Monitoring of Escherichia coli Contamination in Retail Meat from Chungcheongnam-do, South Korea

Background: Escherichia coli is widely used as an indicator organism to assess fecal contamination and the sufficiency of hygienic practices in foods.The presence of antimicrobial resistant pathogenic E. coli in retail meat increases the potential risk of human exposure through food.Objectives: This study investigated the prevalence of E. coli and pathogenic E. coli in retail meat and evaluated the antimicrobial resistance characteristics of the isolates. Methods:A total of 400 samples (beef, pork, chicken, and eggs) were purchased from retail stores in Chungcheongnam-do, Republic of Korea.The samples were tested for total E. coli counts and screened for pathogenic E. coli by PCR.In addition, the isolates were tested for antimicrobial susceptibility to 17 antibiotics using Vitek2.Results: E. coli was detected in 45 (37.5%) of 120 beef samples, 42 (35.0%) of 120 pork samples, and 92 (76.7%) of 120 chicken samples.The mean E. coli counts were approximately 2 Log CFU/g, which is within the recommended limits.No E. coli was detected in any of the 40 egg samples.Pathogenic E. coli associated virulence genes were detected in 14 (11.7%)beef samples, five (4.2%) pork samples, and 83 (69.2%) chicken samples.Eighteen enteropathogenic E. coli strains isolated from chicken samples exhibited resistance to three or more antibiotics, indicating multidrug resistance.Notably, all isolates from chicken meat were resistant to nalidixic acid, with high resistance rates also observed for cephalothin, ampicillin, tetracycline, chloramphenicol, and ciprofloxacin.Conclusions: This study demonstrated the prevalence of E. coli in retail meat.Moreover, pathogenic E. coli was frequently detected in chicken meat.The isolates from chicken meat exhibited multidrug resistance, suggesting a potential risk to human health through unhygienic food handling or the consumption of undercooked meat.