title: National survey of Escherichia coli causing extraintestinal infections reveals the spread of drug-resistant clonal groups O25b:H4-B2-ST131, O15:H1-D-ST393 and CGA-D-ST69 with high virulence gene content in Spain.
abstract: OBJECTIVE
  To evaluate the current prevalence of the three clonal groups O25b:H4-B2-ST131, O15:H1-D-ST393 and CGA-D-ST69 (where ST stands for sequence type) among Escherichia coli isolates causing extraintestinal infections in Spain and to characterize their virulence background, 500 consecutive non-duplicate E. coli isolates causing extraintestinal infections were analysed.
  
  
  METHODS
  The 500 isolates were collected during February 2009 from five hospitals in different Spanish regions. Phylogenetic groups, STs, serotypes, virulence genes, PFGE profiles, antimicrobial resistance and extended-spectrum β-lactamase (ESBL) enzymes were determined.
  
  
  RESULTS
  The three clonal groups accounted for 19% of the 500 isolates. Furthermore, they accounted for 37% of the isolates exhibiting trimethoprim/sulfamethoxazole plus ciprofloxacin resistance, 34% of aminoglycoside-resistant isolates and 30% of multidrug-resistant isolates. Clonal group ST131 was the most prevalent, and accounted for 12% of isolates overall and for 23% of multidrug-resistant isolates. The ST131 isolates exhibited a significantly higher virulence score (mean of virulence genes 8.1) compared with the ST393 (6.0) and ST69 (5.4) isolates. The prevalence of ESBL-producing isolates was 7%. Six (10%) of the 59 ST131 isolates were positive for CTX-M-15 and one (6%) of the 16 ST393 isolates was positive for CTX-M-14, whereas none of the 22 ST69 isolates produced ESBL enzymes.
  
  
  CONCLUSIONS
  The three clonal groups investigated accounted for 30% of the multidrug-resistant isolates, which gives evidence of an important clonal component in the emergence of resistances among extraintestinal pathogenic E. coli. Notably, a single high virulence clonal group (O25b:H4-B2-ST131) causes approximately 1 in every 10 extraintestinal infections in Spain, representing an important public health threat. A new variant of the ST131 clonal group, which is non-ESBL-producing but trimethoprim/sulfamethoxazole resistant and with high virulence content, is reported.
authors.affiliation: Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain. jorge.blanco@usc.es
authors.forename: Jorge
authors.initials: J
authors.lastname: Blanco
authors.forename: Azucena
authors.initials: A
authors.lastname: Mora
authors.forename: Rosalia
authors.initials: R
authors.lastname: Mamani
authors.forename: Cecilia
authors.initials: C
authors.lastname: López
authors.forename: Miguel
authors.initials: M
authors.lastname: Blanco
authors.forename: Ghizlane
authors.initials: G
authors.lastname: Dahbi
authors.forename: Alexandra
authors.initials: A
authors.lastname: Herrera
authors.forename: Jesús E
authors.initials: JE
authors.lastname: Blanco
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Alonso
authors.forename: Fernando
authors.initials: F
authors.lastname: García-Garrote
authors.forename: Fernando
authors.initials: F
authors.lastname: Chaves
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Orellana
authors.forename: Luis
authors.initials: L
authors.lastname: Martínez-Martínez
authors.forename: Jorge
authors.initials: J
authors.lastname: Calvo
authors.forename: Guillem
authors.initials: G
authors.lastname: Prats
authors.forename: María Nieves
authors.initials: MN
authors.lastname: Larrosa
authors.forename: Juan José
authors.initials: JJ
authors.lastname: González-López
authors.forename: Lorena
authors.initials: L
authors.lastname: López-Cerero
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodríguez-Baño
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000892:Anti-Infective Agents, Urinary / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D005798:Genes, Bacterial / Q000235:genetics*; D006761:Hospitals; D006801:Humans; D058885:Multilocus Sequence Typing; D019081:O Antigens / Q000032:analysis; D011159:Population Surveillance; D013030:Spain / Q000453:epidemiology; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D000892:Anti-Infective Agents, Urinary; D019081:O Antigens; D037521:Virulence Factors; D002939:Ciprofloxacin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D001618:beta-Lactamases