title: Impact of medicated feed along with clay mineral supplementation on Escherichia coli resistance to antimicrobial agents in pigs after weaning in field conditions.
abstract: The aim of this study was to examine changes in antimicrobial resistance (AMR) phenotype and virulence and AMR gene profiles in Escherichia coli from pigs receiving in-feed antimicrobial medication following weaning and the effect of feed supplementation with a clay mineral, clinoptilolite, on this dynamic. Eighty E. coli strains isolated from fecal samples of pigs receiving a diet containing chlortetracycline and penicillin, with or without 2% clinoptilolite, were examined for antimicrobial resistance to 15 antimicrobial agents. Overall, an increased resistance to 10 antimicrobials was observed with time. Supplementation with clinoptilolite was associated with an early increase but later decrease in blaCMY-2, in isolates, as shown by DNA probe. Concurrently, a later increase in the frequency of blaCMY-2 and the virulence genes iucD and tsh was observed in the control pig isolates, being significantly greater than in the supplemented pigs at day 28. Our results suggest that, in the long term, supplementation with clinoptilolite could decrease the prevalence of E. coli carrying certain antimicrobial resistance and virulence genes.
authors.affiliation: OIE Reference Laboratory for Escherichia coli (EcL), Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Seyedehameneh
authors.initials: S
authors.lastname: Jahanbakhsh
authors.affiliation: OIE Reference Laboratory for Escherichia coli (EcL), Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Kiswendsida Paul
authors.initials: KP
authors.lastname: Kabore
authors.affiliation: Research Chair in Meat Safety, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Fravalo
authors.affiliation: Research Chair in Meat Safety, Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Ann
authors.initials: A
authors.lastname: Letellier
authors.affiliation: OIE Reference Laboratory for Escherichia coli (EcL), Faculty of Veterinary Medicine, Université de Montréal, St-Hyacinthe, QC, Canada. Electronic address: john.morris.fairbrother@umontreal.ca.
authors.forename: John Morris
authors.initials: JM
authors.lastname: Fairbrother
mesh_terms: D000538:Aluminum Silicates; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002751:Chlortetracycline / Q000008:administration & dosage / Q000494:pharmacology*; D000077215:Clay; D004032:Diet; D019587:Dietary Supplements; D004926:Escherichia coli / Q000187:drug effects*; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D013552:Swine / Q000382:microbiology*; D014886:Weaning
chemical_list: D000538:Aluminum Silicates; D000900:Anti-Bacterial Agents; D000077215:Clay; D002751:Chlortetracycline
keywords: Antimicrobial resistance; Clay mineral (clinoptilolite); E. coli; Pig; Virulence gene