Correlation between veterinary antimicrobial use and antimicrobial resistance in food-producing animals: a report on seven countries J Antimicrob Chemother 69: 827–834

Objectives: To evaluate correlations between antimicrobial use and the prevalence of resistance in commensal Escherichia coli isolates from pigs, poultry and cattle, using data from publicly available national or international reports from seven European countries. Methods: The link between the quantities of different classes of antimicrobials administered to food-producing animalspercountry (expressed inmg/populationcorrectionunit)andtheprevalenceof resistancetothedifferentanti-microbial classes (interpreted by EUCASTepidemiological cut-off values) in E. coli isolates (4831 isolates in total) was assessed by means of polynomial regression analysis and determination of Spearman’s rank correlation coefficient. Results: A quadratic regression best fitted the antimicrobial use and antimicrobial resistance data. The coefficient of determination was, in decreasing order, 0.99 for fluoroquinolones and amphenicols, 0.94 for third-generation cepha-losporins and sulphonamides, 0.93 for aminopenicillins, 0.86 for fluoroquinolones, 0.81 for streptomycin and 0.80 for gentamicin and tetracycline. Spearman’s rank correlation coefficient was 1 for amphenicols, 0.96 for sulphonamides, 0.93 for streptomycin and tetracycline, 0.89 for aminopenicillins, 0.71 for gentamicin and 0.70 for third-generation cephalosporins. Conclusions:These remarkably high coefficients indicate that, at a national level, the level of use of specific antimicro-bials stronglycorrelatestothe levelof resistancetowardstheseagents in commensalE.coli isolates inpigs, poultryan