The prevalence of antimicrobial resistance of bacterial strains from large-scale healthy chicken flocks in the Észak-Alföld region of Hungary

Introduction Antimicrobial resistance (AMR) represents one of the major public health challenges of the 21st century, with profound implications for both human and veterinary medicine. Isolates recovered from clinically healthy birds from food-producing animals play a critical role as reservoirs and potential vectors for resistance genes, underscoring the importance of continuous surveillance. This study aimed to evaluate the phenotypic resistance profiles of Staphylococcus aureus , Enterococcus spp. and Escherichia coli isolated from large-scale chicken flocks in the Észak-Alföld region of Hungary. Methods A total of 24 flocks were sampled, and bacterial isolates were subjected to antimicrobial susceptibility testing using the broth microdilution method. Minimum inhibitory concentrations (MICs) were interpreted according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical Laboratory Standard Institute (CLSI) guidelines. Results Extremely high (>70.0%) levels of resistance were detected against doxycycline, amoxicillin, and florfenicol, while resistance to critically important antimicrobials such as ceftriaxone, imipenem and vancomycin remained comparatively low (1.0–10.0%) or rare (