Occurrence of extended-spectrum beta-lactamase producing E. coli in broiler farm workers and the farm environment in Chiang Mai-Lamphun, Thailand

Antimicrobial resistance has become a major global public health threat. Extended-spectrum beta-lactamase (ESBL) producing E. coli appears as an emergence cause of treatment failure and increase mortality due to limited available effective antimicrobial agents. This study was conducted to determine the occurrence and antimicrobial resistance of ESBL producing E. coli in broilers, farm workers and environment in broiler farms in Chiang Mai-Lamphun, Thailand. The prevalence of ESBL producing E. coli in the broiler farms was 60.4% (29/48). The prevalence of ESBL producing E. coli from boot swabs, farm worker’s rectal swabs, feed and water samples were 43.8%, 55.7%, 12.5% and 2.1%, respectively. All isolates showed susceptible to imipenem and, in contrast, resistant to ampicillin. The results demonstrated high antimicrobial resistant rate to streptomycin (94.3%), gentamicin (86.8%), tetracycline (77.4%), chloramphenicol (66.0%), nalidixic acid (58.5%), and sulfamethoxazole/trimethoprim (56.6%). High percentage (96.2%) of isolates was classified as multidrug resistance (MDR). Thirty-five antimicrobial resistance profiles were identified with AMP-GEN-SXT-NAL-TET-CHL-STR, AMP-GEN-SXT-TET-CHL-STR (14.3%) as the 2 most prevalent profiles. The common resistance profiles between farm workers and broilers was demonstrated. These findings are suggestive for possible transmission between poultry and humans in broiler farms, most likely via close contact. Antimicrobial usage should be strictly controlled together with increase awareness on hygiene practices in broiler farms.