Comparison of antimicrobial resistant Escherichia coli isolated from Irish commercial pig farms with and without zinc oxide and antimicrobial usage

Gut Pathogens

Research

Héctor Argüello¹  Catherine M. Burgess²  Daniel Ekhlas³  Juan M. Ortiz Sanjuán⁴  Finola C. Leonard⁵  Edgar G. Manzanilla⁶ 

[1] Animal Health Department, Veterinary Faculty, Universidad de León, León, Spain;Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland;Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland;School of Veterinary Medicine, University College Dublin, Dublin, Ireland;Pig Development Department, Teagasc Moorepark, Fermoy, Co. Cork, Ireland;Pig Development Department, Teagasc Moorepark, Fermoy, Co. Cork, Ireland;Grupo de Genómica Y Mejora Animal, Departamento de Genética, Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spain;School of Veterinary Medicine, University College Dublin, Dublin, Ireland;School of Veterinary Medicine, University College Dublin, Dublin, Ireland;Pig Development Department, Teagasc Moorepark, Fermoy, Co. Cork, Ireland;

关键词: Pig farms;    Antimicrobial prophylaxis;    Zinc oxide;    Antimicrobial resistance;    Multi-drug resistance;    Escherichia coli;    Whole-genome sequencing;   

DOI  :  10.1186/s13099-023-00534-3

 received in 2022-11-22, accepted in 2023-02-09,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundThe prophylactic use of antimicrobials and zinc oxide (ZnO) in pig production was prohibited by the European Union in 2022 due to potential associations between antimicrobial and heavy metal usage with antimicrobial resistance (AMR) and concerns regarding environmental pollution. However, the effects of their usage on the bacterial AMR profiles on commercial pig farms are still not fully understood and previous studies examining the effect of ZnO have reported contrasting findings. The objective of this study was to examine the effects of antimicrobial and ZnO usage on AMR on commercial pig farms. Faecal and environmental samples were taken on 10 Irish commercial farms, of which 5 farms regularly used ZnO and antimicrobials (amoxicillin or sulphadiazine-trimethoprim) for the prevention of disease. The other 5 farms did not use ZnO or any other form of prophylaxis. Escherichia coli numbers were quantified from all samples using non-supplemented and supplemented Tryptone Bile X-glucuronide agar.ResultsIn total 351 isolates were phenotypically analysed, and the genomes of 44 AmpC/ESBL-producing E. coli isolates from 4 farms were characterised using whole-genome sequencing. Phenotypic analysis suggested higher numbers of multi-drug resistant (MDR) E. coli isolates on farms using prophylaxis. Furthermore, farms using prophylaxis were associated with higher numbers of isolates resistant to apramycin, trimethoprim, tetracycline, streptomycin, and chloramphenicol, while resistance to ciprofloxacin was more associated with farms not using any prophylaxis. Thirty-four of the 44 AmpC/ESBL-producing E. coli strains harboured the blaCTX-M-1 resistance gene and were multi drug resistant (MDR). Moreover, network analysis of plasmids and analysis of integrons showed that antimicrobial and biocide resistance genes were frequently co-located on mobile genetic elements, indicating the possibility for co-selection during antimicrobial or biocide usage as a contributor to AMR occurrence and persistence on farms.ConclusionsThe results of this study showed evidence that antimicrobial and ZnO treatment of pigs post-weaning can favour the selection and development of AMR and MDR E. coli. Co-location of resistance genes on mobile genetic elements was observed. This study demonstrated the usefulness of phenotypic and genotypic detection of antimicrobial resistance by combining sequencing and microbiological methods.

【 授权许可】

CC BY   
© The Author(s) 2023

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