title: Molecular epidemiology and virulence of Escherichia coli O16:H5-ST131: comparison with H30 and H30-Rx subclones of O25b:H4-ST131.
abstract: The present study was carried out to evaluate the prevalence of the clonal subgroup O16:H5-ST131 and the H30 and H30-Rx subclones among E. coli isolates causing extraintestinal infections and to know their virulence potential. The ST131 clonal group accounted for 490 (16%) of the 2995 isolates obtained from clinical samples in five Spanish hospitals during the study period (2005-2012). Among those 490 ST131 isolates, 456 belonged to serotype O25b:H4, 27 to O16:H5 and seven were O-non-typeable:H4 (ONT:H4). All 27 O16:H5 isolates showed fimH41, whereas fimH30 and fimH22 alleles were the most frequently detected among O25b:H4 isolates. The majority (381/490; 78%) of ST131 isolates belonged to H30 subclone, and 302 of 381 (79%) H30 isolates belonged to the H30-Rx subclone. Of the 27 O16:H5 isolates, 48% produced CTX-M-14; however, none produced CTX-M-15. In contrast, 46% of O25b:H4 isolates produced CTX-M-15 while only 2% produced CTX-M-14. More than a half of the O16:H5 isolates (56%) showed the ExPEC status which was significantly more prevalent within O25b:H4 isolates (81%) (P<0.01), especially among H30-Rx (97%) isolates. In the present study, a modified virotype scheme was applied within which approximately half (52%) of the O16:H5 isolates showed the C1 specific virotype. Despite their low virulence-gene score (mean of virulence genes 6.4 versus 8.5 in O25b:H4 isolates), six out of the 10 O16:H5 isolates assayed showed high virulence in the mouse model of sepsis (killed 90-100% of mice challenged). Furthermore, four O16:H5 isolates of virotypes A and C1, carrying K2 variant of group II capsule, showed lethality at 24h. Thus, certain O16:H5 fimH41 isolates show a similar in vivo virulence to that reported with the highly virulent O25b:H4 H30-Rx isolates (Mora et al., PLOS ONE 2014, e87025), supporting their potential virulence for humans.
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.
authors.forename: Ghizlane
authors.initials: G
authors.lastname: Dahbi
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.
authors.forename: Azucena
authors.initials: A
authors.lastname: Mora
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.
authors.forename: Rosalia
authors.initials: R
authors.lastname: Mamani
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.
authors.forename: Cecilia
authors.initials: C
authors.lastname: López
authors.affiliation: Unidade de Microbioloxía Clínica, Hospital Universitario Lucus Augusti, Lugo, Spain.
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Alonso
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.
authors.forename: Juan
authors.initials: J
authors.lastname: Marzoa
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.
authors.forename: Miguel
authors.initials: M
authors.lastname: Blanco
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.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Herrera
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.
authors.forename: Susana
authors.initials: S
authors.lastname: Viso
authors.affiliation: Unidade de Microbioloxía Clínica, Hospital Universitario Lucus Augusti, Lugo, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: García-Garrote
authors.affiliation: Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States.
authors.forename: Veronika
authors.initials: V
authors.lastname: Tchesnokova
authors.affiliation: Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States.
authors.forename: Mariya
authors.initials: M
authors.lastname: Billig
authors.affiliation: Instituto de Biomedicina y Biotecnología, Universidad de Cantabria, Santander, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: de la Cruz
authors.affiliation: Instituto de Biomedicina y Biotecnología, Universidad de Cantabria, Santander, Spain.
authors.forename: María
authors.initials: M
authors.lastname: de Toro
authors.affiliation: Servei de Microbiología, Hospital Vall d'Hebron, Barcelona, Spain; Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Spain.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: González-López
authors.affiliation: Servei de Microbiología, Hospital Vall d'Hebron, Barcelona, Spain; Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Prats
authors.affiliation: Servicio de Microbiología, Hospital 12 de Octubre, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Chaves
authors.affiliation: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla-IDIVAL, Santander, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Martínez-Martínez
authors.affiliation: Servicio de Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: López-Cerezo
authors.affiliation: INSERM, IAME, UMR 1137, F-75018 Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, F-75018 Paris, France.
authors.forename: Erick
authors.initials: E
authors.lastname: Denamur
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. Electronic address: jorge.blanco@usc.es.
authors.forename: Jorge
authors.initials: J
authors.lastname: Blanco
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004926:Escherichia coli / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology*; D005260:Female; D005838:Genotype; D006801:Humans; D051379:Mice; D017720:Molecular Epidemiology; D058889:Molecular Typing; D018805:Sepsis / Q000382:microbiology; D065288:Serogroup; D013030:Spain / Q000453:epidemiology; D016019:Survival Analysis; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D037521:Virulence Factors
keywords: E. coli; ExPEC; H30 and H30-Rx subclones; O16:H5; O25b:H4; ST131 clonal group