title: Extended-spectrum β-lactamase-producing Escherichia coli from retail chicken meat and humans: comparison of strains, plasmids, resistance genes, and virulence factors.
abstract: BACKGROUND
  The worldwide prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is increasing rapidly both in hospitals and in the community. A connection between ESBL-producing bacteria in food animals, retail meat, and humans has been suggested. We previously reported on the genetic composition of a collection of ESBL-producing Escherichia coli (ESBL-EC) from chicken meat and humans from a restricted geographic area. Now, we have extended the analysis with plasmid replicons, virulence factors, and highly discriminatory genomic profiling methods.
  
  
  METHODS
  One hundred forty-five ESBL-EC isolates from retail chicken meat, human rectal carriers, and blood cultures were analyzed using multilocus sequence typing, phylotyping, ESBL genes, plasmid replicons, virulence genes, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE).
  
  
  RESULTS
  Three source groups overlapped substantially when their genetic composition was compared. A combined analysis using all variables yielded the highest resolution (Wilks lambda [Λ]: 0.08). Still, a prediction model based on the combined data classified 40% of the human isolates as chicken meat isolates. AFLP and PFGE showed that the isolates from humans and chicken meat could not be segregated and identified 1 perfect match between humans and chicken meat.
  
  
  CONCLUSIONS
  We found significant genetic similarities among ESBL-EC isolates from chicken meat and humans according to mobile resistance elements, virulence genes, and genomic backbone. Therefore, chicken meat is a likely contributor to the recent emergence of ESBL-EC in human infections in the study region. This raises serious food safety questions regarding the abundant presence of ESBL-EC in chicken meat.
authors.affiliation: Laboratory for Medical Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands. jankluytmans@gmail.com
authors.forename: Jan A J W
authors.initials: JA
authors.lastname: Kluytmans
authors.forename: Ilse T M A
authors.initials: IT
authors.lastname: Overdevest
authors.forename: Ina
authors.initials: I
authors.lastname: Willemsen
authors.forename: Marjolein F Q
authors.initials: MF
authors.lastname: Kluytmans-van den Bergh
authors.forename: Kim
authors.initials: K
authors.lastname: van der Zwaluw
authors.forename: Max
authors.initials: M
authors.lastname: Heck
authors.forename: Martine
authors.initials: M
authors.lastname: Rijnsburger
authors.forename: Christina M J E
authors.initials: CM
authors.lastname: Vandenbroucke-Grauls
authors.forename: Paul H M
authors.initials: PH
authors.lastname: Savelkoul
authors.forename: Brian D
authors.initials: BD
authors.lastname: Johnston
authors.forename: David
authors.initials: D
authors.lastname: Gordon
authors.forename: James R
authors.initials: JR
authors.lastname: Johnson
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D002645:Chickens; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology*; D058885:Multilocus Sequence Typing / Q000379:methods; D009426:Netherlands; D010957:Plasmids / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D037521:Virulence Factors; D001618:beta-Lactamases