title: Impact of colistin sulfate treatment of broilers on the presence of resistant bacteria and resistance genes in stored or composted manure.
abstract: The application of manure may result in contamination of the environment with antimicrobials, antimicrobial-resistant bacteria, resistance genes and plasmids. The aim of this study was to investigate the impact of the administration of colistin and of manure management on (i) the presence of colistin-resistant Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa and (ii) the prevalence of various antimicrobial resistance genes in feces and in composted or stored manure. One flock of chickens was treated with colistin at the recommended dosage and a second flock was kept as an untreated control. Samples of feces, litter and stored or composted manure from both flocks were collected for isolation and determination of the colistin-susceptibility of E. coli, K. pneumoniae and P. aeruginosa and quantification of genes coding for resistance to different antimicrobials. The persistence of plasmids in stored or composted manure from colistin-treated broilers was also evaluated by plasmid capturing experiments. Results revealed that colistin administration to chickens had no apparent impact on the antimicrobial resistance of the dominant Enterobacteriaceae and P. aeruginosa populations in the chicken gut. Composting stimulated an apparently limited decrease in genes coding for resistance to different antimicrobial families. Importantly, it was shown that even after six weeks of composting or storage, plasmids carrying antimicrobial resistance genes could still be transferred to a recipient E. coli. In conclusion, composting is insufficient to completely eliminate the risk of spreading antimicrobial resistance through chicken manure.
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Le Devendec
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Gwenaelle
authors.initials: G
authors.lastname: Mourand
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Bougeard
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Léaustic
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Jouy
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France.
authors.forename: Alassane
authors.initials: A
authors.lastname: Keita
authors.affiliation: Inserm U1070, Pôle Biologie Santé, F-86000 Poitiers, France; Université de Poitiers, UFR Médecine-Pharmacie, F-86000 Poitiers, France; CHU Poitiers, Service de Toxicologie-Pharmacocinétique, F-86021 Poitiers Cedex, France.
authors.forename: William
authors.initials: W
authors.lastname: Couet
authors.affiliation: ITAVI, Beaucemaine, F-22440 Ploufragan, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Rousset
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, F-22440 Ploufragan, France; Université Européenne de Bretagne, F-35000 Rennes, France. Electronic address: isabelle.kempf@anses.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Kempf
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001512:Bedding and Linens / Q000382:microbiology; D002645:Chickens; D003091:Colistin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D022761:Gene Transfer, Horizontal; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D007422:Intestines / Q000382:microbiology; D008372:Manure / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics; D012988:Soil Microbiology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D008372:Manure; D003091:Colistin
keywords: Antimicrobial resistance; Chicken; Colistin; Manure; Resistance gene