Distribution and characterization of integrons in Escherichia coli strains of animal and human origin

Authors


  • Present addresses: Elena Grasselli, Michaela Gutaker and Cinzia Benagli, Dipartimento di Biologia, sezione di Fisiologia Generale e Comparata, Università degli Studi di Genova, Corso Europa 26 V piano, 16132 Genova, Italy. Maruska Convert, Interlifescience, Via San Gottardo 92, 6900 Massagno, Switzerland

  • Editor: Artur Ulmer

Correspondence: Jean-Claude Piffaretti, Interlifescience, Via San Gottardo 92, 6900 Massagno, Switzerland. Tel.: +41 91 960 05 55; fax: +41 91 960 05 56; e-mail: piffaretti@interlifescience.ch

Abstract

One hundred and twenty clinical and commensal Escherichia coli strains isolated in Switzerland from humans and from companion and farm animals were analysed for the prevalence of integrons of classes 1, 2, and 3 and for the characterization of their gene cassettes. The relationships between integron carriage and host category, and between integron carriage and phylogenetic E. coli lineage were also analysed. Integrons were detected in 48 (40%) of the isolates and were thus widely disseminated in the human and animal E. coli strains considered. Moreover, the association between integron carriage and certain animal categories (farm animals) suggests that animals that are raised for economic purposes might be exposed to a major antibiotic pressure. Finally, our data confirm that E. coli commensal strains represent a significant source of antibiotic-resistant determinants.

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