Antibiotic Resistance Profiles, Genetic Diversity, and Virulence Determinants of Enterococcus Strains Isolated from Diabetic Foot Ulcers

Diabetic foot ulcer (DFU) is a severe complication of diabetes, often complicated by polymicrobial infec-tions. Enterococcus species, notably E. faecalis and E. faecium, are frequently isolated from DFUs and pose therapeutic challenges due to antimicrobial resistance and virulence factors. This study aimed to characterize the antibiotic resistance patterns, genetic diversity, and virulence gene profiles of Enterococ-cus isolates from DFU patients in Babol, Iran. A total of 100 bone biopsy samples were collected, yielding 43 Enterococcus isolates (43%). E. faecalis (48.8%) was the most prevalent species, followed by E. fae-cium (37.2%). High resistance rates were observed for ampicillin (90.6%), rifampin (72.1%), and eryth-romycin (65.1%). Vancomycin resistance was detected in two E. faecium isolates (12.5%). Virulence genes asa1 (86.0%), hyl (72.1%), and efaA (62.7%) were highly prevalent, with E. faecalis carrying more virulence determinants than E. faecium. RAPD-PCR analysis revealed significant genetic diversity, with isolates grouped into three main clusters. The coexistence of multidrug resistance and virulence genes highlights the pathogenic potential of Enterococcus in DFUs. These findings emphasize the need for tai-lored antimicrobial therapy and infection control strategies in managing DFU infections.