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High prevalence of antimicrobial-resistant Escherichia coli from animals at slaughter: a food safety risk

Authors

  • Sónia Ramos,

    1. Centre of Studies of Animal and Veterinary Sciences, Vila Real, Portugal
    2. Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
    3. Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
    4. Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
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    • Sónia Ramos and Nuno Silva contributed equally to this study and should be considered as joint first authors.

  • Nuno Silva,

    1. Centre of Studies of Animal and Veterinary Sciences, Vila Real, Portugal
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    • Sónia Ramos and Nuno Silva contributed equally to this study and should be considered as joint first authors.

  • Manuela Caniça,

    1. Laboratory of Antimicrobial Resistance, National Institute of Health Dr Ricardo Jorge, Lisbon, Portugal
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  • José Luis Capelo-Martinez,

    1. BIOSCOPE Group, Physical Chemistry Department, Science Faculty, University of Vigo at Ourense Campus, Ourense, Spain
    2. REQUIMTE, Chemistry Department, Science and Technology Faculty, FCT, New University of Lisbon, Caparica, Portugal
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  • Francisco Brito,

    1. Centre of Studies of Animal and Veterinary Sciences, Vila Real, Portugal
    2. Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
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  • Gilberto Igrejas,

    1. Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
    2. Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
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  • Patrícia Poeta

    Corresponding author
    1. Centre of Studies of Animal and Veterinary Sciences, Vila Real, Portugal
    2. Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
      Patrícia Poeta, Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal. E-mail: ppoeta@utad.pt
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Patrícia Poeta, Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal. E-mail: ppoeta@utad.pt

Abstract

BACKGROUND: There has been concern about the increase of antimicrobial resistant bacteria and protection of animal and public health, along with food safety. In the present study, we evaluate the incidence of antimicrobial resistance among 192 strains of Escherichia coli isolated from faecal samples of healthy food-producing animals at slaughter in Portugal.

RESULTS: Ninety-seven % of the pig isolates, 74% from sheep and 55% from cattle were resistant to one or more antimicrobial agents, with the resistances to ampicillin, streptomycin, tetracycline and trimethoprim–sulfamethoxazole the most common phenotype detected. Genes encoding resistance to antimicrobial agents were detected in most of the resistant isolates. Ninety-three % of the resistant isolates were included in the A or B1 phylogenetic groups, and the virulence gene fimA (alone or in association with papC or aer genes) was detected in 137 of the resistant isolates. Five isolates from pigs belonging to phylogroup B2 and D were resistant to five different antimicrobial agents.

CONCLUSION: Our data shows a high percentage of antibiotic resistance in E. coli isolates from food animals, and raises important questions in the potential impact of antibiotic use in animals and the possible transmission of resistant bacteria to humans through the food chain. © 2012 Society of Chemical Industry

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