Enterococcus faecalis in Traditional Cheeses: Prevalence and Antibiotic Resistance Profile

Background: This study aimed to determine the prevalence and phenotypic and genotypic characteristics of Enterococcus faecalis strains in traditionally produced cheeses in Ankara, Türkiye. Methods: Enterococcal isolates from cheese samples were identified using phenotypic and molecular methods. Given the public health relevance of E. faecalis, antimicrobial resistance testing was conducted on 33 isolates using a panel of commonly used antibiotics representing a broad range of clinically relevant classes. Antimicrobial resistance of E. faecalis isolates was evaluated using the disk diffusion method following standard guidelines. Results: A total of 98 probable enterococcal isolates were obtained from 108 cheese samples and identified phenotypically and molecularly. E. faecium was the most prevalent species (63.27%), followed by E. faecalis (33.67%) and E. lactis (3.06%), with the predominance of E. faecium being statistically significant (p < 0.05). High resistance rates were observed to rifampicin and kanamycin (100%), followed by ciprofloxacin (90.91%), enrofloxacin (84.85%), trimethoprim (78.79%), and ampicillin (60.61%). Moderate resistance was detected to several β-lactams and other antibiotic classes, whereas lower resistance frequencies were observed for erythromycin, chloramphenicol, and gentamicin. Notably, all E. faecalis isolates were fully susceptible to vancomycin. Multidrug resistance was common among E. faecalis isolates, with 33.33% of isolates resistant to six or more antibiotics. Resistance patterns differed significantly among antibiotic classes (p < 0.05), indicating a heterogeneous resistance distribution. The Multiple Antibiotic Resistance (MAR) index ranged from 0.166 to 0.333, with a mean of 0.27 ± 0.06, exceeding the threshold for high-risk contamination sources. Conclusions: The high prevalence of multidrug-resistant E. faecalis in traditional cheeses highlights the need for improved hygienic practices during artisanal production, rational antimicrobial use in animal husbandry, and ongoing resistance surveillance to mitigate potential risks to food safety and public health.