title: Poultry as reservoir for extraintestinal pathogenic Escherichia coli O45:K1:H7-B2-ST95 in humans.
abstract: Escherichia coli strains O45:K1:H7 are implicated in severe human infections such as meningitis. Since an increasing prevalence of serogroup O45 among avian pathogenic (APEC) and human extraintestinal pathogenic (ExPEC) E. coli strains isolated in Spain have been noticed, the aims of the present study were to investigate similarities between poultry and human O45 isolates, and to investigate the evolutionary relationship of ST95 types. The genetic relatedness and virulence gene profiles of 55 O45 APEC obtained from an avian colibacillosis collection (1991-2011) and 19 human O45 ExPEC from a human septicemic/uropathogenic (UPEC) E. coli collection (1989-2010) were determined by multilocus sequence typing (MLST), pulsed-field-gel-electrophoresis (PFGE), ECOR phylogrouping, and PCR-based genotyping. Two main clonal groups were established. The most prevalent and highly pathogenic O45:K1:H7-B2-ST95 shows a successful persistence since the 90s to the present, with parallel evolution both in human and poultry, on the basis of their PFGE and virulence gene profile similarities (9 human strains and 15 avian strains showed ≥85% PFGE identity). Comparison of this group with other ST95 closely related members (O1:K1:H7 and O18:K1:H7 isolates from our collections) shows pathogenic specialization through conserved virulence genotypes. The other prevalent O45 clonal group characterized in this study, the O45:HNM/H19-D-ST371/ST2676 was only detected in APEC strains suggesting host specificity. In conclusion, poultry could be acting as a reservoir of O45:K1:H7-B2-ST95 and other pathogenic ST95 serotypes in humans. Further studies would be necessary to clarify if pathogenic mechanisms used by ST95 strains are the same in avian and human hosts.
authors.affiliation: Department of Microbiology and Parasitology, Faculty of Veterinary Sciences, University of Santiago de Compostela, 27002 Lugo, Spain. Electronic address: azucena.mora@usc.es.
authors.forename: Azucena
authors.initials: A
authors.lastname: Mora
authors.forename: Susana
authors.initials: S
authors.lastname: Viso
authors.forename: Cecilia
authors.initials: C
authors.lastname: López
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Alonso
authors.forename: Fernando
authors.initials: F
authors.lastname: García-Garrote
authors.forename: Ghizlane
authors.initials: G
authors.lastname: Dabhi
authors.forename: Rosalía
authors.initials: R
authors.lastname: Mamani
authors.forename: Alexandra
authors.initials: A
authors.lastname: Herrera
authors.forename: Juan
authors.initials: J
authors.lastname: Marzoa
authors.forename: Miguel
authors.initials: M
authors.lastname: Blanco
authors.forename: Jesús E
authors.initials: JE
authors.lastname: Blanco
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Moulin-Schouleur
authors.forename: Catherine
authors.initials: C
authors.lastname: Schouler
authors.forename: Jorge
authors.initials: J
authors.lastname: Blanco
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D004197:Disease Reservoirs / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000635:transmission; D029968:Escherichia coli Proteins / Q000235:genetics; D005838:Genotype; D006801:Humans; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D011200:Poultry / Q000382:microbiology*; D011201:Poultry Diseases / Q000382:microbiology*; D013030:Spain; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D037521:Virulence Factors
keywords: APEC; Escherichia coli; ExPEC; NMEC; O45; ST95