High Prevalence of Methicillin-Resistant Staphylococcus aureus and Multidrug-Resistant Gram-Negative Bacilli in Diabetic Foot Infections in Algeria

AbstractBackground: Diabetic foot infections (DFIs) are a major complication of diabetes mellitus and an important cause of hospitalization, morbidity, and mortality. The emergence of multidrug-resistant bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA), further complicates management. This study was conducted in 2022 at the Bacteriology Laboratory of the Internal Medicine Department, Hospital Mohammed Boudiaf, Constantine, Algeria. Methods: A cross-sectional study was conducted in 2022 on 172 diabetic patients with foot infections. Clinical data were collected. Pus samples were cultured, and bacteria were identified using standard microbiological techniques. Antimicrobial susceptibility testing was performed by Kirby–Bauer disk diffusion following CLSI guidelines. MRSA was confirmed by cefoxitin disk diffusion, latex agglutination for PBP2a, and PCR detection of mecA. Results: Among 172 patients, most were male (68.6%) and ≥60 years old (59.3%). Hypertension (40.7%) and smoking (27.9%) were common comorbidities. Mortality was 13.4%, while 25% required amputation. A total of 172 S. aureus isolates were recovered, all positive for mecA and PBP2a (100% MRSA). MRSA showed 100% resistance to β-lactams, high resistance to fluoroquinolones (65%) and macrolides (72%), but remained fully susceptible to vancomycin and teicoplanin. Gram-negative bacilli (E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) exhibited high resistance to third-generation cephalosporins and ciprofloxacin, but retained susceptibility to carbapenems. Conclusion: DFIs in Algeria are dominated by MRSA and ESBL-producing Enterobacterales. These findings underscore the need for systematic microbiological diagnosis and rational antibiotic use in diabetic patients. Keywords: Diabetic foot infections, MRSA, Staphylococcus aureus, antimicrobial resistance, Algeria, ESBL This work is based on Master’s thesis research conducted in 2022.