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Townsend EC, Cheong JZA, Radzietza M, Fritz B, Malone M, Bjarnsholt T, Ousey K, Swanson T, Schultz G, Gibson ALF, Kalan LR. What is slough? Defining the proteomic and microbial composition of slough and its implications for wound healing. Wound Repair Regen 2024. [PMID: 38558438 DOI: 10.1111/wrr.13170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 02/06/2024] [Accepted: 02/19/2024] [Indexed: 04/04/2024]
Abstract
Slough is a well-known feature of non-healing wounds. This pilot study aims to determine the proteomic and microbiologic components of slough as well as interrogate the associations between wound slough components and wound healing. Ten subjects with slow-to-heal wounds and visible slough were enrolled. Aetiologies included venous stasis ulcers, post-surgical site infections and pressure ulcers. Patient co-morbidities and wound healing outcome at 3-months post-sample collection was recorded. Debrided slough was analysed microscopically, through untargeted proteomics, and high-throughput bacterial 16S-ribosomal gene sequencing. Microscopic imaging revealed wound slough to be amorphous in structure and highly variable. 16S-profiling found slough microbial communities to associate with wound aetiology and location on the body. Across all subjects, slough largely consisted of proteins involved in skin structure and formation, blood-clot formation and immune processes. To predict variables associated with wound healing, protein, microbial and clinical datasets were integrated into a supervised discriminant analysis. This analysis revealed that healing wounds were enriched for proteins involved in skin barrier development and negative regulation of immune responses. While wounds that deteriorated over time started off with a higher baseline Bates-Jensen Wound Assessment Score and were enriched for anaerobic bacterial taxa and chronic inflammatory proteins. To our knowledge, this is the first study to integrate clinical, microbiome, and proteomic data to systematically characterise wound slough and integrate it into a single assessment to predict wound healing outcome. Collectively, our findings underscore how slough components can help identify wounds at risk of continued impaired healing and serves as an underutilised biomarker.
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Affiliation(s)
- Elizabeth C Townsend
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Medical Scientist Training Program, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - J Z Alex Cheong
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Michael Radzietza
- Infectious Diseases and Microbiology, Western Sydney University, Sydney, Australia
| | - Blaine Fritz
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Matthew Malone
- Infectious Diseases and Microbiology, Western Sydney University, Sydney, Australia
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Microbiology, Copenhagen University Hospital, Copenhagen, Denmark
- International Wound Infection Institute, London, UK
| | - Karen Ousey
- International Wound Infection Institute, London, UK
- Institute of Skin Integrity and Infection Prevention, University of Huddersfield, West Yorkshire, UK
| | | | - Gregory Schultz
- International Wound Infection Institute, London, UK
- Department of Obstetrics and Gynecology, University of Florida, Gainesville, Florida, USA
| | - Angela L F Gibson
- Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Lindsay R Kalan
- Department of Medical Microbiology and Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- International Wound Infection Institute, London, UK
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
- David Braley Centre for Antibiotic Discovery, McMaster University, Hamilton, Ontario, Canada
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2
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DeLong MR, Wells MW, Chang IA, Vardanian AJ, Harris H. Data Requirement for Animal-Derived Wound Care Devices: Limitations of the 510(k) Regulatory Pathway. J Am Coll Surg 2024; 238:218-224. [PMID: 37796150 DOI: 10.1097/xcs.0000000000000884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/06/2023]
Abstract
BACKGROUND Device classification and preclinical data requirements for animal-derived wound care products were recently reviewed by the FDA. Given the possible performance differences for these products, we evaluated the FDA data requirements as well as the published literature for all animal-derived wound care products ever cleared through the FDA. STUDY DESIGN The publicly available online database was queried for all animal-derived wound products; premarket data requirements for each product were recorded. A PubMed search was conducted to determine the number of published clinical studies for each product, and manufacturer websites were accessed to obtain the price for each product. RESULTS A total of 132 animal-derived wound products have been cleared by the FDA since the Center for Devices and Radiological Health was established in 1976. Of these, 114 had a publicly available clearance statement online. Preclinical biocompatibility testing was performed in 85 products (74.6%) and referenced in 10 (8.8%). Preclinical animal wound healing testing took place in 17 (14.9%). Only 9 products (7.9%) had clinical safety testing, and no products had clinical effectiveness data. We found no published peer-reviewed clinical data for 97 products (73%). Cost was infrequently available but ranged from $4.79 to $2,178 per unit. CONCLUSIONS Although the current pathway is appropriate for efficiently clearing new wound care products, clinical effectiveness is not included in the regulatory review process. Wound care products are primarily evaluated by the FDA for safety and biocompatibility. Thus, any claims of clinical effectiveness require independent validation, which is often lacking.
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Affiliation(s)
- Michael R DeLong
- From the division of Plastic and Reconstructive Surgery, Department of Surgery, University of California, Los Angeles, CA (DeLong, Vardanian)
| | - Michael W Wells
- From the division of Plastic and Reconstructive Surgery, Department of Surgery, University of California, Los Angeles, CA (DeLong, Vardanian)
- Case Western Reserve University, School of Medicine, Cleveland OH (Wells, Chang)
| | - Irene A Chang
- Case Western Reserve University, School of Medicine, Cleveland OH (Wells, Chang)
| | - Andrew J Vardanian
- From the division of Plastic and Reconstructive Surgery, Department of Surgery, University of California, Los Angeles, CA (DeLong, Vardanian)
| | - Hobart Harris
- Division of Gastrointestinal Surgery, Department of Surgery, University of California, San Francisco, CA (Harris)
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3
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Malone M, Nygren E, Hamberg T, Radzieta M, Jensen SO. In vitro and in vivo evaluation of the antimicrobial effectiveness of non-medicated hydrophobic wound dressings. Int Wound J 2024; 21:e14416. [PMID: 37770025 PMCID: PMC10824701 DOI: 10.1111/iwj.14416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 10/03/2023] Open
Abstract
There is an increasing use of non-medicated wound dressing with claims of irreversible bacterial binding. Most of the data are from in vitro models which lack clinical relevance. This study employed a range of in vitro experiments to address this gap and we complemented our experimental designs with in vivo observations using dressings obtained from patients with diabetes-related foot ulcers. A hydrophobic wound dressing was compared with a control silicone dressing in vitro. Test dressings were placed on top of a Pseudomonas aeruginosa challenge suspension with increasing concentrations of suspension inoculum in addition to supplementation with phosphate buffered saline (PBS) or increased protein content (IPC). Next, we used the challenge suspensions obtained at the end of the first experiment, where bacterial loads from the suspensions were enumerated following test dressing exposure. Further, the time-dependent bacterial attachment was investigated over 1 and 24 h. Lastly, test dressings were exposed to a challenge suspension with IPC, with or without the addition of the bacteriostatic agent Deferiprone to assess the impacts of limiting bacterial growth in the experimental design. Lastly, two different wound dressings with claims of bacterial binding were obtained from patients with chronic diabetes-related foot ulcers after 72 h of application and observed using scanning electron microscope (SEM). Bacteria were enumerated from each dressing after a 1-h exposure time. There was no statistical difference in bacterial attachment between both test dressings when using different suspension inoculum concentrations or test mediums. Bacterial attachment to the two test dressings was significantly lower (p < 0.0001) when IPC was used instead of PBS. In the challenge suspension with PBS, only the hydrophobic dressing achieved a statistically significant reduction in bacterial loads (0.5 ± 0.05 log colony forming units; p = 0.001). In the presence of IPC, there was no significant reduction in bacterial loads for either test dressing. When bacterial growth was arrested, attachment to the test dressings did not increase over time, suggesting that the number of bacteria on the test dressings increases over time due to bacterial growth. SEM identified widespread adsorption of host fouling across the test dressings which occurred prior to microbial binding. Therein, microbial attachment occurred predominantly to host fouling and not directly to the dressings. Bacterial binding is not unique to dialkylcarbamoyl chloride (DACC) dressings and under clinically relevant in vitro conditions and in vivo observations, we demonstrate (in addition to previously published work) that the bacterial binding capabilities are not effective at reducing the number of bacteria in laboratory models or human wounds.
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Affiliation(s)
- Matthew Malone
- Research and DevelopmentMolnlycke Healthcare ABGothenburgSweden
- South West Sydney Limb Preservation and Wound ResearchSouth West Sydney Local Health DistrictSydneyNew South WalesAustralia
- Infectious Diseases and Microbiology, School of MedicineWestern Sydney UniversitySydneyNew South WalesAustralia
| | - Erik Nygren
- Research and DevelopmentMolnlycke Healthcare ABGothenburgSweden
| | - Tina Hamberg
- Research and DevelopmentMolnlycke Healthcare ABGothenburgSweden
| | - Michael Radzieta
- South West Sydney Limb Preservation and Wound ResearchSouth West Sydney Local Health DistrictSydneyNew South WalesAustralia
- Infectious Diseases and Microbiology, School of MedicineWestern Sydney UniversitySydneyNew South WalesAustralia
| | - Slade O. Jensen
- South West Sydney Limb Preservation and Wound ResearchSouth West Sydney Local Health DistrictSydneyNew South WalesAustralia
- Infectious Diseases and Microbiology, School of MedicineWestern Sydney UniversitySydneyNew South WalesAustralia
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4
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Astrada A, Pamungkas RA, Abidin KR. Advancements in Managing Wound Biofilm: A Systematic Review and Meta-analysis of Randomized Controlled Trials on Topical Modalities. Foot Ankle Spec 2024:19386400231225708. [PMID: 38282327 DOI: 10.1177/19386400231225708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Despite numerous available agents claiming anti-biofilm properties on wounds, the substantiating evidence remains inconclusive. This study aimed to assess the immediate impact of topical wound treatments on wound biofilm and healing outcomes in acute and chronic ulcers. We comprehensively searched PubMed, ClinicalTrials.gov, and Google Scholar. In addition, eligible gray literature was incorporated. English-language randomized controlled trials (RCTs), observational, cohort, and case-control studies targeting biofilm prevention, inhibition, or elimination across diverse wound types were included. Primary outcomes included biofilm presence and elimination, supplemented by secondary outcomes encompassing reduced wound size, complete closure, and diminished infection indicators. Bacterial load reduction and biofilm presence were also assessed. Twenty-eight articles met the inclusion criteria. Various modalities were identified, including biofilm-visualization techniques, such as wound blotting and handheld autofluorescence imaging. Pooled analysis for the primary outcomes was infeasible due to limited eligible studies and data-reporting challenges. As for the secondary outcomes, the pooled analysis for complete surgical wound closure (2 RCTs, yielding n=284) and presence of surgical site infections/inflammation (2 RCTs, yielding n=284) showed no significant difference, with a log odds ratio (LOD) of 0.58 (95% confidence interval [CI]: -.33, 1.50) and LOD -0.95 (95% CI: -3.54, 1.64; τ2 = 2.32, Q = 2.71, P = .10), respectively. Our findings suggest insufficient evidence to support anti-biofilm claims of topical modalities. Clinicians' skill appears to play a pivotal role in biofilm elimination and wound healing enhancement, with potential optimization through visual-guided techniques, such as wound blotting and autofluorescence imaging. More rigorous clinical trials are warranted to ascertain the efficacy of these techniques.Level of Evidence: Therapeutic, 1A.
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Affiliation(s)
- Adam Astrada
- School of Nursing, Faculty of Health Sciences, Esa Unggul University, Jakarta Barat, Indonesia
| | - Rian Adi Pamungkas
- School of Nursing, Faculty of Health Sciences, Esa Unggul University, Jakarta Barat, Indonesia
- School of Nursing, University of Michigan, Ann Arbor, Michigan
| | - Khoirul Rista Abidin
- Department of Medical Laboratory Technology, Politeknik 'Aisyiyah Pontianak, Pontianak City, Indonesia
- Department of Biotechnology, Postgraduate School, Padjadjaran University, Indonesia
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5
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Labens R, Raidal S, Borgen-Nielsen C, Pyecroft S, Pant SD, De Ridder T. Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment. Front Vet Sci 2023; 10:1294021. [PMID: 38155761 PMCID: PMC10752953 DOI: 10.3389/fvets.2023.1294021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 11/23/2023] [Indexed: 12/30/2023] Open
Abstract
Introduction Topical wound treatments rely on carrier formulations with little to no biological impact. The potential for a common vehicle, a propylene glycol (PG) gel, to affect wound healing measures including microbiota is not known. Microbiome characterization, based on next generation sequencing methods is typically performed on tissue or directly obtained wound fluid samples. The utility for primary wound dressings to characterize equine wound microbiota in the context of topical treatments is currently unknown. This investigation reports the topical effect of an 80% PG based gel on wound healing and microbiota in wound dressings. Methods Experiments were performed in six mature horses utilizing a surgical, distal limb wound model, histology of sequential wound biopsies, photographic wound measurements and microbiota profiling via 16s rRNA sequencing of wound dressing samples. Experimental wounds were surveyed for 42 days and either treated (Day 7, 14, 21 and 28; at 0.03 ml/cm2) or unexposed to the PG gel. Wound surface area, relative and absolute microbial abundances, diversity indices and histologic parameters were analyzed in the context of the experimental group (treatment; control) using qualitative or quantitative methods depending on data characteristics. Results Compared to controls, treatment slowed the wound healing rate (17.17 ± 4.27 vs. 18.56 ± 6.3 mm2/day), delayed the temporal decline of polymorphonucleated cells in wound beds and operational taxonomic units (OTU) in wound dressings and lowered alpha-diversity indices for microbiota in primary wound dressing. Relative abundances of OTUs were in line with those previously reported for equine wounds. Clinical outcomes 42 days post wounding were considered similar irrespective of PG gel exposure. Discussion Results highlight the potential for vehicle exposure to alter relevant wound outcome measures, imposing the need for stringent experimental control measures. Primary wound dressings may represent an alternate sample source for characterization of the wound microbiome alleviating the need for additional interventions. Further studies are warranted to contrast the microbiome in wound dressings against that present on wound surfaces to conclude on the validity of this approach.
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Affiliation(s)
- Raphael Labens
- School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
- QBiotics Group Ltd., Yungaburra, QLD, Australia
| | - Sharanne Raidal
- School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Cathrine Borgen-Nielsen
- School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Stephen Pyecroft
- School of Animal and Veterinary Sciences, Faculty of Sciences, Engineering and Technology, University of Adelaide, Roseworthy, SA, Australia
| | - Sameer D. Pant
- School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
- Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, Australia
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6
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Master NG, Markande AR. Importance of microbial amphiphiles: interaction potential of biosurfactants, amyloids, and other exo-polymeric-substances. World J Microbiol Biotechnol 2023; 39:320. [PMID: 37747579 DOI: 10.1007/s11274-023-03751-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 09/04/2023] [Indexed: 09/26/2023]
Abstract
Microorganisms produce a diverse group of biomolecules having amphipathic nature (amphiphiles). Microbial amphiphiles, including amyloids, bio-surfactants, and other exo-polymeric substances, play a crucial role in various biological processes and have gained significant attention recently. Although diverse in biochemical composition, these amphiphiles have been reported for common microbial traits like biofilm formation and pathogenicity due to their ability to act as surface active agents with active interfacial properties essential for microbes to grow in various niches. This enables microbes to reduce surface tension, emulsification, dispersion, and attachment at the interface. In this report, the ecological importance and biotechnological usage of important amphiphiles have been discussed. The low molecular weight amphiphiles like biosurfactants, siderophores, and peptides showing helical and antimicrobial activities have been extensively reported for their ability to work as quorum-sensing mediators. While high molecular weight amphiphiles make up amyloid fibers, exopolysaccharides, liposomes, or magnetosomes have been shown to have a significant influence in deciding microbial physiology and survival. In this report, we have discussed the functional similarities and biochemical variations of several amphipathic biomolecules produced by microbes, and the present report shows these amphiphiles showing polyphyletic and ecophysiological groups of microorganisms and hence can `be replaced in biotechnological applications depending on the compatibility of the processes.
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Affiliation(s)
- Nishita G Master
- Department of Biological Sciences, P.D. Patel Institute of Applied Sciences (PDPIAS), Charotar University of Science and Technology (CHARUSAT), Changa, Anand, Gujarat, 388421, India
| | - Anoop R Markande
- Department of Biological Sciences, P.D. Patel Institute of Applied Sciences (PDPIAS), Charotar University of Science and Technology (CHARUSAT), Changa, Anand, Gujarat, 388421, India.
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7
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Malone M, Radzieta M, Schwarzer S, Walker A, Bradley J, Jensen SO. In vivo observations of biofilm adhering to a dialkylcarbamoyl chloride-coated mesh dressing when applied to diabetes-related foot ulcers: A proof of concept study. Int Wound J 2022. [PMID: 36567138 DOI: 10.1111/iwj.14054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/27/2022] [Accepted: 12/04/2022] [Indexed: 12/27/2022] Open
Abstract
In this proof-of-concept study of twenty participants, we sought to determine if a DACC (Dialkylcarbamoyl chloride)-coated mesh dressing demonstrates an ability to adhere biofilm when placed on Diabetes Related Foot Ulcers (DRFUs) with chronic infection. The study also sought to determine if removal of the DACC-coated mesh dressings contributes to reducing the total number of bacteria in DRFUs, by exploring the total microbial loads, microbial community composition, and diversity. Standard of care was provided in addition to the application of DACC or DACC hydrogel every three days for a total of two weeks. Wound swabs, tissue curettage, and soiled dressings were collected pre and post-treatment. Tissue specimens obtained pre-treatment were analysed with scanning electron microscopy (SEM) and peptide nucleic acid fluorescent in situ hybridisation (PNA-FISH) with confocal laser scanning microscopy and confirmed the presence of biofilm in all DRFUs. SEM confirmed the presence of biofilms readily adhered to soiled DACC-coated mesh dressings pre- and post-treatment in all participants. Real-time quantitative polymerase chain reaction (qPCR) demonstrated the mean total microbial load of DRFUs in 20 participants did not change after two weeks of therapy (pre-treatment = 4.31 Log10 16 S copies (±0.8) versus end of treatment = 4.32 Log10 16 S copies (±0.9), P = .96, 95% CI -0.56 to 0.5). 16 S sequencing has shown the microbial composition of DACC dressings and wound swabs pre- and post-treatment remained similar (DACC; R = -.047, P = .98, Swab; R = -.04, P = .86), indicating the microbial communities originate from the ulcer. Biofilms adhere to DACC-coated mesh dressings; however, this may not reduce the total microbial load present within DRFU tissue. Wound dressings for use in hard-to-heal wounds should be used as an adjunct to a good standard of care which includes debridement and wound bed preparation.
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Affiliation(s)
- Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, New South Wales, Australia.,High Risk Foot Service, Liverpool Hospital, South West Sydney LHD, Sydney, New South Wales, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Michael Radzieta
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, New South Wales, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
| | - Saskia Schwarzer
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, New South Wales, Australia.,High Risk Foot Service, Liverpool Hospital, South West Sydney LHD, Sydney, New South Wales, Australia
| | - Amy Walker
- High Risk Foot Service, Monash Health, Clayton, Victoria, Australia
| | - Justin Bradley
- High Risk Foot Service, Monash Health, Clayton, Victoria, Australia
| | - Slade O Jensen
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, New South Wales, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, New South Wales, Australia
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8
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Radzieta M, Peters TJ, Dickson HG, Cowin AJ, Lavery LA, Schwarzer S, Roberts T, Jensen SO, Malone M. A metatranscriptomic approach to explore longitudinal tissue specimens from non-healing diabetes related foot ulcers. APMIS 2022; 130:383-396. [PMID: 35394091 PMCID: PMC9320801 DOI: 10.1111/apm.13226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 04/05/2022] [Indexed: 12/13/2022]
Abstract
Cellular mechanisms and/or microbiological interactions which contribute to chronic diabetes related foot ulcers (DRFUs) were explored using serially collected tissue specimens from chronic DRFUs and control healthy foot skin. Total RNA was isolated for next-generation sequencing. We found differentially expressed genes (DEGs) and enriched hallmark gene ontology biological processes upregulated in chronic DRFUs which primarily functioned in the host immune response including: (i) Inflammatory response; (ii) TNF signalling via NFKB; (iii) IL6 JAK-STAT3 signalling; (iv) IL2 STAT5 signalling and (v) Reactive oxygen species. A temporal analysis identified RN7SL1 signal recognition protein and IGHG4 immunoglobulin protein coding genes as being the most upregulated genes after the onset of treatment. Testing relative temporal changes between healing and non-healing DRFUs identified progressive upregulation in healed wounds of CXCR5 and MS4A1 (CD20), both canonical markers of lymphocytes (follicular B cells/follicular T helper cells and B cells, respectively). Collectively, our RNA-seq data provides insights into chronic DRFU pathogenesis.
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Affiliation(s)
- Michael Radzieta
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Timothy J Peters
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,University of New South Wales, Sydney, NSW, Australia
| | - Hugh G Dickson
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,South Western Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Allison J Cowin
- Future Industries Institute, University of South Australia, Adelaide, SA, Australia
| | - Lawrence A Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Saskia Schwarzer
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia
| | - Tara Roberts
- Oncology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Slade O Jensen
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
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9
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Malone M, Schultz G. Challenges in the diagnosis and management of wound infection. Br J Dermatol 2022; 187:159-166. [PMID: 35587707 DOI: 10.1111/bjd.21612] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2022] [Indexed: 12/16/2022]
Abstract
Human epithelia are constantly exposed to microorganisms present in the environment or residing as part of commensal flora. Despite this exposure, infections involving the skin and subcutaneous tissue in healthy individuals are, fortunately, quite rare. Many of the wounds that afflict the human body occur in individuals of ill health and/or where the mechanism of wounding is impeded by host immunological, physiological or regenerative dysfunction. The interplay between microorganisms and host immunity is complex and remains ill defined; however, the interpretation of downstream manifestations of the host response to invading microorganisms is still based largely on the clinical signs and symptoms of an active infectious process. In this review article we will provide a brief overview of the current challenges clinicians face in diagnosing wound infections, how chronic infections caused by biofilms are a major challenge, and how there have been minimal advancements in developing new diagnostics or therapeutics in the identification and management of wound infections.
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Affiliation(s)
- Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Gregory Schultz
- Institute for Wound Research, University of Florida, Gainesville, FL, USA
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10
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Chen V, Burgess JL, Verpile R, Tomic-Canic M, Pastar I. Novel Diagnostic Technologies and Therapeutic Approaches Targeting Chronic Wound Biofilms and Microbiota. CURRENT DERMATOLOGY REPORTS 2022; 11:60-72. [PMID: 37007641 PMCID: PMC10065746 DOI: 10.1007/s13671-022-00354-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Purpose of Review To provide an up-to-date overview of recent developments in diagnostic methods and therapeutic approaches for chronic wound biofilms and pathogenic microbiota. Recent Findings Biofilm infections are one of the major contributors to impaired wound healing in chronic wounds, including diabetic foot ulcers, venous leg ulcers, pressure ulcers, and nonhealing surgical wounds. As an organized microenvironment commonly including multiple microbial species, biofilms develop and persist through methods that allow evasion from host immune response and antimicrobial treatments. Suppression and reduction of biofilm infection have been demonstrated to improve wound healing outcomes. However, chronic wound biofilms are a challenge to treat due to limited methods for accurate, accessible clinical identification and the biofilm's protective properties against therapeutic agents. Here we review recent approaches towards visual markers for less invasive, enhanced biofilm detection in the clinical setting. We outline progress in wound care treatments including investigation of their antibiofilm effects, such as with hydrosurgical and ultrasound debridement, negative pressure wound therapy with instillation, antimicrobial peptides, nanoparticles and nanocarriers, electroceutical dressings, and phage therapy. Summary Current evidence for biofilm-targeted treatments has been primarily conducted in preclinical studies, with limited clinical investigation for many therapies. Improved identification, monitoring, and treatment of biofilms require expansion of point-of-care visualization methods and increased evaluation of antibiofilm therapies in robust clinical trials.
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11
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Aswathanarayan JB, Rao P, HM S, GS S, Rai RV. Biofilm-Associated Infections in Chronic Wounds and Their Management. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022. [DOI: 10.1007/5584_2022_738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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12
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Malone M, Radzieta M, Peters TJ, Dickson HG, Schwarzer S, Jensen SO, Lavery LA. Host-microbe metatranscriptome reveals differences between acute and chronic infections in diabetes-related foot ulcers. APMIS 2021; 130:751-762. [PMID: 34888950 DOI: 10.1111/apm.13200] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 12/07/2021] [Indexed: 12/13/2022]
Abstract
Virtually all diabetes-related foot ulcers (DRFUs) will become colonized by microorganisms that may increase the risk of developing an infection. The reasons why some ulcerations develop acute clinical infections (AI-DRFUs) whilst others develop chronic infection (CI-DRFUs) and the preceding host-microbe interactions in vivo remain largely unknown. Establishing that acute and chronic infections are distinct processes requires demonstrating that these are two different strategies employed by microbes when interacting with a host. In this study, dual-RNA seq was employed to differentiate the host-microbe metatranscriptome between DRFUs that had localized chronic infection or acute clinical infection. Comparison of the host metatranscriptome in AI-DRFUs relative to CI-DRFUs identified upregulated differentially expressed genes (DEGs) that functioned as regulators of vascular lymphatic inflammatory responses, T-cell signalling and olfactory receptors. Conversely, CI-DRFUs upregulated DEGs responsible for cellular homeostasis. Gene set enrichment analysis using Hallmark annotations revealed enrichment of immune and inflammatory profiles in CI-DRFUs relative to AI-DRFUs. Analysis of the microbial metatranscriptome identified the DEGs being enriched within AI-DRFUs relative to CI-DRFUs included several toxins, two-component systems, bacterial motility, secretion systems and genes encoding for energy metabolism. Functions relevant to DRFU pathology were further explored, including biofilm and bacterial pathogenesis. This identified that the expression of biofilm-associated genes was higher within CI-DRFUs compared to that of AI-DRFUs, with mucR being the most highly expressed gene. Collectively, these data provide insights into the host-microbe function in two clinically-distinct infective phenotypes that affect DRFUs. The data reveal that bacteria in acutely infected DRFUs prioritize motility over biofilm and demonstrate greater pathogenicity and mechanisms, which likely subvert host cellular and immune pathways to establish infection. Upregulation of genes for key vascular inflammatory mediators in acutely infected ulcers may contribute, in part, to the clinical picture of a red, hot, swollen foot, which differentiates an acutely infected ulcer from that of a chronic infection.
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Affiliation(s)
- Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Michael Radzieta
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Timothy J Peters
- Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,University of New South Wales, Sydney, NSW, Australia
| | - Hugh G Dickson
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia.,South Western Clinical School, University of New South Wales, Sydney, NSW, Australia
| | - Saskia Schwarzer
- South West Sydney Limb Preservation and Wound Research, South Western Sydney LHD, Sydney, NSW, Australia
| | - Slade O Jensen
- Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Lawrence A Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Centre, Dallas, TX, USA
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13
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Malone M, Radzieta M, Schwarzer S, Jensen SO, Lavery LA. Efficacy of a topical concentrated surfactant gel on microbial communities in non-healing diabetic foot ulcers with chronic biofilm infections: A proof-of-concept study. Int Wound J 2021; 18:457-466. [PMID: 33476485 PMCID: PMC8273583 DOI: 10.1111/iwj.13546] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/18/2020] [Accepted: 12/28/2020] [Indexed: 12/15/2022] Open
Abstract
This proof‐of‐concept study sought to determine the effects of standard of care (SOC) and a topically applied concentrated surfactant gel (SG) on the total microbial load, community composition, and community diversity in non‐healing diabetic foot ulcers (DFUs) with chronic biofilm infections. SOC was provided in addition to a topical concentrated SG, applied every 2 days for 6 weeks. Wound swabs were obtained from the base of ulcers at baseline (week 0), week 1, mid‐point (week 3), and end of treatment (week 6). DNA sequencing and real‐time quantitative polymerase chain reaction (qPCR) were employed to determine the total microbial load, community composition, and diversity of patient samples. Tissue specimens were obtained at baseline and scanning electron microscopy and peptide nucleic acid fluorescent in situ hybridisation with confocal laser scanning microscopy were used to confirm the presence of biofilm in all 10 DFUs with suspected chronic biofilm infections. The application of SG resulted in 7 of 10 samples achieving a reduction in mean log10 total microbial load from baseline to end of treatment (0.8 Log10 16S copies, ±0.6), and 3 of 10 samples demonstrated an increase in mean Log10 total microbial load (0.6 log10 16S copies, ±0.8) from baseline to end of treatment. Composition changes in microbial communities were driven by changes to the most dominant bacteria. Corynebacterium sp. and Streptococcus sp. frequently reduced in relative abundance in patient samples from week 0 to week 6 but did not disappear. In contrast, Staphylococcus sp., Finegoldia sp., and Fusobacterium sp., relative abundances frequently increased in patient samples from week 0 to week 6. The application of a concentrated SG resulted in varying shifts to diversity (increase or decrease) between week 0 and week 6 samples at the individual patient level. Any shifts in community diversity were independent to changes in the total microbial loads. SOC and a topical concentrated SG directly affect the microbial loads and community composition of DFUs with chronic biofilm infections.
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Affiliation(s)
- Matthew Malone
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, Australia.,High Risk Foot Service, Liverpool Hospital, South West Sydney LHD, Sydney, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, Australia
| | - Michael Radzieta
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, Australia
| | - Saskia Schwarzer
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, Australia.,High Risk Foot Service, Liverpool Hospital, South West Sydney LHD, Sydney, Australia
| | - Slade O Jensen
- South West Sydney Limb Preservation and Wound Research, South West Sydney Local Health District, Sydney, Australia.,Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, Australia.,Antimicrobial Resistance and Mobile Elements Group, Ingham Institute of Applied Medical Research, Sydney, Australia
| | - Lawrence A Lavery
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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