title: Biofilm and fluoroquinolone resistance of canine Escherichia coli uropathogenic isolates.
abstract: BACKGROUND
  Escherichia coli is the most common uropathogen involved in urinary tract infection (UTI). Virulence of strains may differ, and may be enhanced by antimicrobial resistance and biofilm formation, resulting in increased morbidity and recurrent infections. The aim of this study was to evaluate the in vitro biofilm forming capacity of E. coli isolates from dogs with UTI, by using fluorescent in situ hybridization, and its association with virulence genes and antimicrobial resistance.
  
  
  RESULTS
  The proportion of biofilm-producing isolates significantly increased with the length of incubation time (P < 0.05). Biofilm production was significantly associated with fluoroquinolone resistance at all incubation time points and was independent of the media used (P < 0.05). Biofilm production was not associated with cnf1, hly, pap and sfa genes (P > 0.05), but was significantly associated with afa, aer and the β-lactamase genes (P < 0.05).
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report showing significant association between biofilm production and fluoroquinolone resistance in E. coli isolates from dogs with UTI. Biofilm formation may contribute to UTI treatment failure in dogs, through the development of bacterial reservoirs inside bladder cells, allowing them to overcome host immune defenses and to establish recurrent infections.
authors.affiliation: CIISA/Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisbon, Portugal. moliveira@fmv.ulisboa.pt.
authors.forename: Manuela
authors.initials: M
authors.lastname: Oliveira
authors.forename: Filipa Rocha
authors.initials: FR
authors.lastname: Dias
authors.forename: Constança
authors.initials: C
authors.lastname: Pomba
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D018441:Biofilms; D004285:Dogs; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity; D024841:Fluoroquinolones / Q000627:therapeutic use*; D017404:In Situ Hybridization, Fluorescence; D001743:Urinary Bladder / Q000382:microbiology*; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones
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