Polymicrobial Infections and Rising Resistance in Diabetic Foot Ulcers: Clinical Implications for Antibiotic Management

Abstract

Diabetes mellitus (DM) is a chronic metabolic disorder with significant complications including diabetic foot ulcers (DFUs). These ulcers often infected by a diverse range of bacterial pathogens represent a major challenge due to the rising prevalence of antimicrobial resistance (AMR). Foot infection in diabetic patients with chronic kidney disease (CKD) or diabetic kidney disease (DKD) is worse owing to uremic immune dysfunction, retarded wound healing, poor microvascular circulation, as well as changed antibiotic metabolism. Patients with dialysis-dependent issues and those of kidney-transplant are even at higher risk due to poor immunity and frequent contact with healthcare. It is important to the knowledge of the pathogen behavior and resistance patterns in this population to be informative in nephrology and renal-care management.  This study investigated the antibiogram of bacterial pathogens isolated from male diabetic patients to understand resistance patterns and guide effective therapeutic strategies. Over two years, 102 male patients with DFUs from multispecialty hospitals in and around Madurai, Tamil Nadu, India, were examined. Deep swabs were collected and processed for bacterial isolation. Antibiotic susceptibility testing was conducted on the isolated bacteria. A total of 21 bacterial isolates were identified including 47.6% gram positive and 52.4% gram negative bacteria. Predominant isolates included Staphylococcus aureus, Pseudomonas sp. and Klebsiella sp. Antibiotic susceptibility testing revealed varied responses with cloxacillin and nitrofurantoin showing notable efficacy against gram positive bacteria while doxycycline and ciprofloxacin demonstrated the highest sensitivity against gram negative isolates. However, multidrug resistance was prevalent particularly in Staphylococcus sp., Acinetobacter sp. and Escherichia coli. The study highlights a significant prevalence of advanced stage ulcers delays in care seeking and polymicrobial infections complicating treatment. The findings underscore the necessity for targeted antibiotic therapy informed by routine antibiogram surveillance and the urgent implementation of antibiotic stewardship programs. Understanding pathogen resistance trends is crucial for optimizing treatment outcomes and mitigating the burden of antimicrobial resistance in diabetic populations. These findings have direct implications for kidney disease management, where antimicrobial resistance limits renal-safe antibiotic options for CKD, dialysis, and post-transplant patients.