scholarly journals The Visualization of Biofilms in Chronic Diabetic Foot Wounds Using Routine Diagnostic Microscopy Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Angela Oates ◽  
Frank L. Bowling ◽  
Andrew J. M. Boulton ◽  
Philip G. Bowler ◽  
Daniel G. Metcalf ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Antimicrobial Agents ◽  
Chronic Wounds ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Diabetic Patients ◽  
Gram Stain ◽  
Bright Field ◽  
Planktonic Bacteria ◽  
Biofilm Matrix

Diabetic foot wounds are commonly colonised by taxonomically diverse microbial communities and may additionally be infected with specific pathogens. Since biofilms are demonstrably less susceptible to antimicrobial agents than are planktonic bacteria, and may be present in chronic wounds, there is increasing interest in their aetiological role. In the current investigation, the presence of structured microbial assemblages in chronic diabetic foot wounds is demonstrated using several visualization methods. Debridement samples, collected from the foot wounds of diabetic patients, were histologically sectioned and examined using bright-field, fluorescence, and environmental scanning electron microscopy and assessed by quantitative differential viable counting. All samples (n= 26) harboured bioburdens in excess of 5 log10CFU/g. Microcolonies were identified in 4/4 samples by all three microscopy methods, although bright-field and fluorescence microscopy were more effective at highlighting putative biofilm morphology than ESEM. Results in this pilot study indicate that bacterial microcolonies and putative biofilm matrix can be visualized in chronic wounds using florescence microscopy and ESEM, but also using the simple Gram stain.

scholarly journals Bioactive Antimicrobial Peptides as Therapeutic Agents for Infected Diabetic Foot Ulcers

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1894
Author(s):  
Jessica Da Silva ◽  
Ermelindo C. Leal ◽  
Eugénia Carvalho
Keyword(s):  
Wound Healing ◽  
Antimicrobial Peptides ◽  
Broad Spectrum ◽  
Diabetic Foot ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Chronic Wounds ◽  
Foot Ulcer ◽  
Wound Management ◽  
Diabetic Patients

Diabetic foot ulcer (DFU) is a devastating complication, affecting around 15% of diabetic patients and representing a leading cause of non-traumatic amputations. Notably, the risk of mixed bacterial–fungal infection is elevated and highly associated with wound necrosis and poor clinical outcomes. However, it is often underestimated in the literature. Therefore, polymicrobial infection control must be considered for effective management of DFU. It is noteworthy that antimicrobial resistance is constantly rising overtime, therefore increasing the need for new alternatives to antibiotics and antifungals. Antimicrobial peptides (AMPs) are endogenous peptides that are naturally abundant in several organisms, such as bacteria, amphibians and mammals, particularly in the skin. These molecules have shown broad-spectrum antimicrobial activity and some of them even have wound-healing activity, establishing themselves as ideal candidates for treating multi-kingdom infected wounds. Furthermore, the role of AMPs with antifungal activity in wound management is poorly described and deserves further investigation in association with antibacterial agents, such as antibiotics and AMPs with antibacterial activity, or alternatively the application of broad-spectrum antimicrobial agents that target both aerobic and anaerobic bacteria, as well as fungi. Accordingly, the aim of this review is to unravel the molecular mechanisms by which AMPs achieve their dual antimicrobial and wound-healing properties, and to discuss how these are currently being applied as promising therapies against polymicrobial-infected chronic wounds such as DFUs.

Reducing the burden of chronic wounds: Prevention and management of the diabetic foot in the context of clinical guidelines

2008 ◽  
Vol 13 (3_suppl) ◽  
pp. 82-91 ◽  
Author(s):  
Aidan Searle ◽  
Lone Gale ◽  
Rona Campbell ◽  
Mark Wetherell ◽  
Karen Dawe ◽  
...  
Keyword(s):  
Decision Making ◽  
Shared Decision Making ◽  
Diabetic Foot ◽  
Clinical Guidelines ◽  
Chronic Wounds ◽  
Foot Ulcer ◽  
Foot Ulcers ◽  
Diabetic Patients ◽  
Shared Decision ◽  
Behavioural Factors

Objectives: Chronic wounds such as diabetic foot and venous leg ulcers are a major burden for health services. Our programme was developed to explore the psychological and behavioural factors that may influence both the incidence of chronic wounds and their progression. The present article focuses on two particular aspects of the programme: patient knowledge of diabetic foot ulceration and factors influencing foot-related behaviour in patients with and without foot ulcers; and patient and podiatrist perspectives of consultations for diabetic foot ulcers. Methods: Two independent qualitative studies were undertaken: one with diabetic patients without a history of ulceration; and the other with diabetic patients with active ulceration and podiatrists treating these patients. Results: We found that patients may find it difficult understanding the rationale underlying prevention and treatment of foot ulcers; ulcerated patients may find it difficult to engage in the management of their foot ulcer outside consultations; and some podiatrists feel frustrated and unsupported in their attempts at empowering and building partnerships with patients. Conclusion: Patient and practitioner factors may contribute to the effective implementation of clinical guidelines regarding education, partnership building and shared decision-making. These findings are discussed in relation to patient education, partnership building and shared decision-making as recommended in NICE guidelines.

scholarly journals Linked Redox Precipitation of Sulfur and Selenium under Anaerobic Conditions by Sulfate-Reducing Bacterial Biofilms

2003 ◽  
Vol 69 (12) ◽  
pp. 7063-7072 ◽  
Author(s):  
Simon L. Hockin ◽  
Geoffrey M. Gadd
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Sulfur ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Elemental Selenium ◽  
Sulfate Reducing ◽  
Pass Through ◽  
Biofilm Matrix ◽  
Scanning Electron

ABSTRACT A biofilm-forming strain of sulfate-reducing bacteria (SRB), isolated from a naturally occurring mixed biofilm and identified by 16S rDNA analysis as a strain of Desulfomicrobium norvegicum, rapidly removed 200 μM selenite from solution during growth on lactate and sulfate. Elemental selenium and elemental sulfur were precipitated outside SRB cells. Precipitation occurred by an abiotic reaction with bacterially generated sulfide. This appears to be a generalized ability among SRB, arising from dissimilatory sulfide biogenesis, and can take place under low redox conditions and in the dark. The reaction represents a new means for the deposition of elemental sulfur by SRB under such conditions. A combination of transmission electron microscopy, environmental scanning electron microscopy, and cryostage field emission scanning electron microscopy were used to reveal the hydrated nature of SRB biofilms and to investigate the location of deposited sulfur-selenium in relation to biofilm elements. When pregrown SRB biofilms were exposed to a selenite-containing medium, nanometer-sized selenium-sulfur granules were precipitated within the biofilm matrix. Selenite was therefore shown to pass through the biofilm matrix before reacting with bacterially generated sulfide. This constitutes an efficient method for the removal of toxic concentrations of selenite from solution. Implications for environmental cycling and the fate of sulfur and selenium are discussed, and a general model for the potential action of SRB in selenium transformations is presented.

scholarly journals Aesthetic Alteration of Marble Surfaces Caused by Biofilm Formation: Effects of Chemical Cleaning

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 122 ◽  
Author(s):  
Federica Villa ◽  
Davide Gulotta ◽  
Lucia Toniolo ◽  
Luigimaria Borruso ◽  
Cristina Cattò ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Specific Substrate ◽  
Chemical Cleaning ◽  
Aesthetic Results ◽  
Cleaning Procedures ◽  
Functional Profiles ◽  
The Impact ◽  
Cleaning Treatment

Despite the massive presence of biofilms causing aesthetic alteration to the façade of the Monza Cathedral, our team in a previous work proved that the biocolonization was not a primary damaging factor if compared to chemical-physical deterioration due to the impact of air pollution. Nonetheless, the conservators tried to remove the sessile dwelling microorganisms to reduce discolouration. In this research, two nearby sculpted leaves made of Candoglia marble were selected to study the effects of a chemical treatment combining the biocides benzalkonium chloride, hydrogen peroxide and Algophase® and mechanical cleaning procedures. One leaf was cleaned with the biocides and mechanically, and the other was left untreated as control. The impact of the treatment was investigated after 1 month from the cleaning by digital microscopy, environmental scanning electron microscopy, confocal microscopy and molecular methods to determine the composition and the functional profiles of the bacterial communities. Despite the acceptable aesthetic results obtained, the overall cleaning treatment was only partially effective in removing the biofilm from the colonized surfaces and, therefore, not adequately suitable for the specific substrate. Furthermore, the cleaning process selected microorganisms potentially more resistant to biocides so that the efficacy of future re-treatment by antimicrobial agents could be negatively affected.

scholarly journals Bacteriological profile and antimicrobial sensitivity pattern of isolates from diabetic foot of patients attending a teaching hospital in Northern India

2021 ◽  
Vol 12 (5) ◽  
pp. 83-87
Author(s):  
Seema Aleem ◽  
Harman Multani ◽  
Humaira Bashir
Keyword(s):  
Diabetic Foot ◽  
Antimicrobial Agents ◽  
Diabetic Patients ◽  
Age Group ◽  
Sensitivity Testing ◽  
Bacteriological Profile ◽  
Foot Injury ◽  
Increased Risk ◽  
Sensitivity Pattern ◽  
Study Participants

Background: Diabetic foot ulcer is a major cause for diabetes related morbidity and hospitalization. Up to one-third of people with diabetes develop diabetic foot ulceration (DFU) during their lifetime and over 50% of these ulcerations become infected. Diabetic foot infections (DFIs) are associated with major morbidity, increasing mortality, high costs, increased risk of lower extremity amputation (LEA), and reduced quality of life. Aims and Objective: The current study was conducted to determine the microbiological profile and antibiotic susceptibility pattern of organisms in diabetic foot ulcers patients at a tertiary care center in Srinagar province. Material and Methods: This was a Cross-sectional, observational study conducted in diabetic patients with diabetic foot infection, randomly selected from outpatient departments (OPDs) and wards of Surgery and Medicine department, with Wagner grade 1-5 ulcers and irrespective of anti-diabetic treatment and diabetic foot injury treatment. Samples were processed and bacterial isolates were identified by standard microbiological procedures. Results: After following inclusion and exclusion criteria, 120 patients were considered for this study. In present study most common age group was 51-60 years age group (44%) followed by 41-50 years (32%). 66% of participants were males. 55% patients had diabetes for more than 10 years. 43% patients had ulcer size less than 5 cm2. The most common category as per Wagner’s classification was Grade 1, which comprised of 48% of study participants, followed by Grade 0 (28%) and Grade 2 (18%). Grade 3 and above comprised 7% of cases. Of the 120 study participants, 103 (86%) showed growth on culture. Among these 62 (60%) showed mono-microbial growth with 41 cases showing mixed growth. The most commonly isolated bacteria were Methicillin Resistant Staphylococcus aureus (MRSA) (23%), Coagulase Negative Staphylococci (CoNS) (18%), pseudomonas aeruginosa (18%), Methicillin Sensitive-Staphylococci Aureus (9%), Klebsiella Pneumoniae (9%), and Escherichia Coli (8%). Linezolid, vancomycin, clindamycin, gentamicin were most effective antimicrobial agents against gram positive bacteria. Iimipenem, piperacillin tazobactam, cefoperazone sulbactam & gentamicin were most effective antimicrobial agents against gram negative bacteria. Conclusion: Early microbiological evaluation for bacteriological profile, the nature of the infection either monomicrobial or polymicrobial and antibiotic sensitivity testing can improve treatmentoutcome, reduces complications, morbidity as well as multidrug resistance.

scholarly journals Urinary Extracellular Vesicles: Potential Biomarkers of Renal Function in Diabetic Patients

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Agnieszka Kamińska ◽  
Mark Platt ◽  
Joanna Kasprzyk ◽  
Beata Kuśnierz-Cabala ◽  
Agnieszka Gala-Błądzińska ◽  
...  
Keyword(s):  
Renal Failure ◽  
Renal Function ◽  
Size Distribution ◽  
Renal Damage ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Diabetic Patients ◽  
Type 2 Diabetic Patients ◽  
Distribution Study ◽  
Urine Albumin

The aim of this study was to check the relationship between the density of urinary EVs, their size distribution, and the progress of early renal damage in type 2 diabetic patients (DMt2). Patients were enrolled to this study, and glycated hemoglobin (HbA1c) below 7% was a threshold for properly controlled diabetic patients (CD) and poorly controlled diabetic patients (UD). Patients were further divided into two groups: diabetic patients without renal failure (NRF) and with renal failure (RF) according to the Glomerular Filtration Rate. Density and diameter of EVs were determined by Tunable Resistive Pulse Sensing. Additionally, EVs were visualized by means of Transmission and Environmental Scanning Electron Microscopy. Nano-liquid chromatography coupled offline with mass spectrometry (MALDI-TOF-MS/MS) was applied for proteomic analysis. RF had reduced density of EVs compared to NRF. The size distribution study showed that CD had larger EVs (mode) than UD (115 versus 109 nm; p<0.05); nevertheless the mean EVs diameter was smaller in controls than in the CD group (123 versus 134 nm; p<0.05). It was demonstrated that EVs are abundant in urine. Albumin, uromodulin, and number of unique proteins related to cell stress and secretion were detected in the EVs fraction. Density and size of urinary EVs reflect deteriorated renal function and can be considered as potential renal damage biomarkers.

Therapeutic Options for Diabetic Foot Infections

2010 ◽  
Vol 100 (1) ◽  
pp. 52-63 ◽  
Author(s):  
David P. Nicolau ◽  
Gary E. Stein
Keyword(s):  
Diabetic Foot ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Therapeutic Options ◽  
Diabetic Patients ◽  
Chronic Infections ◽  
Gram Positive Bacteria ◽  
Diabetic Foot Infections ◽  
Foot Complications ◽  
Optimal Drug

Foot complications are common in diabetic patients; foot ulcers are among the more serious consequences. These ulcers frequently become infected, and if not treated promptly and appropriately, diabetic foot infections can lead to septic gangrene and amputation. Foot infections may be classified as mild, moderate, or severe; this largely determines the approach to therapy. Staphylococcus aureus is the most common pathogen in these infections, and the increasing incidence of methicillin-resistant S aureus during the past two decades has further complicated antibiotic treatment. Chronic infections are often polymicrobial. Physiologic changes, and local and systemic inflammation, can affect the plasma and tissue pharmacokinetics of antimicrobial agents in diabetic patients, leading to impaired target-site penetration. Knowledge of the serum and tissue concentrations of antibiotics in diabetic patients is, therefore, important for choosing the optimal drug and dose. This article reviews the commonly used therapeutic options for treatment, including many newer antibiotics developed to target multidrug-resistant gram-positive bacteria, and includes available data relating specifically to the tissue penetration of these agents. (J Am Podiatr Med Assoc 100(1): 52–63, 2010)

scholarly journals Oral carriage of methicillin-resistant Staphylococcus aureus strains among patients with diabetic foot ulcer

2020 ◽  
pp. 5-12
Keyword(s):  
Staphylococcus Aureus ◽  
Oral Cavity ◽  
Diabetic Foot ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Foot Ulcer ◽  
Diabetic Foot Ulcer ◽  
Diabetic Patients ◽  
Methicillin Resistant ◽  
Mrsa Strains

Introduction: Diabetic foot ulcer (DFU) caused by Staphylococcus aureus is one of the most feared complications of diabetes mellitus. The studies reporting the oral cavity as a potential reservoir of S. aureus in diabetic patients are sparse. The aim of the study was to compare the prevalence of methicillin-resistant Staphylococcus aureus strains in the oral and in the diabetic foot specimens from DFU patients. Materials and Methods: A total 80 specimens (40 oral swabs and 40 DFU swabs) were collected from diabetic patients with foot ulcer. The specimens were subcultured and the susceptibility of isolated S. aureus strains to antimicrobial agents was determined. Suspected methicillin-resistant S. aureus (MRSA) strains were further examined for the presence of modified PBP2a protein. Results: Less than one-fifth of patients with DFU had oral S. aureus carriage, however the colonization is significantly associated with S. aureus diabetic foot infection. S. aureus strains were isolated from 52.5% of DFU specimens, 17.5% were resistant to methicillin. S. aureus strains were isolated from 17.5% of oral specimens of diabetic patients; 2.5% were methicillin-resistant. The MRSA strains were isolated sevenfold more frequently from the diabetic foot than from the oral cavity. Conclusions: Although diabetic foot infections caused by an endogenous S. aureus strains colonizing the oral cavity of diabetic patients seems unlikely, it is evidently important to monitor the oral S. aureus carriage in diabetic patients and their resistance to antibiotics.

scholarly journals Long-Term Intrahost Evolution of Staphylococcus aureus Among Diabetic Patients With Foot Infections

2021 ◽  
Vol 12 ◽  
Author(s):  
Jean-Philippe Lavigne ◽  
Michel Hosny ◽  
Catherine Dunyach-Remy ◽  
Adeline Boutet-Dubois ◽  
Sophie Schuldiner ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Diabetic Foot ◽  
Chronic Wounds ◽  
Bacterial Genome ◽  
Rare Event ◽  
Diabetic Patients ◽  
Virulence Markers ◽  
Diabetic Foot Infections ◽  
Genes Encoding

Staphylococcus aureus is one of the main pathogens isolated from diabetic foot infections (DFI). The purpose of this study was to evaluate the importance of the persistence of S. aureus in this environment and the possible modifications of the bacterial genome content over time. Molecular typing of S. aureus isolates cultured from patients with the same DFI over a 7-year study revealed a 25% rate of persistence of this species in 48 patients, with a short median persistence time of 12weeks (range: 4–52weeks). Non-specific clonal complexes were linked to this persistence. During the follow-up, bla genes were acquired in three cases, whereas some virulence markers were lost in all cases after a long period of colonization (21.5weeks). Only one patient (2%) had a long-term persistence of 48weeks. The genome sequencing of a clonal pair of early/late strains isolated in this patient showed mutations in genes encoding bacterial defence and two-component signal transduction systems. Although, this study suggests that the long-term persistence of S. aureus in DFI is a rare event, genomic evolution is observed, highlighting the low adaptive ability of S. aureus to the specific environment and stressful conditions of diabetic foot ulcers. These results provide the basis for better understanding of S. aureus dynamics during persistent colonization in chronic wounds.

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