title: Antibiotic Resistance in Escherichia coli from Pigs in Organic and Conventional Farming in Four European Countries.
abstract: Organic pig production differs in many ways from conventional production of pigs, e.g., in antibiotic use, herd structure, feeding regimes, access to outdoor areas and space allowance per pig. This study investigated if these differences result in a lower occurrence of antibiotic resistance in organic slaughter pigs in Denmark, France, Italy and Sweden. Samples were taken from the colon content and/or faeces and minimum inhibitory concentrations (MIC) of ten antibiotics were determined in isolates of Escherichia coli. In addition, the proportion of tetracycline (TET) resistant E. coli in colon content and/or faeces from individual pigs was determined. In all four countries the percentage resistance to ampicillin, streptomycin, sulphonamides or trimethoprim was significantly lower in E. coli from organic pigs. In France and Italy, the percentage of isolates resistant to chloramphenicol, ciprofloxacin, nalidixic acid or gentamicin was also significantly lower in the E. coli from organic pigs. Resistance to cefotaxime, was not found in any country. The percentage of E. coli isolates resistant to TET as well as the proportion of TET-resistant E. coli was significantly lower in organic than in conventional pigs, except in Sweden where TET-resistance was equally low in both production types. There were also differences between countries within production type in the percentage resistance to individual antibiotics as well as the proportion of TET-resistant E. coli with lower median proportions in Sweden and Denmark compared to France and Italy. The study shows that in each of the four countries resistance in intestinal E. coli was less common in organic than in conventional pigs, but that there were also large differences in resistance between countries within each production type, indicating that both country- and production-specific factors influence the occurrence of resistance.
authors.affiliation: National Veterinary Institute (SVA), Uppsala, Sweden.
authors.forename: Julia
authors.identifier: http://orcid.org/0000-0003-4859-4269
authors.initials: J
authors.lastname: Österberg
authors.affiliation: National Food Institute, Technical University of Denmark (DTU), Copenhagen, Denmark.
authors.forename: Anne
authors.initials: A
authors.lastname: Wingstrand
authors.affiliation: National Food Institute, Technical University of Denmark (DTU), Copenhagen, Denmark.
authors.forename: Annette
authors.initials: A
authors.lastname: Nygaard Jensen
authors.affiliation: French Agency for Food, Environment and Occupational Health Safety (ANSES), Ploufragan, France.
authors.forename: Annaelle
authors.initials: A
authors.lastname: Kerouanton
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Legnaro, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Cibin
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Legnaro, Italy.
authors.forename: Lisa
authors.initials: L
authors.lastname: Barco
authors.affiliation: French Agency for Food, Environment and Occupational Health Safety (ANSES), Ploufragan, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Denis
authors.affiliation: National Food Institute, Technical University of Denmark (DTU), Copenhagen, Denmark.
authors.forename: Sören
authors.initials: S
authors.lastname: Aabo
authors.affiliation: National Veterinary Institute (SVA), Uppsala, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Bengtsson
mesh_terms: D000383:Agriculture; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004926:Escherichia coli / Q000302:isolation & purification*; D005060:Europe; D005243:Feces / Q000382:microbiology; D013552:Swine
chemical_list: D000900:Anti-Bacterial Agents