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Biology and Regulation of Staphylococcal Biofilm. Int J Mol Sci 2023; 24:ijms24065218. [PMID: 36982293 PMCID: PMC10049468 DOI: 10.3390/ijms24065218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 03/11/2023] Open
Abstract
Despite continuing progress in medical and surgical procedures, staphylococci remain the major Gram-positive bacterial pathogens that cause a wide spectrum of diseases, especially in patients requiring the utilization of indwelling catheters and prosthetic devices implanted temporarily or for prolonged periods of time. Within the genus, if Staphylococcus aureus and S. epidermidis are prevalent species responsible for infections, several coagulase-negative species which are normal components of our microflora also constitute opportunistic pathogens that are able to infect patients. In such a clinical context, staphylococci producing biofilms show an increased resistance to antimicrobials and host immune defenses. Although the biochemical composition of the biofilm matrix has been extensively studied, the regulation of biofilm formation and the factors contributing to its stability and release are currently still being discovered. This review presents and discusses the composition and some regulation elements of biofilm development and describes its clinical importance. Finally, we summarize the numerous and various recent studies that address attempts to destroy an already-formed biofilm within the clinical context as a potential therapeutic strategy to avoid the removal of infected implant material, a critical event for patient convenience and health care costs.
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Bai X, Nakatsu CH, Bhunia AK. Bacterial Biofilms and Their Implications in Pathogenesis and Food Safety. Foods 2021; 10:2117. [PMID: 34574227 PMCID: PMC8472614 DOI: 10.3390/foods10092117] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 08/21/2021] [Accepted: 08/30/2021] [Indexed: 12/28/2022] Open
Abstract
Biofilm formation is an integral part of the microbial life cycle in nature. In food processing environments, bacterial transmissions occur primarily through raw or undercooked foods and by cross-contamination during unsanitary food preparation practices. Foodborne pathogens form biofilms as a survival strategy in various unfavorable environments, which also become a frequent source of recurrent contamination and outbreaks of foodborne illness. Instead of focusing on bacterial biofilm formation and their pathogenicity individually, this review discusses on a molecular level how these two physiological processes are connected in several common foodborne pathogens such as Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Escherichia coli. In addition, biofilm formation by Pseudomonas aeruginosa is discussed because it aids the persistence of many foodborne pathogens forming polymicrobial biofilms on food contact surfaces, thus significantly elevating food safety and public health concerns. Furthermore, in-depth analyses of several bacterial molecules with dual functions in biofilm formation and pathogenicity are highlighted.
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Affiliation(s)
- Xingjian Bai
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA;
| | - Cindy H. Nakatsu
- Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
| | - Arun K. Bhunia
- Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA;
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
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Nguyen HTT, Nguyen TH, Otto M. The staphylococcal exopolysaccharide PIA - Biosynthesis and role in biofilm formation, colonization, and infection. Comput Struct Biotechnol J 2020; 18:3324-3334. [PMID: 33240473 PMCID: PMC7674160 DOI: 10.1016/j.csbj.2020.10.027] [Citation(s) in RCA: 104] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/23/2020] [Accepted: 10/25/2020] [Indexed: 12/20/2022] Open
Abstract
PIA is a key extracellular matrix component in staphylococci and other bacteria. PIA is a cationic, partially deacetylated N-acetylglucosamine polymer. PIA has a major role in bacterial biofilms and biofilm-associated infection.
Exopolysaccharide is a key part of the extracellular matrix that contributes to important mechanisms of bacterial pathogenicity, most notably biofilm formation and immune evasion. In the human pathogens Staphylococcus aureus and S. epidermidis, as well as in many other staphylococcal species, the only exopolysaccharide is polysaccharide intercellular adhesin (PIA), a cationic, partially deacetylated homopolymer of N-acetylglucosamine, whose biosynthetic machinery is encoded in the ica locus. PIA production is strongly dependent on environmental conditions and controlled by many regulatory systems. PIA contributes significantly to staphylococcal biofilm formation and immune evasion mechanisms, such as resistance to antimicrobial peptides and ingestion and killing by phagocytes, and presence of the ica genes is associated with infectivity. Due to its role in pathogenesis, PIA has raised considerable interest as a potential vaccine component or target.
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Affiliation(s)
- Hoai T T Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA.,School of Biotechnology, International University, Vietnam National University of Ho Chi Minh City, Khu Pho 6, Thu Duc, Ho Chi Minh City, Viet Nam
| | - Thuan H Nguyen
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda 20814, MD, USA
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Baker JE, Seitz AP, Boudreau RM, Skinner MJ, Beydoun A, Kaval N, Caldwell CC, Gulbins E, Edwards MJ, Gobble RM. Doxycycline-Coated Silicone Breast Implants Reduce Acute Surgical-Site Infection and Inflammation. Plast Reconstr Surg 2020; 146:1029-1041. [PMID: 33141530 DOI: 10.1097/prs.0000000000007277] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Surgical-site infection after implant-based breast reconstruction remains a leading cause of morbidity. Doxycycline is an antibiotic used to treat soft-tissue infections. The authors hypothesize that doxycycline-coated breast implants will significantly reduce biofilm formation, surgical-site infection, and inflammation after bacterial infection. METHODS Pieces of silicone breast implants were coated in doxycycline. In vitro studies to characterize the coating include Fourier transmission infrared spectroscopy, elution data, and toxicity assays (n = 4). To evaluate antimicrobial properties, coated implants were studied after methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa inoculation in vitro and in a mouse model at 3 and 7 days (n = 8). Studies included bacterial quantification, cytokine profiles, and histology. RESULTS Coated silicone breast implants demonstrated a color change, increased mass, and Fourier transmission infrared spectroscopy consistent with a doxycycline coating. Coated implants were nontoxic to fibroblasts and inhibited biofilm formation and bacterial adherence after MRSA and P. aeruginosa incubation in vitro, and measurable doxycycline concentrations at 24 hours were seen. In a mouse model, a significant reduction of MRSA and P. aeruginosa bacterial colonization after 3 and 7 days in the doxycycline-coated implant mice was demonstrated when compared to the control mice, control mice treated with intraperitoneal doxycycline, and control mice treated with a gentamicin/cefazolin/bacitracin wash. Decreased inflammatory cytokines and inflammatory cell infiltration were demonstrated in the doxycycline-coated mice. CONCLUSIONS A method to coat silicone implants with doxycycline was developed. The authors' doxycycline-coated silicone implants significantly reduced biofilm formation, surgical-site infections, and inflammation. Further studies are needed to evaluate the long-term implications.
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Affiliation(s)
- Jennifer E Baker
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Aaron P Seitz
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Ryan M Boudreau
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Mitchell J Skinner
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Ahmed Beydoun
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Necati Kaval
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Charles C Caldwell
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Erich Gulbins
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Michael J Edwards
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
| | - Ryan M Gobble
- From the Sections of Surgical Research and Plastic, Reconstructive, and Hand Surgery, Department of Surgery, and the Department of Chemistry, College of Arts and Science, University of Cincinnati; the Division of Surgery, Shriners Hospital for Children; and the Department of Molecular Biology, University Hospital Essen, University of Duisburg-Essen
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Witsø E, Hoang L, Løseth K, Bergh K. Establishment of an in vivo rat model for chronic musculoskeletal implant infection. J Orthop Surg Res 2020; 15:23. [PMID: 31964416 PMCID: PMC6975053 DOI: 10.1186/s13018-020-1546-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/05/2020] [Indexed: 01/22/2023] Open
Abstract
Background The aim of the study was to establish an experimental chronic musculoskeletal infection model in vivo characterized by (a) a small bacterial inoculum, (b) no general or local signs of infection, (c) several parallels (implants) in each animal and finally (d) a model that is technically easy to perform. Methods Bone xenografts with steel plates were implanted intramuscularly in rats. To the xenografts, different inocula of Staphylococcus aureus and two strains of Staphylococcus epidermidis were added. The animals were observed for different time periods before the removal of the xenografts. The xenografts and steel plates were subjected to quantitative bacterial culture after sonication. Additional steel plates were subjected to scanning electron microscopy (SEM) for visualization of biofilm formation. Results Inoculation of bone grafts with S. aureus did produce a pyogenic infection in all animals. A chronic infection was established in rats where the bone grafts were inoculated with S. epidermidis. A bacterial inoculum of 100 colony-forming units (CFU) of S. epidermidis was adequate as a minimum infective dose. During a period of up until 42 days, the animals infected with S. epidermidis had no general or local signs of infection. According to the results of the quantitative bacterial culture of sonicate fluid and SEM, a biofilm was developed on all implants. Conclusion In the present in vivo model, a very small bacterial inoculum succeeded in establishing a chronic musculoskeletal implant infection where a biofilm was formed on the implants. The experimental model is easy to perform and allows several implants in each animal. The model could be useful for the study of biofilm formation in vivo on different implants and different surfaces.
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Affiliation(s)
- Eivind Witsø
- Department of Orthopaedic Surgery, St Olav's University Hospital, Trondheim, Norway.
| | - Linh Hoang
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kirsti Løseth
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Kåre Bergh
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Medical Microbiology, St Olav's University Hospital, Trondheim, Norway
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Abstract
The primary virulence factor of the skin commensal and opportunistic pathogen, Staphylococcus epidermidis, is the ability to form biofilms on surfaces of implanted materials. Much of this microorganism’s pathogenic success has been attributed to its ability to evade the innate immune system. The primary defense against S. epidermidis biofilm infection consists of complement activation, recruitment and subsequent killing of the pathogen by effector cells. Among pathogen-derived factors, the biofilm exopolysaccharide polysaccharide intercellular adhesion (PIA), as well as the accumulation-associated protein (Aap), and the extracellular matrix binding protein (Embp) have been shown to modulate effector cell-mediated killing of S. epidermidis. Phenol-soluble modulins (PSMs) constitute the only class of secreted toxins by S. epidermidis, at least one type of which (PSMδ) possesses strong cytolytic properties toward leukocytes. However, through selective production of non-cytolytic subtypes of PSMs, S. epidermidis is able to maintain a low inflammatory infection profile and avoid eradication by the host immune system. Taken together, our emerging understanding of the mechanisms behind immune modulation by S. epidermidis elucidates the microorganism’s success in the initial colonization of device surfaces as well as the maintenance of a chronic and indolent course of biofilm infection.
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Affiliation(s)
- Katherine Y Le
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.,Division of Hospital Internal Medicine, Department of Medicine, Mayo Clinic College of Medicine and Science, Rochester, MN, United States
| | - Matthew D Park
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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Harraghy N, Seiler S, Jacobs K, Hannig M, Menger MD, Herrmann M. Advances in in Vitro and in Vivo Models for Studying the Staphylococcal Factors Involved in Implant Infections. Int J Artif Organs 2018; 29:368-78. [PMID: 16705605 DOI: 10.1177/039139880602900406] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Implant infections due to staphylococci are one of the greatest threats facing patients receiving implant devices. For many years researchers have sought to understand the mechanisms involved in the adherence of the bacterium to the implanted device and the formation of the unique structure, the biofilm, which protects the indwelling bacteria from the host defence and renders them resistant to antibiotic treatment. A major goal has been to develop in vitro and in vivo models that adequately reflect the real-life situation. From the simple microtiter plate assay and scanning electron microscopy, tools for studying adherence and biofilm formation have since evolved to include specialised equipment for studying adherence, flow cell systems, real-time analysis of biofilm formation using reporter gene assays both in vitro and in vivo, and a wide variety of animal models. In this article, we discuss advances in the last few years in selected in vitro and in vivo models as well as future developments in the study of adherence and biofilm formation by the staphylococci.
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Affiliation(s)
- N Harraghy
- Institute of Medical Microbiology and Hygiene, University of Saarland, Homburg/Saar, Germany.
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Oyama T, Miyazaki M, Yoshimura M, Takata T, Ohjimi H, Jimi S. Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Survive in Kupffer Cells and Exhibit High Virulence in Mice. Toxins (Basel) 2016; 8:toxins8070198. [PMID: 27376326 PMCID: PMC4963831 DOI: 10.3390/toxins8070198] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 06/15/2016] [Accepted: 06/24/2016] [Indexed: 11/26/2022] Open
Abstract
Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA). MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF) and low-biofilm formers (L-BF). These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections.
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Affiliation(s)
- Takuto Oyama
- Department of Plastic, Reconstructive and Aesthetic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Motoyasu Miyazaki
- Department of Pharmacy, Fukuoka University Chikushi Hospital, Chikusino 818-8502, Japan.
| | - Michinobu Yoshimura
- Department of Medical Oncology, Hematology, and Infectious Diseases, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Tohru Takata
- Department of Medical Oncology, Hematology, and Infectious Diseases, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Hiroyuki Ohjimi
- Department of Plastic, Reconstructive and Aesthetic Surgery, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
| | - Shiro Jimi
- Central Laboratory for Pathology and Morphology, Department of Pathology, Faculty of Medicine, Fukuoka University, Fukuoka 814-0180, Japan.
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Rahim MI, Rohde M, Rais B, Seitz JM, Mueller PP. Susceptibility of metallic magnesium implants to bacterial biofilm infections. J Biomed Mater Res A 2016; 104:1489-99. [DOI: 10.1002/jbm.a.35680] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/29/2016] [Accepted: 02/05/2016] [Indexed: 12/29/2022]
Affiliation(s)
- Muhammad Imran Rahim
- Helmholtz Centre for Infection Research; Inhoffenstrasse 7 Braunschweig 38124 Germany
| | - Manfred Rohde
- Helmholtz Centre for Infection Research; Inhoffenstrasse 7 Braunschweig 38124 Germany
| | - Bushra Rais
- Helmholtz Centre for Infection Research; Inhoffenstrasse 7 Braunschweig 38124 Germany
| | - Jan-Marten Seitz
- Institute of Materials Science, Leibniz University of Hannover; An Der Universität 2 Garbsen 30823 Germany
- Department of Materials Science and Engineering; Michigan Technological University; 1400 Townsend Dr Houghton Michigan 49931
| | - Peter P. Mueller
- Helmholtz Centre for Infection Research; Inhoffenstrasse 7 Braunschweig 38124 Germany
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Abdulamir AS, Jassim SAA, Hafidh RR, Bakar FA. The potential of bacteriophage cocktail in eliminating Methicillin-resistant Staphylococcus aureus biofilms in terms of different extracellular matrices expressed by PIA, ciaA-D and FnBPA genes. Ann Clin Microbiol Antimicrob 2015; 14:49. [PMID: 26558683 PMCID: PMC4642773 DOI: 10.1186/s12941-015-0106-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 10/05/2015] [Indexed: 11/26/2022] Open
Abstract
Background This study assessed novel approach of using highly lytic phages against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) biofilms with and without biofilm extracellular matrix- disrupting chemical. Method The resultant phage-based control was assessed in relation to the type of biofilm extracellular matrix namely, polysaccharide intercellular adhesion (PIA) or proteinacious fibronectin-binding protein A (FnBPA). The biofilms were formed in vitro by 24 h incubation of bacteria in 96 wells microtiter plates at room temperature. The formed biofilms were assessed by tissue culture plate (TCP). Moreover, the nature of the biofilm was assessed by scanning electron microscopy (SEM) and PCR assay for detecting PIA genes, ciaA-D and FnBPA genes. Results this study showed that applied phages with 0.08 % benezenthonium chloride, for PIA biofilms, and 0.06 % ethanol, for proteinacious FnBPA biofilms, exerted 100 % eradication for MSSA biofilms and about 78 % of MRSA biofilms. The phage-based control of biofilms with chemical adjuvant showed significantly higher efficiency than that without adjuvant (P < 0.05). Moreover, FnBPA biofilms were more common in MRSA than in MSSA while PIA biofilms were more common in MSSA than in MRSA. And the most resistant type of biofilms to phage-based control was FnBPA in MRSA where 50 % of biofilms were reduced but not eradicated completely. Conclusions It is concluded that PIA-disturbing agent and protein denaturing alcohol can increase the efficiency of attacking phages in accessing host cell walls and lysing them which in turn lead to much more efficient MRSA and MSSA biofilm treatment and prevention.
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Affiliation(s)
- Ahmed Sahib Abdulamir
- Microbiology Department, College of Medicine, Alnahrain University, 14222, Baghdad, Iraq.
| | - Sabah A A Jassim
- Applied Bio Research Inc., Windsor, Canada. .,Environmental Engineering, University of Windsor, Windsor, Canada.
| | - Rand R Hafidh
- Microbiology Department, College of Medicine, Baghdad University, Baghdad, Iraq.
| | - Fatimah Abu Bakar
- Faculty of Food Science, University Putra Malaysia, Serdang, 43400, Selangor, Malaysia.
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Decker R, Burdelski C, Zobiak M, Büttner H, Franke G, Christner M, Saß K, Zobiak B, Henke HA, Horswill AR, Bischoff M, Bur S, Hartmann T, Schaeffer CR, Fey PD, Rohde H. An 18 kDa scaffold protein is critical for Staphylococcus epidermidis biofilm formation. PLoS Pathog 2015; 11:e1004735. [PMID: 25799153 PMCID: PMC4370877 DOI: 10.1371/journal.ppat.1004735] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 02/06/2015] [Indexed: 12/15/2022] Open
Abstract
Virulence of the nosocomial pathogen Staphylococcus epidermidis is crucially linked to formation of adherent biofilms on artificial surfaces. Biofilm assembly is significantly fostered by production of a bacteria derived extracellular matrix. However, the matrix composition, spatial organization, and relevance of specific molecular interactions for integration of bacterial cells into the multilayered biofilm community are not fully understood. Here we report on the function of novel 18 kDa Small basic protein (Sbp) that was isolated from S. epidermidis biofilm matrix preparations by an affinity chromatographic approach. Sbp accumulates within the biofilm matrix, being preferentially deposited at the biofilm–substratum interface. Analysis of Sbp-negative S. epidermidis mutants demonstrated the importance of Sbp for sustained colonization of abiotic surfaces, but also epithelial cells. In addition, Sbp promotes assembly of S. epidermidis cell aggregates and establishment of multilayered biofilms by influencing polysaccharide intercellular-adhesin (PIA) and accumulation associated protein (Aap) mediated intercellular aggregation. While inactivation of Sbp indirectly resulted in reduced PIA-synthesis and biofilm formation, Sbp serves as an essential ligand during Aap domain-B mediated biofilm accumulation. Our data support the conclusion that Sbp serves as an S. epidermidis biofilm scaffold protein that significantly contributes to key steps of surface colonization. Sbp-negative S. epidermidis mutants showed no attenuated virulence in a mouse catheter infection model. Nevertheless, the high prevalence of sbp in commensal and invasive S. epidermidis populations suggests that Sbp plays a significant role as a co-factor during both multi-factorial commensal colonization and infection of artificial surfaces. Biofilm formation is a key phenotype allowing the otherwise harmless skin commensal S. epidermidis to establish chronic implant-associated infections, affecting millions of patients worldwide. S. epidermidis biofilm assembly relies on the production of an extracellular matrix that serves as glue to stabilize the multilayered bacterial architecture. Here we identified novel 18 kDa Small basic protein (Sbp) as a key component of the extracellular matrix that promotes pivotal steps of bacterial biofilm formation in vitro. Importantly, Sbp is deposited specifically at the interface between biofilm and substrate, as well as in larger humps interspersed within the bacterial cell architecture, thereby forming a proteinaceous biofilm scaffold. This localization enables Sbp to foster stable S. epidermidis interactions with an artificial surface and also contributes to S. epidermidis cell aggregation mechanisms, i.e., polysaccharide intercellular adhesin (PIA) and accumulation associated protein (Aap). In fact, by demonstrating direct Sbp-Aap interactions we provide the first evidence supporting the idea that specific molecular interactions between S. epidermidis and matrix components are involved in S. epidermidis biofilm accumulation. In conclusion, we here show that Sbp promotes key phenotypic features important for S. epidermidis to evolve as an opportunistic pathogen.
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Affiliation(s)
- Rahel Decker
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Christoph Burdelski
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Melanie Zobiak
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Henning Büttner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Gefion Franke
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Martin Christner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Katharina Saß
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Bernd Zobiak
- UKE Microscopy Imaging Facility, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Hanae A. Henke
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
| | - Alexander R. Horswill
- Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Markus Bischoff
- Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum des Saarlandes, Homburg, Germany
| | - Stephanie Bur
- Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum des Saarlandes, Homburg, Germany
| | - Torsten Hartmann
- Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum des Saarlandes, Homburg, Germany
| | - Carolyn R. Schaeffer
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Paul D. Fey
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Hamburg, Germany
- * E-mail:
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Büttner H, Mack D, Rohde H. Structural basis of Staphylococcus epidermidis biofilm formation: mechanisms and molecular interactions. Front Cell Infect Microbiol 2015; 5:14. [PMID: 25741476 PMCID: PMC4330918 DOI: 10.3389/fcimb.2015.00014] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 01/26/2015] [Indexed: 02/01/2023] Open
Abstract
Staphylococcus epidermidis is a usually harmless commensal bacterium highly abundant on the human skin. Under defined predisposing conditions, most importantly implantation of a medical device, S. epidermidis, however, can switch from a colonizing to an invasive life style. The emergence of S. epidermidis as an opportunistic pathogen is closely linked to the biofilm forming capability of the species. During the past decades, tremendous advance regarding our understanding of molecular mechanisms contributing to surface colonization has been made, and detailed information is available for several factors active during the primary attachment, accumulative or dispersal phase of biofilm formation. A picture evolved in which distinct factors, though appearing to be redundantly organized, take over specific and exclusive functions during biofilm development. In this review, these mechanisms are described in molecular detail, with a highlight on recent insights into multi-functional S. epidermidis cell surface proteins contributing to surface adherence and intercellular adhesion. The integration of distinct biofilm-promoting factors into regulatory networks is summarized, with an emphasis on mechanism that could allow S. epidermidis to flexibly adapt to changing environmental conditions present during colonizing or invasive life-styles.
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Affiliation(s)
- Henning Büttner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf Hamburg, Germany
| | - Dietrich Mack
- Mikrobiologie/Infektiologie, Bioscientia Labor Ingelheim, Institut für Medizinische Diagnostik GmbH Ingelheim, Germany
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf Hamburg, Germany
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Weidenmaier C, Lee JC. Structure and Function of Surface Polysaccharides of Staphylococcus aureus. Curr Top Microbiol Immunol 2015; 409:57-93. [PMID: 26728067 DOI: 10.1007/82_2015_5018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The major surface polysaccharides of Staphylococcus aureus include the capsular polysaccharide (CP), cell wall teichoic acid (WTA), and polysaccharide intercellular adhesin/poly-β(1-6)-N-acetylglucosamine (PIA/PNAG). These glycopolymers are important components of the staphylococcal cell envelope, but none of them is essential to S. aureus viability and growth in vitro. The overall biosynthetic pathways of CP, WTA, and PIA/PNAG have been elucidated, and the functions of most of the biosynthetic enzymes have been demonstrated. Because S. aureus CP and WTA (but not PIA/PNAG) utilize a common cell membrane lipid carrier (undecaprenyl-phosphate) that is shared by the peptidoglycan biosynthesis pathway, there is evidence that these processes are highly integrated and temporally regulated. Regulatory elements that control glycopolymer biosynthesis have been described, but the cross talk that orchestrates the biosynthetic pathways of these three polysaccharides remains largely elusive. CP, WTA, and PIA/PNAG each play distinct roles in S. aureus colonization and the pathogenesis of staphylococcal infection. However, they each promote bacterial evasion of the host immune defences, and WTA is being explored as a target for antimicrobial therapeutics. All the three glycopolymers are viable targets for immunotherapy, and each (conjugated to a carrier protein) is under evaluation for inclusion in a multivalent S. aureus vaccine. Future research findings that increase our understanding of these surface polysaccharides, how the bacterial cell regulates their expression, and their biological functions will likely reveal new approaches to controlling this important bacterial pathogen.
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Affiliation(s)
- Christopher Weidenmaier
- Interfaculty Institute for Microbiology and Infection Medicine Tübingen, University of Tübingen and German Center for Infection Research, Tübingen, Germany
| | - Jean C Lee
- Division of Infectious Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Accumulation-associated protein enhances Staphylococcus epidermidis biofilm formation under dynamic conditions and is required for infection in a rat catheter model. Infect Immun 2014; 83:214-26. [PMID: 25332125 DOI: 10.1128/iai.02177-14] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Biofilm formation is the primary virulence factor of Staphylococcus epidermidis. S. epidermidis biofilms preferentially form on abiotic surfaces and may contain multiple matrix components, including proteins such as accumulation-associated protein (Aap). Following proteolytic cleavage of the A domain, which has been shown to enhance binding to host cells, B domain homotypic interactions support cell accumulation and biofilm formation. To further define the contribution of Aap to biofilm formation and infection, we constructed an aap allelic replacement mutant and an icaADBC aap double mutant. When subjected to fluid shear, strains deficient in Aap production produced significantly less biofilm than Aap-positive strains. To examine the in vivo relevance of our findings, we modified our previously described rat jugular catheter model and validated the importance of immunosuppression and the presence of a foreign body to the establishment of infection. The use of our allelic replacement mutants in the model revealed a significant decrease in bacterial recovery from the catheter and the blood in the absence of Aap, regardless of the production of polysaccharide intercellular adhesin (PIA), a well-characterized, robust matrix molecule. Complementation of the aap mutant with full-length Aap (containing the A domain), but not the B domain alone, increased initial attachment to microtiter plates, as did in trans expression of the A domain in adhesion-deficient Staphylococcus carnosus. These results demonstrate Aap contributes to S. epidermidis infection, which may in part be due to A domain-mediated attachment to abiotic surfaces.
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Foreign Body Infection Models to Study Host-Pathogen Response and Antimicrobial Tolerance of Bacterial Biofilm. Antibiotics (Basel) 2014; 3:378-97. [PMID: 27025752 PMCID: PMC4790362 DOI: 10.3390/antibiotics3030378] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 07/01/2014] [Accepted: 08/06/2014] [Indexed: 12/13/2022] Open
Abstract
The number of implanted medical devices is steadily increasing and has become an effective intervention improving life quality, but still carries the risk of infection. These infections are mainly caused by biofilm-forming staphylococci that are difficult to treat due to the decreased susceptibility to both antibiotics and host defense mechanisms. To understand the particular pathogenesis and treatment tolerance of implant-associated infection (IAI) animal models that closely resemble human disease are needed. Applications of the tissue cage and catheter abscess foreign body infection models in the mouse will be discussed herein. Both models allow the investigation of biofilm and virulence of various bacterial species and a comprehensive insight into the host response at the same time. They have also been proven to serve as very suitable tools to study the anti-adhesive and anti-infective efficacy of different biomaterial coatings. The tissue cage model can additionally be used to determine pharmacokinetics, efficacy and cytotoxicity of antimicrobial compounds as the tissue cage fluid can be aspirated repeatedly without the need to sacrifice the animal. Moreover, with the advance in innovative imaging systems in rodents, these models may offer new diagnostic measures of infection. In summary, animal foreign body infection models are important tools in the development of new antimicrobials against IAI and can help to elucidate the complex interactions between bacteria, the host immune system, and prosthetic materials.
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Fux CA, Stoodley P, Hall-Stoodley L, Costerton JW. Bacterial biofilms: a diagnostic and therapeutic challenge. Expert Rev Anti Infect Ther 2014; 1:667-83. [PMID: 15482163 DOI: 10.1586/14787210.1.4.667] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bacteria have traditionally been regarded as individual organisms growing in homogeneous planktonic populations. However, bacteria in natural environments usually form communities of surface-adherent organisms embedded in an extracellular matrix, called biofilms. Current antimicrobial strategies often fail to control bacteria in the biofilm mode of growth. Treatment failure is particularly frequent in association with intracorporeal or transcutaneous medical devices and compromised host immunity. The rising prevalence of these risk factors over the last decades has paralleled the increase in biofilm infections. This review discusses the shortcomings of current therapies against biofilms both in theory and with clinical examples. Biofilm characteristics are described with a focus on new diagnostic and therapeutic targets.
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Affiliation(s)
- Christoph A Fux
- Center for Biofilm Engineering, Montana State University, USA.
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McLean RJC, Kakirde KS. Enhancing metagenomics investigations of microbial interactions with biofilm technology. Int J Mol Sci 2013; 14:22246-57. [PMID: 24284397 PMCID: PMC3856063 DOI: 10.3390/ijms141122246] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 10/25/2013] [Accepted: 10/29/2013] [Indexed: 11/16/2022] Open
Abstract
Investigations of microbial ecology and diversity have been greatly enhanced by the application of culture-independent techniques. One such approach, metagenomics, involves sample collections from soil, water, and other environments. Extracted nucleic acids from bulk environmental samples are sequenced and analyzed, which allows microbial interactions to be inferred on the basis of bioinformatics calculations. In most environments, microbial interactions occur predominately in surface-adherent, biofilm communities. In this review, we address metagenomics sampling and biofilm biology, and propose an experimental strategy whereby the resolving power of metagenomics can be enhanced by incorporating a biofilm-enrichment step during sample acquisition.
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Affiliation(s)
- Robert J C McLean
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666, USA.
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Abstract
Bacteria living as biofilms have been recognised as the ultimate cause of persistent and destructive inflammatory processes. Biofilm formation is a well-organised, genetically-driven process, which is well characterised for numerous bacteria species. In contrast, the host response to bacterial biofilms is less well analysed, and there is the general believe that bacteria in biofilms escape recognition or eradication by the immune defence. In this review the host response to bacterial biofilms is discussed with particular focus on the role of neutrophils because these phagocytic cells are the first to infiltrate areas of bacterial infection, and because neutrophils are equipped with a wide arsenal of bactericidal and toxic entities. I come to the conclusion that bacterial biofilms are not inherently protected against the attack by neutrophils, but that control of biofilm formation is possible depending on a timely and sufficient host response.
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Christner M, Heinze C, Busch M, Franke G, Hentschke M, Bayard Dühring S, Büttner H, Kotasinska M, Wischnewski V, Kroll G, Buck F, Molin S, Otto M, Rohde H. sarAnegatively regulatesStaphylococcus epidermidisbiofilm formation by modulating expression of 1 MDa extracellular matrix binding protein and autolysis-dependent release of eDNA. Mol Microbiol 2012; 86:394-410. [DOI: 10.1111/j.1365-2958.2012.08203.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2012] [Indexed: 12/13/2022]
Affiliation(s)
- Martin Christner
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Constanze Heinze
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Michael Busch
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Gefion Franke
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Moritz Hentschke
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Sara Bayard Dühring
- Center for Systems Microbiology, Department of Systems Biology; Technical University of Denmark; 2800; Lyngby; Denmark
| | - Henning Büttner
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Marta Kotasinska
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Victoria Wischnewski
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Gesche Kroll
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Friedrich Buck
- Institute for Clinical Chemistry; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
| | - Soeren Molin
- Center for Systems Microbiology, Department of Systems Biology; Technical University of Denmark; 2800; Lyngby; Denmark
| | - Michael Otto
- Laboratory of Human Bacterial Pathogenesis; National Institute of Allergy and Infectious Diseases; The National Institutes of Health; Bethesda; MD; 20892; USA
| | - Holger Rohde
- Institute for Medical Microbiology, Virology and Hygiene; University Medical Centre Hamburg-Eppendorf; Martinistraße 52; 20246; Hamburg; Germany
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Archer NK, Mazaitis MJ, Costerton JW, Leid JG, Powers ME, Shirtliff ME. Staphylococcus aureus biofilms: properties, regulation, and roles in human disease. Virulence 2011; 2:445-59. [PMID: 21921685 DOI: 10.4161/viru.2.5.17724] [Citation(s) in RCA: 612] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Increasing attention has been focused on understanding bacterial biofilms and this growth modality's relation to human disease. In this review we explore the genetic regulation and molecular components involved in biofilm formation and maturation in the context of the Gram-positive cocci, Staphylococcus aureus. In addition, we discuss diseases and host immune responses, along with current therapies associated with S. aureus biofilm infections and prevention strategies.
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Affiliation(s)
- Nathan K Archer
- Department of Microbial Pathogenesis, Dental School, University of Maryland, Baltimore, MD, USA
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21
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Jia P, Xue Y, Duan X, Shao S. Effect of cinnamaldehyde on biofilm formation and sarA expression by methicillin-resistant Staphylococcus aureus. Lett Appl Microbiol 2011; 53:409-16. [DOI: 10.1111/j.1472-765x.2011.03122.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Staphylococcus epidermidis uses distinct mechanisms of biofilm formation to interfere with phagocytosis and activation of mouse macrophage-like cells 774A.1. Infect Immun 2011; 79:2267-76. [PMID: 21402760 DOI: 10.1128/iai.01142-10] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Assembly of adherent biofilms is the key mechanism involved in Staphylococcus epidermidis virulence during device-associated infections. Aside from polysaccharide intercellular adhesin (PIA), the accumulation-associated protein Aap and the extracellular matrix binding protein Embp act as intercellular adhesins, mediating S. epidermidis cell aggregation and biofilm accumulation. The aim of this study was to investigate structural features of PIA-, Aap-, and Embp-mediated S. epidermidis biofilms in more detail and to evaluate their specific contributions to biofilm-related S. epidermidis immune escape. PIA-, Embp-, and Aap-mediated biofilms exhibited substantial morphological differences. Basically, PIA synthesis induced formation of macroscopically visible, rough cell clusters, whereas Aap- and Embp-dependent biofilms preferentially displayed a smooth layer of aggregated bacteria. On the microscopic level, PIA was found to form a string-like organized extracellular matrix connecting the bacteria, while Embp produced small deposits of intercellular matrix and Aap was strictly localized to the bacterial surface. Despite marked differences, S. epidermidis strains using PIA, Aap, or Embp for biofilm formation were protected from uptake by J774A.1 macrophages, with similarly efficiencies. In addition, compared to biofilm-negative S. epidermidis strains, isogenic biofilm-forming S. epidermidis induced only a diminished inflammatory J774A.1 macrophage response, leading to significantly (88.2 to 88.7%) reduced NF-κB activation and 68.8 to 83% reduced interleukin-1β (IL-1β) production. Mechanical biofilm dispersal partially restored induction of NF-κB activation, although bacterial cell surfaces remained decorated with the respective intercellular adhesins. Our results demonstrate that distinct S. epidermidis biofilm morphotypes are similarly effective at protecting S. epidermidis from phagocytic uptake and at counteracting macrophage activation, providing novel insights into mechanisms that could contribute to the chronic and persistent course of biofilm-related S. epidermidis foreign material infections.
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Jabbouri S, Sadovskaya I. Characteristics of the biofilm matrix and its role as a possible target for the detection and eradication ofStaphylococcus epidermidisassociated with medical implant infections. ACTA ACUST UNITED AC 2010; 59:280-91. [DOI: 10.1111/j.1574-695x.2010.00695.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Cheung GYC, Otto M. Understanding the significance of Staphylococcus epidermidis bacteremia in babies and children. Curr Opin Infect Dis 2010; 23:208-16. [PMID: 20179594 PMCID: PMC2874874 DOI: 10.1097/qco.0b013e328337fecb] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE OF REVIEW This article provides an overview of Staphylococcus epidermidis bacteremia/sepsis and coagulase-negative staphylococci (CoNS) infections in neonates and children. RECENT FINDINGS The incidence of S. epidermidis and CoNS sepsis in neonates is still very high and preventing and treating disease remains difficult. There has been recent progress in understanding the pathogenesis of S. epidermidis infection, interaction of S. epidermidis with host defenses, and risk factors for the development of S. epidermidis disease. For example, we have gained more insight into the development of biofilm-associated catheter infections, which are responsible for recurrent CoNS infections in hospitalized premature neonates and are especially difficult to treat owing to intrinsic resistance of biofilms to antibiotics. SUMMARY Biofilm-associated catheter infections by S. epidermidis occur frequently in neonates and adults. S. epidermidis bloodstream infections are particularly problematic in neonates. Prophylaxis in the form of eradicating colonizing S. epidermidis may be a double-edged sword, as S. epidermidis colonization may be beneficial to the host. New drugs may arise from a better understanding of S. epidermidis virulence and analysis of risk factors may help identify neonates susceptible to bacterial sepsis. However, reducing morbidity should always begin by increasing hygiene in hospital settings to reduce the introduction of potentially harmful opportunistic pathogens such as S. epidermidis on indwelling medical devices or during surgery.
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Affiliation(s)
- Gordon Y C Cheung
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 33 North Drive, Building 33, Room 1W10A, Bethesda, MD, 20892
| | - Michael Otto
- Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 33 North Drive, Building 33, Room 1W10A, Bethesda, MD, 20892
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Christner M, Franke GC, Schommer NN, Wendt U, Wegert K, Pehle P, Kroll G, Schulze C, Buck F, Mack D, Aepfelbacher M, Rohde H. The giant extracellular matrix-binding protein of Staphylococcus epidermidis mediates biofilm accumulation and attachment to fibronectin. Mol Microbiol 2009; 75:187-207. [PMID: 19943904 DOI: 10.1111/j.1365-2958.2009.06981.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Virulence of nosocomial pathogen Staphylococcus epidermidis is essentially related to formation of adherent biofilms, assembled by bacterial attachment to an artificial surface and subsequent production of a matrix that mediates interbacterial adhesion. Growing evidence supports the idea that proteins are functionally involved in S. epidermidis biofilm accumulation. We found that in S. epidermidis 1585v overexpression of a 460 kDa truncated isoform of the extracellular matrix-binding protein (Embp) is necessary for biofilm formation. Embp is a giant fibronectin-binding protein harbouring 59 Found In Various Architectures (FIVAR) and 38 protein G-related albumin-binding (GA) domains. Studies using defined Embp-positive and -negative S. epidermidis strains proved that Embp is sufficient and necessary for biofilm formation. Further data showed that the FIVAR domains of Embp mediate binding of S. epidermidis to solid-phase attached fibronectin, constituting the first step of biofilm formation on conditioned surfaces. The binding site in fibronectin was assigned to the fibronectin domain type III12. Embp-mediated biofilm formation also protected S. epidermidis from phagocytosis by macrophages. Thus, Embp is a multifunctional cell surface protein that mediates attachment to host extracellular matrix, biofilm accumulation and escape from phagocytosis, and therefore is well suited for promoting implant-associated infections.
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Affiliation(s)
- Martin Christner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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Rohde H, Frankenberger S, Zähringer U, Mack D. Structure, function and contribution of polysaccharide intercellular adhesin (PIA) to Staphylococcus epidermidis biofilm formation and pathogenesis of biomaterial-associated infections. Eur J Cell Biol 2009; 89:103-11. [PMID: 19913940 DOI: 10.1016/j.ejcb.2009.10.005] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Staphylococcus epidermidis is of major importance in infections associated with indwelling medical devices. The tight pathogenic association is essentially linked to the species ability to form adherent biofilms on artificial surfaces. Aiming at identifying novel targets for vaccination or therapy much effort has been made to unravel the molecular mechanisms leading to S. epidermidis biofilm formation. At present, polysaccharide intercellular adhesin (PIA) is the best studied factor involved in S. epidermidis biofilm accumulation. PIA is a glycan of beta-1,6-linked 2-acetamido-2-deoxy-D-glucopyranosyl residues of which 15 % are non-N-acetylated. PIA-producing S. epidermidis are widespread in clinical strain collections and PIA synthesis has been shown to be essential for S. epidermidis virulence. Moreover, PIA homologues have been identified in many other staphylococcal species, including the major human pathogen Staphylococcus aureus, and also Gram-negative human pathogens, suggesting that it might represent a more general pathogenicity principle in biofilm-related infections. In this review the current knowledge about the structure and biosynthesis of PIA is summarized. Additionally, information on its role in pathogenesis of biomaterial-related and other type of infections and the potential use of PIA and related compounds for prevention of infection is discussed.
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Affiliation(s)
- Holger Rohde
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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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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Relevant role of fibronectin-binding proteins in Staphylococcus aureus biofilm-associated foreign-body infections. Infect Immun 2009; 77:3978-91. [PMID: 19581398 DOI: 10.1128/iai.00616-09] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Staphylococcus aureus can establish chronic infections on implanted medical devices due to its capacity to form biofilms. Analysis of the factors that assemble cells into a biofilm has revealed the occurrence of strains that produce either a polysaccharide intercellular adhesin/poly-N-acetylglucosamine (PIA/PNAG) exopolysaccharide- or a protein-dependent biofilm. Examination of the influence of matrix nature on the biofilm capacities of embedded bacteria has remained elusive, because a natural strain that readily converts between a polysaccharide- and a protein-based biofilm has not been studied. Here, we have investigated the clinical methicillin (meticillin)-resistant Staphylococcus aureus strain 132, which is able to alternate between a proteinaceous and an exopolysaccharidic biofilm matrix, depending on environmental conditions. Systematic disruption of each member of the LPXTG surface protein family identified fibronectin-binding proteins (FnBPs) as components of a proteinaceous biofilm formed in Trypticase soy broth-glucose, whereas a PIA/PNAG-dependent biofilm was produced under osmotic stress conditions. The induction of FnBP levels due to a spontaneous agr deficiency present in strain 132 and the activation of a LexA-dependent SOS response or FnBP overexpression from a multicopy plasmid enhanced biofilm development, suggesting a direct relationship between the FnBP levels and the strength of the multicellular phenotype. Scanning electron microscopy revealed that cells growing in the FnBP-mediated biofilm formed highly dense aggregates without any detectable extracellular matrix, whereas cells in a PIA/PNAG-dependent biofilm were embedded in an abundant extracellular material. Finally, studies of the contribution of each type of biofilm matrix to subcutaneous catheter colonization revealed that an FnBP mutant displayed a significantly lower capacity to develop biofilm on implanted catheters than the isogenic PIA/PNAG-deficient mutant.
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Wang X, Yao X, Zhu Z, Tang T, Dai K, Sadovskaya I, Flahaut S, Jabbouri S. Effect of berberine on Staphylococcus epidermidis biofilm formation. Int J Antimicrob Agents 2009; 34:60-6. [DOI: 10.1016/j.ijantimicag.2008.10.033] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Revised: 10/28/2008] [Accepted: 10/29/2008] [Indexed: 01/29/2023]
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Genetic evidence for an alternative citrate-dependent biofilm formation pathway in Staphylococcus aureus that is dependent on fibronectin binding proteins and the GraRS two-component regulatory system. Infect Immun 2008; 76:2469-77. [PMID: 18347039 DOI: 10.1128/iai.01370-07] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We reported previously that low concentrations of sodium citrate strongly promote biofilm formation by Staphylococcus aureus laboratory strains and clinical isolates. Here, we show that citrate promotes biofilm formation via stimulating both cell-to-surface and cell-to-cell interactions. Citrate-stimulated biofilm formation is independent of the ica locus, and in fact, citrate represses polysaccharide adhesin production. We show that fibronectin binding proteins FnbA and FnbB and the global regulator SarA, which positively regulates fnbA and fnbB gene expression, are required for citrate's positive effects on biofilm formation, and citrate also stimulates fnbA and fnbB gene expression. Biofilm formation is also stimulated by several other tricarboxylic acid (TCA) cycle intermediates in an FnbA-dependent fashion. While aconitase contributes to biofilm formation in the absence of TCA cycle intermediates, it is not required for biofilm stimulation by these compounds. Furthermore, the GraRS two-component regulator and the GraRS-regulated efflux pump VraFG, identified for their roles in intermediate vancomycin resistance, are required for citrate-stimulated cell-to-cell interactions, but the GraRS regulatory system does not impact the expression of the fnbA and fnbB genes. Our data suggest that distinct genetic factors are required for the early steps in citrate-stimulated biofilm formation. Given the role of FnbA/FnbB and SarA in virulence in vivo and the lack of a role for ica-mediated biofilm formation in S. aureus catheter models of infection, we propose that the citrate-stimulated biofilm formation pathway may represent a clinically relevant pathway for the formation of these bacterial communities on medical implants.
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Staphylococcus epidermidis Biofilms: Functional Molecules, Relation to Virulence, and Vaccine Potential. GLYCOSCIENCE AND MICROBIAL ADHESION 2008; 288:157-82. [DOI: 10.1007/128_2008_19] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Brady RA, Leid JG, Calhoun JH, Costerton JW, Shirtliff ME. Osteomyelitis and the role of biofilms in chronic infection. ACTA ACUST UNITED AC 2007; 52:13-22. [PMID: 18081847 DOI: 10.1111/j.1574-695x.2007.00357.x] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Understanding the mechanisms implicated in the initial attachment, development, and maturation of a biofilm phenotype are of tremendous importance for their effect on the medical, industrial, and public health arenas. This review explores the current understanding of the nature of biofilms and the impact that molecular interactions between the bacteria themselves, as well as between bacteria and the host, may have on biofilm development and phenotype using the nonmotile Gram-positive coccus, Staphylococcus aureus, as an example.
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Affiliation(s)
- Rebecca A Brady
- Department of Microbiology and Immunology, University of Maryland-Baltimore, School of Medicine, Baltimore, MD 21201, USA
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Begun J, Gaiani JM, Rohde H, Mack D, Calderwood SB, Ausubel FM, Sifri CD. Staphylococcal biofilm exopolysaccharide protects against Caenorhabditis elegans immune defenses. PLoS Pathog 2007; 3:e57. [PMID: 17447841 PMCID: PMC1853117 DOI: 10.1371/journal.ppat.0030057] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Accepted: 03/05/2007] [Indexed: 12/28/2022] Open
Abstract
Staphylococcus epidermidis and Staphylococcus aureus are leading causes of hospital-acquired infections that have become increasingly difficult to treat due to the prevalence of antibiotic resistance in these organisms. The ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere to living and artificial surfaces and to resist host immune factors and antibiotics. Here, we show that the icaADBC locus, which synthesizes the biofilm-associated polysaccharide intercellular adhesin (PIA) in staphylococci, is required for the formation of a lethal S. epidermidis infection in the intestine of the model nematode Caenorhabditis elegans. Susceptibility to S. epidermidis infection is influenced by mutation of the C. elegans PMK-1 p38 mitogen-activated protein (MAP) kinase or DAF-2 insulin-signaling pathways. Loss of PIA production abrogates nematocidal activity and leads to reduced bacterial accumulation in the C. elegans intestine, while overexpression of the icaADBC locus in S. aureus augments virulence towards nematodes. PIA-producing S. epidermidis has a significant survival advantage over ica-deficient S. epidermidis within the intestinal tract of wild-type C. elegans, but not in immunocompromised nematodes harboring a loss-of-function mutation in the p38 MAP kinase pathway gene sek-1. Moreover, sek-1 and pmk-1 mutants are equally sensitive to wild-type and icaADBC-deficient S. epidermidis. These results suggest that biofilm exopolysaccharide enhances virulence by playing an immunoprotective role during colonization of the C. elegans intestine. These studies demonstrate that C. elegans can serve as a simple animal model for studying host–pathogen interactions involving staphylococcal biofilm exopolysaccharide and suggest that the protective activity of biofilm matrix represents an ancient conserved function for resisting predation. Biofilm is an agglomeration of microbes bound together by a slimy matrix composed of excreted proteins and polysaccharide polymers. Most bacteria in the environment reside in biofilms, as do 80% or more of those causing human infections, according to some estimates. During infection, biofilm matrix acts as a safe haven, protecting bacterial cells from antibiotics, immune cells, and antimicrobial factors. In this report, we demonstrate that the ability of Staphylococcus epidermidis to produce a lethal infection within the intestinal tract of the roundworm Caenorhabditis elegans depends on the S. epidermidis intercellular adhesion (ica) locus, which is responsible for the synthesis of the principal exopolysaccharide of staphylococcal biofilm, polysaccharide intercellular adhesin (PIA). Using a collection of bacterial and nematode mutants, we show that PIA promotes infection by working against protective immune factors controlled by the C. elegans SEK-1 PMK-1 p38 mitogen-activated protein kinase pathway. In addition to providing further evidence for the immunoprotective function of the biofilm polymer PIA, these results show that C. elegans can be used in a simple, live animal model for the study of host–pathogen interactions involving biofilm matrix.
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Affiliation(s)
- Jakob Begun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jessica M Gaiani
- Division of Infectious Diseases and International Health, University of Virginia Health System, Charlottesville, Virginia, United States of America
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Dietrich Mack
- Medical Microbiology and Infectious Diseases, The School of Medicine, University of Wales Swansea, Swansea, United Kingdom
| | - Stephen B Calderwood
- Division of Infectious Diseases, Massachusetts General Hospital, Boston Massachusetts, United States of America
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Frederick M Ausubel
- Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Costi D Sifri
- Division of Infectious Diseases and International Health, University of Virginia Health System, Charlottesville, Virginia, United States of America
- Division of Infectious Diseases, Massachusetts General Hospital, Boston Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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Cerca N, Jefferson KK, Maira-Litrán T, Pier DB, Kelly-Quintos C, Goldmann DA, Azeredo J, Pier GB. Molecular basis for preferential protective efficacy of antibodies directed to the poorly acetylated form of staphylococcal poly-N-acetyl-beta-(1-6)-glucosamine. Infect Immun 2007; 75:3406-13. [PMID: 17470540 PMCID: PMC1932961 DOI: 10.1128/iai.00078-07] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Poly-N-acetyl-glucosamine (PNAG) is a staphylococcal surface polysaccharide influencing biofilm formation that is also under investigation for its vaccine potential. Antibodies that bind to PNAG with either low (<15%) or high (>90%) levels of acetate are superior at opsonic and protective activity compared with antibodies that bind to PNAG with only high levels (>70%) of acetate. PNAG is synthesized by four proteins encoded within the intercellular adhesin (ica) locus icaADBC. In Staphylococcus epidermidis, icaB encodes a deacetylase needed for the surface retention of PNAG and optimal biofilm formation. In this study, we confirmed that icaB plays a similar role in Staphylococcus aureus and found that an icaB mutant of S. aureus expressed significantly less surface-associated PNAG, was highly susceptible to antibody-independent opsonic killing that could not be enhanced with antibody raised against deacetylated PNAG (dPNAG), and had reduced survival capacity in a murine model of bacteremia. In contrast, an icaB-overexpressing strain produced primarily surface-associated PNAG, was more susceptible to opsonophagocytosis with antibody to dPNAG, and had increased survival in a murine bacteremia model. The highly acetylated secreted PNAG was more effective at blocking opsonic killing mediated by a human monoclonal antibody (mAb) to native PNAG than it was at blocking killing mediated by a human mAb to dPNAG, which by itself was a more effective opsonin. Retention of dPNAG on the surface of S. aureus is key to increased survival during bacteremia and also provides a molecular mechanism explaining the superior opsonic and protective activity of antibody to dPNAG.
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Affiliation(s)
- Nuno Cerca
- Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA
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Rohde H, Burandt EC, Siemssen N, Frommelt L, Burdelski C, Wurster S, Scherpe S, Davies AP, Harris LG, Horstkotte MA, Knobloch JKM, Ragunath C, Kaplan JB, Mack D. Polysaccharide intercellular adhesin or protein factors in biofilm accumulation of Staphylococcus epidermidis and Staphylococcus aureus isolated from prosthetic hip and knee joint infections. Biomaterials 2006; 28:1711-20. [PMID: 17187854 DOI: 10.1016/j.biomaterials.2006.11.046] [Citation(s) in RCA: 331] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 11/29/2006] [Indexed: 12/20/2022]
Abstract
Nosocomial staphylococcal foreign-body infections related to biofilm formation are a serious threat, demanding new therapeutic and preventive strategies. As the use of biofilm-associated factors as vaccines is critically restricted by their prevalence in natural staphylococcal populations we studied the distribution of genes involved in biofilm formation, the biofilm phenotype and production of polysaccharide intercellular adhesin (PIA) in clonally independent Staphylococcus aureus and Staphylococcus epidermidis strains isolated from prosthetic joint infections after total hip or total knee arthroplasty. Biofilm formation was detected in all S. aureus and 69.2% of S. epidermidis strains. Importantly, 27% of biofilm-positive S. epidermidis produced PIA-independent biofilms, in part mediated by the accumulation associated protein (Aap). Protein-dependent biofilms were exclusively found in S. epidermidis strains from total hip arthroplasty (THA). In S. aureus PIA and proteins act cooperatively in biofilm formation regardless of the infection site. PIA and protein factors like Aap are of differential importance for the pathogenesis of S. epidermidis in prosthetic joint infections (PJI) after THA and total knee arthroplasty (TKA), implicating that icaADBC cannot serve as a general virulence marker in this species. In S. aureus biofilm formation proteins are of overall importance and future work should focus on the identification of functionally active molecules.
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Affiliation(s)
- Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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Broekhuizen CAN, de Boer L, Schipper K, Jones CD, Quadir S, Feldman RG, Dankert J, Vandenbroucke-Grauls CMJE, Weening JJ, Zaat SAJ. Peri-implant tissue is an important niche for Staphylococcus epidermidis in experimental biomaterial-associated infection in mice. Infect Immun 2006; 75:1129-36. [PMID: 17158900 PMCID: PMC1828560 DOI: 10.1128/iai.01262-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Biomaterial-associated infections (BAI), which are predominantly caused by Staphylococcus epidermidis, are a significant problem in modern medicine. Biofilm formation is considered the pivotal element in the pathogenesis, but in previous mouse studies we retrieved S. epidermidis from peri-implant tissue. To assess the kinetics and generality of tissue colonization, we investigated BAI using two S. epidermidis strains, two biomaterials, and two mouse strains. With small inocula all implants were culture negative, whereas surrounding tissues were positive. When higher doses were used, tissues were culture positive more often than implants, with higher numbers of CFU. This was true for the different biomaterials tested, for both S. epidermidis strains, at different times, and for both mouse strains. S. epidermidis colocalized with host cells at a distance that was >10 cell layers from the biomaterial-tissue interface. We concluded that in mouse experimental BAI S. epidermidis peri-implant tissue colonization is more important than biofilm formation.
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Affiliation(s)
- Corine A N Broekhuizen
- Department of Medical Microbiology, CINIMA (Center for Infection and Immunity Amsterdam), Academic Medical Center, Meibergdreef 15, L1-116, 1105 AZ Amsterdam, The Netherlands
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Nohynek LJ, Alakomi HL, Kähkönen MP, Heinonen M, Helander IM, Oksman-Caldentey KM, Puupponen-Pimiä RH. Berry phenolics: antimicrobial properties and mechanisms of action against severe human pathogens. Nutr Cancer 2006; 54:18-32. [PMID: 16800770 DOI: 10.1207/s15327914nc5401_4] [Citation(s) in RCA: 306] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Antimicrobial activity and mechanisms of phenolic extracts of 12 Nordic berries were studied against selected human pathogenic microbes. The most sensitive bacteria on berry phenolics were Helicobacter pylori and Bacillus cereus. Campylobacter jejuni and Candida albicans were inhibited only with phenolic extracts of cloudberry, raspberry, and strawberry, which all were rich in ellagitannins. Cloudberry extract gave strong microbicidic effects on the basis of plate count with all studied strains. However, fluorescence staining of liquid cultures of virulent Salmonella showed viable cells not detectable by plate count adhering to cloudberry extract, whereas Staphylococcus aureus cells adhered to berry extracts were dead on the basis of their fluorescence and plate count. Phenolic extracts of cloudberry and raspberry disintegrated the outer membrane of examined Salmonella strains as indicated by 1-N-phenylnaphthylamine (NPN) uptake increase and analysis of liberation of [14C]galactose- lipopolysaccharide. Gallic acid effectively permeabilized the tested Salmonella strains, and significant increase in the NPN uptake was recorded. The stability of berry phenolics and their antimicrobial activity in berries stored frozen for a year were examined using Escherichia coli and nonvirulent Salmonella enterica sv. Typhimurium. The amount of phenolic compounds decreased in all berries, but their antimicrobial activity was not influenced accordingly. Cloudberry, in particular, showed constantly strong antimicrobial activity during the storage.
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Mack D, Rohde H, Harris LG, Davies AP, Horstkotte MA, Knobloch JKM. Biofilm formation in medical device-related infection. Int J Artif Organs 2006; 29:343-59. [PMID: 16705603 DOI: 10.1177/039139880602900404] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Medical device-associated infections, most frequently caused by coagulase-negative staphylococci, especially Staphylococcus epidermidis, are of increasing importance in modern medicine. Regularly, antimicrobial therapy fails without removal of the implanted device. The most important factor in the pathogenesis of medical device-associated staphylococcal infections is the formation of adherent, multilayered bacterial biofilms. There is urgent need for an increased understanding of the functional factors involved in biofilm formation, the regulation of their expression, and the interaction of those potential virulence factors in device related infection with the host. Significant progress has been made in recent years which may ultimately lead to new rational approaches for better preventive, therapeutic, and diagnostic measures.
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Affiliation(s)
- D Mack
- Medical Microbiology and Infectious Diseases, The School of Medicine, University of Wales Swansea, Swansea, UK.
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Chokr A, Leterme D, Watier D, Jabbouri S. Neither the presence of ica locus, nor in vitro-biofilm formation ability is a crucial parameter for some Staphylococcus epidermidis strains to maintain an infection in a guinea pig tissue cage model. Microb Pathog 2006; 42:94-7. [PMID: 17084581 DOI: 10.1016/j.micpath.2006.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 09/08/2006] [Accepted: 09/15/2006] [Indexed: 10/23/2022]
Abstract
The pathogenesis of Staphylococcus epidermidis is thought to be based on its capacity to colonize medical devices by forming a biofilm. Biofilm formation is in part mediated by the polysaccharide intercellular adhesin (PIA), which is encoded by the icaADBC operon. We have previously investigated in vitro the correlation existing between biofilm formation (B+/-), presence of ica locus (I+/-) and PIA production (P+/-) in some clinical isolates of coagulase-negative staphylococci (CoNS). Here, we used a guinea pig model of subcutaneous implanted tissue cages to assess the implication of B, I and P parameters in the capacity of nine S. epidermidis and one S. carnosus strains to develop and maintain an infection in vivo. Using clinical isolates and a model strain of S. epidermidis, we showed that the "B+, I+, P+" type confers the ability to maintain an infection in vivo. Surprisingly, the opposite type "B-, I-, P-" tested with clinical and commensal isolates, presented infection rates ranging from 25% to 60%. Other clinical isolates having a "B+, I+, P-" type, were not able to cause an infection in the present model. These results showed that, depending on the strains the capacity to colonize the tissue cage might be independent of the ability to form biofilm.
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Affiliation(s)
- Ali Chokr
- Laboratoire de Recherche sur les Biomatériaux et les Biotechnologies, Inserm-ERI 002, Université du Littoral Côte d'Opale, Bassin Napoléon, BP 120, 62327 Boulogne sur mer, France
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40
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Agalar C, Ozdogan M, Agalar F, Saygun O, Aydinuraz K, Akkuş A, Ceken S, Akturk S. A RAT MODEL OF POLYPROPYLENE GRAFT INFECTION CAUSED BY STAPHYLOCOCCUS EPIDERMIDIS. ANZ J Surg 2006; 76:387-91. [PMID: 16768701 DOI: 10.1111/j.1445-2197.2006.03728.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim of this study was to constitute a valid graft infection model with Staphylococcus epidermidis in rats. METHODS Rats were divided into seven groups. In groups 1 and 2, 2 cm x 2 cm polypropylene grafts were incubated with 10(8) c.f.u./mL slime-positive S. epidermidis at 37 degrees C for 2 and 24 h and were then placed subfascially to the groins of rats. In the third group, naive grafts were placed and 0.5 mL of 3 x 10(7) c.f.u. slime-positive S. epidermidis were injected on the inside of the wounds. Rifampicin (30 mg/kg) in group 4 and teicoplanin (20 mg/kg) in group 5 were applied i.p. to rats with 2-h incubated grafts for prophylaxis. The same prophylactic regimens were given to groups 6 and 7 in which rats were incubated for 24 h. At eighth day, rats were killed and wounds were assessed with macroscopic evaluation and cultures. RESULTS No death occurred in any of the groups. In groups 1 and 2, 100% infection rates were achieved. However, graft infection was detected in only two (20%) of the rats in group 3 (P = 0.001). Prophylactic application of teicoplanin or rifampicin decreased the infection rates significantly in the short-incubation groups. CONCLUSION Incubation of polypropylene grafts with slime-producing S. epidermidis for 2 and 24 h in the pre-application period achieved the occurrence of a standardized graft infection. Prophylactic use of teicoplanin and rifampicin decreased the infection rates. We propose to use this reproducible and reliable animal model of graft infection in future studies.
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Affiliation(s)
- Canan Agalar
- Department of Clinical Microbiology and Infection, Kirikkale University Medical School, Kirikkale, Turkey
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Fitzpatrick F, Humphreys H, O'Gara JP. The genetics of staphylococcal biofilm formation--will a greater understanding of pathogenesis lead to better management of device-related infection? Clin Microbiol Infect 2006; 11:967-73. [PMID: 16307550 DOI: 10.1111/j.1469-0691.2005.01274.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Staphylococcus epidermidis and Staphylococcus aureus are common causes of biofilm-mediated prosthetic device-related infection. The polysaccharide adhesion mechanism encoded by the ica operon is currently the best understood mediator of biofilm development, and represents an important virulence determinant. More recently, the contributions of other virulence regulators, including the global regulators agr, sarA and sigmaB, to the biofilm phenotype have also been investigated. Nevertheless, little has changed at the bedside; the clinical and laboratory diagnosis of device-related infection can be difficult, and biofilm resistance frequently results in failure of therapy. This review assesses the way in which advances in the understanding of biofilm genetics may impact on the clinical management of device-related infection.
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Affiliation(s)
- F Fitzpatrick
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Education and Research Centre, Dublin, Ireland
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Johnson M, Cockayne A, Williams PH, Morrissey JA. Iron-responsive regulation of biofilm formation in staphylococcus aureus involves fur-dependent and fur-independent mechanisms. J Bacteriol 2005; 187:8211-5. [PMID: 16291697 PMCID: PMC1291266 DOI: 10.1128/jb.187.23.8211-8215.2005] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have shown that Staphylococcus aureus biofilm production is induced in iron-restricted conditions and is repressed by iron via a Fur-independent mechanism, while Fur has both positive and negative regulatory roles in low iron. Furthermore, there is no significant increase in polymeric N-acetylglucosamine polysaccharide expression to account for induction of biofilms in low iron.
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Kropec A, Maira-Litran T, Jefferson KK, Grout M, Cramton SE, Götz F, Goldmann DA, Pier GB. Poly-N-acetylglucosamine production in Staphylococcus aureus is essential for virulence in murine models of systemic infection. Infect Immun 2005; 73:6868-76. [PMID: 16177366 PMCID: PMC1230935 DOI: 10.1128/iai.73.10.6868-6876.2005] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The contribution of the Staphylococcus aureus surface polysaccharide poly-N-acetylglucosamine (PNAG) to virulence was evaluated in three mouse models of systemic infection: bacteremia, renal abscess formation, and lethality following high-dose intraperitoneal (i.p.) infection. Deletion of the intercellular adhesin (ica) locus that encodes the biosynthetic enzymes for PNAG production in S. aureus strains Mn8, Newman, and NCTC 10833 resulted in mutant strains with significantly reduced abilities to maintain bacterial levels in blood following intravenous or i.p. injection, to spread systemically to the kidneys following i.p. injection, or to induce a moribund/lethal state following i.p. infection. In the bacteremia model, neither growth phase nor growth medium used to prepare the S. aureus inoculum affected the conclusion that PNAG production was needed for full virulence. As the SarA regulatory protein has been shown to affect ica transcription, PNAG synthesis, and biofilm formation, we also evaluated S. aureus strains Mn8 and 10833 deleted for the sarA gene in the renal infection model. A decrease in PNAG production was seen in sarA mutants using immunoblots of cell surface extracts but was insufficient to reduce the virulence of sarA-deleted strains in this model. S. aureus strains deleted for the ica genes were much more susceptible to antibody-independent opsonic killing involving human peripheral blood leukocytes and rabbit complement. Thus, PNAG confers on S. aureus resistance to killing mediated by these innate host immune mediators. Overall, PNAG production by S. aureus appears to be a critical virulence factor as assessed in murine models of systemic infection.
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Affiliation(s)
- Andrea Kropec
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
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Li H, Xu L, Wang J, Wen Y, Vuong C, Otto M, Gao Q. Conversion of Staphylococcus epidermidis strains from commensal to invasive by expression of the ica locus encoding production of biofilm exopolysaccharide. Infect Immun 2005; 73:3188-91. [PMID: 15845531 PMCID: PMC1087319 DOI: 10.1128/iai.73.5.3188-3191.2005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To test if biofilm formation in Staphylococcus epidermidis is dependent on the polysaccharide intercellular adhesin, whose biosynthesis is driven by the ica locus, a plasmid containing the ica locus was transferred to three ica-negative strains. Using in vitro biofilm assays and a rat central venous catheter infection model, we confirmed the importance of the ica locus for biofilm production and pathogenesis of S. epidermidis.
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Affiliation(s)
- Hualin Li
- Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai, 200032, PR China
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45
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Fluckiger U, Ulrich M, Steinhuber A, Döring G, Mack D, Landmann R, Goerke C, Wolz C. Biofilm formation, icaADBC transcription, and polysaccharide intercellular adhesin synthesis by staphylococci in a device-related infection model. Infect Immun 2005; 73:1811-9. [PMID: 15731082 PMCID: PMC1064907 DOI: 10.1128/iai.73.3.1811-1819.2005] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Biofilm formation of Staphylococcus epidermidis and S. aureus is mediated by the polysaccharide intercellular adhesin (PIA) encoded by the ica operon. We used a device-related animal model to investigate biofilm formation, PIA expression (immunofluorescence), and ica transcription (quantitative transcript analysis) throughout the course of infection by using two prototypic S. aureus strains and one S. epidermidis strain as well as corresponding ica mutants. During infection, the ica mutants were growth attenuated when inoculated in competition with the corresponding wild-type strains but not when grown singly. A typical biofilm was observed at the late course of infection. Only in S. aureus RN6390, not in S. aureus Newman, were PIA and ica-specific transcripts detectable after anaerobic growth in vitro. However, both S. aureus strains were PIA positive in vivo by day 8 of infection. ica transcription preceded PIA expression and biofilm formation in vivo. In S. epidermidis, both PIA and ica expression levels were elevated compared to those in the S. aureus strains in vitro as well as in vivo and were detectable throughout the course of infection. In conclusion, in S. aureus, PIA expression is dependent on the genetic background of the strain as well as on strong inducing conditions, such as those dominating in vivo. In S. epidermidis, PIA expression is elevated and less vulnerable to environmental conditions.
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Affiliation(s)
- Ursula Fluckiger
- Division of Infectious Diseases and Department of Research, University Hospital, Basel, Switzerland
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46
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Puupponen-Pimiä R, Nohynek L, Alakomi HL, Oksman-Caldentey KM. The action of berry phenolics against human intestinal pathogens. Biofactors 2005; 23:243-51. [PMID: 16498212 DOI: 10.1002/biof.5520230410] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Phenolic compounds present in berries selectively inhibit the growth of human gastrointestinal pathogens. Especially cranberry, cloudberry, raspberry, strawberry and bilberry possess clear antimicrobial effects against e.g. salmonella and staphylococcus. Complex phenolic polymers, such as ellagitannins, are strong antibacterial agents present in cloudberry, raspberry and strawberry. Berry phenolics seem to affect the growth of different bacterial species with different mechanisms. Adherence of bacteria to epithelial surfaces is a prerequisite for colonization and infection of many pathogens. Antimicrobial activity of berries may also be related to anti-adherence activity of the berries. Utilization of enzymes in berry processing increases the amount of phenolics and antimicrobial activity of the berry products. Antimicrobial berry compounds are likely to have many important applications in the future as natural antimicrobial agents for food industry as well as for medicine.
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Andes D, Nett J, Oschel P, Albrecht R, Marchillo K, Pitula A. Development and characterization of an in vivo central venous catheter Candida albicans biofilm model. Infect Immun 2004; 72:6023-31. [PMID: 15385506 PMCID: PMC517581 DOI: 10.1128/iai.72.10.6023-6031.2004] [Citation(s) in RCA: 296] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2004] [Accepted: 06/16/2004] [Indexed: 01/09/2023] Open
Abstract
Biofilms represent a niche for microorganisms where they are protected from both the host immune system and antimicrobial therapies. Biofilm growth serves as an increasing source of clinical infections. Candida infections are difficult to manage due to their persistent nature and associated drug resistance. Observations made in biofilm research have generally been limited to in vitro models. Using a rat central venous catheter model, we characterized in vivo Candida albicans biofilm development. Time-course quantitative culture demonstrated a progressive increase in the burden of viable cells for the first 24 h of development. Fluorescence and scanning electron microscopy revealed a bilayered architecture. Adjacent to the catheter surface, yeast cells were densely embedded in an extracellular matrix. The layer adjacent to the catheter lumen was less dense. The outermost surface of the biofilm contained both yeast and hyphal forms, and the extracellular material in which they were embedded appeared fibrous. These architectural features were similar in many respects to those described for in vitro models. However, scanning electron microscopy also revealed host cells embedded within the biofilm matrix. Drug susceptibility was determined by using two assays and demonstrated a biofilm-associated drug resistance phenotype. The first assay demonstrated continued growth of cells in the presence of supra-MIC antifungal drug concentrations. The second assay demonstrated reduced susceptibility of biofilm-grown cells following removal from the biofilm structure. Lastly, the model provided sufficient nucleic material for study of differential gene expression associated with in vivo biofilm growth. Two fluconazole efflux pumps, CDR1 and CDR2, were upregulated in the in vivo biofilm-associated cells. Most importantly, the studies described provide a model for further investigation into the molecular mechanisms of C. albicans biofilm biology and drug resistance. In addition, the model provides a means to study novel drug therapies and device technologies targeted to the control of biofilm-associated infections.
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MESH Headings
- Animals
- Biofilms/drug effects
- Biofilms/growth & development
- Candida albicans/cytology
- Candida albicans/drug effects
- Candida albicans/growth & development
- Candida albicans/ultrastructure
- Candidiasis/microbiology
- Catheterization, Central Venous
- Drug Resistance, Fungal
- Female
- Fluconazole/pharmacology
- Gene Expression Regulation, Fungal
- Genes, Fungal/genetics
- Hyphae/cytology
- Hyphae/growth & development
- Hyphae/isolation & purification
- Hyphae/ultrastructure
- Kidney/microbiology
- Microscopy, Confocal
- Models, Animal
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Sonication
- Time Factors
- Transcription, Genetic/genetics
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Affiliation(s)
- D Andes
- Department of Medicine, University of Wisconsin, Madison, Wisconsin 53792, USA.
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48
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Mack D, Becker P, Chatterjee I, Dobinsky S, Knobloch JKM, Peters G, Rohde H, Herrmann M. Mechanisms of biofilm formation in Staphylococcus epidermidis and Staphylococcus aureus: functional molecules, regulatory circuits, and adaptive responses. Int J Med Microbiol 2004; 294:203-12. [PMID: 15493831 DOI: 10.1016/j.ijmm.2004.06.015] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Biomaterial-associated infections, most frequently caused by Staphylococcus epidermidis and Staphylococcus aureus, are of increasing importance in modern medicine. Regularly, antimicrobial therapy fails without removal of the implanted device. The most important factor in the pathogenesis of biomaterial-associated staphylococcal infections is the formation of adherent, multilayered bacterial biofilms. In this review, recent insights regarding factors functional in biofilm formation of S. epidermidis, their role in pathogenesis, and regulation of their expression are presented. Similarly, in S. aureus the biofilm mode of growth affects gene expression and the overall metabolic status. Experimental approaches for analysis of differential expression of genes involved in these adaptive responses and evolving patterns of gene expression are discussed.
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Affiliation(s)
- Dietrich Mack
- Institut für Infektionsmedizin, Zentrum für Klinisch-Theoretische Medizin I, Universitätsklinikum Hamburg-Eppendorf Martinistr 52, D-20246 Hamburg, Germany.
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49
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Beenken KE, Dunman PM, McAleese F, Macapagal D, Murphy E, Projan SJ, Blevins JS, Smeltzer MS. Global gene expression in Staphylococcus aureus biofilms. J Bacteriol 2004; 186:4665-84. [PMID: 15231800 PMCID: PMC438561 DOI: 10.1128/jb.186.14.4665-4684.2004] [Citation(s) in RCA: 443] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We previously demonstrated that mutation of the staphylococcal accessory regulator (sarA) in a clinical isolate of Staphylococcus aureus (UAMS-1) results in an impaired capacity to form a biofilm in vitro (K. E. Beenken, J. S. Blevins, and M. S. Smeltzer, Infect. Immun. 71:4206-4211, 2003). In this report, we used a murine model of catheter-based biofilm formation to demonstrate that a UAMS-1 sarA mutant also has a reduced capacity to form a biofilm in vivo. Surprisingly, mutation of the UAMS-1 ica locus had little impact on biofilm formation in vitro or in vivo. In an effort to identify additional loci that might be relevant to biofilm formation and/or the adaptive response required for persistence of S. aureus within a biofilm, we isolated total cellular RNA from UAMS-1 harvested from a biofilm grown in a flow cell and compared the transcriptional profile of this RNA to RNA isolated from both exponential- and stationary-phase planktonic cultures. Comparisons were done using a custom-made Affymetrix GeneChip representing the genomic complement of six strains of S. aureus (COL, N315, Mu50, NCTC 8325, EMRSA-16 [strain 252], and MSSA-476). The results confirm that the sessile lifestyle associated with persistence within a biofilm is distinct by comparison to the lifestyles of both the exponential and postexponential phases of planktonic culture. Indeed, we identified 48 genes in which expression was induced at least twofold in biofilms over expression under both planktonic conditions. Similarly, we identified 84 genes in which expression was repressed by a factor of at least 2 compared to expression under both planktonic conditions. A primary theme that emerged from the analysis of these genes is that persistence within a biofilm requires an adaptive response that limits the deleterious effects of the reduced pH associated with anaerobic growth conditions.
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Affiliation(s)
- Karen E Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR 72205, USA
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50
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Abstract
Bone and joint infections are painful for patients and frustrating for both them and their doctors. The high success rates of antimicrobial therapy in most infectious diseases have not yet been achieved in bone and joint infections owing to the physiological and anatomical characteristics of bone. The key to successful management is early diagnosis, including bone sampling for microbiological and pathological examination to allow targeted and long-lasting antimicrobial therapy. The various types of osteomyelitis require differing medical and surgical therapeutic strategies. These types include, in order of decreasing frequency: osteomyelitis secondary to a contiguous focus of infection (after trauma, surgery, or insertion of a joint prosthesis); that secondary to vascular insufficiency (in diabetic foot infections); or that of haematogenous origin. Chronic osteomyelitis is associated with avascular necrosis of bone and formation of sequestrum (dead bone), and surgical debridement is necessary for cure in addition to antibiotic therapy. By contrast, acute osteomyelitis can respond to antibiotics alone. Generally, a multidisciplinary approach is required for success, involving expertise in orthopaedic surgery, infectious diseases, and plastic surgery, as well as vascular surgery, particularly for complex cases with soft-tissue loss.
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Affiliation(s)
- Daniel P Lew
- Services of Infectious Diseases and Medicine 2, Department of Internal Medicine, Geneva University Hospitals, Geneva, Switzerland.
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