Microbiological Species and Antibiotic Resistance in Diabetic and Nondiabetic Lower Extremity Wounds: A Comparative Cross-Sectional Study

Severe lower extremity wounds have an increased risk of complications and limb loss. The aim of this study was to evaluate and compare the microbiological profile and antibiotic resistance of wounds in diabetic and nondiabetic patients. A cross-sectional comparative study was carried out at a public hospital including 111 patients with moderate to severe wound infections. Tissue samples were collected during a surgical procedure. One hundred and four patients (94%) had positive cultures and 88 (79%) had a Gram-negative microorganism. Among the 185 cultured microorganisms, 133 (72%) were Gram-negative species. Pseudomonas aeruginosa (23 cases) was the most isolated Gram-negative species, and Enterococcus faecalis (26 cases) was the most prevalent Gram-positive species. Among 185 isolated species, 45 (24%) were extended-spectrum beta-lactamase producers, 23 (12%) were carbapenem-resistant, and 5 (3%) were methicillin-resistant Staphylococcus aureus. Findings revealed that there was no significant difference in the microbiological profile and antibiotic resistance among patients with lower extremity wounds whether they were diabetic or nondiabetic.

Bioadhesives with Antimicrobial Properties

Bioadhesives with antimicrobial properties enable easier and safer treatment of wounds as compared to the traditional methods such as suturing and stapling. Composed of natural or synthetic polymers, these bioadhesives seal wounds and facilitate healing while preventing infections through the activity of locally released antimicrobial drugs, nanocomponents, or inherently antimicrobial polers. Although many different materials and strategies are employed to develop antimicrobial bioadhesives, the design of these biomaterials necessitates a prudent approach as achieving all the required properties including optimal adhesive and cohesive properties, biocompatibility, and antimicrobial activity can be challenging. Designing antimicrobial bioadhesives with tunable physical, chemical, and biological properties will shed light on the path for future advancement of bioadhesives with antimicrobial properties. In this review, the requirements and commonly used strategies for developing bioadhesives with antimicrobial properties are discussed. In particular, different methods for their synthesis and their experimental and clinical applications on a variety of organs are reviewed. Advances in the design of bioadhesives with antimicrobial properties will pave the way for a better management of wounds to increase positive clinical outcomes.

Examining the effect of polyurethane dressing containing silver particles on the rate of diabetic foot ulcer infection in hospitalized patients: A randomized control study

Background and Aims

One of the new types of dressings is the polyurethane dressing containing silver particles. This study was designed to evaluate the effect of polyurethane dressing containing silver particles on the rate of diabetic foot ulcer infection in hospitalized patients in a military hospital.

Methods

This was a randomized clinical trial study on 48 patients with diabetic foot ulcers who were referred to the wound clinic of Shahid Dr. Chamran Hospital in 2022. The qualified samples were divided into two groups of silver polyurethane dressing and simple sterile dressing based on a randomization block method. The wounds of both groups of patients were initially cleaned with normal saline and in the first round of dressing, and a sample of tissue secretions was collected by the researcher using a sterile swab from the wounds of the patients on two occasions, superficially and deeply. The patients' wounds in the intervention group were dressed with polyurethane foam dressing containing silver particles, while the simple sterile routine dressing was used in the control group. The rate of infection and wound secretions were examined and recorded on the first, seventh, fourteenth, and twenty-first days from the start of dressing in both groups. To collect data, the IDSA tool was used.

Results

The rates of wound infection before the intervention showed no significant differences in the two groups (p = 0.242). However, these rates changed on the 7th, 14th, and 21st days after the intervention. Moreover, the infection rate was significantly lower in the polyurethane dressing group containing silver particles (p < 0.001 and F = 30.31).

Conclusions

Using polyurethane dressing was proven to be more effective in this study on the rate of diabetic ulcer infection in patients compared to the simple sterile dressing. Thus, nurses can use this dressing for faster treatment of diabetic foot ulcers infection.

Prospective randomised placebo-controlled trial assessing the efficacy of silver dressings to enhance healing of acute diabetes-related foot ulcers

AIMS/HYPOTHESIS

Silver dressings are used for their antimicrobial properties but there is limited evidence of clinical benefit when managing diabetes-related foot ulcers (DFUs). We aimed to assess whether silver dressings in acute DFUs increased the proportion of ulcers healed compared with non-silver dressings.

METHODS

In this open-labelled, randomised controlled trial, consecutive individuals who presented to a tertiary multidisciplinary diabetic foot service with a DFU without osteomyelitis or tendon on view of <6 weeks' duration were randomised 1:1 via a computer-generated randomisation process to receive Acticoat (Smith & Nephew, England) dressing (silver group) or dressing without silver (control group) in addition to standard care. Stratified randomisation was performed to ensure that the presence of peripheral arterial disease and infection were equally managed within the two groups. The primary outcome was the proportion of ulcers healed at 12 weeks. Secondary outcomes included time to heal and to 50% ulcer reduction, rates of osteomyelitis and amputation, and need for and duration of antibiotics.

RESULTS

Seventy-six ulcers (55 participants) in the control group and 91 ulcers (63 participants) in the silver group were included. There was no difference in the proportion of ulcers healed by 12 weeks in the control vs silver group (75% vs 69%, p=0.49). After adjustment for presence of peripheral arterial disease, infection and initial ulcer size, silver dressing was not associated with odds of healing (OR 0.92; CI 0.26, 3.22; p=0.53). There was no difference in time to healing, progression to osteomyelitis, need for amputation, or duration of or need for antibiotic treatment.

CONCLUSIONS/INTERPRETATION

In individuals with acute DFUs without osteomyelitis or tendon on view, Acticoat silver dressings did not improve wound healing or reduce need for antibiotics compared with non-silver dressings.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN12614001234606 FUNDING: Australian Diabetes Society-unrestricted research award.

Evaluating polymeric biomaterials to improve next generation wound dressing design

Wound healing is a dynamic series of interconnected events with the ultimate goal of promoting neotissue formation and restoration of anatomical function. Yet, the complexity of wound healing can often result in development of complex, chronic wounds, which currently results in a significant strain and burden to our healthcare system. The advancement of new and effective wound care therapies remains a critical issue, with the current therapeutic modalities often remaining inadequate. Notably, the field of tissue engineering has grown significantly in the last several years, in part, due to the diverse properties and applications of polymeric biomaterials. The interdisciplinary cohesion of the chemical, biological, physical, and material sciences is pertinent to advancing our current understanding of biomaterials and generating new wound care modalities. However, there is still room for closing the gap between the clinical and material science realms in order to more effectively develop novel wound care therapies that aid in the treatment of complex wounds. Thus, in this review, we discuss key material science principles in the context of polymeric biomaterials, provide a clinical breadth to discuss how these properties affect wound dressing design, and the role of polymeric biomaterials in the innovation and design of the next generation of wound dressings.

An Overview of Diabetic Foot Ulcers and Associated Problems with Special Emphasis on Treatments with Antimicrobials

One of the most significant challenges of diabetes health care is diabetic foot ulcers (DFU). DFUs are more challenging to cure, and this is particularly true for people who already have a compromised immune system. Pathogenic bacteria and fungi are becoming more resistant to antibiotics, so they may be unable to fight microbial infections at the wound site with the antibiotics we have now. This article discusses the dressings, topical antibacterial treatment, medications and debridement techniques used for DFU and provides a deep discussion of DFU and its associated problems. English-language publications on DFU were gathered from many different databases, such as Scopus, Web of Science, Science Direct, Springer Nature, and Google Scholar. For the treatment of DFU, a multidisciplinary approach involving the use of diagnostic equipment, skills, and experience is required. Preventing amputations starts with patient education and the implementation of new categorization systems. The microbiota involved in DFU can be better understood using novel diagnostic techniques, such as the 16S-ribosomal DNA sequence in bacteria. This could be achieved by using new biological and molecular treatments that have been shown to help prevent infections, to control local inflammation, and to improve the healing process.

Clinical Study on the Efficacy of Silver Ion Dressing Combined with Prontosan Gel Dressing in the Treatment of Diabetic Foot Ulcers and the Effect on Serum Inflammatory Factors

Diabetic foot ulcers (DFUs) have a high disability rate and have a great impact on patients and society, and the search for effective and economical treatment options is a major clinical concern. In this study, 112 patients with DFU admitted to two hospitals from October 2018 to November 2020 were randomly divided into 56 cases each in the single group treated with Prontosan gel dressing and the joint group treated on silver ion dressing combined with Prontosan gel dressing. Both groups of patients were evaluated for efficacy after 30 days of treatment. The number of days for debridement, granulation tissue growth time, epithelial tissue formation time, and wound healing time were observed and recorded in both groups. The trauma area, visual analogue score (VAS), and levels of inflammatory factors such as vascular endothelial adhesion molecule-1 (VCAM-1), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) were recorded before and after treatment in both groups. The occurrence of adverse reactions such as edema, fever, infection, and rash during treatment was recorded in both groups for safety assessment. Comparison of the abovementioned data showed that the clinical efficacy of the joint group was significantly higher than that of the single group. The number of days to clear wounds, granulation tissue growth time, epithelial tissue formation time, and wound healing time were significantly lower in the joint group than in the single group. The trauma area, VAS score, VCAM-1, IL-6, TNF-α, and CRP levels decreased in both groups after treatment compared with the pretreatment levels, with the joint group being lower than the single group. The results also showed that the difference in the overall incidence of adverse reactions between the two groups was not statistically significant, and the incidence was low and transient. In addition to the usual treatment regimen of blood glucose control and improvement of microcirculation for patients with DFU, combined treatment with silver ionomer dressings and Prontosan gel dressings can promote ulcer healing and improve foot wound regression. It has a stronger antibacterial effect and can more effectively reduce the inflammatory response of the ulcerated surface with fewer adverse effects, making it an effective and safe method for the treatment of DFU, and has implications for promotion.

Green and Chemical Silver Nanoparticles and Pomegranate Formulations to Heal Infected Wounds in Diabetic Rats

Infected cutaneous ulcers from diabetic rats with Candida albicans and Streptococcus aureus were treated with spray formulations containing green silver nanoparticles (GS), chemical silver nanoparticles (CS), or pomegranate peel extract (PS). After wound development and infection, the treatments were performed twice per day for 14 days. The wound healing was analyzed on days 2, 7, and 14 through the determination of CFUs, inflammatory infiltrate, angiogenesis, fibroplasia, myeloperoxidase, and collagen determination. Expressive improvement in wound healing was noted using both silver nanoparticles for 7 days. All the treatments were superior to controls and promoted significant S. aureus reduction after 14 days. CS presented better anti-inflammatory results, and GS and CS the highest number of fibroblasts. Despite the techniques' limitations, GS and CS demonstrated considerable potential for managing infected wounds, especially considering no early strategies prior to the drugs, such as the debridement of these wounds, were included.

Testing the efficacy of topical antimicrobial treatments using a two- and five-species chronic wound biofilm model

AIMS

The effectiveness of commercially available wound dressings and a HOCl gel formulation was tested against two- and five-species biofilms in a dynamic in vitro chronic wound infection model.

METHOD

Two-species biofilms (Pseudomonas aeruginosa and Staphylococcus aureus) were cultured using a biofilm flow device and treated with wound dressings containing silver, iodine, polyhexamethylene biguanide, crystal violet or HOCl gel at 5 h. Five-species biofilms (P. aeruginosa, S. aureus, Enterococcus faecalis, Streptococcus pyogenes and Escherichia coli) were similarly cultured and treated with HOCl gel at 5 and 24 h. Multidose experiments used two- and five-species biofilms with HOCl applied at 24, 48 and 72 h.

RESULTS

None of the treatments completely disrupted the biofilms and, with the exception of silver, bacteria recovered in number post-treatment. HOCl was most effective when applied to 24 h established biofilms with most activity against P. aeruginosa. Recovery post-treatment was negligible with HOCl applied at 24 h and multiple doses indicated that bacteria were not becoming tolerant to treatment.

CONCLUSIONS

Realistic models are necessary to test the effectiveness of antimicrobial wound treatments to ensure findings are clinically translatable. HOCl gel shows promise as a new topical antimicrobial for wounds, especially due to its ability to inhibit P. aeruginosa.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study highlights a need for robust in vitro data to support development and use of wound treatments that can only be obtained from the refinement of realistic infection models. Furthermore, it indicates the potential use of HOCl gel for chronic wound management.

The Influence of Multidrug-Resistant Bacteria on Clinical Outcomes of Diabetic Foot Ulcers: A Systematic Review

Multidrug-resistant organism infections have become important in recent years due to the increased prevalence of diabetic foot ulcers and their possible consequences. This study aimed to systematically review and evaluate ulcer duration, healing time, hospital stay, amputation, and mortality rates in patients with diabetic foot ulcers caused by infection with multidrug-resistant organisms. PubMed, the Cochrane Library, and Web of Science were searched in May 2020 to find observational studies in English about the clinical outcomes of multidrug-resistant organism infection in diabetic foot ulcers. Eight studies met the inclusion criteria, and these studies included 923 patients. The overall methodological quality of the study was moderate. Ulcer duration was described in six studies, and there was no practical association with multidrug-resistant organisms. Two out of three studies reported a longer healing time in multidrug-resistant organism infections than in non-multidrug-resistant organism infections. Clinical outcomes included the duration of hospitalisation, surgeries, amputations, and deaths. Lower limb amputation was the most reported clinical outcome in the included studies, and was more prevalent in the multidrug-resistant organism infections. We concluded that there was not enough evidence that multidrug-resistant organisms hindered the healing of diabetic foot ulcers. In contrast to the clinical outcomes, multidrug-resistant organisms affect both amputation rates and mortality rates.

Culture Concordance in Different Sections of the Metatarsal Head: Interpretations of Microbiological Results

Microbiological cultures of per-wound bone biopsies have shown a lack of correlation and a high rate of false-negative results when compared with bone biopsy cultures in diabetic foot osteomyelitis. The selection of samples from the area of active osteomyelitis, which contains a complete census of the microorganisms responsible for the infection, is essential to properly guide antimicrobial treatment. We aimed to comparatively evaluate the quantitative and qualitative cultures taken from different areas, in metatarsal heads resected for osteomyelitis. For this purpose, we consecutively selected 13 metatarsal heads from 12 outpatients with plantar ulcers admitted to our diabetic foot unit. Metatarsal heads were divided transversally into 3 portions: plantar (A), central (B), and dorsal (C), and the 39 resulting samples were cultured. Qualitative and quantitative microbiological analysis was performed, and the isolated species and bacterial load, total and species specific, were compared between the 3 metatarsal bone segments. The primary outcome of the study was the bacterial diversity detected in the different bone sections. Cultures were positive in 12 of the 13 included metatarsal heads (92%). A total of 34 organisms were isolated from all specimens. Ten of the 12 cultures (83%) were polymicrobial. Ten of the 13 metatarsal heads (77%) had identical microbiological results in each of the 3 bone sections. The largest number of microorganisms was found in the central section. The overall concordance between sections was 91%. The predominant microorganisms were coagulase-negative staphylococci (41%). Statistical differences were not found in the bioburden between sections (range 3.25-3.41 log₁₀ colony-forming unit/g for all sections; P = .511). The results of our study suggest that microorganisms exhibit a high tendency to spread along the metatarsal bone and that the degree of progression along the bone is species dependent. The central portions of metatarsal bones tend to accumulate a higher diversity of species. Thus, we recommend this area of bone for targeted biopsy in patients with suspected osteomyelitis.

The Effects of Silver-Releasing Foam Dressings on Diabetic Foot Ulcer Healing

Diabetic foot ulcers (DFUs) are a serious complication in diabetic patients and lead to high morbidity and mortality. Numerous dressings have been developed to facilitate wound healing of DFUs. This study investigated the wound healing efficacy of silver-releasing foam dressings versus silver-containing cream in managing outpatients with DFUs. Sixty patients with Wagner Grade 1 to 2 DFUs were recruited. The treatment group received silver-releasing foam dressing (Biatain^® Ag Non-Adhesive Foam dressing; Coloplast, Humlebaek, Denmark). The control group received 1% silver sulfadiazine (SSD) cream. The ulcer area in the silver foam group was significantly reduced compared with that in the SSD group after four weeks of treatment (silver foam group: 76.43 ± 7.41%, SSD group: 27.00 ± 4.95%, p < 0.001). The weekly wound healing rate in the silver foam group was superior to the SSD group during the first three weeks of treatment (p < 0.05). The silver-releasing foam dressing is more effective than SSD in promoting wound healing of DFUs. The effect is more pronounced in the initial three weeks of the treatment. Thus, silver-releasing foam could be an effective wound dressing for DFUs, mainly in the early period of wound management.

Silver dressing in the treatment of diabetic foot: A protocol for systematic review and meta-analysis

BACKGROUND

Diabetic foot (DF) is one of the most common and serious chronic complications of diabetes. At present, there are many dressings used in the treatment of the diabetic foot. Among them, silver dressings are widely used, but the conclusion has not yet been formed. The purpose of this study is to search for relevant studies on the treatment of DF with silver dressings through evidence-based medicine methods and to draw conclusions with higher levels of evidence to provide a basis for the clinical treatment of DF.

METHODS

Computer search of databases such as CNKI, SinoMed, VIP, Wanfang, PubMed, Embase, and Cochrane Library. The search time is from the establishment of the database to January 23, 2021. Two researchers will independently select studies, collect data, and assess the methodology quality by the Cochrane risk of bias tool. The meta-analysis will be completed by RevMan 5.3 software.

RESULTS

This systematic review will provide an assessment of the current state of DF, aiming to assess the efficacy of silver dressings for patients with DF.

CONCLUSION

This systematic review will provide a credible evidence-based for the clinical treatment of DF with silver dressings.

Adipose-Derived Mesenchymal Stem Cells in the Treatment of Diabetic Foot Ulcers: A Review of Preclinical and Clinical Studies

This review provides an outline of the use of adipose-derived mesenchymal stem cells (AMSCs) in the treatment of diabetic foot ulcers (DFUs). A systematic search of PubMed and the Cochrane database was performed on October 2, 2019. Eighteen studies were identified (14 preclinical and 4 clinical). Studies in animal models have demonstrated that AMSCs enhance diabetic wound healing, accelerate granulation tissue formation, and increase reepithelialization and neovascularization. Only 1 randomized control trial has been published so far. Patients (n = 25) with DFUs were treated using an allogeneic AMSC directly on the wound bed as a primary dressing, and improvements were found in complete wound closure in the treatment group (n = 16). Three clinical studies showed that autologous AMSC might be a safe alternative to achieve therapeutic angiogenesis in patients with diabetes and peripheral arterial disease. Based on the available evidence, AMSCs hold promise in the treatment of DFUs. However, this evidence requires confirmation by well-designed trials. Additional studies are also required to understand some issues regarding this treatment for DFUs. For example, the potential application of autologous or allogeneic AMSCs in different types of DFUs, optimal dose/infusion schedules, safety evaluations, and cost-effectiveness.