Alternative Approaches for the Management of Diabetic Foot Ulcers

Causes, prevention, and management of diabetes-related foot ulcers

In this Review, we aim to complement the 2023 update of the guidelines of the International Working Group on the Diabetic Foot. We highlight the complexity of the pathological processes that underlie diabetes-related foot ulceration (DFU) and draw attention to the potential implications for clinical management and outcome. Variation observed in the incidence and outcome of DFUs in different communities might result from differences in study populations and the accessibility of care. Comparing differences in incidence, management, and outcome of DFUs in different communities is an essential component of the quality of disease care. Additionally, these comparisons can also highlight the relationship between DFU incidence, management, and outcome and the structure of local clinical services and the availability of staff with the necessary skills. The clinical outcome is, however, also dependent on the availability of multidisciplinary care and the ability of people with DFUs to gain access to that care.

Diabetes-related lower limb wounds: Antibiotic susceptibility pattern and biofilm formation

The expeditious incidence of diabetes mellitus in Riyadh, Saudi Arabia, there is a significant increase in the total number of people with diabetic foot ulcers. For diabetic lower limb wound infections (DLWs) to be effectively treated, information on the prevalence of bacteria that cause in this region as well as their patterns of antibiotic resistance is significant. Growing evidence indicates that biofilm formers are present in chronic DFU and that these biofilm formers promote the emergence of multi-drug antibiotic resistant (MDR) strains and therapeutic rejection. The current study targeted to isolate bacteria from wounds caused by diabetes specifically at hospitals in Riyadh and assess the bacterium's resistance to antibiotics and propensity to develop biofilms. Totally 63 pathogenic microbes were identified from 70 patients suffering from DFU. Sixteen (25.4%) of the 63 bacterial strains were gram-positive, and 47 (74.6%) were gram-negative. Most of the gram-negative bacteria were resistant to tigecycline, nitrofurantoin, ampicillin, amoxicillin, cefalotin, and cefoxitin. Several gram-negative bacteria are susceptible to piperacillin, meropenem, amikacin, gentamicin, imipenem, ciprofloxacin, and trimethoprim. The most significant antibiotic that demonstrated 100% susceptibility to all pathogens was meropenem. Serratia marcescens and Staphylococcus aureus were shown to have significant biofilm formers. MDR bacterial strains comprised about 87.5% of the biofilm former strains. To the best of our knowledge, Riyadh, Saudi Arabia is the first region where Serratia marcescens was the most common bacteria from DFU infections. Our research findings would deliver information on evidence-based alternative strategies to develop effective treatment approaches for DFU treatment.

Confronting a New Challenge in Plastic Surgery: MDR Infections in Patients with Chronic Wounds

BACKGROUND

The presence of a wound can be anywhere from non-problematic to life-threatening on a severity spectrum, with bacterial infection and resistance playing a major role in the development of chronicity, delaying wound healing. Wound colonization with multiple organisms and the limited number of effective antibiotics place a heavy burden on the healthcare system, with patients going through multiple surgeries during a prolonged hospitalization time. By analyzing the resistance patterns of pluri-bacterial populations and the approach used in managing complex cases, we aim to improve the protocols applied in caring for chronic wounds in our practice and share our experiences and observations.

METHODS

We designed a retrospective study on 212 diabetic and non-diabetic patients, aiming to evaluate the course of chronic wound treatment in our practice. We focused on the impact that MDR bacteria and diabetes have on surgical outcomes and their role in the healing process.

RESULTS

Patients who received empiric antibiotic therapy before being admitted eventually presented with multiple MDR bacteria compared to those who did not receive antibiotics (p = 0.014). The presence of at least one MDR bacteria in the wound bed was associated with ulcers reaching bone (p = 0.02) and was positively correlated with the number of surgeries performed (p < 0.001). Diabetes played a significant role in surgery-related complications (p = 0.02) and hospitalization time (p < 0.001).

CONCLUSIONS

Proper management of chronic wounds requires a comprehensive, multidisciplinary approach and a thorough understanding of antibiotic usage. To address this need, we have developed and implemented a chronic wound treatment protocol in our clinic, with the goal of discharging patients once their ulcers have been treated and closed. A key summary of the protocol presented is to reduce the incidence of MDR bacteria and improve the patient's quality of life.

Panthenol Citrate Biomaterials Accelerate Wound Healing and Restore Tissue Integrity

Impaired wound healing is a common complication for diabetic patients and effective diabetic wound management remains a clinical challenge. Furthermore, a significant problem that contributes to patient morbidity is the suboptimal quality of healed skin, which often leads to reoccurring chronic skin wounds. Herein, a novel compound and biomaterial building block, panthenol citrate (PC), is developed. It has interesting fluorescence and absorbance properties, and it is shown that PC can be used in soluble form as a wash solution and as a hydrogel dressing to address impaired wound healing in diabetes. PC exhibits antioxidant, antibacterial, anti-inflammatory, and pro-angiogenic properties, and promotes keratinocyte and dermal fibroblast migration and proliferation. When applied in a splinted excisional wound diabetic rodent model, PC improves re-epithelialization, granulation tissue formation, and neovascularization. It also reduces inflammation and oxidative stress in the wound environment. Most importantly, it improves the regenerated tissue quality with enhanced mechanical strength and electrical properties. Therefore, PC could potentially improve wound care management for diabetic patients and play a beneficial role in other tissue regeneration applications.

Isolation and Characterization of New Bacteriophages against Staphylococcal Clinical Isolates from Diabetic Foot Ulcers

Staphylococcus sp. is the most common bacterial genus in infections related to diabetic foot ulcers (DFUs). The emergence of multidrug-resistant bacteria places a serious burden on public health systems. Phage therapy is an alternative treatment to antibiotics, overcoming the issue of antibiotic resistance. In this study, six phages (SAVM01 to SAVM06) were isolated from effluents and were used against a panel of staphylococcal clinical samples isolated from DFUs. A genomic analysis revealed that the phages belonged to the Herelleviridae family, with sequences similar to those of the Kayvirus genus. No lysogeny-associated genes, known virulence or drug resistance genes were identified in the phage genomes. The phages displayed a strong lytic and antibiofilm activity against DFU clinical isolates, as well as against opportunistic pathogenic coagulase-negative staphylococci. The results presented here suggest that these phages could be effective biocontrol agents against staphylococcal clinical isolates from DFUs.

Multi-Instrumental Analysis Toward Exploring the Diabetic Foot Infection Microbiota

The polymicrobial nature of diabetic foot infection (DFI) makes accurate identification of the DFI microbiota, including rapid detection of drug resistance, challenging. Therefore, the main objective of this study was to apply matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF MS) technique accompanied by multiply culture conditions to determine the microbial patterns of DFIs, as well as to assess the occurrence of drug resistance among Gram-negative bacterial isolates considered a significant cause of the multidrug resistance spread. Furthermore, the results were compared with those obtained using molecular techniques (16S rDNA sequencing, multiplex PCR targeting drug resistance genes) and conventional antibiotic resistance detection methods (Etest strips). The applied MALDI-based method revealed that, by far, most of the infections were polymicrobial (97%) and involved many Gram-positive and -negative bacterial species-19 genera and 16 families in total, mostly Enterobacteriaceae (24.3%), Staphylococcaceae (20.7%), and Enterococcaceae (19.8%). MALDI drug-resistance assay was characterized by higher rate of extended-spectrum beta-lactamases (ESBLs) and carbapenemases producers compared to the reference methods (respectively 31% and 10% compared to 21% and 2%) and revealed that both the incidence of drug resistance and the species composition of DFI were dependent on the antibiotic therapy used. MALDI approach included antibiotic resistance assay and multiply culture conditions provides microbial identification at the level of DNA sequencing, allow isolation of both common (eg. Enterococcus faecalis) and rare (such as Myroides odoratimimus) bacterial species, and is effective in detecting antibiotic-resistance, especially those of particular interest-ESBLs and carbapenemases.

What’s old is new again: Insights into diabetic foot microbiome

Diabetes is a chronic disease that is considered one of the most stubborn global health problems that continues to defy the efforts of scientists and physicians. The prevalence of diabetes in the global population continues to grow to alarming levels year after year, causing an increase in the incidence of diabetes complications and health care costs all over the world. One major complication of diabetes is the high susceptibility to infections especially in the lower limbs due to the immunocompromised state of diabetic patients, which is considered a definitive factor in all cases. Diabetic foot infections continue to be one of the most common infections in diabetic patients that are associated with a high risk of serious complications such as bone infection, limb amputations, and life-threatening systemic infections. In this review, we discussed the circumstances associated with the high risk of infection in diabetic patients as well as some of the most commonly isolated pathogens from diabetic foot infections and the related virulence behavior. In addition, we shed light on the different treatment strategies that aim at eradicating the infection.

Diabetic foot ulcer-a systematic review on relevant microbial etiology and antibiotic resistance in Asian countries

BACKGROUND AND AIMS

Diabetic foot ulcer (DFU) is one of the most common but uncontrolled health issues of diabetic patients that needs more therapeutic considerations. This systematic review aims to study the current status of the etiological agents responsible for DFU, their frequency in some of the most occurring Asian countries, and their antibiotic resistance pattern based on available studies.

METHODS

Here, the literature survey was conducted on all the DFU studies with the records of etiological agents and conventional therapeutic treatment published until March 2021 using Medical Literature Analysis and Retrieval System Online (MEDLINE) and Web of Science Core Collection (WoSCC) database.

RESULTS

Overall, in our study, a total of 73 studies representing 12 Asian countries worldwide have been included. We found that the highest number of studies were reported from India (45%) followed by Pakistan (11%), China, Iran and others. 71% of recent studies reported DFU being attributed to poly-microbial infections while the dominant position was significantly secured by Gram- negative bacteria (77%, p = 0.34). Staphylococcus aureus was found to be the most prevalent isolate followed by Pseudomonas and then Escherichia coli (mean value - 22%, 17%, and 15% respectively). Antibiotic sensitivity pattern was determined based on availability in terms of median resistance (MR) and interquartile range (IQR) which showed the growing resistance developed by both Gram-positive and Gram-negative isolates. Gram positive pathogens were still reported as susceptible to vancomycin (MR 0%, IQR 0-22.8%), linezolid (MR 0%, IQR 0-15.53%) and imipenem (MR 11%, IQR 0-23.53%). Carbapenem genera, colistin, and amikacin were the most effective drugs against Gram-negative pathogens.

CONCLUSION

The findings of this study highly recommend searching for alternative and complementary therapeutic regimens instead of prescribing conventional drugs blindly without investigating the progression of the stages of the ulcer, which may help reduce the medical and economic burden of this disease.

Novel Amoxicillin-Loaded Sericin Biopolymeric Nanoparticles: Synthesis, Optimization, Antibacterial and Wound Healing Activities

Infected wounds are a major threat among diabetic patients. Technological advancements are currently increasing the number of new adjunctive therapies that may be potent agents for speeding recovery, lowering the amputation rate and limiting infection recurrences. A novel formula with promising antibacterial activity, namely sericin/propolis/Amoxicillin nanoparticles, was assessed as a potent treatment of infected wounds in normal and diabetic rats. Skin wound healing efficiency was assessed through wound healing scorings, bacterial load assessment and histological examinations. It was revealed that upon using sericin/propolis/Amoxicillin nanoparticles, complete wound healing was successfully achieved after 10 and 15 days postinjury for nondiabetic and diabetic rats, respectively. However, the bacterial load in the induced infected wounds was extremely low (0-10 CFU/mL) after 15 days post-treatment. The histological studies revealed that the dermis was more organized with new matrix deposition, and mature collagen fibers were observed among the treated animal groups. The present study is the first preclinical study which reported the importance of silk sericin in the form of nano-sericin/propolis loaded with Amoxicillin as an effective treatment against bacterial wound infections.

Bioengineering Approaches to Fight against Orthopedic Biomaterials Related-Infections

One of the most serious complications following the implantation of orthopedic biomaterials is the development of infection. Orthopedic implant-related infections do not only entail clinical problems and patient suffering, but also cause a burden on healthcare care systems. Additionally, the ageing of the world population, in particular in developed countries, has led to an increase in the population above 60 years. This is a significantly vulnerable population segment insofar as biomaterials use is concerned. Implanted materials are highly susceptible to bacterial and fungal colonization and the consequent infection. These microorganisms are often opportunistic, taking advantage of the weakening of the body defenses at the implant surface–tissue interface to attach to tissues or implant surfaces, instigating biofilm formation and subsequent development of infection. The establishment of biofilm leads to tissue destruction, systemic dissemination of the pathogen, and dysfunction of the implant/bone joint, leading to implant failure. Moreover, the contaminated implant can be a reservoir for infection of the surrounding tissue where microorganisms are protected. Therefore, the biofilm increases the pathogenesis of infection since that structure offers protection against host defenses and antimicrobial therapies. Additionally, the rapid emergence of bacterial strains resistant to antibiotics prompted the development of new alternative approaches to prevent and control implant-related infections. Several concepts and approaches have been developed to obtain biomaterials endowed with anti-infective properties. In this review, several anti-infective strategies based on biomaterial engineering are described and discussed in terms of design and fabrication, mechanisms of action, benefits, and drawbacks for preventing and treating orthopaedic biomaterials-related infections.

Antibiofilm Properties of Antiseptic Agents Used on Pseudomonas aeruginosa Isolated from Diabetic Foot Ulcers

In diabetic foot ulcers (DFUs), biofilm formation is a major challenge that promotes wound chronicity and delays healing. Antiseptics have been proposed to combat biofilms in the management of DFUs. However, there is limited evidence on the activity of these agents against biofilms, and there are questions as to which agents have the best efficiency. Here, we evaluated the antibiofilm activity of sodium hypochlorite, polyvinylpyrrolidoneIodine (PVPI), polyhexamethylenebiguanide (PHMB) and octenidine against Pseudomonas aeruginosa strains using static and dynamic systems in a chronic-wound-like medium (CWM) that mimics the chronic wound environment. Using Antibiofilmogram®, a technology assessing the ability of antiseptics to reduce the initial phase of biofilm formation, we observed the significant activity of antiseptics against biofilm formation by P. aeruginosa (at 1:40 to 1:8 dilutions). Moreover, 1:100 to 1:3 dilutions of the different antiseptics reduced mature biofilms formed after 72 h by 10-log, although higher concentrations were needed in CWM (1:40 to 1:2). Finally, in the BioFlux200TM model, after biofilm debridement, sodium hypochlorite and PHMB were the most effective antiseptics. In conclusion, our study showed that among the four antiseptics tested, sodium hypochlorite demonstrated the best antibiofilm activity against P. aeruginosa biofilms and represents an alternative in the management of DFUs.

Bacteriophage Therapy for Staphylococcus Aureus Infections: A Review of Animal Models, Treatments, and Clinical Trials

Staphylococcus aureus (S. aureus) is a common and virulent human pathogen causing several serious illnesses including skin abscesses, wound infections, endocarditis, osteomyelitis, pneumonia, and toxic shock syndrome. Antibiotics were first introduced in the 1940s, leading to the belief that bacterial illnesses would be eradicated. However, microorganisms, including S. aureus, began to develop antibiotic resistance from the increased use and abuse of antibiotics. Antibiotic resistance is now one of the most serious threats to global public health. Bacteria like methicillin-resistant Staphylococcus aureus (MRSA) remain a major problem despite several efforts to find new antibiotics. New treatment approaches are required, with bacteriophage treatment, a non-antibiotic strategy to treat bacterial infections, showing particular promise. The ability of S. aureus to resist a wide range of antibiotics makes it an ideal candidate for phage therapy studies. Bacteriophages have a relatively restricted range of action, enabling them to target pathogenic bacteria. Their usage, usually in the form of a cocktail of bacteriophages, allows for more focused treatment while also overcoming the emergence of resistance. However, many obstacles remain, particularly in terms of their effects in vivo, necessitating the development of animal models to assess the bacteriophage efficiency. Here, we provide a review of the animal models, the various clinical case treatments, and clinical trials for S. aureus phage therapy.

Antiseptic Agents for Chronic Wounds: A Systematic Review

In many parts of the world, antiseptic agents remain non-indicated in chronic wound care. In the current context of bacterial resistance to antibiotics and the development of new-generation antiseptic agents, wound antisepsis represents an asset for the prevention of wound infection. We aimed to evaluate four common antiseptic agents in chronic wound care complete healing. The review protocol was based on the Cochrane Handbook for Systematic Reviews of Intervention and devised in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement guidelines. Five databases and three clinical trials registries were searched from inception to 30 June 2021 without language restrictions. We included randomised trials evaluating the efficacy of antiseptic agents in chronic wound care in adults. Interventions considered were those using antiseptics for cleansing or within a dressing. Risk of bias was assessed using the bias excel tool provided by the Bristol Academy. Evidence quality was assessed using Grading of Recommendation Assessment, Development and Evaluation (GRADE) criteria. Of 838 studies, 6 were finally included, with a total of 725 patients. The included studies assessed iodine (cadexomer or povidone iodine) (n = 3), polyhexanide (n = 2), and octenidine (n = 1). Limited evidence suggested a better wound healing completion with iodine compared to saline (two randomised controlled trials (RCT), 195 patients, pooled RR 1.85 (95%CI (1.27 to 2.69)), moderate-quality evidence). There was not enough evidence to suggest a difference in wound healing using octenidine or polyhexamide. None of the antiseptic agents influenced adverse event occurrence compared to saline.

Four in one-Combination therapy using live Lactococcus lactis expressing three therapeutic proteins for the treatment of chronic non-healing wounds

Diabetes mellitus is one of the major concerns for health care systems, affecting 382 million people worldwide. Among the different complications of diabetes, lower limbs chronic ulceration is a common, severe and costly cause of morbidity. Diabetic foot ulcers are a leading cause of hospitalization in diabetic patients and its rate exceed the ones of congestive heart failure, depression or renal disease. Diabetic non-healing ulcers account for more than 60% of all non-traumatic lower limb amputations and the five-year mortality after amputation is higher than 50%, being equal to several types of advanced cancer. The primary management goals for an existing diabetic foot ulcer are to achieve primary healing as expeditiously as possible and to achieve a reduction of the amputation rate in the patients. Unfortunately, approximately a quarter of patients do not partially or fully respond to the standard of care. Advanced therapies for chronic wounds are existing, however, recent guidelines including the latest reviews and meta-analyses of the scientific and clinical evidence available from current treatment strategies and new therapeutic agents revealed that there is a lack of clinical data and persistent gap of evidence for many of the advanced therapeutic approaches. In addition, no pharmacological wound healing product has gained authority approval for more than 10 years in both US and EU, constituting a highly unmet medical need. In this publication we present data from a live biopharmaceutical product AUP1602-C designed as a single pharmaceutical entity based on the non-pathogenic, food-grade lactic acid bacterium Lactococcus lactis subsp. cremoris that has been genetically engineered to produce human fibroblast growth factor 2,interleukin4 and colony stimulating factor 1. Designed to address different aspects of wound healing (i.e. fibroblast proliferation, angiogenesis and immune cell activation) and currently in phase I clinical study, we show how the combination of the individual components on the wound micro-environment initiates and improves the wound healing in chronic wounds.