Next Article in Journal
A Review of Quality Measures for Assessing the Impact of Antimicrobial Stewardship Programs in Hospitals
Previous Article in Journal
Going beyond the Control of Quorum-Sensing to Combat Biofilm Infections
Previous Article in Special Issue
Co-Selection of Resistance to Antibiotics, Biocides and Heavy Metals, and Its Relevance to Foodborne Pathogens
Article Menu

Export Article

Open AccessArticle
Antibiotics 2016, 5(1), 4;

Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry

Faculty of Pharmacy, University of Coimbra, Health Sciences Campus, Azinhaga de Santa Comba, 3000-458 Coimbra, Portugal
Centre for Neuroscience and Cell Biology, University of Coimbra, 3000-548 Coimbra, Portugal
Department of Bacteriology, Animal and Plant Health Agency, Weybridge, New Haw, Addlestone, KT15 3NB Surrey, UK
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Academic Editor: Martin J. Woodward
Received: 8 June 2015 / Revised: 15 December 2015 / Accepted: 5 January 2016 / Published: 13 January 2016
(This article belongs to the Special Issue The Use of Antibiotics in Food-Producing Animals)
Full-Text   |   PDF [382 KB, uploaded 13 January 2016]   |  


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. View Full-Text
Keywords: Escherichia coli; microarray; virulence factors; antibiotic resistance; poultry Escherichia coli; microarray; virulence factors; antibiotic resistance; poultry

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material


Share & Cite This Article

MDPI and ACS Style

Mendonça, N.; Figueiredo, R.; Mendes, C.; Card, R.M.; Anjum, M.F.; Da Silva, G.J. Microarray Evaluation of Antimicrobial Resistance and Virulence of Escherichia coli Isolates from Portuguese Poultry. Antibiotics 2016, 5, 4.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Antibiotics EISSN 2079-6382 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top