# Flux of antimicrobial resistance genes in the poultry production pyramid

Sylvie Baucheron, Angelique Travel, Isabelle Foubert, Yannick Baumard, Sébastien Leclercq, Isabelle Bouvarel, Maria-Céleste Le Bourhis, Benoît Doublet

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## To cite this version:

Sylvie Baucheron, Angelique Travel, Isabelle Foubert, Yannick Baumard, Sébastien Leclercq, et al. Flux of antimicrobial resistance genes in the poultry production pyramid. 8. Symposium on Antimicrobial Resistance in Animals and the Environment (ARAE 2019), Jul 2019, Tours, France. 87. hal-03356656

HAL Id: hal-03356656

https://hal.inrae.fr/hal-03356656

Submitted on 28 Sep 2021

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# Flux of antimicrobial resistance genes in the poultry production pyramid

Sylvie BAUCHERON<fnref n="1" />, Angélique TRAVEL<fnref n="2" />, Isabelle FOUBERT<fnref n="1" />, Yannick BAUMARD<fnref n="3" />, Sébastien LECLERQ<fnref n="1" />, Isabelle BOUVAREL<fnref n="2" />, Maria-Céleste LE BOURHIS<fnref n="3" />, Benoît DOUBLET<fnref n="1" />

The transmission of antimicrobial resistant (AMR) bacteria from food-producing animals to humans is an important public health issue. The aim of this project was to characterize the vertical and horizontal transmission as well as the persistence of AMR in the broiler production pyramid, considering all steps over three successive generations of animals and their associated environments, to identify new levels of risk control. Two approaches were considered, in first the analyses by bacterial cultures and then a global approach by metagenomic sequencing of the caecal microbiota.

The sampling was realized at the experimental unit PEAT of INRA, which reproduces all steps of the broiler production chain in a single site. AMR monitoring was carried out according to the breeding scheme on three successive generations of breeders and their offspring, with an individual follow-up of birds. For each generation, representative birds were chosen in three successive flocks of parent stock layers reared in two protected poultry houses and two broilers flocks in distinct production houses. Biological samples consisted of feces at different ages and incubated eggs, and of post-slaughtering caecal contents, neck skin, filet and leg meat. Several environment samples were also collected, including the drinking water, the water bath before plucking at the slaughterhouse, surfaces in the different poultry houses and the animal feed. AMR bacteria were selected from samples on Mac Conkey agar with the following antibiotics: ampicillin + tetracyclin, enrofloxacin, colistin, trimethoprim + sulfonamide. Resistant strains were identified by *E. coli* specific PCR and MALDI-TOF MS. Antimicrobial susceptibility testing was performed by the disk diffusion method on Mueller-Hinton agar.

AMR bacteria were characterized after the breeding of two generations of chickens. Fecal *E. coli* strains were mainly multidrug resistant, with different phenotypes (Str, Sul, Tet, Tmp, Amp). Moreover, multidrug resistant *Proteus mirabilis* isolates showed an additional resistance to quinolones. The environmental multidrug resistant bacteria were mainly *Pseudomonas aeruginosa*, *Pseudomonas fulva*, *Acinetobacter baumanii*, and *Klebsiella pneumoniae*. Preliminary conjugation assays using AMR *E. coli* donor strains identified IncF, IncI1 and IncN plasmids as vectors of resistance. The molecular typing of the mobile genetic elements is in progress. To complete the culture-dependent approach, whole genome sequencing of representative resistant isolates will be realized.

Our first results indicate that multidrug resistant bacteria are widespread in the experimental poultry production pyramid in spite of the non-use of antibiotics for a decade. Further investigations will be conducted to decipher the transmission of multidrug resistant bacteria and AMR mobile genetic elements in this system.

This study is supported by the grant (2017-448) from the french national plan for the reduction of the risks of antimicrobial resistance in veterinary medicine (Ecoantibio2) of the Ministère de l'agriculture et de l'alimentation.

<footnote n="1">¹ISP UMR 1282, INRA, University of Tours, Nouzilly, France</footnote>

<footnote n="2">² ITAVI, French technical Institute for Poultry, France</footnote>

<footnote n="3">³ Pôle d'Expérimentation Avicole de Tours 1295, INRA, Nouzilly, France</footnote>