Association of farm-related factors with characteristics profiles of extended-spectrum β-lactamase- / plasmid-mediated AmpC β-lactamase-producing Escherichia coli isolates from German livestock farms.
Resistance to β-lactam antibiotics, including third-generation cephalosporins, is of major concern for animal and human health. In this study, extended-spectrum β-lactamase (ESBL) / plasmid-mediated AmpC (pAmpC) β-lactamase -producing Escherichia coli isolates from German livestock farms were characterised and associations of these isolate characteristics with farm-related factors were investigated across different types of livestock. A total of 469 isolates originating from 150 farms (34 broiler farms, 38 fattening pig farms, 43 dairy cattle farms, 35 beef cattle farms) was included in the analyses. ESBL-gene family, phylogroup and phenotypic antimicrobial susceptibility for several antimicrobial agents were determined. This data was used to define different profiles characterising the isolates. Multivariate analyses using a distance-based non-parametric approach were performed to investigate associations between the profiles of the isolates and farm-related factors (e.g. management, husbandry, and environment of the farms). Co-occurrence of ESBL-gene families were not found in any of the isolates analysed. Sixty-eight percent of the isolates carried bla