of Agr during bacteremia and explain why the loss of this major virulence regulator is sometimes a price worth paying for S. aureus.
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Affiliation(s)
- Kimberley L Painter
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Aishwarya Krishna
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Sivaramesh Wigneshweraraj
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK
| | - Andrew M Edwards
- Section of Microbiology, MRC Centre for Molecular Bacteriology and Infection, Imperial College, Armstrong Road, London SW7 2AZ, UK.
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Priya R, Mythili A, Singh YRB, Sreekumar H, Manikandan P, Panneerselvam K, Shobana CS. Virulence, Speciation and Antibiotic Susceptibility of Ocular Coagualase Negative Staphylococci (CoNS). J Clin Diagn Res 2014; 8:DC33-7. [PMID: 24995181 DOI: 10.7860/jcdr/2014/7867.4395] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 03/12/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND Coagulase negative Staphylococci (CoNS) are common inhabitants of human skin and mucous membranes. With the emergence of these organisms as prominent pathogens in patients with ocular infections, investigation has intensified in an effort to identify important virulence factors and to inform new approaches to treatment and prevention. AIM To isolate CoNS from ocular specimens; to study the possible virulence factors; speciation of coagulase negative staphylococci (CoNS) which were isolated from ocular complications; antibiotic susceptibility testing of ocular CoNS. MATERIALS AND METHODS The specimens were collected from the target patients who attended the Microbiology Laboratory of a tertiary care eye hospital in Coimbatore, Tamilnadu state, India. The isolates were subjected to tube and slide coagulase tests for the identification of CoNS. All the isolates were subjected to screening for lipase and protease activities. Screening for other virulence factors viz., slime production on Congo red agar medium and haemagglutination assay with use of 96-well microtitre plates. These isolates were identified upto species level by performing biochemical tests such as phosphatase test, arginine test, maltose and trehalose fermentation tests and novobiocin sensitivity test. The isolates were subjected to antibiotic susceptibility studies, based on the revised standards of Clinical and Laboratory Standards Institutes (CLSI). RESULTS During the one year of study, among the total 260 individuals who were screened, 100 isolates of CoNS were obtained. Lipolytic activity was seen in all the isolates, whereas 38 isolates showed a positive result for protease. A total of 63 isolates showed slime production. Of 100 isolates, 30 isolates were analyzed for haemagglutination, where 4 isolates showed the capacity to agglutinate the erythrocytes. The results of the biochemical analysis revealed that of the 100 isolates of CoNS, 43% were Staphylococcus epidermidis. The other isolates were identified as S. xylosus (n=8), S. captis (n=16), S. haemolyticus (n=10), S. saccharolyticus (n=2), S. hominis (n=5), S. saprophyticus (n=6) and S. intermedius (n=1). On the other hand, 9 isolates were not identified. In the antibiotic susceptibility analysis, it was found that most of the isolates were sensitive to vancomycin, amikacin and linczolid and resistant to cefatoxime, oxacillin, bacitracin and nalidixic acid. CONCLUSION S. epidermidis was found to be predominant in causing the ocular complications. Slime production, heamagglutination, protease and lipase activities could be the putative virulence factors of CoNS. Antibiotic susceptibility patterns of CoNS against antibacterial agents revealed maximum resistance to beta lactam groups, and the resistance was found to be higher to oxacillin, and lowest to vancomycin.
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Affiliation(s)
- Ravindran Priya
- Research Scholar, Department of Microbiology, Dr. G.R. Damodaran College of Science , Coimbatore, Tamilnadu, India
| | - Arumugam Mythili
- Research Scholar, Department of Microbiology, Dr. G.R. Damodaran College of Science , Coimbatore, Tamilnadu, India
| | | | - Haridas Sreekumar
- Research Scholar, Department of Microbiology, Dr. G.R. Damodaran College of Science , Coimbatore, Tamilnadu, India
| | - Palanisamy Manikandan
- Scientist and Head, Department of Microbiology, Aravind Eye Hospital and Post Graduate institute of Ophthalmology , Coimbatore, Tamilnadu, India
| | - Kanesan Panneerselvam
- Assistant Professor and Head, Department of Microbiology, M.R Government Arts College , Mannargudi, Tamilnadu, India
| | - Coimbatore Subramanian Shobana
- Associate Professor and Head, Department of Microbiology, Dr. G.R. Damodaran College of Science , Coimbatore, Tamilnadu, India
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Fall C, Richard V, Dufougeray A, Biron A, Seck A, Laurent F, Breurec S. Staphylococcus aureus nasal and pharyngeal carriage in Senegal. Clin Microbiol Infect 2013; 20:O239-41. [PMID: 24707853 DOI: 10.1111/1469-0691.12385] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Revised: 09/02/2013] [Accepted: 09/02/2013] [Indexed: 11/28/2022]
Abstract
Nasal and pharyngeal swabs were collected from 132 patients admitted to the Principal Hospital in Dakar (Senegal), in January and February 2012. The prevalence of Staphylococcus aureus carriage was 56.1% (n = 74): 40.2% for pharyngeal samples and 36.4% for nasal samples. None of the isolates was methicillin-resistant. Carriage was independently associated with being female (p <0.01) and large households (≥15 members) (p 0.04). The luk-PV genes encoding Panton-Valentine leukocidin (PVL) were present in 26.2% of the isolates. These data highlight the importance of the oropharynx as a site of colonization, and the high prevalence of PVL-positive isolates in Senegal as compared with industrialized countries.
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Affiliation(s)
- C Fall
- Institut Pasteur, Unité de Bactériologie médicale et Environnementale, Dakar, Sénégal
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25
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Kenny JG, Moran J, Kolar SL, Ulanov A, Li Z, Shaw LN, Josefsson E, Horsburgh MJ. Mannitol utilisation is required for protection of Staphylococcus aureus from human skin antimicrobial fatty acids. PLoS One 2013; 8:e67698. [PMID: 23861785 PMCID: PMC3701532 DOI: 10.1371/journal.pone.0067698] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 05/21/2013] [Indexed: 11/30/2022] Open
Abstract
Mannitol (Mtl) fermentation, with the subsequent production of acid, is a species signature of Staphylococcus aureus, and discriminates it from most other members of the genus. Inactivation of the gene mtlD, encoding Mtl-1-P dehydrogenase was found to markedly reduce survival in the presence of the antimicrobial fatty acid, linoleic acid. We demonstrate that the sugar alcohol has a potentiating action for this membrane-acting antimicrobial. Analysis of cellular metabolites revealed that, during exponential growth, the mtlD mutant accumulated high levels of Mtl and Mtl-P. The latter metabolite was not detected in its isogenic parent strain or a deletion mutant of the entire mtlABFD operon. In addition, the mtlD mutant strain exhibited a decreased MIC for H2O2, however virulence was unaffected in a model of septic arthritis.
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Affiliation(s)
- John G. Kenny
- Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Josephine Moran
- Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
| | - Stacey L. Kolar
- Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, Florida, United States of America
| | - Alexander Ulanov
- Roy J. Carver Biotechnology Center, University of Illinois, Urbana-Champaign, Illinois, United States of America
| | - Zhong Li
- Roy J. Carver Biotechnology Center, University of Illinois, Urbana-Champaign, Illinois, United States of America
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology & Molecular Biology, University of South Florida, Tampa, Florida, United States of America
| | - Elisabet Josefsson
- Department of Rheumatology and Inflammation Research, University of Gothenburg, Göteborg, Sweden
| | - Malcolm J. Horsburgh
- Institute of Integrative Biology, University of Liverpool, Liverpool, Merseyside, United Kingdom
- * E-mail:
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Crombé F, Argudín MA, Vanderhaeghen W, Hermans K, Haesebrouck F, Butaye P. Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs. Front Microbiol 2013; 4:57. [PMID: 23518663 PMCID: PMC3602589 DOI: 10.3389/fmicb.2013.00057] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 02/28/2013] [Indexed: 12/14/2022] Open
Abstract
From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms.
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Affiliation(s)
- Florence Crombé
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - M. Angeles Argudín
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
| | - Wannes Vanderhaeghen
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Katleen Hermans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
| | - Patrick Butaye
- Department of Bacterial Diseases, Veterinary and Agrochemical Research CentreBrussels, Belgium
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent UniversityGhent, Belgium
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27
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La importancia clínica actual de Staphylococcus aureus en el ambiente intrahospitalario. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/s0187-893x(13)73188-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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28
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Otto M. Coagulase-negative staphylococci as reservoirs of genes facilitating MRSA infection: Staphylococcal commensal species such as Staphylococcus epidermidis are being recognized as important sources of genes promoting MRSA colonization and virulence. Bioessays 2012; 35:4-11. [PMID: 23165978 DOI: 10.1002/bies.201200112] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recent research has suggested that Staphylococcus epidermidis is a reservoir of genes that, after horizontal transfer, facilitate the potential of Staphylococcus aureus to colonize, survive during infection, or resist antibiotic treatment, traits that are notably manifest in methicillin-resistant S. aureus (MRSA). S. aureus is a dangerous human pathogen and notorious for acquiring antibiotic resistance. MRSA in particular is one of the most frequent causes of morbidity and death in hospitalized patients. S. aureus is an extremely versatile pathogen with a multitude of mechanisms to cause disease and circumvent immune defenses. In contrast, most other staphylococci, such as S. epidermidis, are commonly benign commensals and only occasionally cause disease. Recent findings highlight the key importance of efforts to better understand how genes of staphylococci other than S. aureus contribute to survival in the human host, how they are transferred to S. aureus, and why this exchange appears to be uni-directional.
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Affiliation(s)
- Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, MD, USA.
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29
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Rutherford ST, Bassler BL. Bacterial quorum sensing: its role in virulence and possibilities for its control. Cold Spring Harb Perspect Med 2012; 2:2/11/a012427. [PMID: 23125205 DOI: 10.1101/cshperspect.a012427] [Citation(s) in RCA: 1091] [Impact Index Per Article: 90.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Quorum sensing is a process of cell-cell communication that allows bacteria to share information about cell density and adjust gene expression accordingly. This process enables bacteria to express energetically expensive processes as a collective only when the impact of those processes on the environment or on a host will be maximized. Among the many traits controlled by quorum sensing is the expression of virulence factors by pathogenic bacteria. Here we review the quorum-sensing circuits of Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, and Vibrio cholerae. We outline these canonical quorum-sensing mechanisms and how each uniquely controls virulence factor production. Additionally, we examine recent efforts to inhibit quorum sensing in these pathogens with the goal of designing novel antimicrobial therapeutics.
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Affiliation(s)
- Steven T Rutherford
- Department of Molecular Biology, Princeton University, New Jersey 08544, USA
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30
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Begović J, Jovčić B, Papić-Obradović M, Veljović K, Lukić J, Kojić M, Topisirović L. Genotypic diversity and virulent factors of Staphylococcus epidermidis isolated from human breast milk. Microbiol Res 2012; 168:77-83. [PMID: 23098640 DOI: 10.1016/j.micres.2012.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/08/2012] [Accepted: 09/13/2012] [Indexed: 01/15/2023]
Abstract
Staphylococcus epidermidis strains were isolated from the expressed human breast milk (EHM) of 14 healthy donor mothers. Genetic diversity was evaluated using RAPD-PCR REP-PCR and pulse-field gel electrophoresis (PFGE). PFGE allowed the best discrimination of the isolates, since it provided for the greatest diversity of the analyzed genomes. Among the S. epidermidis strains, resistance to gentamicin, tetracycline, erythromycin, clindamycin or vancomycin was detected, whilst four isolates were multiresistant. The results from our study demonstrate that staphylococci from EHM could be reservoirs of resistance genes, since we showed that tetK could be transferred from EHM staphylococci to Gram-negative Escherichia coli. Most of the staphylococcal strains displayed excellent proteolytic and lipolytic activities. Additionally, the presence of ica genes, which was related to their ability to form a biofilm on tissue culture plates, and the presence of virulence factors including autolysin/adhesin AtLE, point to their pathogenic potential.
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Affiliation(s)
- Jelena Begović
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Laboratory for Molecular Genetics of Industrial Microorganisms, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia.
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Le KY, Sohail MR, Friedman PA, Uslan DZ, Cha SS, Hayes DL, Wilson WR, Steckelberg JM, Baddour LM. Clinical features and outcomes of cardiovascular implantable electronic device infections due to staphylococcal species. Am J Cardiol 2012; 110:1143-9. [PMID: 22762715 DOI: 10.1016/j.amjcard.2012.05.052] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 05/24/2012] [Accepted: 05/24/2012] [Indexed: 10/28/2022]
Abstract
Staphylococci account for the bulk of cardiovascular implantable electronic device (CIED) infections. However, a detailed analysis of clinical features and outcomes of CIED infections due to staphylococcal species has not been published. We retrospectively reviewed all cases of CIED infection seen at the Mayo Clinic from 1991 through 2008. Differences in device and host factors, clinical features, and patient outcomes were compared between cases of early and late Staphylococcus aureus and coagulase-negative staphylococci (CoNS) CIED infections. Of 280 cases of staphylococcal CIED infections, 43.9% were due to S. aureus and 56.0% were due to CoNS. Staphylococcus aureus CIED infection cases more frequently involved initially implanted devices. Late S. aureus CIED infection cases compared to late CoNS cases were associated with corticosteroid therapy, hemodialysis, implanted catheters, prosthetic valves, and remote sources of bacteremia. Cases of S. aureus endovascular infections had longer duration of bacteremia (56.0% vs 20.3% ≥3 days), longer hospitalization (37.4% vs 15.2% >20 days), and increased mortality (25.2% vs 9.5%) compared to cases of CoNS endovascular infections (p <0.001 for all comparisons). Overall, CoNS CIED infections compared to S. aureus were associated with a history of multiple device revisions and a higher number of total and abandoned leads at presentation (p <0.001 for all comparisons). In conclusion, CIED infections due to S. aureus and CoNS have distinct clinical features and outcomes.
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32
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Fall C, Seck A, Richard V, Ndour M, Sembene M, Laurent F, Breurec S. Epidemiology of Staphylococcus aureus in Pigs and Farmers in the Largest Farm in Dakar, Senegal. Foodborne Pathog Dis 2012; 9:962-5. [DOI: 10.1089/fpd.2012.1197] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Cheikh Fall
- Unit of Medical Biology and Environment, Institut Pasteur, Dakar, Senegal
| | - Abdoulaye Seck
- Unit of Medical Biology and Environment, Institut Pasteur, Dakar, Senegal
| | - Vincent Richard
- Unit of Medical Biology and Environment, Institut Pasteur, Dakar, Senegal
| | - Moustapha Ndour
- Department of Breeding, Ministry of Breeding, Dakar, Senegal
| | - Mbacke Sembene
- Department of Animal Biology, Faculty of Sciences and Technology, Cheikh Anta Diop University, Dakar, Senegal
| | - Frederic Laurent
- National Reference Center for Staphylococci, University of Lyon, Lyon, France
| | - Sebastien Breurec
- Unit of Medical Biology and Environment, Institut Pasteur, Dakar, Senegal
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33
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Influence of Prophylactic Antibiotics on Tissue Integration versus Bacterial Colonization on Poly(Methyl Methacrylate). Int J Artif Organs 2012; 35:840-6. [DOI: 10.5301/ijao.5000155] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2012] [Indexed: 11/20/2022]
Abstract
Purpose Biomaterial-associated infections (BAI) remain a major concern in modern health care. BAI is difficult to treat and often results in implant replacement or removal. Pathogens can be introduced on implant surfaces during surgery and compete with host cells attempting to integrate the implant. Here we studied the influence of prophylactically given cephatholin in the competition between highly virulent Staphylococcus aureus and human osteoblast-like cells (U-2 OS, ATCC HTB-94) for a poly(methyl methacrylate) surface in vitro using a peri-operative contamination model. Method S. aureus was seeded on the acrylic surface in a parallel plate flow chamber prior to adhesion of U-2 OS cells. Next, S. aureus and U-2 OS cells were allowed to grow simultaneously under shear (0.14 1/s) in a modified culture medium containing cephatholin for 8 h, the time period this drug is supposed to be active in situ. Subsequently, the flow was continued with modified culture medium for another 64 h. Results In the absence of cephatholin, highly virulent S. aureus caused U-2 OS cell death within 18 h. In contrast, the presence of cephatholin for 8 h resulted in survival of U-2 OS cell up to 72 h during simultaneous growth of U-2 OS cells and bacteria. Not all adhering bacteria were killed however, but they showed a delayed growth. Conclusions These findings are in line with the recalcitrance of biofilms against antibiotic treatment observed clinically, and represent another support for the use of in vitro co-culture models in mimicking the clinical situation.
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Comparative genomics of vancomycin-resistant Staphylococcus aureus strains and their positions within the clade most commonly associated with Methicillin-resistant S. aureus hospital-acquired infection in the United States. mBio 2012; 3:mBio.00112-12. [PMID: 22617140 PMCID: PMC3372964 DOI: 10.1128/mbio.00112-12] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are leading causes of hospital-acquired infections in the United States, and clonal cluster 5 (CC5) is the predominant lineage responsible for these infections. Since 2002, there have been 12 cases of vancomycin-resistant S. aureus (VRSA) infection in the United States—all CC5 strains. To understand this genetic background and what distinguishes it from other lineages, we generated and analyzed high-quality draft genome sequences for all available VRSA strains. Sequence comparisons show unambiguously that each strain independently acquired Tn1546 and that all VRSA strains last shared a common ancestor over 50 years ago, well before the occurrence of vancomycin resistance in this species. In contrast to existing hypotheses on what predisposes this lineage to acquire Tn1546, the barrier posed by restriction systems appears to be intact in most VRSA strains. However, VRSA (and other CC5) strains were found to possess a constellation of traits that appears to be optimized for proliferation in precisely the types of polymicrobic infection where transfer could occur. They lack a bacteriocin operon that would be predicted to limit the occurrence of non-CC5 strains in mixed infection and harbor a cluster of unique superantigens and lipoproteins to confound host immunity. A frameshift in dprA, which in other microbes influences uptake of foreign DNA, may also make this lineage conducive to foreign DNA acquisition. Invasive methicillin-resistant Staphylococcus aureus (MRSA) infection now ranks among the leading causes of death in the United States. Vancomycin is a key last-line bactericidal drug for treating these infections. However, since 2002, vancomycin resistance has entered this species. Of the now 12 cases of vancomycin-resistant S. aureus (VRSA), each was believed to represent a new acquisition of the vancomycin-resistant transposon Tn1546 from enterococcal donors. All acquisitions of Tn1546 so far have occurred in MRSA strains of the clonal cluster 5 genetic background, the most common hospital lineage causing hospital-acquired MRSA infection. To understand the nature of these strains, we determined and examined the nucleotide sequences of the genomes of all available VRSA. Genome comparison identified candidate features that position strains of this lineage well for acquiring resistance to antibiotics in mixed infection.
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35
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Molecular basis of Staphylococcus epidermidis infections. Semin Immunopathol 2011; 34:201-14. [PMID: 22095240 DOI: 10.1007/s00281-011-0296-2] [Citation(s) in RCA: 157] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 10/14/2011] [Indexed: 12/28/2022]
Abstract
Staphylococcus epidermidis is the most important member of the coagulase-negative staphylococci and one of the most abundant colonizers of human skin. While for a long time regarded as innocuous, it has been identified as the most frequent cause of device-related infections occurring in the hospital setting and is therefore now recognized as an important opportunistic pathogen. S. epidermidis produces a series of molecules that provide protection from host defenses. Specifically, many proteins and exopolymers, such as the exopolysaccharide PIA, contribute to biofilm formation and inhibit phagocytosis and the activity of human antimicrobial peptides. Furthermore, recent research has identified a family of pro-inflammatory peptides in S. epidermidis, the phenol-soluble modulins (PSMs), which have multiple functions in immune evasion and biofilm development, and may be cytolytic. However, in accordance with the relatively benign relationship that S. epidermidis has with its host, production of aggressive members of the PSM family is kept at a low level. Interestingly, in contrast to S. aureus with its large arsenal of toxins developed for causing infection in the human host, most if not all "virulence factors" of S. epidermidis appear to have original functions in the commensal lifestyle of this bacterium.
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36
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Edwards AM, Massey RC, Clarke SR. Molecular mechanisms of Staphylococcus aureus nasopharyngeal colonization. Mol Oral Microbiol 2011; 27:1-10. [PMID: 22230461 DOI: 10.1111/j.2041-1014.2011.00628.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Staphylococcus aureus is responsible for a wide range of different infections ranging in severity from mild to fatal. However, it primarily exists as a commensal organism in a number of different anatomical sites including the nasopharynx. Although colonization itself is a harmless state, colonized individuals are at risk of endogenous infection when S. aureus enters otherwise sterile sites via wounds or indwelling medical devices. As such, studies of colonization may identify important targets for vaccines or other prophylactic approaches. Colonization is a dynamic process; S. aureus must attach to host surfaces, overcome immune components and compete with other commensal microbes. This occurs via a number of surface-attached and secreted proteins and other factors such as wall teichoic acid. In addition, colonizing S. aureus must constantly replicate to maintain its niche and exclude other strains. These myriad interactions provide a strong selective pressure for the maintenance or enhancement of mechanisms of adhesion, invasion and immune evasion. The evolutionary implications of this may explain why S. aureus is such a capable pathogen because many of the proteins involved in colonization have also been identified as virulence factors. This review describes the diverse molecular mechanisms used by S. aureus to colonize the host and discusses how the pressures that have selected for these may have led to its virulence.
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Affiliation(s)
- A M Edwards
- Department of Biology and Biochemistry, University of Bath, Bath, UK.
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37
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In vitro interactions between bacteria, osteoblast-like cells and macrophages in the pathogenesis of biomaterial-associated infections. PLoS One 2011; 6:e24827. [PMID: 21931858 PMCID: PMC3172284 DOI: 10.1371/journal.pone.0024827] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 08/18/2011] [Indexed: 11/19/2022] Open
Abstract
Biomaterial-associated infections constitute a major clinical problem that is difficult to treat and often necessitates implant replacement. Pathogens can be introduced on an implant surface during surgery and compete with host cells attempting to integrate the implant. The fate of a biomaterial implant depends on the outcome of this race for the surface. Here we studied the competition between different bacterial strains and human U2OS osteoblast-like cells (ATCC HTB-94) for a poly(methylmethacrylate) surface in the absence or presence of macrophages in vitro using a peri-operative contamination model. Bacteria were seeded on the surface at a shear rate of 11 1/s prior to adhesion of U2OS cells and macrophages. Next, bacteria, U2OS cells and macrophages were allowed to grow simultaneously under low shear conditions (0.14 1/s). The outcome of the competition between bacteria and U2OS cells for the surface critically depended on bacterial virulence. In absence of macrophages, highly virulent Staphylococcus aureus or Pseudomonas aeruginosa stimulated U2OS cell death within 18 h of simultaneous growth on a surface. Moreover, these strains also caused cell death despite phagocytosis of adhering bacteria in presence of murine macrophages. Thus U2OS cells are bound to loose the race for a biomaterial surface against S. aureus or P. aeruginosa, even in presence of macrophages. In contrast, low-virulent Staphylococcus epidermidis did not cause U2OS cell death even after 48 h, regardless of the absence or presence of macrophages. Clinically, S. aureus and P. aeruginosa are known to yield acute and severe biomaterial-associated infections in contrast to S. epidermidis, mostly known to cause more low-grade infection. Thus it can be concluded that the model described possesses features concurring with clinical observations and therewith has potential for further studies on the simultaneous competition for an implant surface between tissue cells and pathogenic bacteria in presence of immune system components.
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Tang J, Kang M, Chen H, Shi X, Zhou R, Chen J, Du Y. The staphylococcal nuclease prevents biofilm formation in Staphylococcus aureus and other biofilm-forming bacteria. SCIENCE CHINA-LIFE SCIENCES 2011; 54:863-9. [DOI: 10.1007/s11427-011-4195-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 05/30/2011] [Indexed: 10/18/2022]
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Effects of Orange II and Sudan III azo dyes and their metabolites on Staphylococcus aureus. J Ind Microbiol Biotechnol 2011; 38:1729-38. [PMID: 21451978 DOI: 10.1007/s10295-011-0962-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Accepted: 03/12/2011] [Indexed: 12/25/2022]
Abstract
Azo dyes are widely used in the plastic, paper, cosmetics, food, and pharmaceutical industries. Some metabolites of these dyes are potentially genotoxic. The toxic effects of azo dyes and their potential reduction metabolites on Staphylococcus aureus ATCC BAA 1556 were studied. When the cultures were incubated with 6, 18, and 36 μg/ml of Orange II and Sudan III for 48 h, 76.3, 68.5, and 61.7% of Orange II and 97.8, 93.9, and 75.8% of Sudan III were reduced by the bacterium, respectively. In the presence of 36 μg/ml Sudan III, the cell viability of the bacterium decreased to 61.9% after 48 h of incubation, whereas the cell viability of the control culture without the dye was 71.5%. Moreover, the optical density of the bacterial cultures at 10 h decreased from 0.74 to 0.55, indicating that Sudan III is able to inhibit growth of the bacterium. However, Orange II had no significant effects on either cell growth or cell viability of the bacterium at the tested concentrations. 1-Amino-2-naphthol, a metabolite common to Orange II and Sudan III, was capable of inhibiting cell growth of the bacterium at 1 μg/ml and completely stopped bacterial cell growth at 24-48 μg/ml. On the other hand, the other metabolites of Orange II and Sudan III, namely sulfanilic acid, p-phenylenediamine, and aniline, showed no significant effects on cell growth. p-Phenylenediamine exhibited a synergistic effect with 1-amino-2-naphthol on cell growth inhibition. All of the dye metabolites had no significant effects on cell viability of the bacterium.
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Subbiahdoss G, Kuijer R, Busscher HJ, van der Mei HC. Mammalian cell growth versus biofilm formation on biomaterial surfaces in an in vitro post-operative contamination model. Microbiology (Reading) 2010; 156:3073-3078. [DOI: 10.1099/mic.0.040378-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biomaterial-associated infections are the major cause of implant failure and can develop many years after implantation. Success or failure of an implant depends on the balance between host tissue integration and bacterial colonization. Here, we describe a new in vitro model for the post-operative bacterial contamination of implant surfaces and investigate the effects of contamination on the balance between mammalian cell growth and bacterial biofilm formation. U2OS osteosarcoma cells were seeded on poly(methyl methacrylate) in different densities and allowed to grow for 24 h in a parallel-plate flow chamber at a low shear rate (0.14 s−1), followed by contamination with Staphylococcus epidermidis ATCC 35983 at a shear rate of 11 s−1. The U2OS cells and staphylococci were allowed to grow simultaneously for another 24 h under low-shear conditions (0.14 s−1). Mammalian cell growth was severely impaired when the bacteria were introduced to surfaces with a low initial cell density (2.5×104 cells cm−2), but in the presence of higher initial cell densities (8.2×104 cells cm−2 and 17×104 cells cm−2), contaminating staphylococci did not affect cell growth. This study is believed to be the first to show that a critical coverage by mammalian cells is needed to effectively protect a biomaterial implant against contaminating bacteria.
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Affiliation(s)
- Guruprakash Subbiahdoss
- Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, PO Box 196, 9700 AD Groningen, The Netherlands
| | - Roel Kuijer
- Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, PO Box 196, 9700 AD Groningen, The Netherlands
| | - Henk J. Busscher
- Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, PO Box 196, 9700 AD Groningen, The Netherlands
| | - Henny C. van der Mei
- Department of Biomedical Engineering, University Medical Center Groningen and University of Groningen, PO Box 196, 9700 AD Groningen, The Netherlands
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Fey PD, Olson ME. Current concepts in biofilm formation of Staphylococcus epidermidis. Future Microbiol 2010; 5:917-33. [PMID: 20521936 DOI: 10.2217/fmb.10.56] [Citation(s) in RCA: 258] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Staphylococcus epidermidis is a highly significant nosocomial pathogen mediating infections primarily associated with indwelling biomaterials (e.g., catheters and prostheses). In contrast to Staphylococcus aureus, virulence properties associated with S. epidermidis are few and biofilm formation is the defining virulence factor associated with disease, as demonstrated by animal models of biomaterial-related infections. However, other virulence factors, such as phenol-soluble modulins and poly-gamma-DL-glutamic acid, have been recently recognized that thwart innate immune system mechanisms. Formation of S. epidermidis biofilm is typically considered a four-step process consisting of adherence, accumulation, maturation and dispersal. This article will discuss recent advances in the study of these four steps, including accumulation, which can be either polysaccharide or protein mediated. It is hypothesized that studies focused on understanding the biological function of each step in staphylococcal biofilm formation will yield new treatment modalities to treat these recalcitrant infections.
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Affiliation(s)
- Paul D Fey
- Department of Pathology & Microbiology, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5900, USA.
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Foster TJ. Colonization and infection of the human host by staphylococci: adhesion, survival and immune evasion. Vet Dermatol 2010; 20:456-70. [PMID: 20178484 DOI: 10.1111/j.1365-3164.2009.00825.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The natural habitat of Staphylococcus aureus in humans is the moist squamous epithelium of the anterior nares. Several bacterial surface proteins are implicated in promoting adhesion to desquamated epithelial cells. Clumping factor B (ClfB) and iron-regulated surface determinant A both promote nasal colonization in rodent models, and in the case of ClfB, humans. One of the ligands involved in adhesion is cytokeratin 10. Reduction in nasal colonization can be achieved by active and passive immunization. S. aureus is well endowed with secreted and surface components that compromise innate immune responses, particularly the function of neutrophils. S. aureus secretes proteins that reduce migration of neutrophils from the bloodstream to the site of infection by impeding diapedesis and receptors for chemotactic molecules. Several secreted proteins interfere with complement C3 and C5 convertases, thus reducing the level of C3b opsonin and the chemotactic peptide C5a. Host proteases are recruited to the cell surface to enhance destruction of opsonic C3b and IgG. Surface components ClfA, protein A and polysaccharide capsule compromise the recognition of opsonins on the bacterial cell surface. If engulfed by neutrophils the intracellular bacterium can resist reactive oxygen intermediates, nitric oxide radicals, defensin peptides and bactericidal proteins. A prior infection by S. aureus does not induce complete protective immunity. This could be due to immunosuppression caused by expression of superantigen proteins that disrupt normal activation of T cells and B cells during antigen presentation. By studying the molecular pathogenesis of S. aureus infections markers might be found for investigating S. pseudintermedius infections of dogs.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland.
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Abstract
We described the colonization dynamics of Staphylococcus aureus in a group of 266 healthy carriers over a period of approximately 1 year. We used precise genotyping methods, i.e., amplified fragment length polymorphism (AFLP), spa typing, and double-locus sequence typing (DLST), to detect changes in strain identity. Strain change took place rather rarely: out of 89 carriers who had initially been colonized, only 7 acquired a strain different from the original one. Approximately one-third of the carriers eliminated the colonization, and a similar number became newly colonized. Some of these events probably represent detection failure rather than genuine colonization loss or acquisition. Lower bacterial counts were associated with increased probability of eliminating the colonization. We have confirmed a high mutation rate in the spa locus: 6 out of 53 strains underwent mutation in the spa locus. There was no overall change in S. aureus genotype composition.
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Antunes LCM, Ferreira RBR, Buckner MMC, Finlay BB. Quorum sensing in bacterial virulence. MICROBIOLOGY-SGM 2010; 156:2271-2282. [PMID: 20488878 DOI: 10.1099/mic.0.038794-0] [Citation(s) in RCA: 330] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Bacteria communicate through the production of diffusible signal molecules termed autoinducers. The molecules are produced at basal levels and accumulate during growth. Once a critical concentration has been reached, autoinducers can activate or repress a number of target genes. Because the control of gene expression by autoinducers is cell-density-dependent, this phenomenon has been called quorum sensing. Quorum sensing controls virulence gene expression in numerous micro-organisms. In some cases, this phenomenon has proven relevant for bacterial virulence in vivo. In this article, we provide a few examples to illustrate how quorum sensing can act to control bacterial virulence in a multitude of ways. Several classes of autoinducers have been described to date and we present examples of how each of the major types of autoinducer can be involved in bacterial virulence. As quorum sensing controls virulence, it has been considered an attractive target for the development of new therapeutic strategies. We discuss some of the new strategies to combat bacterial virulence based on the inhibition of bacterial quorum sensing systems.
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Affiliation(s)
- L Caetano M Antunes
- Michael Smith Laboratories, The University of British Columbia, Vancouver, Canada
| | - Rosana B R Ferreira
- Michael Smith Laboratories, The University of British Columbia, Vancouver, Canada
| | - Michelle M C Buckner
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, Canada.,Michael Smith Laboratories, The University of British Columbia, Vancouver, Canada
| | - B Brett Finlay
- Department of Microbiology and Immunology, The University of British Columbia, Vancouver, Canada.,Michael Smith Laboratories, The University of British Columbia, Vancouver, Canada
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Daniel A, Euler C, Collin M, Chahales P, Gorelick KJ, Fischetti VA. Synergism between a novel chimeric lysin and oxacillin protects against infection by methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2010; 54:1603-12. [PMID: 20086153 PMCID: PMC2849374 DOI: 10.1128/aac.01625-09] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 12/14/2009] [Accepted: 01/07/2010] [Indexed: 01/21/2023] Open
Abstract
Staphylococcus aureus is the causative agent of several serious infectious diseases. The emergence of antibiotic-resistant S. aureus strains has resulted in significant treatment difficulties, intensifying the need for new antimicrobial agents. Toward this end, we have developed a novel chimeric bacteriophage (phage) lysin that is active against staphylococci, including methicillin-resistant S. aureus (MRSA). The chimeric lysin (called ClyS) was obtained by fusing the N-terminal catalytic domain of the S. aureus Twort phage lysin with the C-terminal cell wall-targeting domain from another S. aureus phage lysin (phiNM3), which displayed Staphylococcus-specific binding. ClyS was expressed in Escherichia coli, and the purified protein lysed MRSA, vancomycin-intermediate strains of S. aureus (VISA), and methicillin-sensitive (MSSA) strains of S. aureus in vitro. In a mouse nasal decolonization model, a 2-log reduction in the viability of MRSA cells was seen 1 h following a single treatment with ClyS. One intraperitoneal dose of ClyS also protected against death by MRSA in a mouse septicemia model. ClyS showed a typical pattern of synergistic interactions with both vancomycin and oxacillin in vitro. More importantly, ClyS and oxacillin at doses that were not protective individually protected synergistically against MRSA septic death in a mouse model. These results strongly support the development of ClyS as an attractive addition to the current treatment options of multidrug-resistant S. aureus infections and would allow for the reinstatement of antibiotics shelved because of mounting resistance.
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Affiliation(s)
- Anu Daniel
- The Laboratory of Bacterial Pathogenesis and Immunology, The Rockefeller University, 1230 York Ave., Box 172, New York, NY 10065, USA.
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Yanaka S, Kudou M, Tanaka Y, Sasaki T, Takemoto S, Sakata A, Hattori Y, Koshi T, Futaki S, Tsumoto K, Nakashima T. Contribution of the flexible loop region to the function of staphylococcal enterotoxin B. Protein Eng Des Sel 2010; 23:415-21. [PMID: 20181657 DOI: 10.1093/protein/gzq006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Staphylococcal enterotoxin B (SEB), a toxin produced by Staphylococcus aureus, causes food poisoning and other fatal diseases by inducing high levels of pro-inflammatory cytokines. These cytokines are released from CD4+ T cells and major histocompatibility complex (MHC) class II antigen-presenting cells, which are activated through binding of wild-type (WT) SEB to both the MHC class II molecule and specific T-cell receptor Vbeta chains. Here, we focused on a trypsin/cathepsin cleavage site of WT SEB, which is known to be cleaved in vivo between Lys97 and Lys98, located within the loop region. To know the function of the cleavage, an SEB mutant, in which both of these Lys residues have been changed to Ser, was examined. This mutant showed prolonged tolerance to protease cleavage at a different site between Thr107 and Asp108, and structural analyses revealed no major conformational differences between WT SEB and the mutant protein. However, differential scanning calorimetric analysis showed an increase in enthalpy upon thermal denaturation of the mutant protein, which correlated with the speed of cleavage between Thr107 and Asp108. The mutant protein also had slightly increased affinity for MHC. In the in vivo experiment, the SEB mutant showed lower proliferative response in peripheral blood mononuclear cells and had lower cytokine-induction activity, compared with WT SEB. These results highlight the importance of the flexible loop region for the functional, physical and chemical properties of WT SEB, thus providing insight into the nature of WT SEB that was unrevealed previously.
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Affiliation(s)
- Saeko Yanaka
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan
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Collins J, Rudkin J, Recker M, Pozzi C, O'Gara JP, Massey RC. Offsetting virulence and antibiotic resistance costs by MRSA. ISME JOURNAL 2010; 4:577-84. [PMID: 20072161 DOI: 10.1038/ismej.2009.151] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The prevalence of diverse MRSA (methicillin-resistant Staphylococcus aureus) types in both hospital and community settings is a major health problem worldwide. Here we compare hospital-acquired MRSAs with large type II SCCmec elements with those prevalent in both hospital and community settings with smaller type IV SCCmec elements. We find that the type II but not the type IV SCCmec element causes the bacteria to reduce their levels of costly toxin expression. We compare the relative growth rates of these MRSA types and show that the type II SCCmec carrying MRSAs are more affected than those carrying type IV elements and from this we hypothesize that offsetting the costs associated with antibiotic resistance and toxin expression is why the type II are confined to hospital environments where antibiotic use, the prevalence of immunocompromised individuals and vector-mediated transmission is high. In contrast, those MRSAs that are also successful in the community can maintain their high levels of toxin expression due to a lower fitness burden associated with the smaller SCCmec element.
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Affiliation(s)
- James Collins
- Department of Zoology, University of Oxford, Oxford, UK
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Danchin A. A challenge to vaccinology: living organisms trap information. Vaccine 2009; 27 Suppl 6:G13-6. [PMID: 20006133 PMCID: PMC7115390 DOI: 10.1016/j.vaccine.2009.10.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 10/11/2009] [Accepted: 10/14/2009] [Indexed: 11/03/2022]
Abstract
Life couples reproduction of the cell machinery with replication of the genetic program. Both processes are linked to the expression of some information. Over time, reproduction can enhance the information of the machine. We show that accumulation of valuable information results from degradative processes required to make room for novel entities. Degradation systems act as Maxwell's demons, using energy not to make room per se, but to prevent degradation of what has some functional features. This myopic process will accumulate information, whatever its source, in a ratchet-like manner. The consequence is that genes acquired by horizontal transfer as well as viruses will tend to perpetuate in niches where they are functional, creating recurrent conditions for emergence of diseases.
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Affiliation(s)
- Antoine Danchin
- CEA/Genoscope, Amabiotics, 2, rue Gaston Crémieux, 91057 Evry Cedex, France.
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Abstract
Although nosocomial infections by Staphylococcus epidermidis have gained much attention, this skin-colonizing bacterium has apparently evolved not to cause disease, but to maintain the commonly benign relationship with its host. Accordingly, S. epidermidis does not produce aggressive virulence determinants. Rather, factors that normally sustain the commensal lifestyle of S. epidermidis seem to give rise to additional benefits during infection. Furthermore, we are beginning to comprehend the roles of S. epidermidis in balancing the epithelial microflora and serving as a reservoir of resistance genes. In this Review, I discuss the molecular basis of the commensal and infectious lifestyles of S. epidermidis.
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Monecke S, Ehricht R, Slickers P, Tan HL, Coombs G. The molecular epidemiology and evolution of the Panton–Valentine leukocidin-positive, methicillin-resistant Staphylococcus aureus strain USA300 in Western Australia. Clin Microbiol Infect 2009; 15:770-6. [DOI: 10.1111/j.1469-0691.2009.02792.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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