Macrolide resistance in isolates associated with bovine respiratory disease from the German national resistance monitoring program GE-Vet 2009 to 2020.

Data collected from the German national resistance monitoring program GE-Vet showed slowly increasing prevalence of macrolide resistance among bovine respiratory disease (BRD)-associated from cattle over the last decade. The focus of this study was to analyze the genetic basis of antimicrobial resistance (AMR) and the prevalence of multidrug-resistance (MDR)-mediating integrative and conjugative elements (ICEs) in 13 German BRD-associated isolates collected between 2009 and 2020 via whole-genome sequencing. Antimicrobial susceptibility testing (AST) was performed via broth microdilution according to the recommendations of the Clinical and Laboratory Standards Institute for the macrolides erythromycin, tilmicosin, tulathromycin, gamithromycin, tildipirosin, and tylosin as well as 25 other antimicrobial agents.