Antibiotic therapy of diabetic foot infections: A systematic review of randomized controlled trials

Anaerobic bacteria in chronic wounds: Roles in disease, infection and treatment failure

Infection is among the most common factors that impede wound healing, yet standard treatments routinely fail to resolve chronic wound infections. The chronic wound environment is largely hypoxic/anoxic, and wounds are predominantly colonised by facultative and obligate anaerobic bacteria. Oxygen (O2) limitation is an underappreciated driver of microbiota composition and behaviour in chronic wounds. In this perspective article, we examine how anaerobic bacteria and their distinct physiologies support persistent, antibiotic-recalcitrant infections. We describe the anaerobic energy metabolisms bacteria rely on for long-term survival in the wound environment, and why many antibiotics become less effective under hypoxic conditions. We also discuss obligate anaerobes, which are among the most prevalent taxa to colonise chronic wounds, yet their potential roles in influencing the microbial community and wound healing have been overlooked. All of the most common obligate anaerobes found in chronic wounds are opportunistic pathogens. We consider how these organisms persist in the wound environment and interface with host physiology to hinder wound healing processes or promote chronic inflammation. Finally, we apply our understanding of anaerobic physiologies to evaluate current treatment practices and to propose new strategies for treating chronic wound infections.

Systemic Antimicrobial Therapy for Diabetic Foot Infections: An Overview of Systematic Reviews

Diabetic foot infections (DFIs) are a common complication of diabetes; however, there is clinical uncertainty regarding the optimal antimicrobial selection. The aim of this review was to critically evaluate the recent systematic reviews on the efficacy and safety of systemic (parenteral or oral) antimicrobials for DFI. Medline, Embase, CENTRAL, and CINAHL databases and the PROSPERO register were searched from January 2015 to January 2023. Systematic reviews with or without meta-analyses on systemic antimicrobials for DFI, with outcomes of clinical infection resolution or complications, were included. Of the 413 records identified, 6 systematic reviews of 29 individual studies were included. Heterogeneity of individual studies precluded meta-analysis, except for ertapenem versus piperacillin-tazobactam (RR 1.07, 95% CI [0.96-1.19]) and fluoroquinolones versus piperacillin-tazobactam (RR 1.03, 95% CI [0.89-1.20]) in one review. The application of the AMSTAR-2 tool determined two reviews to be of high quality. There was no statistical difference in the clinical resolution of infections for 24 different antimicrobial regimens (penicillins, cephalosporins, carbapenems, fluoroquinolones, vancomycin, metronidazole, clindamycin, linezolid, daptomycin, and tigecycline). However, tigecycline did not meet non-inferiority against ertapenem ± vancomycin (absolute difference -5.5%, 95% CI [-11.0-0.1]) and was associated with a higher incidence of adverse drug events. There is minimal systematic review evidence to suggest one regimen is superior to another for DFI.

Prenylated phenolics from Morus alba against MRSA infections as a strategy for wound healing

Antimicrobial resistance is a public health threat and the increasing number of multidrug-resistant bacteria is a major concern worldwide. Common antibiotics are becoming ineffective for skin infections and wounds, making the search for new therapeutic options increasingly urgent. The present study aimed to investigate the antibacterial potential of prenylated phenolics in wound healing. Phenolic compounds isolated from the root bark of Morus alba L. were investigated for their antistaphylococcal potential both alone and in combination with commonly used antibiotics. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined by microdilution and agar method. Synergy was investigated using the checkerboard titration technique. Membrane-disrupting activity and efflux pump inhibition were evaluated to describe the potentiating effect. Prenylated phenolics inhibited bacterial growth of methicillin-resistant Staphylococcus aureus (MRSA) at lower concentrations (MIC 2-8 μg/ml) than commonly used antibiotics. The combination of active phenolics with kanamycin, oxacillin, and ciprofloxacin resulted in a decrease in the MIC of the antimicrobial agent. Kuwanon C, E, T, morusin, and albafuran C showed synergy (FICi 0.375-0.5) with oxacillin and/or kanamycin. Prenylated phenolics disrupted membrane permeability statistically significantly (from 28 ± 16.48% up to 73 ± 2.83%), and membrane disruption contributes to the complex antibacterial activity against MRSA. In addition, kuwanon C could be considered an efflux pump inhibitor. Despite the antibacterial effect on MRSA and the multiple biological activities, the prenylated phenolics at microbially significant concentrations have a minor effect on human keratinocyte (HaCaT) viability. In conclusion, prenylated phenolics in combination with commonly used antibiotics are promising candidates for the treatment of MRSA infections and wound healing, although further studies are needed.

A Systematic Review of Randomized Controlled Trials of Antibiotic Use in Diabetic Foot Ulcer Infections: Focus on Clinical Cure

BACKGROUND

The use of antibiotics in diabetic foot ulcer infections (DFUI) is essential in reducing morbidity. Optimal administration of antibiotics can improve clinical outcomes and reduce the risk of antibiotic resistance. This study aims to review the efficacy, in terms of clinical cure, of various regimens and the duration of antibiotic administration in DFUI patients, based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The efficacy based on microbiological response is also reviewed as the secondary outcome.

MATERIALS AND METHODS

We used three databases, namely PubMed, Scopus, and ScienceDirect, to search for randomized controlled trials (RCTs) in patients with DFUI who required antibiotics.

RESULTS

A total of 16 studies were included in the systematic review. The study locations and bacterial patterns varied, with the most common pathogen being Staphylococcus aureus. Most studies did not demonstrate a significant difference in clinical cure and pathogen eradication, either in the comparison between systemic and topical antibiotics or in the duration of administration. Some studies had similar characteristics and were analyzed to conclude. These studies showed that ertapenem had comparable efficacy to piperacillin/tazobactam. Similar results were also conducted from studies of piperacillin-tazobactam+amoxicillin-clavulanic acid vs. moxifloxacin.

CONCLUSION

Most studies have heterogeneous characteristics, possibly due to differences in research location. Therefore, there is no strong evidence to recommend a specific antibiotic with the highest efficacy. However, since all included studies are RCTs, this review provides a good summary in considering antibiotic choices when treating DFUI patients.

The Insights of Microbes' Roles in Wound Healing: A Comprehensive Review

A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

[Multidisciplinary management of diabetic foot ulcer infection]

Infection is one of the most common complications of diabetic foot ulceration resulting in lower extremity amputations and early mortality in this population. Several factors influence the course of diabetic foot ulceration infection and in that context, integrated multidisciplinary management is required as soon as possible. In fact, a holistic interdisciplinary approach should be the standard of care. Whether the infection is categorized as mild, moderate or severe, with or without bone infection, the overall individual's characteristics must be addressed, in addition to local wound care, offloading and antibiotic therapy. Some severe infections have potential indications for hospitalization and are considered as surgical emergencies. In some DFU cases, surgical revascularization of the limb is mandatory to treat the infection. However, surgical interventions and amputations, are sometimes inevitable, they are predictors of bad prognosis. Although some adjuvant therapies are effective to promote wound healing, their use is not recommended to treat diabetic foot ulcer infection. Infection management can be divided into three general interventions: proper clinical diagnosis, microbiological and imaging investigations, and treatment. This review is an update on the up-to-date evidences in scientific literature and includes the latest recommendations from the International Working Group on the Diabetic Foot (IWGDF).

Prevalence and interrelationships of foot ulcer, risk-factors and antibiotic resistance in foot ulcers in diabetic populations: A systematic review and meta-analysis

BACKGROUND

Diabetic foot ulceration (DFU) is the prime health concern globally. It accounts for the major burden related to disease mortality and morbidity and economic cost. The timely and early recognition of the DFU can help present its occurrence and improve clinical outcomes.

AIM

To evaluate interrelationships between foot ulcers, risk factors, and antibiotic resistance among diabetic patients having ulcers in their foot.

METHODS

The databases such as PubMed, ERIC, Medline, and Google Scholar were extensively used for the extraction of studies. The selected studies were published within the time-period of 2014-2018. Ten studies were selected, which were found to be completely relevant to the current study.

RESULTS

The prevalence of diabetic foot ulcers among the population was evaluated, and the associated risk factors with its prevalence. Moreover, few studies also reported on the bacteria that are found to be most prevailing among diabetic patients. A narrative discussion was drawn through this analysis, which was used to highlight the specific area of research through selected studies, extraction of the significant information that matched with the topic of research, and analysis of problem through the findings of the selected articles. The results helped in assessing significant knowledge regarding the risk factors of diabetic foot ulcers and the role of antimicrobial resistant in its treatment.

CONCLUSION

The gram-negative bacteria were found to be the most common reason for diabetic foot ulcers. The study only included 10 studies that are not sufficient to produce generalized results, and no information was reported on the tests required to analyze antimicrobial susceptibility that can guide clinicians to propose better and sound treatment plans. It is evident that most study results depicted that the most common risk factors were found to be hypertension and neuropathy.

A Clinical Review of Diabetic Foot Infections

"Diabetic foot infections (DFIs) are a common cause of morbidity and mortality. This article summarizes current knowledge regarding DFI epidemiology, disease pathogenesis, and the impact of antimicrobial resistance among DFI. An evidence-based approach to clinical assessment, diagnosing osteomyelitis, as well as medical and surgical treatment is discussed, including a review of empiric and directed antibiotic treatment recommendations. The current state and needs of the clinical literature are identified throughout, with a discussion of the supporting role of infectious diseases specialists as well as future directions of the field."

Plasma NAP-2 levels are associated with critical limb ischemia in peripheral arterial disease patients

IMPACT STATEMENT

Critical limb ischemia (CLI) is a serious arterial obstruction, resulting in serious reduction of blood flow to the extremities. CLI is a symptomatic disorder and is frequently not diagnosed in time. This results in a high mortality and elevated risk of limb amputation. Serum or plasma biomarkers play important roles in disease prevention, diagnosis, and prognosis. Elevated plasma neutrophil-activating peptide-2 (NAP-2) was found independently associated with CLI, but not with T2DM. Plasma NAP-2 levels might be an early CLI diagnostic biomarker and might provide a novel target for CLI treatment.