title: UK epidemic Escherichia coli strains A-E, with CTX-M-15 beta-lactamase, all belong to the international O25:H4-ST131 clone.
abstract: OBJECTIVE
  Uropathogenic and invasive Escherichia coli O25:H4-ST131 isolates producing CTX-M-15 extended-spectrum beta-lactamase (ESBL) enzymes have recently been shown to be disseminated across the globe. In the UK, many CTX-M-15 ESBL-producing E. coli strains have been previously defined as belonging to the epidemic strains A-E, as determined by PFGE. The present study was carried out to define the relationship between these two groups of pathogenic E. coli.
  
  
  METHODS
  Multilocus sequence typing and PFGE were used for molecular characterization of a collection of 61 ESBL-producing E. coli isolates from across the UK.
  
  
  RESULTS
  Strains A to E all belonged to the ST131 clone, further underscoring the epidemiological importance of this lineage.
  
  
  CONCLUSIONS
  The future spread of the ST131 clone, and its UK variants, should be monitored closely and the pathogenic mechanisms explaining their success should be investigated.
authors.affiliation: Department of Medical Microbiology, School of Medicine, University of Manchester, Clinical Sciences Building, Manchester Royal Infirmary, Manchester M13 9WL, UK.
authors.forename: Siu Ha
authors.initials: SH
authors.lastname: Lau
authors.forename: Mary E
authors.initials: ME
authors.lastname: Kaufmann
authors.forename: David M
authors.initials: DM
authors.lastname: Livermore
authors.forename: Neil
authors.initials: N
authors.lastname: Woodford
authors.forename: Geraldine A
authors.initials: GA
authors.lastname: Willshaw
authors.forename: Tom
authors.initials: T
authors.lastname: Cheasty
authors.forename: Katie
authors.initials: K
authors.lastname: Stamper
authors.forename: Suganya
authors.initials: S
authors.lastname: Reddy
authors.forename: John
authors.initials: J
authors.lastname: Cheesbrough
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Bolton
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Fox
authors.forename: Mathew
authors.initials: M
authors.lastname: Upton
mesh_terms: D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000145:classification* / Q000201:enzymology / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D017422:Sequence Analysis, DNA; D012703:Serotyping; D006113:United Kingdom / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases