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Savitskaya A, Masso-Silva J, Haddaoui I, Enany S. Exploring the arsenal of antimicrobial peptides: Mechanisms, diversity, and applications. Biochimie 2023; 214:216-227. [PMID: 37499896 DOI: 10.1016/j.biochi.2023.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/09/2023] [Accepted: 07/24/2023] [Indexed: 07/29/2023]
Abstract
Antimicrobial peptides (AMPs) are essential for defence against pathogens in all living organisms and possessed activities against bacteria, fungi, viruses, parasites and even cancer cells. AMPs are short peptides containing 12-100 amino acids conferring a net positive charge and an amphiphilic property in most cases. Although, anionic AMPs also exist. AMPs can be classified based on the types of secondary structures, charge, hydrophobicity, amino acid composition, length, etc. Their mechanism of action usually includes a membrane disruption process through pore formation (three different models have been described, barrel-stave, toroidal or carpet model) but AMPs can also penetrate and impair intracellular functions. Besides their activity against pathogens, they have also shown immunomodulatory properties in complex scenarios through many different interactions. The aim of this review to summarize knowledge about AMP's and discuss the potential application of AMPs as therapeutics, the challenges due to their limitations, including their susceptibility to degradation, the potential generation of AMP resistance, cost, etc. We also discuss the current FDA-approved drugs based on AMPs and strategies to circumvent natural AMPs' limitations.
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Affiliation(s)
- Anna Savitskaya
- Institute of Bioorganic Chemistry of Russian Academy of Science, Moscow, Russian Federation
| | - Jorge Masso-Silva
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, University of California San Diego, La Jolla, CA, USA
| | - Imen Haddaoui
- National Research Institute of Rural Engineering, Water and Forestry, University of Carthage, LR Valorization of Unconventional Waters, Ariana, Tunisia
| | - Shymaa Enany
- Microbiology and Immunology Department, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt; Biomedical Research Department, Armed Force College of Medicine, Cairo, Egypt.
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2
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França A. The Role of Coagulase-Negative Staphylococci Biofilms on Late-Onset Sepsis: Current Challenges and Emerging Diagnostics and Therapies. Antibiotics (Basel) 2023; 12:antibiotics12030554. [PMID: 36978421 PMCID: PMC10044083 DOI: 10.3390/antibiotics12030554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/24/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Infections are one of the most significant complications of neonates, especially those born preterm, with sepsis as one of the principal causes of mortality. Coagulase-negative staphylococci (CoNS), a group of staphylococcal species that naturally inhabit healthy human skin and mucosa, are the most common cause of late-onset sepsis, especially in preterms. One of the risk factors for the development of CoNS infections is the presence of implanted biomedical devices, which are frequently used for medications and/or nutrient delivery, as they serve as a scaffold for biofilm formation. The major concerns related to CoNS infections have to do with the increasing resistance to multiple antibiotics observed among this bacterial group and biofilm cells’ increased tolerance to antibiotics. As such, the treatment of CoNS biofilm-associated infections with antibiotics is increasingly challenging and considering that antibiotics remain the primary form of treatment, this issue will likely persist in upcoming years. For that reason, the development of innovative and efficient therapeutic measures is of utmost importance. This narrative review assesses the current challenges and emerging diagnostic tools and therapies for the treatment of CoNS biofilm-associated infections, with a special focus on late-onset sepsis.
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Affiliation(s)
- Angela França
- Centre of Biological Engineering, LIBRO—Laboratório de Investigação em Biofilmes Rosário Oliveira, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal;
- LABBELS—Associate Laboratory in Biotechnology and Bioengineering and Microelectromechanical Systems, Braga and Guimarães, Portugal
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3
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Lu Y, Cai WJ, Ren Z, Han P. The Role of Staphylococcal Biofilm on the Surface of Implants in Orthopedic Infection. Microorganisms 2022; 10:1909. [PMID: 36296183 PMCID: PMC9612000 DOI: 10.3390/microorganisms10101909] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/11/2022] [Accepted: 09/20/2022] [Indexed: 08/27/2023] Open
Abstract
Despite advanced implant sterilization and aseptic surgical techniques, implant-associated infection remains a major challenge for orthopedic surgeries. The subject of bacterial biofilms is receiving increasing attention, probably as a result of the wide acknowledgement of the ubiquity of biofilms in the clinical environment, as well as the extreme difficulty in eradicating them. Biofilm can be defined as a structured microbial community of cells that are attached to a substratum and embedded in a matrix of extracellular polymeric substances (EPS) that they have produced. Biofilm development has been proposed as occurring in a multi-step process: (i) attachment and adherence, (ii) accumulation/maturation due to cellular aggregation and EPS production, and (iii) biofilm detachment (also called dispersal) of bacterial cells. In all these stages, characteristic proteinaceous and non-proteinaceous compounds are expressed, and their expression is strictly controlled. Bacterial biofilm formation around implants shelters the bacteria and encourages the persistence of infection, which could lead to implant failure and osteomyelitis. These complications need to be treated by major revision surgeries and extended antibiotic therapies, which could lead to high treatment costs and even increase mortality. Effective preventive and therapeutic measures to reduce risks for implant-associated infections are thus in urgent need.
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Affiliation(s)
| | | | | | - Pei Han
- Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
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4
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Spiegel C, Steixner SJM, Coraça-Huber DC. Antibiofilm Activity of Omega-3 Fatty Acids and Its Influence on the Expression of Biofilm Formation Genes on Staphylococcus aureus. Antibiotics (Basel) 2022; 11:antibiotics11070932. [PMID: 35884185 PMCID: PMC9311851 DOI: 10.3390/antibiotics11070932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 06/29/2022] [Accepted: 07/08/2022] [Indexed: 02/05/2023] Open
Abstract
Background: Currently, 1–2% of all prosthetic joint surgeries are followed by an infection. These infections cause approximately 4% of deaths in the first year after surgery, while the 5-year mortality rate is up to 21%. Prosthetic joint infections are mainly caused by Staphylococcus aureus or Staphylococcus epidermis strains. Both species share the capability of biofilm formation and methicillin resistance. The formation of biofilm helps bacterial cells to withstand critical environmental conditions. Due to their tolerance against antibacterial substances, biofilms are a significant problem in modern medicine. Alternatives for the use of methicillin as a therapeutic are not yet widespread. The use of omega-3 fatty acids, such as docosahexaenoic acid, may help against prosthetic joint infections and lower mortality rates. The aim of this study is to evaluate if docosahexaenoic acid offers a safe anti-biofilm activity against Staphylococcus aureus and MRSA without enhancing icaADBC-dependent biofilm formation or additional stress responses, therefore enhancing antibiotic tolerance and resistance. Methods: In this study, we examined the gene expression of biofilm-associated genes and regulators. We performed RT-qPCR after RNA extraction of Staphylococcus aureus ATCC 29213 and one clinical MRSA strain. We compared gene expression of icaADBC, SarA, SigB, and agrAC under the influence of 1.25 mg /L and 0.625 mg/L of docosahexaenoic acid to their controls. Results: We found a higher expression of regulatory genes such as SarA, SigB, agrA, and agrC at 1.25 mg/L of docosahexaenoic acid in ATCC 29213 and a lower increase in gene expression levels in clinical MRSA isolates. icaADBC was not affected in both strains at both concentration levels by docosahexaenoic acid. Conclusions: Docosahexaenoic acid does not enhance icaADBC-dependent biofilm formation while still reducing bacterial CFU in biofilms. Docosahexaenoic acid can be considered an option as a therapeutic substance against biofilm formation and may be a good alternative in reducing the risk of MRSA formation.
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5
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The Transcription Factor SpoVG Is of Major Importance for Biofilm Formation of Staphylococcus epidermidis under In Vitro Conditions, but Dispensable for In Vivo Biofilm Formation. Int J Mol Sci 2022; 23:ijms23063255. [PMID: 35328675 PMCID: PMC8949118 DOI: 10.3390/ijms23063255] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus epidermidis is a common cause of device related infections on which pathogens form biofilms (i.e., multilayered cell populations embedded in an extracellular matrix). Here, we report that the transcription factor SpoVG is essential for the capacity of S. epidermidis to form such biofilms on artificial surfaces under in vitro conditions. Inactivation of spoVG in the polysaccharide intercellular adhesin (PIA) producing S. epidermidis strain 1457 yielded a mutant that, unlike its parental strain, failed to produce a clear biofilm in a microtiter plate-based static biofilm assay. A decreased biofilm formation capacity was also observed when 1457 ΔspoVG cells were co-cultured with polyurethane-based peripheral venous catheter fragments under dynamic conditions, while the cis-complemented 1457 ΔspoVG::spoVG derivative formed biofilms comparable to the levels seen with the wild-type. Transcriptional studies demonstrated that the deletion of spoVG significantly altered the expression of the intercellular adhesion (ica) locus by upregulating the transcription of the ica operon repressor icaR and down-regulating the transcription of icaADBC. Electrophoretic mobility shift assays (EMSA) revealed an interaction between SpoVG and the icaA-icaR intergenic region, suggesting SpoVG to promote biofilm formation of S. epidermidis by modulating ica expression. However, when mice were challenged with the 1457 ΔspoVG mutant in a foreign body infection model, only marginal differences in biomasses produced on the infected catheter fragments between the mutant and the parental strain were observed. These findings suggest that SpoVG is critical for the PIA-dependent biofilm formation of S. epidermis under in vitro conditions, but is largely dispensable for biofilm formation of this skin commensal under in vivo conditions.
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6
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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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7
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Huebinger RM, Do DH, Carlson DL, Yao X, Stones DH, De Souza Santos M, Vaz DP, Keen E, Wolf SE, Minei JP, Francis KP, Orth K, Krachler AM. Bacterial adhesion inhibitor prevents infection in a rodent surgical incision model. Virulence 2021; 11:695-706. [PMID: 32490711 PMCID: PMC7550027 DOI: 10.1080/21505594.2020.1772652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Surgical site infection risk continues to increase due to lack of efficacy in current standard of care drugs. New methods to treat or prevent antibiotic-resistant bacterial infections are needed. Multivalent Adhesion Molecules (MAM) are bacterial adhesins required for virulence. We developed a bacterial adhesion inhibitor using recombinant MAM fragment bound to polymer scaffold, mimicking MAM7 display on the bacterial surface. Here, we test MAM7 inhibitor efficacy to prevent Gram-positive and Gram-negative infections. Using a rodent model of surgical infection, incision sites were infected with antibiotic-resistant bioluminescent strains of Staphylococcus aureus or Pseudomonas aeruginosa. Infections were treated with MAM7 inhibitor or control suspension. Bacterial abundance was quantified for nine days post infection. Inflammatory responses and histology were characterized using fixed tissue sections. MAM7 inhibitor treatment decreased burden of S. aureus and P. aeruginosa below detection threshold. Bacterial load of groups treated with control were significantly higher than MAM7 inhibitor-treated groups. Treatment with inhibitor reduced colonization of clinically-relevant pathogens in an in vivo model of surgical infection. Use of MAM7 inhibitor to block initial adhesion of bacteria to tissue in surgical incisions may reduce infection rates, presenting a strategy to mitigate overuse of antibiotics to prevent surgical site infections.
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Affiliation(s)
- R M Huebinger
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - D H Do
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - D L Carlson
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - X Yao
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - D H Stones
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham , Birmingham, UK.,University of Gloucestershire, School of Natural and Social Sciences , Cheltenham, UK
| | - M De Souza Santos
- Department of Molecular Biology, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - D P Vaz
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, McGovern Medical School , Houston, TX, USA
| | - E Keen
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham , Birmingham, UK
| | - S E Wolf
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA.,UTMB Department of Surgery, Shriners Hospitals for Children , Galveston, TX, USA
| | - J P Minei
- Department of Surgery, Division of General and Acute Care Surgery, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | | | - K Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center , Dallas, TX, USA.,Department of Biochemistry, University of Texas Southwestern Medical Center , Dallas, TX, USA.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center , Dallas, TX, USA
| | - A M Krachler
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, McGovern Medical School , Houston, TX, USA
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8
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Pätzold L, Brausch AC, Bielefeld EL, Zimmer L, Somerville GA, Bischoff M, Gaupp R. Impact of the Histidine-Containing Phosphocarrier Protein HPr on Carbon Metabolism and Virulence in Staphylococcus aureus. Microorganisms 2021; 9:microorganisms9030466. [PMID: 33668335 PMCID: PMC7996215 DOI: 10.3390/microorganisms9030466] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 02/18/2021] [Accepted: 02/19/2021] [Indexed: 01/01/2023] Open
Abstract
Carbon catabolite repression (CCR) is a common mechanism pathogenic bacteria use to link central metabolism with virulence factor synthesis. In gram-positive bacteria, catabolite control protein A (CcpA) and the histidine-containing phosphocarrier protein HPr (encoded by ptsH) are the predominant mediators of CCR. In addition to modulating CcpA activity, HPr is essential for glucose import via the phosphotransferase system. While the regulatory functions of CcpA in Staphylococcus aureus are largely known, little is known about the function of HPr in CCR and infectivity. To address this knowledge gap, ptsH mutants were created in S. aureus that either lack the open reading frame or harbor a ptsH variant carrying a thymidine to guanosine mutation at position 136, and the effects of these mutations on growth and metabolism were assessed. Inactivation of ptsH altered bacterial physiology and decreased the ability of S. aureus to form a biofilm and cause infections in mice. These data demonstrate that HPr affects central metabolism and virulence in S. aureus independent of its influence on CcpA regulation.
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Affiliation(s)
- Linda Pätzold
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
| | - Anne-Christine Brausch
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
| | - Evelyn-Laura Bielefeld
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
| | - Lisa Zimmer
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
| | - Greg A. Somerville
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE 68588, USA;
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
- Correspondence: ; Tel.: +49-6841-162-39-63
| | - Rosmarie Gaupp
- Institute of Medical Microbiology and Hygiene, Saarland University, D-66421 Homburg, Germany; (L.P.); (A.-C.B.); (E.-L.B.); (L.Z.); (R.G.)
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9
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França A, Gaio V, Lopes N, Melo LDR. Virulence Factors in Coagulase-Negative Staphylococci. Pathogens 2021; 10:170. [PMID: 33557202 PMCID: PMC7913919 DOI: 10.3390/pathogens10020170] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/29/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) have emerged as major pathogens in healthcare-associated facilities, being S. epidermidis, S. haemolyticus and, more recently, S. lugdunensis, the most clinically relevant species. Despite being less virulent than the well-studied pathogen S. aureus, the number of CoNS strains sequenced is constantly increasing and, with that, the number of virulence factors identified in those strains. In this regard, biofilm formation is considered the most important. Besides virulence factors, the presence of several antibiotic-resistance genes identified in CoNS is worrisome and makes treatment very challenging. In this review, we analyzed the different aspects involved in CoNS virulence and their impact on health and food.
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Affiliation(s)
- Angela França
- Laboratory of Research in Biofilms Rosário Oliveira, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (V.G.); (N.L.)
| | | | | | - Luís D. R. Melo
- Laboratory of Research in Biofilms Rosário Oliveira, Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; (V.G.); (N.L.)
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10
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Schulze A, Mitterer F, Pombo JP, Schild S. Biofilms by bacterial human pathogens: Clinical relevance - development, composition and regulation - therapeutical strategies. MICROBIAL CELL (GRAZ, AUSTRIA) 2021; 8:28-56. [PMID: 33553418 PMCID: PMC7841849 DOI: 10.15698/mic2021.02.741] [Citation(s) in RCA: 70] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
Notably, bacterial biofilm formation is increasingly recognized as a passive virulence factor facilitating many infectious disease processes. In this review we will focus on bacterial biofilms formed by human pathogens and highlight their relevance for diverse diseases. Along biofilm composition and regulation emphasis is laid on the intensively studied biofilms of Vibrio cholerae, Pseudomonas aeruginosa and Staphylococcus spp., which are commonly used as biofilm model organisms and therefore contribute to our general understanding of bacterial biofilm (patho-)physiology. Finally, therapeutical intervention strategies targeting biofilms will be discussed.
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Affiliation(s)
- Adina Schulze
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Fabian Mitterer
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- A.S. and F.M. contributed equally to this work
| | - Joao P. Pombo
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
| | - Stefan Schild
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, 8010 Graz, Austria
- BioTechMed Graz, Austria
- Field of Excellence Biohealth – University of Graz, Graz, Austria
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11
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Cardoso P, Glossop H, Meikle TG, Aburto-Medina A, Conn CE, Sarojini V, Valery C. Molecular engineering of antimicrobial peptides: microbial targets, peptide motifs and translation opportunities. Biophys Rev 2021; 13:35-69. [PMID: 33495702 PMCID: PMC7817352 DOI: 10.1007/s12551-021-00784-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023] Open
Abstract
The global public health threat of antimicrobial resistance has led the scientific community to highly engage into research on alternative strategies to the traditional small molecule therapeutics. Here, we review one of the most popular alternatives amongst basic and applied research scientists, synthetic antimicrobial peptides. The ease of peptide chemical synthesis combined with emerging engineering principles and potent broad-spectrum activity, including against multidrug-resistant strains, has motivated intense scientific focus on these compounds for the past decade. This global effort has resulted in significant advances in our understanding of peptide antimicrobial activity at the molecular scale. Recent evidence of molecular targets other than the microbial lipid membrane, and efforts towards consensus antimicrobial peptide motifs, have supported the rise of molecular engineering approaches and design tools, including machine learning. Beyond molecular concepts, supramolecular chemistry has been lately added to the debate; and helped unravel the impact of peptide self-assembly on activity, including on biofilms and secondary targets, while providing new directions in pharmaceutical formulation through taking advantage of peptide self-assembled nanostructures. We argue that these basic research advances constitute a solid basis for promising industry translation of rationally designed synthetic peptide antimicrobials, not only as novel drugs against multidrug-resistant strains but also as components of emerging antimicrobial biomaterials. This perspective is supported by recent developments of innovative peptide-based and peptide-carrier nanobiomaterials that we also review.
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Affiliation(s)
- Priscila Cardoso
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia.,School of Science, RMIT University, Melbourne, Australia
| | - Hugh Glossop
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | | | | | | | | | - Celine Valery
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Australia
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12
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The staphylococcal exopolysaccharide PIA - Biosynthesis and role in biofilm formation, colonization, and infection. Comput Struct Biotechnol J 2020. [PMID: 33240473 DOI: 10.1016/jcsbj202010027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
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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13
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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: 102] [Impact Index Per Article: 25.5] [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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14
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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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15
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Dapunt U, Prior B, Oelkrug C, Kretzer JP. IgY Targeting Bacterial Quorum-Sensing Molecules in Implant-Associated Infections. Molecules 2020; 25:molecules25174027. [PMID: 32899313 PMCID: PMC7504788 DOI: 10.3390/molecules25174027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 09/01/2020] [Indexed: 12/27/2022] Open
Abstract
Background: Implant-associated infections are still a major complication in the field of orthopedics. Bacteria can form biofilms on implant surfaces, making them more difficult to detect and treat. Since standard antibiotic therapy is often impaired in biofilm infections, particular interest is directed towards finding treatment alternatives. Biofilm-formation is a well-organized process during which bacteria communicate via quorum-sensing molecules (QSM). The aim of this study was to inhibit bacterial communication by directing avian IgY against specific QSM. Methods: Chicken were immunized against the following QSM: (1) AtlE, a member of the autolysin family which mediates attachment to a surface in Staphylococcus epidermidis; (2) GroEL, the bacterial heat shock protein; (3) PIA (polysaccharide intercellular adhesion), which is essential for cell–cell adhesion in biofilms. Staphylococcus epidermidis biofilms were grown and inhibition of biofilm-formation by IgYs was evaluated. Additionally, human osteoblasts were cultivated and biocompatibility of IgYs was tested. Results: We were able to demonstrate that all IgYs reduced biofilm-formation, also without prior immunization. Therefore, the response was probably not specific with regard to the QSM. Osteoblasts were activated by all IgYs which was demonstrated by microscopy and an increased release of IL-8. Conclusions: In conclusion, avian IgY inhibits biofilm-formation, though the underlying mechanism is not yet clear. However, adverse effects on local tissue cells (osteoblasts) were also observed.
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Affiliation(s)
- Ulrike Dapunt
- Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany
- Correspondence: ; Tel.: +49/6221-5625000
| | - Birgit Prior
- Department of Anesthesiology, Heidelberg University Hospital, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany;
| | - Christopher Oelkrug
- Oelkrug Enterprises UG (haftungsbeschraenkt), Gerhart Hauptmann Str. 10, 59387 Ascheberg, Germany;
| | - Jan Philippe Kretzer
- Laboratory of Biomechanics and Implant Research, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Schlierbacher Landstrasse 200a, 69118 Heidelberg, Germany;
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16
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Alhede M, Lorenz M, Fritz BG, Jensen PØ, Ring HC, Bay L, Bjarnsholt T. Bacterial aggregate size determines phagocytosis efficiency of polymorphonuclear leukocytes. Med Microbiol Immunol 2020; 209:669-680. [PMID: 32880037 PMCID: PMC7568703 DOI: 10.1007/s00430-020-00691-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 08/19/2020] [Indexed: 02/06/2023]
Abstract
The ability of bacteria to aggregate and form biofilms impairs phagocytosis by polymorphonuclear leukocytes (PMNs). The aim of this study was to examine if the size of aggregates is critical for successful phagocytosis and how bacterial biofilms evade phagocytosis. We investigated the live interaction between PMNs and Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Staphylococcus epidermidis using confocal scanning laser microscopy. Aggregate size significantly affected phagocytosis outcome and larger aggregates were less likely to be phagocytized. Aggregates of S. epidermidis were also less likely to be phagocytized than equally-sized aggregates of the other three species. We found that only aggregates of approx. 5 μm diameter or smaller were consistently phagocytosed. We demonstrate that planktonic and aggregated cells of all four species significantly reduced the viability of PMNs after 4 h of incubation. Our results indicate that larger bacterial aggregates are less likely to be phagocytosed by PMNs and we propose that, if the aggregates become too large, circulating PMNs may not be able to phagocytose them quickly enough, which may lead to chronic infection.
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Affiliation(s)
- Maria Alhede
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Melanie Lorenz
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Blaine Gabriel Fritz
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Peter Østrup Jensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.,Department of Clinical Microbiology, Rigshospitalet, Afsnit 9301, Juliane Maries Vej 22, DK-2100, Copenhagen Ø, Denmark.,Institute for Inflammation Research, Center for Rheumatology and Spine Diseases, Rigshospitalet, 2100, Copenhagen, Denmark
| | - Hans Christian Ring
- Department of Dermatology, Bispebjerg Hospital, Nielsine Nielsens Vej 9, København, NV, Denmark
| | - Lene Bay
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark. .,Department of Clinical Microbiology, Rigshospitalet, Afsnit 9301, Juliane Maries Vej 22, DK-2100, Copenhagen Ø, Denmark.
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17
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Transcriptional regulation of virulence factors Hla and phenol-soluble modulins α by AraC-type regulator Rbf in Staphylococcus aureus. Int J Med Microbiol 2020; 310:151436. [PMID: 32654771 DOI: 10.1016/j.ijmm.2020.151436] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 05/25/2020] [Accepted: 06/14/2020] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is a gram-positive pathogenic bacterium and is capable of secreting numerous toxins interfering directly with the host to cause acute infections. Rbf, a transcriptional regulator of AraC/XylS family, has been reported to promote biofilm formation in polysaccharide intercellular adhesion (PIA) mediated manner to cause chronic infections. In this study, we revealed the new virulence-mediated role of Rbf that can negatively regulate the hemolytic activity. Furthermore, Rbf can specifically bind to the hla and psmα promoters to repress their expression, resulting in significantly decreased production of phenol-soluble modulins α (PSMα) and alpha-toxin. Accordingly, the rbf mutant strain exhibited the increased pathogenicity compared to the wild-type (WT) strain in a mouse subcutaneous abscess model, representing a type of acute infection by S. aureus. Collectively, our results provide a novel insight into the virulence regulation and acute infections mediated by Rbf in S. aureus.
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18
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Fursova K, Sorokin A, Sokolov S, Dzhelyadin T, Shulcheva I, Shchannikova M, Nikanova D, Artem'eva O, Zinovieva N, Brovko F. Virulence Factors and Phylogeny of Staphylococcus aureus Associated With Bovine Mastitis in Russia Based on Genome Sequences. Front Vet Sci 2020; 7:135. [PMID: 32270001 PMCID: PMC7111254 DOI: 10.3389/fvets.2020.00135] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/24/2020] [Indexed: 12/28/2022] Open
Abstract
Staphylococcus aureus is a causative agent of different infectious processes, food poisoning, and autoimmune disorders. The horizontal transfer of pathogenic strains can occur from animal to human under both house and farm conditions, and the spread of strains with antibiotic resistance is an existing problem. In addition to the spread of antibiotic-resistant strains in clinics, this problem also exists in veterinary medicine. It is especially important to monitor antibiotic resistance on farms where antibiotics are the standard treatment of animals, which may trigger the spread of antibiotic-resistant strains among animals and to the human population, and these strains can also be distributed in milk products produced by these farms (milk, cheese, and butter). In this work, we investigated 21 S. aureus isolates using whole-genome sequence analysis and tried to establish a relationship between these isolates with the development of bovine mastitis in seven regions of Western Russia. An S. aureus virulence profile was identified. We identified two groups of S. aureus associated with subclinical mastitis, namely, the enterotoxin-positive and enterotoxin-negative groups. The most prevalent factor associated with bovine mastitis in Russia was cytotoxins, including hemolysins and leukocidins. Multidrug resistance strains were investigated, and antibiotic resistance genes were identified. We identified S. aureus ST 97 type as the most common type in the regions in Western Russia. To the best of our knowledge, this is the first in-depth study of a range S. aureus isolates originating from cattle infections in Russia.
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Affiliation(s)
- Ksenia Fursova
- Laboratory of Immunochemistry, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Pushchino, Russia
| | - Anatoly Sorokin
- Laboratory of Cell Genome Functioning Mechanisms, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Sergey Sokolov
- Laboratory of Plasmid Biology, G.K. Skryabin Institute of Biochemistry & Physiology of Microorganisms of the Russian Academy of Sciences, Pushchino, Russia
| | - Timur Dzhelyadin
- Laboratory of Cell Genome Functioning Mechanisms, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino, Russia
| | - Irina Shulcheva
- Laboratory of Immunochemistry, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Pushchino, Russia
| | - Margarita Shchannikova
- Laboratory of Immunochemistry, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Pushchino, Russia
| | - Daria Nikanova
- Laboratory of Microbiology, L.K. Ernst Federal Science Center for Animal Husbandry, Moscow, Russia
| | - Olga Artem'eva
- Laboratory of Microbiology, L.K. Ernst Federal Science Center for Animal Husbandry, Moscow, Russia
| | - Natalia Zinovieva
- Laboratory of Microbiology, L.K. Ernst Federal Science Center for Animal Husbandry, Moscow, Russia
| | - Fedor Brovko
- Laboratory of Immunochemistry, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Pushchino, Russia.,Laboratory of Microbiology, L.K. Ernst Federal Science Center for Animal Husbandry, Moscow, Russia
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19
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Kinetic of Adhesion of S. epidermidis with Different EPS Production on Ti6Al4V Surfaces. BIOMED RESEARCH INTERNATIONAL 2020; 2019:1437806. [PMID: 31915679 PMCID: PMC6930745 DOI: 10.1155/2019/1437806] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/20/2019] [Indexed: 11/18/2022]
Abstract
Controlling initial bacterial adhesion is essential to prevent biofilm formation and implant-related infection. The search for surface coatings that prevent initial adhesion is a powerful strategy to obtain implants that are more resistant to infection. Tracking the progression of adhesion on surfaces from the beginning of the interaction between bacteria and the surface provides a deeper understanding of the initial adhesion behavior. To this purpose, we have studied the progression over time of bacterial adhesion from a laminar flow of a bacterial suspension, using a modified Robbins device (MRD). Comparing with other laminar flow devices, such as the parallel plate flow chamber, MRD allows the use of diverse substrata under the same controlled flow conditions simultaneously. Two different surfaces of Ti6Al4V and two strains of Staphylococcus epidermidis with different exopolymer production were tested. In addition, the modified Robbins device was examined for its convenience and suitability for the purpose of this study. Results were analyzed according to a pseudofirst order kinetic. The values of the parameters obtained from this model make it possible to discriminate the adhesive behavior of surfaces and bacteria. One of the fitting parameters depends on the bacterial strain and the other only on the surface properties of the substrate.
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20
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Melo SF, Neves SC, Pereira AT, Borges I, Granja PL, Magalhães FD, Gonçalves IC. Incorporation of graphene oxide into poly(ɛ-caprolactone) 3D printed fibrous scaffolds improves their antimicrobial properties. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 109:110537. [PMID: 32228892 DOI: 10.1016/j.msec.2019.110537] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 12/08/2019] [Accepted: 12/09/2019] [Indexed: 12/12/2022]
Abstract
Implantable medical devices infection and consequent failure is a severe health issue, which can result from bacterial adhesion, growth, and subsequent biofilm formation at the implantation site. Graphene-based materials, namely graphene oxide (GO), have been described as potential antibacterial agents when immobilized and exposed in polymeric matrices. This work focuses on the development of antibacterial and biocompatible 3D fibrous scaffolds incorporating GO. Poly(ε-caprolactone) scaffolds were produced, with and without GO, using wet-spinning combined with additive manufacturing. Scaffolds with different GO loadings were evaluated regarding physical-chemical characterization, namely GO surface exposure, antibacterial properties, and ability to promote human cells adhesion. Antimicrobial properties were evaluated through live/dead assays performed with Gram-positive and Gram-negative bacteria. 2 h and 24 h adhesion assays revealed a time-dependent bactericidal effect in the presence of GO, with death rates of adherent S. epidermidis and E. coli reaching ~80% after 24 h of contact with scaffolds with the highest GO concentration. Human fibroblasts cultured for up to 14 days were able to adhere and spread over the fibers, independently of the presence of GO. Overall, this work demonstrates the potential of GO-containing fibrous scaffolds to be used as biomaterials that hinder bacterial infection, while allowing human cells adhesion.
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Affiliation(s)
- Sofia F Melo
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal; FEUP-Faculdade de Engenharia da Universidade do Porto, Portugal; ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal; LEPABE-Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Portugal
| | - Sara C Neves
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal
| | - Andreia T Pereira
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal; ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal
| | - Inês Borges
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal
| | - Pedro L Granja
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal; FEUP-Faculdade de Engenharia da Universidade do Porto, Portugal; ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal
| | - Fernão D Magalhães
- LEPABE-Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Portugal
| | - Inês C Gonçalves
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Portugal; FEUP-Faculdade de Engenharia da Universidade do Porto, Portugal; ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal.
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21
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Chug MK, Feit C, Brisbois EJ. Increasing the Lifetime of Insulin Cannula with Antifouling and Nitric Oxide Releasing Properties. ACS APPLIED BIO MATERIALS 2019; 2:5965-5975. [DOI: 10.1021/acsabm.9b00908] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Manjyot Kaur Chug
- Department of Materials Science & Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - Corbin Feit
- Department of Materials Science & Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - Elizabeth J. Brisbois
- Department of Materials Science & Engineering, University of Central Florida, Orlando, Florida 32816, United States
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22
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Cholic Acid-Peptide Conjugates as Potent Antimicrobials against Interkingdom Polymicrobial Biofilms. Antimicrob Agents Chemother 2019; 63:AAC.00520-19. [PMID: 31427303 DOI: 10.1128/aac.00520-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 08/10/2019] [Indexed: 12/14/2022] Open
Abstract
Interkingdom polymicrobial biofilms formed by Gram-positive Staphylococcus aureus and Candida albicans pose serious threats of chronic systemic infections due to the absence of any common therapeutic target for their elimination. Herein, we present the structure-activity relationship (SAR) of membrane-targeting cholic acid-peptide conjugates (CAPs) against Gram-positive bacterial and fungal strains. Structure-activity investigations validated by mechanistic studies revealed that valine-glycine dipeptide-derived CAP 3 was the most effective broad-spectrum antimicrobial against S. aureus and C. albicans CAP 3 was able to degrade the preformed single-species and polymicrobial biofilms formed by S. aureus and C. albicans, and CAP 3-coated materials prevented the formation of biofilms. Murine wound and catheter infection models further confirmed the equally potent bactericidal and fungicidal effect of CAP 3 against bacterial, fungal, and polymicrobial infections. Taken together, these results demonstrate that CAPs, as potential broad-spectrum antimicrobials, can effectively clear the frequently encountered polymicrobial infections and can be fine-tuned further for future applications.
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23
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Le KY, Villaruz AE, Zheng Y, He L, Fisher EL, Nguyen TH, Ho TV, Yeh AJ, Joo HS, Cheung GYC, Otto M. Role of Phenol-Soluble Modulins in Staphylococcus epidermidis Biofilm Formation and Infection of Indwelling Medical Devices. J Mol Biol 2019; 431:3015-3027. [PMID: 30954574 PMCID: PMC10999989 DOI: 10.1016/j.jmb.2019.03.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/10/2019] [Accepted: 03/22/2019] [Indexed: 12/20/2022]
Abstract
Phenol-soluble modulins (PSMs) are amphipathic, alpha-helical peptides that are secreted by staphylococci in high amounts in a quorum-sensing-controlled fashion. Studies performed predominantly in Staphylococcus aureus showed that PSMs structure biofilms, which results in reduced biofilm mass, while it has also been reported that S. aureus PSMs stabilize biofilms due to amyloid formation. We here analyzed the roles of PSMs in in vitro and in vivo biofilms of Staphylococcus epidermidis, the leading cause of indwelling device-associated biofilm infection. We produced isogenic deletion mutants for every S. epidermidis psm locus and a sequential deletion mutant in which production of all PSMs was abolished. In vitro analysis substantiated the role of all PSMs in biofilm structuring. PSM-dependent biofilm expansion was not observed, in accordance with our finding that no S. epidermidis PSM produced amyloids. In a mouse model of indwelling device-associated infection, the total psm deletion mutant had a significant defect in dissemination. Notably, the total psm mutant produced a significantly more substantial biofilm on the implanted catheter than the wild-type strain. Our study, which for the first time directly quantified the impact of PSMs on biofilm expansion on an implanted device, shows that the in vivo biofilm infection phenotype in S. epidermidis is in accordance with the PSM biofilm structuring and detachment model, which has important implications for the potential therapeutic application of quorum-sensing blockers.
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Affiliation(s)
- Katherine Y Le
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA; Division of Hospital Internal Medicine, Department of Medicine, Mayo Clinic College of Medicine, 200 1st Street SW, Rochester, MN 55902, USA
| | - Amer E Villaruz
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Lei He
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA; Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, No. 160 Pujian Road, Shanghai 200127, China
| | - Emilie L Fisher
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - 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, MD 20814, USA
| | - Trung V Ho
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Anthony J Yeh
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, USA
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, 50 South Drive, Bethesda, MD 20814, 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, MD 20814, USA.
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24
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Little SV, Bryan LK, Hillhouse AE, Cohen ND, Lawhon SD. Characterization of agr Groups of Staphylococcus pseudintermedius Isolates from Dogs in Texas. mSphere 2019; 4:e00033-19. [PMID: 30918056 PMCID: PMC6437270 DOI: 10.1128/msphere.00033-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/13/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus pseudintermedius is an important canine pathogen implicated in an increasing number of human infections. Along with rising levels of methicillin and multidrug resistance, staphylococcal biofilms are a complicating factor for treatment and contribute to device, implant, and surgical infections. Staphylococcal virulence, including biofilm formation, is regulated in part by the quorum sensing accessory gene regulator system (agr). The signal molecule for agr, known as the autoinducing peptide molecule, contains polymorphisms that result in the formation of distinct groups. In S. pseudintermedius, 4 groups (i.e., groups I, II, III, and IV) have been identified but not comprehensively examined for associations with infection type, virulence factor carriage, or phylogenetic relationships-all of which have been found to be significant in S. aureus In this study, 160 clinical canine isolates from Texas, including isolates from healthy dogs (n = 40) and 3 different infection groups (pyoderma, urinary tract, and surgical, n = 40 each), were sequenced. The agr group, biofilm-producing capabilities, toxin gene carriage, antimicrobial resistance, and sequence type (ST) were identified for all isolates. While no significant associations were discovered among the clinical infection types and agr groups, agr II isolates were significantly less common than any other group in diseased dogs. Furthermore, agr II isolates were less likely than other agr groups to be multidrug resistant and to carry toxin genes expA and sec-canine Fifty-two (33%) of the 160 isolates were methicillin resistant, and the main sequence types (ST64, ST68, ST71, ST84, ST150, and ST155) of methicillin-resistant strains of S. pseudintermedius (MRSP) were identified for the geographic region.IMPORTANCEStaphylococcus pseudintermedius is an important disease-causing bacterium in dogs and is recognized as a growing threat to human health. Due to increasing multidrug resistance, discovery of alternative methods for treatment of these infections is vital. Interference with one target for alternative treatment, the quorum sensing system agr, has demonstrated clinical improvement of infections in S. aureus animal models. In this study, we sequenced and characterized 160 clinical S. pseudintermedius isolates and their agr systems in order to increase understanding of the epidemiology of the agr group and clarify its associations with types of infection and antimicrobial resistance. We found that isolates with agr type II were significantly less common than other agr types in diseased dogs. This provides valuable information to veterinary clinical microbiologists and clinicians, especially as less research has been performed on infection associations of agr and its therapeutic potential in S. pseudintermedius than in S. aureus.
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Affiliation(s)
- Sara V Little
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Laura K Bryan
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Andrew E Hillhouse
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
- Texas A&M Institute for Genome Sciences and Society, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Noah D Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Sara D Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Transcriptional Regulation of icaADBC by both IcaR and TcaR in Staphylococcus epidermidis. J Bacteriol 2019; 201:JB.00524-18. [PMID: 30602488 DOI: 10.1128/jb.00524-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/17/2018] [Indexed: 12/17/2022] Open
Abstract
S. epidermidis is a primary cause of biofilm-mediated infections in humans due to adherence to foreign bodies. A major staphylococcal biofilm accumulation molecule is polysaccharide intracellular adhesin (PIA), which is synthesized by enzymes encoded by the icaADBC operon. Expression of PIA is highly variable among clinical isolates, suggesting that PIA expression levels are selected in certain niches of the host. However, the mechanisms that govern enhanced icaADBC transcription and PIA synthesis in these isolates are not known. We hypothesized that enhanced PIA synthesis in these isolates was due to function of IcaR and/or TcaR. Thus, two S. epidermidis isolates (1457 and CSF41498) with different icaADBC transcription and PIA expression levels were studied. Constitutive expression of both icaR and tcaR demonstrated that both repressors are functional and can completely repress icaADBC transcription in both 1457 and CSF41498. However, it was found that IcaR was the primary repressor for CSF41498 and TcaR was the primary repressor for 1457. Further analysis demonstrated that icaR transcription was repressed in 1457 in comparison to CSF41498, suggesting that TcaR functions as a repressor only in the absence of IcaR. Indeed, DNase I footprinting suggests IcaR and TcaR may bind to the same site within the icaR-icaA intergenic region. Lastly, we found mutants expressing variable amounts of PIA could rapidly be selected from both 1457 and CSF41498. Collectively, we propose that strains producing enhanced PIA synthesis are selected within certain niches of the host through several genetic mechanisms that function to repress icaR transcription, thus increasing PIA synthesis.IMPORTANCE Staphylococcus epidermidis is a commensal bacterium that resides on our skin. As a commensal, it protects humans from bacterial pathogens through a variety of mechanisms. However, it is also a significant cause of biofilm infections due to its ability to bind to plastic. Polysaccharide intercellular adhesin is a significant component of biofilm, and we propose that the expression of this polysaccharide is beneficial in certain host niches, such as providing extra strength when the bacterium is colonizing the lumen of a catheter, and detrimental in others, such as colonization of the skin surface. We show here that fine-tuning of icaADBC transcription, and thus PIA synthesis, is mediated via two transcriptional repressors, IcaR and TcaR.
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Arunachalam K, Ramar M, Ramanathan S, Govindaraju A, Shunmugiah KP, Kandasamy R, Arumugam VR. In vivo protective effect of geraniol on colonization of Staphylococcus epidermidis in rat jugular vein catheter model. Pathog Dis 2019; 76:5035816. [PMID: 29893828 DOI: 10.1093/femspd/fty055] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 06/08/2018] [Indexed: 01/13/2023] Open
Abstract
Staphylococcal infections associated with indwelling medical devices are difficult to eradicate owing to its recalcitrant nature of biofilms to conventional antibiotics. In our earlier study, we reported the efficacy of geraniol (GE) in inhibiting the in vitro biofilm formation of Staphylococcus epidermidis and adaptive resistant development. To examine the in vivo potential of GE in eradicating the in vivo colonization of S. epidermidis, an implanted rat jugular vein catheter model was developed. Oral supplementation of GE (GE at 200 mg/kg bw for three days) in rats infected with S. epidermidis exhibited a significant reduction of the bacterial burden in catheter, blood, heart and kidney, when compared to the untreated infection control. In addition, GE supplemented animals showed significantly reduced level of inflammatory markers such as nitric oxide and malondialdehyde in heart and kidney tissues. Furthermore, in contrast to the infection control, histopathology analysis of the heart and kidney tissues of the GE-treated group showed a normal histoarchitecture similar to animal control. Thus, the outcome of the present study exhibits the potential of GE as antibiofilm and anti-inflammatory agent against S. epidermidis infections. Furthermore, elucidating the molecular mechanism of GE is important to exploit the therapeutic efficacy of GE.
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Affiliation(s)
- Kannappan Arunachalam
- Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - Mohankumar Ramar
- Department of Pharmaceutical Technology, National Facility for Drug Development (NFDD) for Academia, Pharmaceutical and Allied Industries, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Srinivasan Ramanathan
- Department of Biotechnology, Science Campus, Alagappa University, Karaikudi, 630 003, Tamil Nadu, India
| | - Archunan Govindaraju
- Department of Animal Science, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | | | - Ruckmani Kandasamy
- Department of Pharmaceutical Technology, National Facility for Drug Development (NFDD) for Academia, Pharmaceutical and Allied Industries, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Veera Ravi Arumugam
- Department of Pharmaceutical Technology, National Facility for Drug Development (NFDD) for Academia, Pharmaceutical and Allied Industries, Bharathidasan Institute of Technology, Anna University, Tiruchirappalli, 620 024, Tamil Nadu, India
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Abstract
Staphylococci, with the leading species Staphylococcus aureus and Staphylococcus epidermidis, are the most frequent causes of infections on indwelling medical devices. The biofilm phenotype that those bacteria adopt during device-associated infection facilitates increased resistance to antibiotics and host immune defenses. This review presents and discusses the molecular mechanisms contributing to staphylococcal biofilm development and their in-vivo importance. Furthermore, it summarizes current strategies for the development of therapeutics against staphylococcal biofilm-associated infection.
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Biofilm Inhibition: Compounds with Antibacterial Effects. JOURNAL OF INTERDISCIPLINARY MEDICINE 2018. [DOI: 10.2478/jim-2018-0042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Biofilms can form on living or inert surfaces and prevail in natural, industrial, and hospital environments. They are made of bacteria organized in a coordinated functional community. Biofilms do not respond to antibiotic treatment due to multiple mechanisms of tolerance and resistance. If bacteria are coordinated in a biofilm form, they are significantly less susceptible to antibiotics, thus making the therapeutic approach difficult. The possibility of using drugs aimed at inhibiting the formation of biofilms in combination with current antibiotics is a therapeutic approach with a major potential for this type of persistent bacterial infection. This bibliographic study aims to present the main compounds that act by inhibiting or destroying the bacterial biofilm.
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Zheng Y, He L, Asiamah TK, Otto M. Colonization of medical devices by staphylococci. Environ Microbiol 2018; 20:3141-3153. [PMID: 29633455 DOI: 10.1111/1462-2920.14129] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/16/2018] [Accepted: 04/03/2018] [Indexed: 12/19/2022]
Abstract
The use of medical devices in modern medicine is constantly increasing. Despite the multiple precautionary strategies that are being employed in hospitals, which include increased hygiene and sterilization measures, bacterial infections on these devices still happen frequently. Staphylococci are among the major causes of medical device infection. This is mostly due to the strong capacity of those bacteria to form device-associated biofilms, which provide resistance to chemical and physical treatments as well as attacks by the host's immune system. Biofilm development is a multistep process with specific factors participating in each step. It is tightly regulated to provide a balance between biofilm expansion and detachment. Detachment from a biofilm on a medical device can lead to severe systemic infection, such as bacteremia and sepsis. While our understanding of staphylococcal biofilm formation has increased significantly and staphylococcal biofilm formation on medical devices is among the best understood biofilm-associated infections, the extensive effort put in preclinical studies with the goal to find novel therapies against staphylococcal device-associated infections has not yet resulted in efficient, applicable therapeutic options for that difficult-to-treat type of disease.
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Affiliation(s)
- Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Lei He
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Titus K Asiamah
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
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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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31
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Comparative characterisation of the biofilm-production abilities of Staphylococcus epidermidis isolated from human skin and platelet concentrates. J Med Microbiol 2018; 67:190-197. [DOI: 10.1099/jmm.0.000673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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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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Costerton JW, Montanaro L, Arciola CR. Biofilm in Implant Infections: Its Production and Regulation. Int J Artif Organs 2018; 28:1062-8. [PMID: 16353112 DOI: 10.1177/039139880502801103] [Citation(s) in RCA: 489] [Impact Index Per Article: 81.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A significant proportion of medical implants become the focus of a device-related infection, difficult to eradicate because bacteria that cause these infections live in well-developed biofilms. Biofilm is a microbial derived sessile community characterized by cells that are irreversibly attached to a substratum or interface to each other, embedded in a matrix of extracellular polymeric substances that they have produced. Bacterial adherence and biofilm production proceed in two steps: first, an attachment to a surface and, second, a cell-to-cell adhesion, with pluristratification of bacteria onto the artificial surface. The first step requires the mediation of bacterial surface proteins, the cardinal of which is similar to S. aureus autolysin and is denominated AtlE. In staphylococci the matrix of extracellular polymeric substances of biofilm is a polymer of β-1,6-linked N-acetylglucosamine (PIA), whose synthesis is mediated by the ica operon. Biofilm formation is partially controlled by quorum sensing, an interbacterial communication mechanism dependent on population density. The principal implants that can be compromised by biofilm associated infections are: central venous catheters, heart valves, ventricular assist devices, coronary stents, neurosurgical ventricular shunts, implantable neurological stimulators, arthro-prostheses, fracture-fixation devices, inflatable penile implants, breast implants, cochlear implants, intra-ocular lenses, dental implants. Biofilms play an important role in the spread of antibiotic resistance. Within the high dense bacterial population, efficient horizontal transfer of resistance and virulence genes takes place. In the future, treatments that inhibit the transcription of biofilm controlling genes might be a successful strategy in inhibiting these infections.
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Affiliation(s)
- J W Costerton
- Center for Biofilms, School of Dentistry, University of Southern California, Los Angeles, California, USA
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von Eiff C, Kohnen W, Becker K, Jansen B. Modern Strategies in the Prevention of Implant-Associated Infections. Int J Artif Organs 2018; 28:1146-56. [PMID: 16353121 DOI: 10.1177/039139880502801112] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The application of medical devices either for temporary or permanent use has become an indispensible part of almost all fields of medicine. However, foreign bodies are associated with a substantial risk of bacterial and fungal infections. Implant-associated infections significantly contribute to the still increasing problem of nosocomial infections. To reduce the incidence of such infections, specific guidelines providing evidence-based recommendations and comprising both technological and nontechnological strategies for prevention have been established. Strict adherence to hygienic rules during insertion or implantation of the device are aspects of particular importance. Besides such basic and indispensable aspects, the development of new materials which could withstand microbial adherence and colonization has become a major topic in recent years. Modification of surface by primarily physico-chemical methods may lead to a change in specific and unspecific interactions with microorganisms and, thus, to a reduction in microbial adherence. Medical devices made out of a material that would be ideally antiadhesive or at least colonization-resistant would be the most suitable candidates to avoid colonization and subsequent infection. However, it appears impossible to create a surface with an absolute “zero”-adherence due to thermodynamical reasons and due to the fact that a modified material surface is in vivo rapidly covered by plasma and connective tissue proteins. Therefore, another concept for the prevention of implant-associated infections involves the impregnation of devices with various antimicrobial substances such as antibiotics, antiseptics, and/or metals. In fact, already commercially available materials for clinical use such as antimicrobial catheters have been introduced, in part with considerable impact on subsequent infections. However, future studies are warranted to translate the knowledge on the pathogenesis of device-associated infections into applicable prevention strategies.
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Affiliation(s)
- C von Eiff
- Institute of Medical Microbiology, University of Münster Hospital and Clinics, Münster, Germany.
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Vadyvaloo V, Otto M. Molecular Genetics of Staphylococcus Epidermidis Biofilms on Indwelling Medical Devices. Int J Artif Organs 2018; 28:1069-78. [PMID: 16353113 DOI: 10.1177/039139880502801104] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Staphylococcus epidermidis is an opportunistic pathogen associated with foreign body infections and nosocomial sepsis. The pathogenicity of S. epidermidis is mostly due to its ability to colonize indwelling polymeric devices and form a thick, multilayered biofilm. Biofilm formation is a major problem in treating S. epidermidis infection as biofilms provide significant resistance to antibiotics and to components of the innate host defenses. Various cell surface associated bacterial factors play a role in adherence and accumulation of the biofilm such as the polysaccharide intercellular adhesin and the autolysin AtlE. Furthermore, recent studies have shown that global regulators such as the agr quorum sensing system, the transcriptional regulator sarA and the alternative sigma factor sigB have an important function in the regulation of biofilm formation. Understanding the many complex mechanisms involved in biofilm formation is a key factor in the search for new anti-staphylococcal therapeutics.
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Affiliation(s)
- V Vadyvaloo
- Rocky Mountain Laboratories, NIAID/NIH, Hamilton, MT, USA
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Knobloch KM, Von Osten H, Horstkotte MA, Rohde H, Mack D. Biofilm Formation is not Necessary for Development of Quinolone-Resistant “Persister” cells in an Attached Staphylococcus Epidermidis Population. Int J Artif Organs 2018; 31:752-60. [DOI: 10.1177/039139880803100902] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Staphylococcus epidermidis is a common pathogen in device-associated infections which is able to attach onto polymeric surfaces and develop multilayered biofilms. Attached S. epidermidis displays reduced susceptibility to antimicrobial agents. In this study we investigated the influence of ciprofloxacin and the group IV quinolones gatifloxacin, gemifloxacin, and moxifloxacin with the minimal attachment killing (MAK) assay. MAK concentrations were determined for three biofilm-positive wild-type strains and their isogenic biofilm-negative mutants Depending on strain and investigated quinolone, it was possible to distinguish between a heterogeneous MAK (MAKhetero), and a homogeneous resistance (MAKhomo) which corresponds to the model of a few persisting cells under antibiotic treatment. A lower MAKhomo was detected for the biofilm-negative mutants as well as for the corresponding wild-types for some of the tested quinolones, which seems to be a result of higher bacterial inocula, whereas the MAKhetero concentrations were comparable for mutants and wild-types for nearly all of the tested antibiotics and strains. These data indicate that biofilm formation is not necessary for persistence of attached S. epidermidis cells under treatment with quinolones and could explain therapeutic failure in foreign body-associated infections due to biofilm-negative S. epidermidis isolates. The individual resistance phenotypes of investigated strains indicate that the determination of MAK concentrations might help to predict the therapy outcome of foreign body-associated infections with both biofilm-positive and biofilm-negative S. epidermidis. Thus, the relatively high activity displayed by group IV quinolones against individual attached staphylococcal isolates indicates a possible treatment option with the respective quinolones for foreign body-associated infections due to these isolates. (Int J Artif Organs 2008; 31: 752–60)
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Affiliation(s)
- K.-M. Knobloch
- Institute for Medical Microbiology and Hygiene, University of Lübeck, Lübeck - Germany
| | - H. Von Osten
- Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg - Germany
| | - M. A. Horstkotte
- Bioscientia Institut für Medizinische Diagnostik GmbH, Labor Hamburg, Hamburg, Germany
| | - H. Rohde
- Institute for Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg - Germany
| | - D. Mack
- Medical Microbiology and Infectious Diseases, Institute of Life Science, School of Medicine, Swansea University, Swansea, United Kingdom
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Zacchino SA, Butassi E, Cordisco E, Svetaz LA. Hybrid combinations containing natural products and antimicrobial drugs that interfere with bacterial and fungal biofilms. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2017; 37:14-26. [PMID: 29174600 DOI: 10.1016/j.phymed.2017.10.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Biofilms contribute to the pathogenesis of many chronic and difficult-to eradicate infections whose treatment is complicated due to the intrinsic resistance to conventional antibiotics. As a consequence, there is an urgent need for strategies that can be used for the prevention and treatment of biofilm-associated infections. The combination therapy comprising an antimicrobial drug with a low molecular weight (MW) natural product and an antimicrobial drug (antifungal or antibacterial) appeared as a good alternative to eradicate biofilms. PURPOSE The aims of this review were to perform a literature search on the different natural products that have showed the ability of potentiating the antibiofilm capacity of antimicrobial drugs, to analyze which are the antimicrobial drugs most used in combination, and to have a look on the microbial species most used to prepare biofilms. RESULTS Seventeen papers, nine on combinations against antifungal biofilms and eight against antibacterial biofilms were collected. Within the text, the following topics have been developed: breaf history of the discovery of biofilms; stages in the development of a biofilm; the most used methodologies to assess antibiofilm-activity; the natural products with capacity of eradicating biofilms when acting alone; the combinations of low MW natural products with antibiotics or antifungal drugs as a strategy for eradicating microbial biofilms and a list of the low MW natural products that potentiate the inhibition capacity of antifungal and antibacterial drugs against biofilms. CONCLUSIONS AND PERSPECTIVES Regarding combinations against antifungal biofilms, eight over the nine collected works were carried out with in vitro studies while only one was performed with in vivo assays by using Caenorhabditis elegans nematode. All studies use biofilms of the Candida genus. A 67% of the potentiators were monoterpenes and sesquiterpenes and six over the nine works used FCZ as the antifungal drug. The activity of AmpB and Caspo was enhanced in one and two works respectively. Regarding combinations against bacterial biofilms, in vitro studies were performed in all works by using several different methods of higher variety than the used against fungal biofilms. Biofilms of both the gram (+) and gram (-) bacteria were prepared, although biofilm of Staphylococcus spp. were the most used in the collected works. Among the discovered potentiators of antibacterial drugs, 75% were terpenes, including mono, di- and triterpenes, and, among the atibacterial drugs, several structurally diverse types were used in the combinations: aminoglycosides, β-lactams, glucopeptides and fluoroquinolones. The potentiating capacity of natural products, mainly terpenes, on the antibiofilm effect of antimicrobial drugs opens a wide range of possibilities for the combination antimicrobial therapy. More in vivo studies on combinations of natural products with antimicrobial drugs acting against biofilms are highly required to cope the difficult to treat biofilm-associated infections.
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Affiliation(s)
- Susana A Zacchino
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Estefanía Butassi
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Estefanía Cordisco
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
| | - Laura A Svetaz
- Área Farmacognosia, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina
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Abstract
The staphylococci comprise a diverse genus of Gram-positive, nonmotile commensal organisms that inhabit the skin and mucous membranes of humans and other mammals. In general, staphylococci are benign members of the natural flora, but many species have the capacity to be opportunistic pathogens, mainly infecting individuals who have medical device implants or are otherwise immunocompromised. Staphylococcus aureus and Staphylococcus epidermidis are major sources of hospital-acquired infections and are the most common causes of surgical site infections and medical device-associated bloodstream infections. The ability of staphylococci to form biofilms in vivo makes them highly resistant to chemotherapeutics and leads to chronic diseases. These biofilm infections include osteomyelitis, endocarditis, medical device infections, and persistence in the cystic fibrosis lung. Here, we provide a comprehensive analysis of our current understanding of staphylococcal biofilm formation, with an emphasis on adhesins and regulation, while also addressing how staphylococcal biofilms interact with the immune system. On the whole, this review will provide a thorough picture of biofilm formation of the staphylococcus genus and how this mode of growth impacts the host.
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Bischoff M, Wonnenberg B, Nippe N, Nyffenegger-Jann NJ, Voss M, Beisswenger C, Sunderkötter C, Molle V, Dinh QT, Lammert F, Bals R, Herrmann M, Somerville GA, Tschernig T, Gaupp R. CcpA Affects Infectivity of Staphylococcus aureus in a Hyperglycemic Environment. Front Cell Infect Microbiol 2017; 7:172. [PMID: 28536677 PMCID: PMC5422431 DOI: 10.3389/fcimb.2017.00172] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 04/20/2017] [Indexed: 11/16/2022] Open
Abstract
Many bacteria regulate the expression of virulence factors via carbon catabolite responsive elements. In Gram-positive bacteria, the predominant mediator of carbon catabolite repression is the catabolite control protein A (CcpA). Hyperglycemia is a widespread disorder that predisposes individuals to an array of symptoms and an increased risk of infections. In hyperglycemic individuals, the bacterium Staphylococcus aureus causes serious, life-threatening infections. The importance of CcpA in regulating carbon catabolite repression in S. aureus suggests it may be important for infections in hyperglycemic individuals. To test this suggestion, hyperglycemic non-obese diabetic (NOD; blood glucose level ≥20 mM) mice were challenged with the mouse pathogenic S. aureus strain Newman and the isogenic ccpA deletion mutant (MST14), and the effects on infectivity were determined. Diabetic NOD mice challenged with the ccpA deletion mutant enhanced the symptoms of infection in an acute murine pneumonia model relative to the parental strain. Interestingly, when diabetic NOD mice were used in footpad or catheter infection models, infectivity of the ccpA mutant decreased relative to the parental strain. These differences greatly diminished when normoglycemic NOD mice (blood glucose level ≤ 10 mM) were used. These data suggest that CcpA is important for infectivity of S. aureus in hyperglycemic individuals.
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Affiliation(s)
- Markus Bischoff
- Institute for Medical Microbiology and Hygiene, Saarland UniversityHomburg, Germany
| | - Bodo Wonnenberg
- Institute of Anatomy and Cell Biology, Saarland UniversityHomburg, Germany
| | - Nadine Nippe
- Institute of Immunology, University of MunsterMunster, Germany
| | - Naja J Nyffenegger-Jann
- Division of Infection Biology, Department of Biomedicine, University Hospital BaselBasel, Switzerland
| | - Meike Voss
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University HospitalHomburg, Germany
| | - Christoph Beisswenger
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University HospitalHomburg, Germany
| | | | | | - Quoc Thai Dinh
- Department of Experimental Pneumology and Allergology, Saarland University HospitalHomburg, Germany
| | - Frank Lammert
- Department of Medicine II, Saarland University HospitalHomburg, Germany
| | - Robert Bals
- Department of Internal Medicine V - Pulmonology, Allergology and Critical Care Medicine, Saarland University HospitalHomburg, Germany
| | - Mathias Herrmann
- Institute for Medical Microbiology and Hygiene, Saarland UniversityHomburg, Germany
| | - Greg A Somerville
- School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-LincolnLincoln, NE, USA
| | - Thomas Tschernig
- Institute of Anatomy and Cell Biology, Saarland UniversityHomburg, Germany
| | - Rosmarie Gaupp
- Institute for Medical Microbiology and Hygiene, Saarland UniversityHomburg, Germany
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In Vitro and In Vivo Activities of a Bi-Aryl Oxazolidinone, RBx 11760, against Gram-Positive Bacteria. Antimicrob Agents Chemother 2016; 60:7134-7145. [PMID: 27645240 DOI: 10.1128/aac.00453-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 09/07/2016] [Indexed: 11/20/2022] Open
Abstract
RBx 11760, a bi-aryl oxazolidinone, was investigated for antibacterial activity against Gram-positive bacteria. The MIC90s of RBx 11760 and linezolid against Staphylococcus aureus were 2 and 4 mg/liter, against Staphylococcus epidermidis were 0.5 and 2 mg/liter, and against Enterococcus were 1 and 4 mg/liter, respectively. Similarly, against Streptococcus pneumoniae the MIC90s of RBx 11760 and linezolid were 0.5 and 2 mg/liter, respectively. In time-kill studies, RBx 11760, tedizolid, and linezolid exhibited bacteriostatic effect against all tested strains except S. pneumoniae RBx 11760 showed 2-log10 kill at 4× MIC while tedizolid and linezolid showed 2-log10 and 1.4-log10 kill at 16× MIC, respectively, against methicillin-resistant S. aureus (MRSA) H-29. Against S. pneumoniae 5051, RBx 11760 showed bactericidal activity, with 4.6-log10 kill at 4× MIC compared to 2.42-log10 and 1.95-log10 kill for tedizolid and linezolid, respectively, at 16× MIC. RBx 11760 showed postantibiotic effects (PAE) at 3 h at 4 mg/liter against MRSA H-29, and linezolid showed the same effect at 16 mg/liter. RBx 11760 inhibited biofilm production against methicillin-resistant S. epidermidis (MRSE) ATCC 35984 in a concentration-dependent manner. In a foreign-body model, linezolid and rifampin resulted in no advantage over stasis, while the same dose of RBx 11760 demonstrated a significant killing compared to the initial control against S. aureus (P < 0.05) and MRSE (P < 0.01). The difference in killing was statistically significant for the lower dose of RBx 11760 (P < 0.05) versus the higher dose of linezolid (P > 0.05 [not significant]) in a groin abscess model. In neutropenic mouse thigh infection, RBx 11760 showed stasis at 20 mg/kg of body weight, whereas tedizolid showed the same effect at 40 mg/kg. These data support RBx 11760 as a promising investigational candidate.
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Morgenstern M, Post V, Erichsen C, Hungerer S, Bühren V, Militz M, Richards RG, Moriarty TF. Biofilm formation increases treatment failure in Staphylococcus epidermidis device-related osteomyelitis of the lower extremity in human patients. J Orthop Res 2016; 34:1905-1913. [PMID: 26925869 DOI: 10.1002/jor.23218] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/23/2016] [Indexed: 02/04/2023]
Abstract
UNLABELLED The ability to form biofilm on the surface of implanted devices is often considered the most critical virulence factor possessed by Staphylococcus epidermidis in its role as an opportunistic pathogen in orthopaedic device-related infection (ODRI). Despite this recognition, there is a lack of clinical evidence linking outcome with biofilm forming ability for S. epidermidis ODRIs. We prospectively collected S. epidermidis isolates cultured from patients presenting with ODRI. Antibiotic resistance patterns and biofilm-forming ability was assessed. Patient information was collected and treatment outcome measures were determined after a mean follow-up period of 26 months. The primary outcome measure was cure at follow-up. Univariate logistic regression models were used to determine the influence of biofilm formation and antibiotic resistance on treatment outcome. A total of 124 patients were included in the study, a majority of whom (n = 90) involved infections of the lower extremity. A clear trend emerged in the lower extremity cohort whereby cure rates decreased as the biofilm-forming ability of the isolates increased (84% cure rate for infections caused by non-biofilm formers, 76% cure rate for weak biofilm-formers, and 60% cure rate for the most marked biofilm formers, p = 0.076). Antibiotic resistance did not influence treatment cure rate. Chronic immunosuppression was associated with a statistically significant decrease in cure rate (p = 0.044). CLINICAL SIGNIFICANCE The trend of increasing biofilm-forming ability resulting in lower cure rates for S. epidermidis ODRI indicates biofilm-forming ability of infecting pathogens does influence treatment outcome of infections of the lower extremity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1905-1913, 2016.
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Affiliation(s)
- Mario Morgenstern
- Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.,AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland
| | - Virginia Post
- AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland
| | - Christoph Erichsen
- Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany.,AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland
| | - Sven Hungerer
- Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany
| | - Volker Bühren
- Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany
| | - Matthias Militz
- Department of Trauma-Surgery, Trauma Centre Murnau, Prof. Kuentscher Strasse 8, 82418, Murnau, Germany
| | - R Geoff Richards
- AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland
| | - T Fintan Moriarty
- AO Research Institute Davos, AO Foundation, Clavadelerstrasse 8, Davos Platz CH7270, Switzerland
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Chen J, Howell C, Haller CA, Patel MS, Ayala P, Moravec KA, Dai E, Liu L, Sotiri I, Aizenberg M, Aizenberg J, Chaikof EL. An immobilized liquid interface prevents device associated bacterial infection in vivo. Biomaterials 2016; 113:80-92. [PMID: 27810644 DOI: 10.1016/j.biomaterials.2016.09.028] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 09/20/2016] [Accepted: 09/30/2016] [Indexed: 12/16/2022]
Abstract
Virtually all biomaterials are susceptible to biofilm formation and, as a consequence, device-associated infection. The concept of an immobilized liquid surface, termed slippery liquid-infused porous surfaces (SLIPS), represents a new framework for creating a stable, dynamic, omniphobic surface that displays ultralow adhesion and limits bacterial biofilm formation. A widely used biomaterial in clinical care, expanded polytetrafluoroethylene (ePTFE), infused with various perfluorocarbon liquids generated SLIPS surfaces that exhibited a 99% reduction in S. aureus adhesion with preservation of macrophage viability, phagocytosis, and bactericidal function. Notably, SLIPS modification of ePTFE prevents device infection after S. aureus challenge in vivo, while eliciting a significantly attenuated innate immune response. SLIPS-modified implants also decrease macrophage inflammatory cytokine expression in vitro, which likely contributed to the presence of a thinner fibrous capsule in the absence of bacterial challenge. SLIPS is an easily implementable technology that provides a promising approach to substantially reduce the risk of device infection and associated patient morbidity, as well as health care costs.
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Affiliation(s)
- Jiaxuan Chen
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States
| | - Caitlin Howell
- Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States; John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, United States
| | - Carolyn A Haller
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States
| | - Madhukar S Patel
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States; Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, United States
| | - Perla Ayala
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States
| | - Katherine A Moravec
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States
| | - Erbin Dai
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States
| | - Liying Liu
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States
| | - Irini Sotiri
- Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States; John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, United States
| | - Michael Aizenberg
- Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States
| | - Joanna Aizenberg
- Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States; John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, MA 02138, United States; Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, United States; Kavli Institute for Bionano Science and Technology, Harvard University, 29 Oxford Street, Cambridge, MA 02138, United States.
| | - Elliot L Chaikof
- Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, Boston, MA 02215, United States; Wyss Institute for Biologically Inspired Engineering at Harvard University, 3 Blackfan Circle, Boston, MA 02115, United States; Harvard-MIT Division of Health Sciences and Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, United States.
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Poly-N-Acetylglucosamine Production by Staphylococcus epidermidis Cells Increases Their In Vivo Proinflammatory Effect. Infect Immun 2016; 84:2933-43. [PMID: 27481237 DOI: 10.1128/iai.00290-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/21/2016] [Indexed: 12/12/2022] Open
Abstract
Poly-N-acetylglucosamine (PNAG) is a major component of the Staphylococcus epidermidis biofilm extracellular matrix. However, it is not yet clear how this polysaccharide impacts the host immune response and infection-associated pathology. Faster neutrophil recruitment and bacterial clearance were observed in mice challenged intraperitoneally with S. epidermidis biofilm cells of the PNAG-producing 9142 strain than in mice similarly challenged with the isogenic PNAG-defective M10 mutant. Moreover, intraperitoneal priming with 9142 cells exacerbated liver inflammatory pathology induced by a subsequent intravenous S. epidermidis challenge, compared to priming with M10 cells. The 9142-primed mice had elevated splenic CD4(+) T cells producing gamma interferon and interleukin-17A, indicating that PNAG promoted cell-mediated immunity. Curiously, despite having more marked liver tissue pathology, 9142-primed mice also had splenic T regulatory cells with greater suppressive activity than those of their M10-primed counterparts. By showing that PNAG production by S. epidermidis biofilm cells exacerbates host inflammatory pathology, these results together suggest that this polysaccharide contributes to the clinical features associated with biofilm-derived infections.
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Delayed Propionibacterium acnes surgical site infections occur only in the presence of an implant. Sci Rep 2016; 6:32758. [PMID: 27615686 PMCID: PMC5018724 DOI: 10.1038/srep32758] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/15/2016] [Indexed: 11/09/2022] Open
Abstract
Whether Propionibacterium acnes (P. acnes) causes surgical-site infections (SSI) after orthopedic surgery is controversial. We previously reported that we frequently find P. acnes in intraoperative specimens, yet none of the patients have clinically apparent infections. Here, we tracked P. acnes for 6 months in a mouse osteomyelitis model. We inoculated P. acnes with an implant into the mouse femur in the implant group; the control group was treated with the bacteria but no implant. We then observed over a 6-month period using optical imaging system. During the first 2 weeks, bacterial signals were detected in the femur in the both groups. The bacterial signal completely disappeared in the control group within 28 days. Interestingly, in the implant group, bacterial signals were still present 6 months after inoculation. Histological and scanning electron-microscope analyses confirmed that P. acnes was absent from the control group 6 months after inoculation, but in the implant group, the bacteria had survived in a biofilm around the implant. PCR analysis also identified P. acnes in the purulent effusion from the infected femurs in the implant group. To our knowledge, this is the first report showing that P. acnes causes SSI only in the presence of an implant.
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Joo HS, Fu CI, Otto M. Bacterial strategies of resistance to antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150292. [PMID: 27160595 PMCID: PMC4874390 DOI: 10.1098/rstb.2015.0292] [Citation(s) in RCA: 205] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2016] [Indexed: 02/06/2023] Open
Abstract
Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Chih-Iung Fu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
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46
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Joo HS, Fu CI, Otto M. Bacterial strategies of resistance to antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2016. [PMID: 27160595 DOI: 10.1098/rstb.2015.0292.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
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Affiliation(s)
- Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Chih-Iung Fu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
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Weiser J, Henke HA, Hector N, Both A, Christner M, Büttner H, Kaplan JB, Rohde H. Sub-inhibitory tigecycline concentrations induce extracellular matrix binding protein Embp dependent Staphylococcus epidermidis biofilm formation and immune evasion. Int J Med Microbiol 2016; 306:471-8. [PMID: 27292911 DOI: 10.1016/j.ijmm.2016.05.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/19/2016] [Accepted: 05/24/2016] [Indexed: 12/31/2022] Open
Abstract
Biofilm-associated Staphylococcus epidermidis implant infections are notoriously reluctant to antibiotic treatment. Here we studied the effect of sub-inhibitory concentrations of penicillin, oxacillin, vancomycin, daptomycin, linezolid and tigecycline on S. epidermidis 1585 biofilm formation, expression of extracellular matrix binding protein (Embp) and potential implications for S. epidermidis - macrophage interactions. Penicillin, vancomycin, daptomycin, and linezolid had no biofilm augmenting effect at any of the concentrations tested. In contrast, at sub-inhibitory concentrations tigecycline and oxacillin exhibited significant biofilm inducing activity. In S. epidermidis 1585, SarA is a negative regulator of giant 1 MDa Embp, and down regulation of sarA induces Embp-dependent assembly of a multi-layered biofilm architecture. Dot blot immune assays, confocal laser scanning microscopy, and qPCR showed that under biofilm inducing conditions, tigecycline augmented embp expression compared to the control grown without antibiotics. Conversely, expression of regulator sarA was suppressed, suggesting that tigecycline exerts its effects on embp expression through SarA. Tigecycline failed to induce biofilm formation in embp transposon mutant 1585-M135, proving that under these conditions Embp up-regulation is necessary for biofilm accumulation. As a functional consequence, tigecycline induced biofilm formation significantly impaired the up-take of S. epidermidis by mouse macrophage-like cell line J774A.1. Our data provide novel evidence for the molecular basis of antibiotic induced biofilm formation, a phenotype associated with inherently increased antimicrobial tolerance. While this could explain failure of antimicrobial therapies, persistence of S. epidermidis infections in the presence of sub-inhibitory antimicrobials is additionally propelled by biofilm-related impairment of macrophage-mediated pathogen eradication.
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Affiliation(s)
- Julian Weiser
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Hanae A Henke
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Nina Hector
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Anna Both
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Martin Christner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Henning Büttner
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany
| | - Jeffery B Kaplan
- Department of Biology, American University, Washington, DC 20016, USA
| | - Holger Rohde
- Institut für Medizinische Mikrobiologie, Virologie und Hygiene, Universitätsklinikum Hamburg-Eppendorf, Martinistraße 52, D-20246 Hamburg, Germany.
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Abstract
Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms.
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McCarthy H, Waters EM, Bose JL, Foster S, Bayles KW, O'Neill E, Fey PD, O'Gara JP. The major autolysin is redundant for Staphylococcus aureus USA300 LAC JE2 virulence in a murine device-related infection model. FEMS Microbiol Lett 2016; 363:fnw087. [PMID: 27044299 DOI: 10.1093/femsle/fnw087] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2016] [Indexed: 12/14/2022] Open
Abstract
The major Staphylococcus aureus autolysin, Atl, has been implicated in attachment to surfaces and release of extracellular DNA during biofilm formation under laboratory conditions. Consistent with this, polyclonal antibodies to the amidase and glucosaminidase domains of Atl inhibited in vitro biofilm formation. However, in a murine model of device-related infection the community-associated S. aureus strain USA300 LAC JE2 established a successful infection in the absence of atl These data indicate that Atl activity is not required for biofilm production in this infection model and reveal the importance of characterizing the contribution of biofilm phenotypes to virulence under in vivo conditions.
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Affiliation(s)
- Hannah McCarthy
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Elaine M Waters
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Jeffrey L Bose
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Simon Foster
- Department of Molecular Biology and Biotechnology, The Krebs Institute, University of Sheffield, Sheffield S10 2TN, UK
| | - Kenneth W Bayles
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - Eoghan O'Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Connolly Hospital, Dublin 15, Ireland
| | - Paul D Fey
- Department of Pathology and Microbiology, Center for Staphylococcal Research, University of Nebraska Medical Center, Omaha, NE 68198-5900, USA
| | - James P O'Gara
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
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50
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The degree of virulence does not necessarily affect MRSA biofilm strength and response to photodynamic therapy. Microb Pathog 2016; 91:54-60. [DOI: 10.1016/j.micpath.2015.11.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/05/2015] [Accepted: 11/09/2015] [Indexed: 12/25/2022]
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