Projects per year
AIMS: The aim of this study was to investigate the effect of subtherapeutic intestinal doxycycline (DOX) concentrations (4 and 1 mg l-1 ), caused by cross-contamination of feed, on the enrichment of a DOX-resistant commensal Escherichia coli and its resistance plasmid in an ex vivo model of the porcine caecum.
METHODS AND RESULTS: A DOX-resistant, tet(A)-carrying, porcine commensal E. coli strain (EC 682) was cultivated for 6 days in the porcine caecum model under different conditions (0, 1 and 4 mg l-1 DOX). EC 682, other coliforms and anaerobic bacteria were enumerated daily. A selection of isolated DOX-resistant coliforms (n = 454) was characterized by rep-PCR clustering, PCR assays (Inc1 and tet(A)) and micro broth dilution susceptibility tests (Sensititre). Both 1 and 4 mg l-1 DOX-enriched medium had a significantly higher selective effect on EC 682 and other resistant coliforms than medium without DOX. Transconjugants of EC 682 were isolated more frequently in the presence of 1 and 4 mg l-1 DOX compared to medium without DOX.
CONCLUSIONS: Subtherapeutic intestinal DOX concentrations have the potential to select for DOX-resistant E. coli, and promote the selection of transconjugants in a porcine caecum model.
SIGNIFICANCE AND IMPACT OF THE STUDY: Cross-contamination of feed with antimicrobials such as DOX likely promotes the spread of antimicrobial resistance. Therefore, it is important to develop or fine-tune guidelines for the safe use of antimicrobials in animal feed and its storage.
- Journal Article
FingerprintDive into the research topics of 'Selection and transfer of an IncI1-tet(A) plasmid of <i>Escherichia coli</i> in an<i> ex vivo</i> model of the porcine caecum at doxycycline concentrations caused by crosscontaminated feed'. Together they form a unique fingerprint.
- 1 Types of other (prices, external and other activities) - (Co)promotor PhDthesis
Carry-over of tetracyclines and sulphonamides-trimethoprim in pig feed, resistance selection in the pig microbiota caused by doxycycline (Laura Peeters)
Geertrui Rasschaert (Copromotor)2013 → 19-Feb-2018
Activity: Other › Types of other (prices, external and other activities) - (Co)promotor PhDthesis