Temporal Trends and Associations of Antimicrobial Use and Resistance in Enterococcus Species From Broiler Farms in Canada
Jannetje van den Bergh, Karin Orsel, Agnes Agunos, Audrey Charlebois, Sheryl P. Gow, Richard Reid‐Smith, Diego Borin NobregaABSTRACT
Introduction
Antimicrobials are widely used in animal production for the treatment, prevention, and control of infectious diseases. However, antimicrobial use (AMU) is also a key driver of antimicrobial resistance (AMR). In response, the Canadian poultry sector implemented a phased three‐step AMU reduction strategy to mitigate the emergence and spread of AMR. Enterococci are ubiquitous inhabitants of the gastrointestinal tract of animals and serve as important sentinel organisms for AMR surveillance because of their capacity to acquire AMR.
Methods
This study investigated associations between farm management practices, including AMU, and AMR in enterococci isolated from broiler chickens. Farm management data were collected using standardized questionnaires, and faecal samples were obtained during farm visits. Phenotypic AMR profiles were determined by minimum inhibitory concentration testing of 623 isolates from 419 flocks across five Canadian provinces over a 4‐year period. Generalized linear mixed models were used to evaluate associations between AMR and other factors, including AMU, province, year, breed, stocking density, downtime between flocks, and sanitation practices.
Results
Avilamycin use was significantly associated with avilamycin resistance in both
Conclusions
These findings suggest that targeted AMU reduction strategies were associated with reducing AMR percentages in enterococci from Canadian broilers.