title: Virulence and plasmidic resistance determinants of Escherichia coli isolated from municipal and hospital wastewater treatment plants.
abstract: Escherichia coli is simultaneously an indicator of water contamination and a human pathogen. This study aimed to characterize the virulence and resistance of E. coli from municipal and hospital wastewater treatment plants (WWTPs) in central Portugal. From a total of 193 isolates showing reduced susceptibility to cefotaxime and/or nalidixic acid, 20 E. coli with genetically distinct fingerprint profiles were selected and characterized. Resistance to antimicrobials was determined using the disc diffusion method. Extended spectrum β-lactamase and plasmid-mediated quinolone resistance genes, phylogroups, pathogenicity islands (PAIs) and virulence genes were screened by polymerase chain reaction (PCR). CTX-M producers were typed by multilocus sequence typing. Resistance to beta-lactams was associated with the presence of bla(TEM), bla(SHV), bla(CTX-M-15) and bla(CTX-M-32). Plasmid-mediated quinolone resistance was associated with qnrA, qnrS and aac(6')-Ib-cr. Aminoglycoside resistance and multidrug-resistant phenotypes were also detected. PAI IV(536), PAI II(CFT073), PAI II(536) and PAI I(CFT073), and uropathogenic genes iutA, papAH and sfa/foc were detected. With regard to the clinical ST131 clone, it carried bla(CTX-M-15), blaTEM-type, qnrS and aac(6')-lb-cr; IncF and IncP plasmids, and virulence factors PAI IV(536), PAI I(CFT073), PAI II(CFT073), iutA, sfa/foc and papAH were identified in the effluent of a hospital plant. WWTPs contribute to the dissemination of virulent and resistant bacteria in water ecosystems, constituting an environmental and public health risk.
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail: gjsilva@ci.uc.pt; Center of Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Vera
authors.initials: V
authors.lastname: Calhau
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail: gjsilva@ci.uc.pt.
authors.forename: Catarina
authors.initials: C
authors.lastname: Mendes
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail: gjsilva@ci.uc.pt.
authors.forename: Angelina
authors.initials: A
authors.lastname: Pena
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal E-mail: gjsilva@ci.uc.pt; Center of Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Mendonça
authors.affiliation: Center of Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Gabriela Jorge
authors.initials: GJ
authors.lastname: Da Silva
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D010957:Plasmids; D014774:Virulence; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology; D001618:beta-Lactamases
chemical_list: D000900:Anti-Bacterial Agents; D062065:Wastewater; D001618:beta-Lactamases