Antimicrobial Resistance of Escherichia coli from Retail Poultry Meats in Korea

Antimicrobial-resistant bacteria in poultry meat pose a threat to public health. This article is the first to report the prevalence of antimicrobial-resistant Escherichia coli in retail poultry meat labeled with various claims of antibiotic use in Korea. A total of 719 E. coli strains were isolated from 1,107 raw poultry (chicken and duck) meat samples purchased from nationwide retail stores between 2017 and 2019. All strains were tested for antimicrobial susceptibility with a broth microdilution method. The prevalence of antimicrobial-resistant E. coli in chicken was significantly higher than that in duck for almost all antibiotics tested, and 87.9% of E. coli strains in chicken samples were multidrug resistant. The most prevalent types of antimicrobial resistance in these E. coli strains from poultry meat were to nalidixic acid (75.7%), ampicillin (69.1%), and tetracycline (64.0%), consistent with national sales data for veterinary antibiotics in the Korean poultry production industry. Organic or antibiotic-free and conventional chicken products were equally likely to be contaminated with antimicrobial-resistant E. coli. Contamination may occur during slaughtering and subsequent processing, and antibiotic use is permitted in certain cases under organic or antibiotic-free poultry standards. Therefore, close surveillance is required throughout the chicken production chain to prevent the spread of antimicrobial-resistant E. coli strains.