Meireles, D.Leite-Martins, L.Bessa, L. J.Cunha, S.Fernandes, R.Matos, A. deManaia, C. M.Costa, P. Martins da2016-04-212016-04-212015MEIRELES, D… [et al.] - Molecular characterization of quinolone resistance mechanisms and extended-spectrum β-lactamase production in Escherichia coli isolated from dogs. Comparative Immunology, Microbiology and Infectious Diseases. ISSN 0147-9571. Vol. 41 (2015), p. 43-480147-9571http://hdl.handle.net/10400.14/19935The increasing prevalence of antimicrobial resistances is now a worldwide problem. Investigating the mechanisms by which pets harboring resistant strains may receive and/or transfer resistance determinants is essential to better understanding how owners and pets can interact safely. Here, we characterized the genetic determinants conferring resistance to β-lactams and quinolones in 38 multidrug-resistant Escherichia coli isolated from fecal samples of dogs, through PCR and sequencing. The most frequent geno-type included the β-lactamase groups TEM (n = 5), and both TEM + CTX-M-1 (n = 5). Within the CTX-Mgroup, we identified the genes CTX-M-32, CTX-M-1, CTX-M-15, CTX-M-55/79, CTX-M-14 and CTX-M-2/44. Thirty isolates resistant to ciprofloxacin presented two mutations in the gyrA gene and one or two mutations in the par C gene. A mutation in gyr A (reported here for the first time), due to a transversion andtransition (TCG → GTG) originating a substitution of a serine by a valine in position 83 was also detected.The plasmid-encoded quinolone resistance gene, qnrs1, was detected in three isolates. Dogs can be a reservoir of genetic determinants conferring antimicrobial resistance and thus may play an important role in the spread of antimicrobial resistance to humans and other co-habitant animals.engDogsEscherichia coliAntimicrobial resistanceβ-lactamaseQuinolonesajournal article10.1016/j.cimid.2015.04.0041878-16678493899967825999092000359297900006