Update in Diagnosis and Treatment of Diabetic Foot Infections

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.

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.

Diabetic foot ulcer, antimicrobial remedies and emerging strategies for the treatment

According to the International Diabetes Federation's 2015 study, diabetes affects over 415 million people globally (5 million of whom die each year), and the incidence of diabetes is expected to climb to over 640 million (1 in 10) by 2040. (IDF 2015). Diabetes foot ulcers (DFU) are one of the most significant diabetic health consequences. Antimicrobial treatments, such as dressings, topical therapies, medicines, drugs, debridement procedures, molecular, cellular, and gene therapies, plant extracts, antimicrobial peptides, growth factors, devices, ozone, and energy-based therapies, would be the focus of this study. Scopus, Web of Science, Bentham Science, Science Direct, and Google Scholar were among the sources used to compile the English-language publications on DFU. DFU treatment requires a multidisciplinary approach that includes the use of proper diagnostic tools, competence, and experience. To prevent amputations, this starts with patient education and the use of new categories to steer treatment. New diagnostic methods, such as the 16S ribosomal DNA sequence in bacteria, should become available to acquire a better knowledge of the microbiota in DFUs. 

A neglected causative agent in diabetic foot infection: a retrospective evaluation of 13 patients with fungal etiology

Background/aim

Clinicians often neglect fungal infections and do not routinely investigate deep tissue from the wound for fungal culture and sensitivity due to insufficient information in the literature. In this study, we aimed to evaluate fungal etiology of invasive fungal diabetic foot which is rarely reported in the literature.

Materials and methods

The patients who were unresponsive to antibiotic therapy and those with positive fungal in bone or deep tissue culture were enrolled in the study. Detailed hospital records were retrieved for demographics and clinical features.

Results

A total of 13 patients who were diagnosed with invasive fungal diabetic foot (ten females, three males, mean age 59.8 ± 9 years) were included. All of the patients had type-2 diabetes mellitus. Eleven (84.6%) patients had mixed infection. The most common cause of fungal infections of diabetic foot ulcers was the Candida species. Ten (76.9%) patients underwent amputation, two (15.4%) patients refused amputation, and one patient died before surgery.

Conclusion

Invasive fungal infections may also be a causative pathogen in deep tissue infections. Therefore, fungal pathogens should be considered in patients unresponsive to long-term antibiotic therapy. Early detection of fungal infections in high-risk individuals is critical for the prevention of severe consequences such as foot amputation.

In-vitro diagnosis of single and poly microbial species targeted for diabetic foot infection using e-nose technology

Background

Effective management of patients with diabetic foot infection is a crucial concern. A delay in prescribing appropriate antimicrobial agent can lead to amputation or life threatening complications. Thus, this electronic nose (e-nose) technique will provide a diagnostic tool that will allow for rapid and accurate identification of a pathogen.

Results

This study investigates the performance of e-nose technique performing direct measurement of static headspace with algorithm and data interpretations which was validated by Headspace SPME-GC-MS, to determine the causative bacteria responsible for diabetic foot infection. The study was proposed to complement the wound swabbing method for bacterial culture and to serve as a rapid screening tool for bacteria species identification. The investigation focused on both single and poly microbial subjected to different agar media cultures. A multi-class technique was applied including statistical approaches such as Support Vector Machine (SVM), K Nearest Neighbor (KNN), Linear Discriminant Analysis (LDA) as well as neural networks called Probability Neural Network (PNN). Most of classifiers successfully identified poly and single microbial species with up to 90% accuracy.

Conclusions

The results obtained from this study showed that the e-nose was able to identify and differentiate between poly and single microbial species comparable to the conventional clinical technique. It also indicates that even though poly and single bacterial species in different agar solution emit different headspace volatiles, they can still be discriminated and identified using multivariate techniques.

Diabetic foot infections: the role of microbiology and antibiotic treatment

Diabetes mellitus is a major risk factor for the development of foot infections. Among the risk factors that contribute to the development of diabetic foot infections are local neuropathy, vascular changes and depressed local host defenses. The microbiology of these infections is often complex and can be polymicrobial. Treatment of these infections depends on the severity and extent of infection. Treatment should involve a multi-disciplinary team approach involving surgeons and infectious disease specialists. The current recommendations for treatment are primarily based on expert opinion and consensus rather than clinical trials. No single agent or combination of agents has been shown to be superior to others. The aim of this review is to provide valid options of therapy, especially with regard to newer agents that are currently available for treatment of both soft tissue infections and osteomyelitis.

Factors associated with late specialized rehabilitation among veterans with lower extremity amputation who underwent immediate postoperative rehabilitation

OBJECTIVE

The aim of this study was to determine what patient- and facility-level characteristics drive late specialized rehabilitation among veterans who already received immediate postoperative services.

DESIGN

Data were obtained from eight administrative databases for 2,453 patients who underwent lower limb amputation in Veterans Affairs Medical Centers in 2002-2004. A Cox proportional hazards model was used to determine the hazard ratios and 95% confidence intervals of the factors associated with days to readmission for late services after discharge from surgical hospitalization.

RESULTS

There were 2304 patients who received only immediate postoperative services, whereas 152 also received late specialized rehabilitation. After adjustment, veterans who were less disabled physically, residing in the South Central compared with the Southeast region, and had their surgeries in facilities accredited by the Commission on Accreditation of Rehabilitation Facilities were all more likely to receive late services. The hazard ratios for type of immediate postoperative rehabilitation were not constant over time. At hospital discharge, there was no difference in receipt; however, after 3 mos, those who received early specialized rehabilitation were significantly less likely to receive late services.

CONCLUSIONS

The factors associated with late specialized rehabilitation were due mainly to facility-level characteristics and care process variables. Knowledge of these factors may help with decision-making policies regarding units accredited by the Commission on Accreditation of Rehabilitation Facilities.