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Griffith A, Mateen A, Markowitz K, Singer SR, Cugini C, Shimizu E, Wiedman GR, Kumar V. Alternative Antibiotics in Dentistry: Antimicrobial Peptides. Pharmaceutics 2022; 14:1679. [PMID: 36015305 PMCID: PMC9412702 DOI: 10.3390/pharmaceutics14081679] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 01/12/2023] Open
Abstract
The rise of antibiotic resistant bacteria due to overuse and misuse of antibiotics in medicine and dentistry is a growing concern. New approaches are needed to combat antibiotic resistant (AR) bacterial infections. There are a number of methods available and in development to address AR infections. Dentists conventionally use chemicals such as chlorohexidine and calcium hydroxide to kill oral bacteria, with many groups recently developing more biocompatible antimicrobial peptides (AMPs) for use in the oral cavity. AMPs are promising candidates in the treatment of (oral) infections. Also known as host defense peptides, AMPs have been isolated from animals across all kingdoms of life and play an integral role in the innate immunity of both prokaryotic and eukaryotic organisms by responding to pathogens. Despite progress over the last four decades, there are only a few AMPs approved for clinical use. This review summarizes an Introduction to Oral Microbiome and Oral Infections, Traditional Antibiotics and Alternatives & Antimicrobial Peptides. There is a focus on cationic AMP characteristics and mechanisms of actions, and an overview of animal-derived natural and synthetic AMPs, as well as observed microbial resistance.
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Affiliation(s)
- Alexandra Griffith
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Akilah Mateen
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
| | - Kenneth Markowitz
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - Steven R. Singer
- Department of Diagnostic Sciences, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - Carla Cugini
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - Emi Shimizu
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
- Department of Endodontics, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
| | - Gregory R. Wiedman
- Department of Chemistry and Biochemistry, Seton Hall University, South Orange, NJ 07079, USA
| | - Vivek Kumar
- Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
- Department of Endodontics, Rutgers School of Dental Medicine, Newark, NJ 07103, USA
- Department of Biology, New Jersey Institute of Technology, Newark, NJ 07102, USA
- Department of Chemical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
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Updates in the Use of Antibiotics, Biofilms. Vet Clin North Am Small Anim Pract 2022; 52:e1-e19. [DOI: 10.1016/j.cvsm.2022.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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3
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Di Bonaventura G, Pompilio A. In Vitro Antimicrobial Susceptibility Testing of Biofilm-Growing Bacteria: Current and Emerging Methods. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1369:33-51. [PMID: 33963526 DOI: 10.1007/5584_2021_641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The antibiotic susceptibility of bacterial pathogens is typically determined based on planktonic cells, as recommended by several international guidelines. However, most of chronic infections - such as those established in wounds, cystic fibrosis lung, and onto indwelling devices - are associated to the formation of biofilms, communities of clustered bacteria attached onto a surface, abiotic or biotic, and embedded in an extracellular matrix produced by the bacteria and complexed with molecules from the host. Sessile microorganisms show significantly increased tolerance/resistance to antibiotics compared with planktonic counterparts. Consequently, antibiotic concentrations used in standard antimicrobial susceptibility tests, although effective against planktonic bacteria in vitro, are not predictive of the concentrations required to eradicate biofilm-related infections, thus leading to treatment failure, chronicization and removal of material in patients with indwelling medical devices.Meeting the need for the in vitro evaluation of biofilm susceptibility to antibiotics, here we reviewed several methods proposed in literature highlighting their advantages and limitations to guide scientists towards an appropriate choice.
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Affiliation(s)
- Giovanni Di Bonaventura
- Department of Medical, Oral and Biotechnological Sciences, and Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy. .,Laboratory of Clinical Microbiology, Chieti, Italy.
| | - Arianna Pompilio
- Department of Medical, Oral and Biotechnological Sciences, and Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University of Chieti-Pescara, Chieti, Italy.,Laboratory of Clinical Microbiology, Chieti, Italy
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Transforming an inert nanopolymer into broad-spectrum bactericidal by superstructure tuning. Colloids Surf B Biointerfaces 2019; 178:214-221. [PMID: 30870788 DOI: 10.1016/j.colsurfb.2019.02.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/26/2019] [Accepted: 02/27/2019] [Indexed: 01/19/2023]
Abstract
Poloxamer block copolymers (also known as Pluronic®) are particularly useful for drug delivery and self-assembly techniques. These nanopolymers are generally considered to be biologically inert and they were used to generate only bacteria repellent surfaces but keeps bacteria alive and as a latent threat. However, the inherent capabilities of these nanopolymers to kill bacteria have been largely overlooked. Here, we report that Pluronic shaped as superstructures (self-organized array of micelles) in fact possess a broad-spectrum bactericidal activity (capability of killing bacteria) similar to that shown for some antibiotics. This further represents the first report that shows that appropriate control of superstructured mesophase architecture is a key parameter for bactericidal efficacy. Based on this finding, we have developed a highly bactericidal coating (>99.9% kill) against all tested Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Salmonella typhimurium LT2, Escherichia coli K12 and Pseudomonas aeruginosa PAO1) bacteria which moreover allows the adhesion and proliferation of mammalian cells. The inexpensiveness and ease of production make these versatile nanopolymer structures a powerful tool for the development of a new generation of highly effective antimicrobial coatings.
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Townsend EM, Sherry L, Rajendran R, Hansom D, Butcher J, Mackay WG, Williams C, Ramage G. Development and characterisation of a novel three-dimensional inter-kingdom wound biofilm model. BIOFOULING 2016; 32:1259-1270. [PMID: 27841027 DOI: 10.1080/08927014.2016.1252337] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/19/2016] [Indexed: 06/06/2023]
Abstract
Chronic diabetic foot ulcers are frequently colonised and infected by polymicrobial biofilms that ultimately prevent healing. This study aimed to create a novel in vitro inter-kingdom wound biofilm model on complex hydrogel-based cellulose substrata to test commonly used topical wound treatments. Inter-kingdom triadic biofilms composed of Candida albicans, Pseudomonas aeruginosa, and Staphylococcus aureus were shown to be quantitatively greater in this model compared to a simple substratum when assessed by conventional culture, metabolic dye and live dead qPCR. These biofilms were both structurally complex and compositionally dynamic in response to topical therapy, so when treated with either chlorhexidine or povidone iodine, principal component analysis revealed that the 3-D cellulose model was minimally impacted compared to the simple substratum model. This study highlights the importance of biofilm substratum and inclusion of relevant polymicrobial and inter-kingdom components, as these impact penetration and efficacy of topical antiseptics.
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Affiliation(s)
- Eleanor M Townsend
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Leighann Sherry
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Ranjith Rajendran
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
| | - Donald Hansom
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
| | - John Butcher
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - William G Mackay
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Craig Williams
- b Institute of Healthcare Policy and Practice , University of West of Scotland , Paisley , UK
| | - Gordon Ramage
- a Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences , University of Glasgow , Glasgow , UK
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Gel-Entrapped Staphylococcus aureus Bacteria as Models of Biofilm Infection Exhibit Growth in Dense Aggregates, Oxygen Limitation, Antibiotic Tolerance, and Heterogeneous Gene Expression. Antimicrob Agents Chemother 2016; 60:6294-301. [PMID: 27503656 DOI: 10.1128/aac.01336-16] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/03/2016] [Indexed: 11/20/2022] Open
Abstract
An experimental model that mimicked the structure and characteristics of in vivo biofilm infections, such as those occurring in the lung or in dermal wounds where no biomaterial surface is present, was developed. In these infections, microbial biofilm forms as cell aggregates interspersed in a layer of mucus or host matrix material. This structure was modeled by filling glass capillary tubes with an agarose gel that had been seeded with Staphylococcus aureus bacteria and then incubating the gel biofilm in medium for up to 30 h. Confocal microscopy showed that the bacteria formed in discrete pockets distributed throughout the gel matrix. These aggregates enlarged over time and also developed a size gradient, with the clusters being larger near the nutrient- and oxygen-supplied interface and smaller at greater depths. Bacteria entrapped in gels for 24 h grew slowly (specific growth rate, 0.06 h(-1)) and were much less susceptible to oxacillin, minocycline, or ciprofloxacin than planktonic cells. Microelectrode measurements showed that the oxygen concentration decreased with depth into the gel biofilm, falling to values less than 3% of air saturation at depths of 500 μm. An anaerobiosis-responsive green fluorescent protein reporter gene for lactate dehydrogenase was induced in the region of the gel where the measured oxygen concentrations were low, confirming biologically relevant hypoxia. These results show that the gel biofilm model captures key features of biofilm infection in mucus or compromised tissue: formation of dense, distinct aggregates, reduced specific growth rates, local hypoxia, and antibiotic tolerance.
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Taylor B, Marsh L, Nosworthy J, Williams D. A novel approach to antibiofilm susceptibility testing using a thermo-reversible matrix. J Wound Care 2016; 25:62, 64-7. [DOI: 10.12968/jowc.2016.25.2.62] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- B.J. Taylor
- Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff
| | - L.L. Marsh
- Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff
| | - J.O. Nosworthy
- Advanced Medical Solutions Ltd, 33 Premier Park, Winsford, Cheshire
| | - D.W. Williams
- Oral and Biomedical Sciences, School of Dentistry, Cardiff University, Cardiff
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Kim H, Izadjoo M. Antibiofilm efficacy evaluation of a bioelectric dressing in mono- and multi-species biofilms. J Wound Care 2015; 24 Suppl 2:S10-4. [DOI: 10.12968/jowc.2015.24.sup2.s10] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- H. Kim
- Biosciences Division, Trideum Corporation, 4539 Metropolitan Court, Frederick, MD 21704, USA
| | - M.J. Izadjoo
- Diagnostics and Translational Research Center, The Henry M. Jackson Foundation for the Advancement of Military Medicine, Gaithersburg, MD, USA
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Brackman G, Coenye T. In Vitro and In Vivo Biofilm Wound Models and Their Application. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 897:15-32. [DOI: 10.1007/5584_2015_5002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Percival SL, McCarty S, Hunt JA, Woods EJ. The effects of pH on wound healing, biofilms, and antimicrobial efficacy. Wound Repair Regen 2014; 22:174-86. [DOI: 10.1111/wrr.12125] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 09/04/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Steven L. Percival
- Research & Development; Scapa Healthcare; Greater Manchester United Kingdom
- Surface Science Research Centre; University of Liverpool; Liverpool United Kingdom
- Clinical Engineering; United Kingdom Centre for Tissue Engineering; Institute of Ageing and Chronic Disease; University of Liverpool; Liverpool United Kingdom
| | - Sara McCarty
- Clinical Engineering; United Kingdom Centre for Tissue Engineering; Institute of Ageing and Chronic Disease; University of Liverpool; Liverpool United Kingdom
| | - John A. Hunt
- Clinical Engineering; United Kingdom Centre for Tissue Engineering; Institute of Ageing and Chronic Disease; University of Liverpool; Liverpool United Kingdom
| | - Emma J. Woods
- Research & Development; Scapa Healthcare; Greater Manchester United Kingdom
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Hakonen B, Lönnberg LK, Larkö E, Blom K. A Novel Qualitative and Quantitative Biofilm Assay Based on 3D Soft Tissue. Int J Biomater 2014; 2014:768136. [PMID: 24696687 PMCID: PMC3948644 DOI: 10.1155/2014/768136] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 12/22/2013] [Accepted: 01/09/2014] [Indexed: 12/02/2022] Open
Abstract
The lack of predictable in vitro methods to analyze antimicrobial activity could play a role in the development of resistance to antibiotics. Current used methods analyze planktonic cells but for the method to be clinically relevant, biofilm in in vivo like conditions ought to be studied. Hence, our group has developed a qualitative and quantitative method with in vivo like 3D tissue for prediction of antimicrobial activity in reality. Devices (wound dressings) were applied on top of Pseudomonas aeruginosa inoculated Muller-Hinton (MH) agar or 3D synthetic soft tissues (SST) and incubated for 24 hours. The antibacterial activity was then analyzed visually and by viable counts. On MH agar two out of three silver containing devices showed zone of inhibitions (ZOI) and on SST, ZOI were detected for all three. Corroborating results were found upon evaluating the bacterial load in SST and shown to be silver concentration dependent. In conclusion, a novel method was developed combining visual rapid screening and quantitative evaluation of the antimicrobial activity in both tissue and devices. It uses tissue allowing biofilm formation thus mimicking reality closely. These conditions are essential in order to predict antimicrobial activity of medical devices in the task to prevent device related infections.
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Affiliation(s)
| | - Linnea K. Lönnberg
- Medibiome AB, 431 53 Mölndal, Sweden
- Department of Medical Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, 413 45 Göteborg, Sweden
| | - Eva Larkö
- Medibiome AB, 431 53 Mölndal, Sweden
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Valderrama WB, Cutter CN. An Ecological Perspective ofListeria monocytogenesBiofilms in Food Processing Facilities. Crit Rev Food Sci Nutr 2013; 53:801-17. [DOI: 10.1080/10408398.2011.561378] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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13
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Innovative strategies to overcome biofilm resistance. BIOMED RESEARCH INTERNATIONAL 2012; 2013:150653. [PMID: 23509680 PMCID: PMC3591221 DOI: 10.1155/2013/150653] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/03/2012] [Accepted: 09/19/2012] [Indexed: 12/29/2022]
Abstract
We review the recent literature concerning the efficiency of antimicrobial photodynamic inactivation toward various microbial species in planktonic and biofilm cultures. The review is mainly focused on biofilm-growing microrganisms because this form of growth poses a threat to chronically infected or immunocompromised patients and is difficult to eradicate from medical devices. We discuss the biofilm formation process and mechanisms of its increased resistance to various antimicrobials. We present, based on data in the literature, strategies for overcoming the problem of biofilm resistance. Factors that have potential for use in increasing the efficiency of the killing of biofilm-forming bacteria include plant extracts, enzymes that disturb the biofilm structure, and other nonenzymatic molecules. We propose combining antimicrobial photodynamic therapy with various antimicrobial and antibiofilm approaches to obtain a synergistic effect to permit efficient microbial growth control at low photosensitizer doses.
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Thomas J, Linton S, Corum L, Slone W, Okel T, Percival SL. The affect of pH and bacterial phenotypic state on antibiotic efficacy. Int Wound J 2011; 9:428-35. [PMID: 22182197 DOI: 10.1111/j.1742-481x.2011.00902.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Antibiotics are routinely used in woundcare for the treatment of local and systemic infections. Our goals in this paper were to (i) evaluate the antibiotic sensitivity of bacteria isolated from burn and chronic wounds and (ii) evaluate the effect of pH and bacterial phenotype on the efficacy of antibiotics. Chronic and burn wound isolates, which had been routinely isolated from patients at West Virginia University Hospital, USA, were evaluated for their sensitivity to antibiotics. Antimicrobial susceptibility testing was performed using a standardised disk diffusion assay on agar (quasi/non biofilm) and poloxamer (biofilm). Many of the Gram-positive and -negative isolates demonstrated changes in susceptibility to antibiotics when grown at different pH values and phenotypic states. Findings of this study highlight the clinical relevance that both pH and the phenotypic state of bacteria have on antibiotic performance. The study in particular has shown that bacteria exhibit an enhanced tolerance to antibiotics when grown in the biofilm phenotypic state. Such a finding suggests that more appropriate antibiotic sensitivity testing for woundcare and medicine is warranted to help assist in the enhancement of positive clinical outcomes.
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Affiliation(s)
- John Thomas
- Department of Pathology, West Virginia University, Morgantown, WV, USA
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Thomas J, Slone W, Linton S, Corum L, Okel T, Percival S. A comparison of the antimicrobial efficacy of two silver-containing wound dressings on burn wound isolates. J Wound Care 2011; 20:580-2, 584-6. [PMID: 22240884 DOI: 10.12968/jowc.2011.20.12.580] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- J.G. Thomas
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
| | - W. Slone
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
| | - S. Linton
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
| | - L. Corum
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
| | - T. Okel
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
| | - S.L. Percival
- West Virginia University, Medical School, Department of Pathology, Biofilm Laboratory, Morgantown, W V, US
- Scapa PLC, Manchester, UK
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Percival SL, Thomas JG, Slone W, Linton S, Corum L, Okel T. The efficacy of silver dressings and antibiotics on MRSA and MSSA isolated from burn patients. Wound Repair Regen 2011; 19:767-74. [PMID: 22092847 DOI: 10.1111/j.1524-475x.2011.00739.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 09/08/2011] [Indexed: 11/27/2022]
Abstract
In this study our objectives were (1) to investigate whether meticillin-resistant Staphylococcus aureus (MRSA) showed an increased tolerance to silver wound dressings compared with meticillin-sensitive S. aureus (MSSA); and (2) to evaluate the effects of bacterial phenotypic states of MRSA and MSSA, and pH, on the activity of silver wound dressings and two antibiotics, ampicillin and clindamycin. Twenty MRSA strains and 10 MSSA strains isolated from burns patients in South Africa were evaluated for their susceptibility to a silver alginate and a silver carboxymethyl cellulose wound dressing, employing a corrected zone of inhibition assay, conducted on Mueller Hinton agar and a poloxamer-based biofilm model. When exposed to the two silver dressings, all 30 S. aureus strains showed susceptibility. Possible enhanced antimicrobial efficacy of the silver dressings occurred when pH was lowered to 5.5, compared with a pH of 7.0. When all S. aureus were grown in the biofilm phenotypic state and exposed to both silver dressings and antibiotics, enhanced tolerance was noted. Susceptibility to silver was overall higher for MRSA when compared with MSSA. This study showed that the effect of pH and bacterial phenotypic state must be considered when the antimicrobial activity of silver wound dressings is being investigated. It is evident from the data generated that both pH and the bacterial phenotypic state are factors that induce changes that affect both antimicrobial performance and bacterial susceptibility.
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Affiliation(s)
- Steven L Percival
- Department of Pathology, Biofilm Laboratory, Medical School, West Virginia University, Morgantown, West Virginia, USA.
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Abstract
How can a better understanding of wound biofilms change your clinical practice? And what is the likely impact on clinical outcomes? At this year's JWC lecture, sponsored by sorbion, two of the world's leading microbiologists, Steve Percival and Randy Wolcott, answered these questions. Steve Percival explained what a wound biofilm is, and what diagnostic and management techniques can be used to overcome it. Randy Wolcott described the astonishing success this can bring, with healing rates of up 90% being recorded in patients with recalcitrant chronic wounds.
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Percival SL, Hill KE, Malic S, Thomas DW, Williams DW. Antimicrobial tolerance and the significance of persister cells in recalcitrant chronic wound biofilms. Wound Repair Regen 2011; 19:1-9. [PMID: 21235682 DOI: 10.1111/j.1524-475x.2010.00651.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The application of antimicrobials in the management of wounds is a complex procedure requiring appropriate clinical decision making, judgment and a thorough understanding of antimicrobial therapies, together with their potential disadvantages. There is considerable direct and indirect evidence for the presence of bacterial biofilms in the chronic wound bed, and it has been demonstrated that bacteria within these biofilms may exhibit both specific and nonspecific antimicrobial tolerance. The antimicrobial tolerance of biofilms is a major concern in the treatment of both infected and nonhealing chronic wounds and an understanding of the mechanisms involved is of fundamental importance in managing wound infections and developing future wound management strategies. The aim of this review is therefore to provide an overview of our current understanding of the mechanisms by which bacteria in wound biofilms can resist conventional antibiotic and antibacterial therapies which is very important to wound healing.
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Percival SL, Slone W, Linton S, Okel T, Corum L, Thomas JG. Use of flow cytometry to compare the antimicrobial efficacy of silver-containing wound dressings against planktonic Staphylococcus aureus and Pseudomonas aeruginosa. Wound Repair Regen 2011; 19:436-41. [DOI: 10.1111/j.1524-475x.2011.00685.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Percival SL, Slone W, Linton S, Okel T, Corum L, Thomas JG. The antimicrobial efficacy of a silver alginate dressing against a broad spectrum of clinically relevant wound isolates. Int Wound J 2011; 8:237-43. [PMID: 21470369 DOI: 10.1111/j.1742-481x.2011.00774.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Wound dressings impregnated with silver have a role to play in aiding to reduce both the dressing and wound microbial bioburden. It is therefore imperative that antimicrobial wound dressings have efficacy on a broad range of clinical significant microorganisms. Accordingly, this study aimed to determine the antimicrobial efficacy of a silver alginate dressing against 115 wound isolates that had been isolated routinely from patients at West Virginia University Hospital. Standardised corrected zones of inhibition (CZOIs) were performed on all clinical isolates. It was found that the silver alginate dressing was able to inhibit the growth of all microorganisms tested. In particular, the silver alginate dressing inhibited the growth of Candida albicans and yeasts with CZOI of 3-11·5 mm. All meticillin-resistant Staphylococcus aureus (MRSA) strains were found to be sensitive to the silver alginate dressing with a CZOI range calculated at 3-7·8 mm. Sensitivity to the silver alginate dressing was also evident for S. aureus and vancomycin-resistant Enterococci. CZOIs of 4·25 mm were calculated for Enterococcus faecium and 9·8 mm for viridans streptococcus. The bacteria which demonstrated the highest tolerance to ionic silver included Enterobacter cloacae and Acinetobacter baumannii. Contrary to this the most responsive microorganisms to ionic silver included strains of staphylococci, viridans streptococcus and Candida albicans. No antibiotic-resistant isolates, as identified by Kirby Bauer Clinical Laboratory Standards Institute classification system, were found to be resistant to ionic silver. When a selected number of microorganisms were grown in the biofilm phenotypic state enhanced tolerance to silver was observed, compared to their non biofilm counterparts. Overall, this study has demonstrated the broad antimicrobial activity of a silver alginate dressing on wound isolates grown in the non biofilm and biofilm state. This finding is clinically relevant as both the non biofilm and biofilm phenotypic states of microorganisms are evident in wounds and therefore significant to delayed healing. Consequently, it is imperative that antimicrobial wound dressings demonstrate antimicrobial activity against microorganisms in both phenotypic states.
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Affiliation(s)
- Steven L Percival
- Department of Pathology, Health Sciences Center, West Virginia University, Biofilm Laboratory, Morgantown, WV, USA.
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Black CE, Costerton JW. Current concepts regarding the effect of wound microbial ecology and biofilms on wound healing. Surg Clin North Am 2010; 90:1147-60. [PMID: 21074033 DOI: 10.1016/j.suc.2010.08.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Biofilms are a collection of microbes that adhere to surfaces by manufacturing a matrix that shields them from environmental elements. Wound biofilms are difficult to evaluate clinically, and standard culture methods are inadequate for capturing the true bioburden present in the biofilm. New molecular techniques provide the means for rapid detection and evaluation of wound biofilms, and may prove to be useful in the clinical setting. Studies have shown that many commercial topical agents and wound dressings in use are ineffective against the biofilm matrix. At this stage, mechanical debridement appears to be essential in the eradication of a wound biofilm. Topical antimicrobial agents and antibiotics may be effective in the treatment of the wound bed after debridement in the prevention of biofilm reformation.
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Affiliation(s)
- Carrie E Black
- Department of General Surgery, General Surgery Residency Program, Marshfield Clinic, 1000 North Oak Avenue, Marshfield, WI 54449, USA
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Kim KP, Kim YG, Choi CH, Kim HE, Lee SH, Chang WS, Lee CS. In situ monitoring of antibiotic susceptibility of bacterial biofilms in a microfluidic device. LAB ON A CHIP 2010; 10:3296-9. [PMID: 20938507 DOI: 10.1039/c0lc00154f] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Antibiotic resistance of biofilms is a growing public health concern due to overuse and improper use of antibiotics. Thus, determining an effective minimal concentration of antibiotics to eradicate bacterial biofilms is crucial. Here we present a simple, novel one-pot assay for the analysis of antibiotic susceptibility of bacterial biofilms using a microfluidics system where continuous concentration gradients of antibiotics are generated. The results of minimal biofilm eradication concentration (MBEC) clearly confirm that the concentration required to eradicate biofilm-grown Pseudomonas aeruginosa is higher than the minimal inhibitory concentration (MIC) that has been widely used to determine the lowest concentration of antibiotics against planktonically grown bacteria.
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Affiliation(s)
- Keun Pil Kim
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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Yang J, Evans BA, Rozen DE. Signal diffusion and the mitigation of social exploitation in pneumococcal competence signalling. Proc Biol Sci 2010; 277:2991-9. [PMID: 20462905 DOI: 10.1098/rspb.2010.0659] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Quorum sensing (QS) in bacteria is thought to enable populations of cells to coordinately and cooperatively regulate gene expression for traits that confer group benefits. While this view has strong empirical and theoretical support, it is increasingly appreciated that QS under natural conditions may be incapable of monitoring bacterial numbers and, furthermore, that QS is evolutionarily unstable owing to conflicts of interest among competing cells. An alternative hypothesis, termed diffusion sensing (DS), proposes that autoinducer secretion monitors the diffusive properties of the local environment, with benefits that are directly realized by individual cells rather than populations. Here, we test central predictions of this hypothesis using the competence signalling system of Streptococcus pneumoniae as our model, which regulates the induction of natural transformation by the secretion and detection of a small diffusible peptide, CSP (competence-stimulating peptide). By experimentally manipulating the diffusive properties of the growth medium, we found that there is no fixed quorum for competence induction. Instead, induction cell density scales with diffusivity. In agreement with QS and DS expectations, we show that the benefit of signal exploitation by mutant cells that can use but not secrete CSP is strongly frequency-dependent. However, we also find that the magnitude of this benefit declines significantly as diffusion is reduced, a result more consistent with the predictions of DS. Together, these data provide strong support for the DS hypothesis for autoinducer response systems. More specifically, our results imply that autonomous rather than group benefits should be sought in order to more completely understand the role and evolution of CSP signalling in pneumococci.
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Affiliation(s)
- Jungwoo Yang
- University of Manchester, Manchester M13 9PT, UK
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24
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Martin JM, Zenilman JM, Lazarus GS. Molecular Microbiology: New Dimensions for Cutaneous Biology and Wound Healing. J Invest Dermatol 2010; 130:38-48. [DOI: 10.1038/jid.2009.221] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Bartie KL, Devine DA, Wilson MJ, Lewis MAO. In vitro susceptibility of the Streptococcus milleri group to antimicrobial peptides. Int Endod J 2008; 41:586-92. [PMID: 18479375 DOI: 10.1111/j.1365-2591.2008.01404.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM To determine the susceptibility of strains of the Streptococcus milleri group (SMG) to commercially available antimicrobial peptides. METHODOLOGY Thirty strains of SMG from a range of sources were assessed for their susceptibility to 10 antimicrobial peptides of either human, animal or insect origin, using a double layer diffusion assay. RESULTS The majority of the test strains were sensitive to the amidated peptides, mastoparan (100%; n = 30), magainin 2 amide (95%; n = 21) and indolicin (91%; n = 23). Some strains were susceptible to cecropin B (30%; n = 30) and histatin (10%; n = 30), whilst no activity was observed for the defensins HNP-1 and HNP-2, histatin 8, cecropin P1 and magainin 2. CONCLUSIONS The majority of strains were resistant to the human derived peptides. The ability to resist such peptides may be a factor in the colonisation of the oral cavity and the survival and initiation of infection in the pulp and root canal environment. Interestingly, the present study indicated that amidated and alpha helical peptides exhibit antimicrobial activity against SMG. Structural modification of these peptides may allow a targeted approach for the development of these substances as preventative or therapeutic agents.
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Affiliation(s)
- K L Bartie
- Department of Oral Microbiology, Leeds Dental Institute, Clarendon Way, University of Leeds, Leeds, UK
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