title: Molecular evidence of the close relatedness of clinical, gull and wastewater isolates of quinolone-resistant Escherichia coli.
abstract: Escherichia coli with reduced susceptibility to quinolones isolated from different environmental sources (urban wastewater treatment plants, n=61; hospital effluent, n=10; urban streams, n=9; gulls, n=18; birds of prey, n=17) and from hospitalised patients (n=28) were compared based on multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). The habitats with the most diversified genotypes of quinolone-resistant E. coli, corresponding to the highest genetic diversity (H'), were wastewater and gulls. In addition, genetically distinct populations were observed in clinical samples and birds of prey, suggesting the influence of the habitat or selective pressures on quinolone-resistant E. coli. The close genetic relatedness between isolates of clinical origin and from gulls and wastewater suggests the existence of potential routes of propagation between these sources. The most common sequence types were ST131 and ST10, with ST131 being highly specific to patients, although distributed in all of the other habitats except birds of prey. The prevalence of antimicrobial resistance was significantly higher in isolates from patients and gulls than from other sources (P<0.01), suggesting that the effect of selective pressures met by isolates subjected to strong human impacts. The evidence presented suggests the potential circulation of bacteria between the environmental and clinical compartments, with gulls being a relevant vector of bacteria and resistance genes.
authors.affiliation: Centro de Biotecnologia e Química Fina (CBQF), Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal.
authors.forename: Ana Rita
authors.initials: AR
authors.lastname: Varela
authors.affiliation: National Reference Laboratory of Antimicrobial Resistance and Healthcare Associated Infections, National Institute of Health Dr Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
authors.forename: Vera
authors.initials: V
authors.lastname: Manageiro
authors.affiliation: National Reference Laboratory of Antimicrobial Resistance and Healthcare Associated Infections, National Institute of Health Dr Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
authors.forename: Eugénia
authors.initials: E
authors.lastname: Ferreira
authors.affiliation: Instituto Português de Oncologia Francisco Gentil, E.P.E, 4200-072 Porto, Portugal.
authors.forename: M Augusta
authors.initials: MA
authors.lastname: Guimarães
authors.affiliation: Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
authors.forename: Paulo Martins
authors.initials: PM
authors.lastname: da Costa
authors.affiliation: National Reference Laboratory of Antimicrobial Resistance and Healthcare Associated Infections, National Institute of Health Dr Ricardo Jorge, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
authors.forename: Manuela
authors.initials: M
authors.lastname: Caniça
authors.affiliation: Centro de Biotecnologia e Química Fina (CBQF), Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal. Electronic address: cmanaia@porto.ucp.pt.
authors.forename: Célia M
authors.initials: CM
authors.lastname: Manaia
keywords: Hospital; MLST; PFGE; Quinolone resistance; Wastewater; Wildlife