AbstractObjectivesIn France, a 10 year national policy to reduce antibiotic use (ABU) in animals led, respectively, to an 88% and 94% decrease in animal exposure to fluoroquinolones and third- and fourth-generation cephalosporins (3GC-4GC) between 2011 and 2021.MethodsBuilding on national surveillance data, this study evaluated the impact of this national policy on reducing the occurrence of resistance to fluoroquinolones and 3GC-4GC in clinical Escherichia coli from young cattle and dogs and cats in France. The effect of homologous and heterologous use of antibiotics was explored using multivariate regression modelling. In addition, the time lag between implementation of national policies and subsequent reduction in antibiotic resistance (ABR) was estimated using segmented regression analysis.ResultsStatistical analysis of available ABU and ABR surveillance data demonstrated a significant and sustainable impact on the occurrence of resistance to fluoroquinolones in clinical E. coli (in cattle and in dogs and cats), and to a lesser extent to 3GC-4GC (in cattle). The effects were fast and observed within 1 (in cattle) or 2 years (in dogs and cats) after the implementation of the 2014 national policy targeting specifically the animals’ exposure to 3GC-4GC and fluoroquinolones.ConclusionsThe French 10 year national policy had a successful impact on the occurrence of resistance to fluoroquinolones and 3GC-4GC in clinical E. coli. A potential shift in ABU from the use of fluoroquinolones and 3GC-4GC to other antibiotic classes, such as trimethoprim/sulfonamides (since 2012), and penicillins and tetracyclines (since 2016), was also observed.

AbstractObjectivesIn France, a 10 year national policy to reduce antibiotic use (ABU) in animals led, respectively, to an 88% and 94% decrease in animal exposure to fluoroquinolones and third- and fourth-generation cephalosporins (3GC-4GC) between 2011 and 2021.MethodsBuilding on national surveillance data, this study evaluated the impact of this national policy on reducing the occurrence of resistance to fluoroquinolones and 3GC-4GC in clinical Escherichia coli from young cattle and dogs and cats in France. The effect of homologous and heterologous use of antibiotics was explored using multivariate regression modelling. In addition, the time lag between implementation of national policies and subsequent reduction in antibiotic resistance (ABR) was estimated using segmented regression analysis.ResultsStatistical analysis of available ABU and ABR surveillance data demonstrated a significant and sustainable impact on the occurrence of resistance to fluoroquinolones in clinical E. coli (in cattle and in dogs and cats), and to a lesser extent to 3GC-4GC (in cattle). The effects were fast and observed within 1 (in cattle) or 2 years (in dogs and cats) after the implementation of the 2014 national policy targeting specifically the animals’ exposure to 3GC-4GC and fluoroquinolones.ConclusionsThe French 10 year national policy had a successful impact on the occurrence of resistance to fluoroquinolones and 3GC-4GC in clinical E. coli. A potential shift in ABU from the use of fluoroquinolones and 3GC-4GC to other antibiotic classes, such as trimethoprim/sulfonamides (since 2012), and penicillins and tetracyclines (since 2016), was also observed.