Impact of a Regulation Restricting Critical Antimicrobial Usage on Prevalence of Antimicrobial Resistance in Escherichia coli Isolates From Fecal and Manure Pit Samples on Dairy Farms in Québec, Canada

Maud de Lagarde; John M Fairbrother; Marie Archambault; Simon Dufour; David Francoz; Jonathan Massé; Hélène Lardé; Cécile Aenishaenslin; Marie-Ève Paradis; Jean-Philippe Roy

doi:10.3389/fvets.2022.838498

Impact of a Regulation Restricting Critical Antimicrobial Usage on Prevalence of Antimicrobial Resistance in Escherichia coli Isolates From Fecal and Manure Pit Samples on Dairy Farms in Québec, Canada

Front Vet Sci. 2022 Feb 17:9:838498. doi: 10.3389/fvets.2022.838498. eCollection 2022.

Authors

Maud de Lagarde^{1

2}, John M Fairbrother^{3

4

5}, Marie Archambault^{2

4

5}, Simon Dufour^{2

5}, David Francoz^{1

2}, Jonathan Massé^{2

5}, Hélène Lardé^{1

2

6}, Cécile Aenishaenslin⁵, Marie-Ève Paradis⁷, Jean-Philippe Roy^{1

2}

Affiliations

¹ Department of Clinical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada.
² Regroupement FRQNT Op+lait, Saint-Hyacinthe, QC, Canada.
³ OIE Reference Laboratory for Escherichia coli, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada.
⁴ Swine and Poultry Infectious Research Center (CRIPA-FQRNT), Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada.
⁵ Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, Saint-Hyacinthe, QC, Canada.
⁶ Department of Clinical Sciences, Ross University School of Veterinary Medicine, Basseterre, Federation of Saint Christopher and Nevis.
⁷ Association des Médecins Vétérinaires Praticiens du Québec, Saint-Hyacinthe, QC, Canada.

Abstract

To tackle antimicrobial resistance (AMR), one of the major health threats of this century, the World Health Organization (WHO) endorsed a global action plan in 2015. This plan calls countries to develop national actions to address AMR. The province of Québec, Canada, adopted a new regulation on the 25^th of February 2019, to limit the use in food animals of antimicrobials of very high importance in human medicine. We aimed to establish the impact of this regulation by comparing the AMR situation in dairy cattle in Québec ~2 years before and 2 years after its introduction. We sampled calves, cows, and the manure pit in 87 farms. Generic and putative ESBL/AmpC E. coli were tested for susceptibility to 20 antimicrobials. Logistic regression was used to investigate whether the probability of antimicrobial resistance differed between isolates obtained from the pre and post regulation periods by sample type (calves, cows, manure pit) and in general. To identify AMR genes dissemination mechanisms, we sequenced the whole genome of 15 generic isolates. In the generic collection, at the herd level, the proportion of multidrug resistant (MDR) isolates, decreased significantly from 83 to 71% (p = 0.05). Folate inhibitor and aminoglycoside resistances demonstrated a significant decrease. However, when analyzed by sample type (calves, cows, manure pit), we did not observe a significant AMR decrease in any of these categories. In the ESBL/AmpC collection, we did not detect any significant difference between the two periods. Also, the general resistance gene profile was similar pre and post regulation. We identified both clonal and plasmidic dissemination of resistance genes. In conclusion, as early as 2 years post regulation implementation, we observed a significant decrease in MDR in the dairy industry in Quebec in the generic E. coli collection with folate inhibitor and aminoglycoside resistances showing the most significant decrease. No other significant decreases were yet observed.

Keywords: ESBL/AmpC; Escherichia coli; antimicrobial resistance; bacterial clone; calf/calves; cattle.