Extended period of selection for antimicrobial resistance due to recirculation of persistent antimicrobials in broilers.

Autor:	Swinkels AF; Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands., Berendsen BJA; Wageningen Food Safety Research, Wageningen University & Research, Wageningen, The Netherlands., Fischer EAJ; Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands., Zomer AL; Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.; WHO Collaborating Centre for Reference and Research on Campylobacter and Antimicrobial Resistance from a One Health Perspective/WOAH Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands., Wagenaar JA; Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.; WHO Collaborating Centre for Reference and Research on Campylobacter and Antimicrobial Resistance from a One Health Perspective/WOAH Reference Laboratory for Campylobacteriosis, Utrecht, The Netherlands.; Wageningen Bioveterinary Research, Wageningen University & Research, Lelystad, The Netherlands.
Jazyk:	angličtina
Zdroj:	The Journal of antimicrobial chemotherapy [J Antimicrob Chemother] 2024 Sep 03; Vol. 79 (9), pp. 2186-2193.
DOI:	10.1093/jac/dkae213
Abstrakt:	Objectives: Antimicrobials can select for antimicrobial-resistant bacteria. After treatment the active compound is excreted through urine and faeces. As some antimicrobials are chemically stable, recirculation of subinhibitory concentrations of antimicrobials may occur due to coprophagic behaviour of animals such as chickens. Methods: The persistence of three antimicrobials over time and their potential effects on antimicrobial resistance were determined in four groups of broilers. Groups were left untreated (control) or were treated with amoxicillin (unstable), doxycycline or enrofloxacin (stable). Antimicrobials were extracted from the faecal samples and were measured by LC-MS/MS. We determined the resistome genotypically using shotgun metagenomics and phenotypically by using Escherichia coli as indicator microorganism. Results: Up to 37 days after treatment, doxycycline and enrofloxacin had concentrations in faeces equal to or higher than the minimal selective concentration (MSC), in contrast to the amoxicillin treatment. The amoxicillin treatment showed a significant difference (P ≤ 0.01 and P ≤ 0.0001) in the genotypic resistance only directly after treatment. On the other hand, the doxycycline treatment showed approximately 52% increase in phenotypic resistance and a significant difference (P ≤ 0.05 and P ≤ 0.0001) in genotypic resistance throughout the trial. Furthermore, enrofloxacin treatment resulted in a complete non-WT E. coli population but the quantity of resistance genes was similar to the control group, likely because resistance is mediated by point mutations. Conclusions: Based on our findings, we suggest that persistence of antimicrobials should be taken into consideration in the assessment of priority classification of antimicrobials in livestock. (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)
Databáze:	MEDLINE
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