title: Extended-spectrum β-lactamases, transferable quinolone resistance, and virulotyping in extra-intestinal E. coli in Uruguay.
abstract: BACKGROUND
  To characterize extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) genes in Escherichia coli isolates obtained from extra-intestinal samples in three Uruguayan hospitals.
  
  
  METHODS
  Fifty-five ESBL-producing E. coli isolates were studied. Virulence genes, ESBLs, and PMQR genes were detected by polymerase chain reaction. ESBL-producing isolates were compared by pulsed-field gel electrophoresis. Multi-locus sequence typing was also performed on 13 selected isolates.
  
  
  RESULTS
  Thirty-seven isolates harbored blaCTX-M-15 (67.3%), eight blaCTX-M-2 (14.6%), five blaCTX-M-14 (9.1%), three carried both blaCTX-M-2 and blaCTX-M-14, one blaCTX-M-9, and one blaCTX-M-8. Among the CTX-M-15 producers, 92% belonged to sequence types ST131 and ST405, and carried aac(6')Ib-cr as well. Isolates harboring blaCTX-M-2, blaCTX-M-14, blaCTX-M-9, or blaCTX-M-8 were found to be genetically unrelated.
  
  
  CONCLUSIONS
  The successful dissemination of CTX-M-15-producing E.coli isolates seems to be linked to the spreading of high-risk clones and horizontal gene transfer. A trade-off between carrying more antibiotic resistance and less virulence-related genes could partially account for the evolutionary advantages featured by successful clones.
authors.affiliation: Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. rvignoli@higiene.edu.uy.
authors.forename: Rafael
authors.initials: R
authors.lastname: Vignoli
authors.forename: Virginia
authors.initials: V
authors.lastname: García-Fulgueiras
authors.forename: Nicolás F
authors.initials: NF
authors.lastname: Cordeiro
authors.forename: Inés
authors.initials: I
authors.lastname: Bado
authors.forename: Verónica
authors.initials: V
authors.lastname: Seija
authors.forename: Paula
authors.initials: P
authors.lastname: Aguerrebere
authors.forename: Gabriel
authors.initials: G
authors.lastname: Laguna
authors.forename: Lucía
authors.initials: L
authors.lastname: Araújo
authors.forename: Cristina
authors.initials: C
authors.lastname: Bazet
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gutkind
authors.forename: José
authors.initials: J
authors.lastname: Chabalgoity
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology*; D022761:Gene Transfer, Horizontal; D005838:Genotype; D006801:Humans; D058885:Multilocus Sequence Typing; D010957:Plasmids / Q000032:analysis; D016133:Polymerase Chain Reaction; D015363:Quinolones / Q000494:pharmacology*; D014583:Uruguay; D037521:Virulence Factors / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D015363:Quinolones; D037521:Virulence Factors; D001618:beta-Lactamases