title: Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry.
abstract: The presence of antimicrobial resistance and virulence factors of 174 Escherichia coli strains isolated from healthy Portuguese Gallus gallus was evaluated. Resistance profiles were determined against 33 antimicrobials by microbroth dilution. Resistance was prevalent for tetracycline (70%) and ampicillin (63%). Extended-spectrum beta-lactamase (ESBL) phenotype was observed in 18% of the isolates. Multidrug resistance was found in 56% of isolates. A subset of 74 isolates were screened by DNA microarrays for the carriage of 88 antibiotic resistance genes and 62 virulence genes. Overall, 37 different resistance genes were detected. The most common were tet(A) (72%), blaTEM (68%), and sul1 (47%), while 21% isolates harbored an ESBL gene (blaCTX-M group 1, group 2, or group 9). Of these, 96% carried the increased serum survival (iss) virulence gene, while 89% presented the enterobactin siderophore receptor protein (iroN), 70% the temperature-sensitive hemagglutinin (tsh), and 68% the long polar fimbriae (lpfA) virulence genes associated with extraintestinal pathogenic E. coli. In conclusion, prevalence of antibiotic resistant E. coli from the microbiota of Portuguese chickens was high, including to extended spectrum cephalosporins. The majority of isolates seems to have the potential to trigger extraintestinal human infection due to the presence of some virulence genes. However, the absence of genes specific for enteropathogenic E. coli reduces the risk for human intestinal infection.
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-458 Coimbra, Portugal. nuno.mendonca@uc.pt.|Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548 Coimbra, Portugal. nuno.mendonca@uc.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Mendonça
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-458 Coimbra, Portugal. rfig86@gmail.com.|Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548 Coimbra, Portugal. rfig86@gmail.com.|Department of Bacteriology, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, KT15 3NB Surrey, UK. rfig86@gmail.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Figueiredo
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-458 Coimbra, Portugal. catarrinamendes@gmail.com.
authors.forename: Catarina
authors.initials: C
authors.lastname: Mendes
authors.affiliation: Department of Bacteriology, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, KT15 3NB Surrey, UK. Roderick.Card@apha.gsi.gov.uk.
authors.forename: Roderick M
authors.initials: RM
authors.lastname: Card
authors.affiliation: Department of Bacteriology, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, KT15 3NB Surrey, UK. Muna.Anjum@apha.gsi.gov.uk.
authors.forename: Muna F
authors.initials: MF
authors.lastname: Anjum
authors.affiliation: Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-458 Coimbra, Portugal. gjsilva@ci.uc.pt.|Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548 Coimbra, Portugal. gjsilva@ci.uc.pt.
authors.forename: Gabriela Jorge
authors.initials: GJ
authors.lastname: da Silva
keywords: Escherichia coli; antibiotic resistance; microarray; poultry; virulence factors