Manageiro, VeraClemente, LurdesGraça, RafaelCorreia, IvoneAlbuquerque, TeresaFerreira, EugéniaCaniça, Manuela2018-03-072018-03-072017-12-18Int J Food Microbiol. 2017 Dec 18;263:67-73. doi: 10.1016/j.ijfoodmicro.2017.10.007. Epub 2017 Oct 4.0168-1605http://hdl.handle.net/10400.18/5352The increasing incidence of intestinal colonization with extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and Gram negative organisms that has been observed in food animals such as poultry, cattle and pigs, are suggestive that animals, food and environment are potential sources of ESBL-producing bacteria. Hence, the aim of this study was to characterized commensal E. coli obtained from healthy broiler and turkey flocks at slaughter for the presence of penicillinases-, ESBL-, extended-spectrum AmpC (ESAC)-, plasmid-mediated quinolone resistance- and MCR-encoding genes. Study of clonal relatedness showed genetic diversity among CTX-M-type, SHV-12 and TEM-52 producing isolates with human isolates of the same type, was also assessed. We detected that eleven (5.4%, 11/202) and forty-five (2.2%, 45/185) E. coli isolates from broilers and turkeys, respectively, carried blaESBLor blaESACgenes and two isolates from turkeys carried mcr-1 gene. A new variant blaCTX-M-166was reported in a multidrug resistant isolate from a broiler flock. Overall, we detected a diversity of resistance mechanisms among E. coli from food-producing animals, all of them with high importance at a public health level.Highlights: Detection of blaESBL, blaESAC and the recently described mcr-1 gene; New variant blaCTX-M-166 reported in a MDR isolate from a broiler flock; WGS approach revealed a CTX-M-166-harboring O6:H16 ST48-fimH34 E. coli; ESBL-producing E. coli in the poultry population was not due to one specific clone.engAnimalsAnti-Bacterial AgentsCephalosporinsChickensColistinEscherichia coliEscherichia coli InfectionsEscherichia coli ProteinsFood ContaminationPlasmidsPortugalPoultry DiseasesTurkeysbeta-LactamasesResistência aos Antimicrobianosjournal article10.1016/j.ijfoodmicro.2017.10.007