title: Impact of ceftiofur injection on gut microbiota and Escherichia coli resistance in pigs.
abstract: Resistance to extended-spectrum cephalosporins (ESCs) is an important health concern. Here, we studied the impact of the administration of a long-acting form of ceftiofur on the pig gut microbiota and ESC resistance in Escherichia coli. Pigs were orally inoculated with an ESC-resistant E. coli M63 strain harboring a conjugative plasmid carrying a gene conferring resistance, bla CTX-M-1. On the same day, they were given or not a unique injection of ceftiofur. Fecal microbiota were studied using quantitative PCR analysis of the main bacterial groups and quantification of short-chain fatty acids. E. coli and ESC-resistant E. coli were determined by culture methods, and the ESC-resistant E. coli isolates were characterized. The copies of the bla CTX-M-1 gene were quantified. After ceftiofur injection, the main change in gut microbiota was the significant but transitory decrease in the E. coli population. Acetate and butyrate levels were significantly lower in the treated group. In all inoculated groups, E. coli M63 persisted in most pigs, and the bla CTX-M-1 gene was transferred to other E. coli. Culture and PCR results showed that the ceftiofur-treated group shed significantly more resistant strains 1 and 3 days after ESC injection. Thereafter, on most dates, there were no differences between the groups, but notably, one pig in the nontreated group regularly excreted very high numbers of ESC-resistant E. coli, probably leading to a higher contamination level in its pen. In conclusion, the use of ESCs, and also the presence of high-shedding animals, are important features in the spread of ESC resistance.
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine-Auvergne, EA 4678 CIDAM, Conception, Ingénierie et Développement de l'Aliment et du Médicament, Clermont-Ferrand, France.
authors.forename: M A
authors.initials: MA
authors.lastname: Fleury
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: G
authors.initials: G
authors.lastname: Mourand
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: E
authors.initials: E
authors.lastname: Jouy
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: F
authors.initials: F
authors.lastname: Touzain
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: L
authors.initials: L
authors.lastname: Le Devendec
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: C
authors.initials: C
authors.lastname: de Boisseson
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: F
authors.initials: F
authors.lastname: Eono
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France.
authors.forename: R
authors.initials: R
authors.lastname: Cariolet
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France INRA, UMR408 Sécurité et Qualité des Produits d'Origine Végétale, Avignon, France.
authors.forename: A
authors.initials: A
authors.lastname: Guérin
authors.affiliation: Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine-Auvergne, EA 4678 CIDAM, Conception, Ingénierie et Développement de l'Aliment et du Médicament, Clermont-Ferrand, France.
authors.forename: O
authors.initials: O
authors.lastname: Le Goff
authors.affiliation: Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine-Auvergne, EA 4678 CIDAM, Conception, Ingénierie et Développement de l'Aliment et du Médicament, Clermont-Ferrand, France.
authors.forename: S
authors.initials: S
authors.lastname: Blanquet-Diot
authors.affiliation: Clermont Université, Université d'Auvergne, Centre de Recherche en Nutrition Humaine-Auvergne, EA 4678 CIDAM, Conception, Ingénierie et Développement de l'Aliment et du Médicament, Clermont-Ferrand, France.
authors.forename: M
authors.initials: M
authors.lastname: Alric
authors.affiliation: ANSES, Laboratoire de Ploufragan-Plouzané, Ploufragan, France Université Européenne de Bretagne, Rennes, France isabelle.kempf@anses.fr.
authors.forename: I
authors.initials: I
authors.lastname: Kempf
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D002511:Cephalosporins / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D004926:Escherichia coli / Q000187:drug effects* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology; D000069196:Gastrointestinal Microbiome / Q000187:drug effects*; D013552:Swine; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C053503:ceftiofur; C055184:beta-lactamase TEM-3; D001618:beta-Lactamases