Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates collected from diseased food-producing animals in the GERM-Vet monitoring program 2008-2014

The aim of this study was to identify extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli collected from diseased food-producing animals in Germany. A total of 6849 E. coli isolates, collected from diseased cattle, pigs and poultry in the German national monitoring program GERM-Vet (2008-2014), were characterized by antimicrobial susceptibility testing and screened for the ESBL phenotype. ESBL genes were identified by PCR and sequencing. The isolates were further characterized by PCR-based phylotyping. The 419/6849 (6.1%) ESBL-producers identified included 324/2896 (11.2%) isolates from cattle, 75/1562 (4.8%) from pigs and 20/2391 (0.8%) from poultry. The ESBL genes detected were: bla(CTX-M-1) (69.9%), bla(CTX-M-15) (13.6%), bla(CTX-M-14) (11.7%), bla(TEM-52) (1.9%), bla(SHV-12) (1.4%), bla(CTX-M-3) (1.0%), and bla(CTX-M-2) (0.5%). The phylogroup A was the dominant phylogroup (57.0%) followed by phylogroups D (23.4%), B1 (17.9%), and B2 (1.7%). Bovine isolates belonged predominantly to the phylogroups A and D, whereas the porcine and avian isolates mainly belonged to A and B1. The majority of the ESBL-producing isolates found in each phylogroup were from animals suffering from gastrointestinal infections. In 399/419 isolates (95.2%), additional resistance to non-beta-lactam antibiotics was seen. Multidrug-resistance [resistance to aminoglycosides, fluoro(quinolones), sulphonamides, tetracyclines, and trimethoprim] was seen in 369/419 (88.1%) isolates, which may facilitate the co-selection of ESBL genes, when located on the same mobile genetic element as the others resistance genes, and may compromise the therapeutic options. (C) 2016 Elsevier B.V. All rights reserved.