AUTHOR=Strong Kayla M. , Marasco Kaitlin L. , Invik Jesse , Ganshorn Heather , Reid-Smith Richard J. , Waldner Cheryl L. , Otto Simon J. G. , Kastelic John P. , Checkley Sylvia L. 

TITLE=Factors associated with antimicrobial resistant enterococci in Canadian beef cattle: A scoping review

JOURNAL=Frontiers in Veterinary Science

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1155772

DOI=10.3389/fvets.2023.1155772

ISSN=2297-1769

ABSTRACT=<sec><title>Introduction</title><p>Antimicrobial resistance (AMR) is a global health concern, occurring when bacteria evolve to render antimicrobials no longer effective. Antimicrobials have important roles in beef production; however, the potential to introduce AMR to people through beef products is a concern. This scoping review identifies factors associated with changes in the prevalence of antimicrobial-resistant <italic>Enterococcus</italic> spp. applicable to the Canadian farm-to-fork beef continuum.</p></sec><sec><title>Methods</title><p>Five databases (MEDLINE, BIOSIS, Web of Science, Embase, and CAB Abstracts) were searched for articles published from January 1984 to March 2022, using <italic>a priori</italic> inclusion criteria. Peer-reviewed articles were included if they met all the following criteria: written in English, applicable to the Canadian beef production context, primary research, <italic>in vivo</italic> research, describing an intervention or exposure, and specific to <italic>Enterococcus</italic> spp.</p></sec><sec><title>Results</title><p>Out of 804 screened articles, 26 were selected for inclusion. The included articles discussed 37 factors potentially associated with AMR in enterococci, with multiple articles discussing at least two of the same factors. Factors discussed included antimicrobial administration (<italic>n</italic> = 16), raised without antimicrobials (<italic>n</italic> = 6), metal supplementation (<italic>n</italic> = 4), probiotics supplementation (<italic>n</italic> = 3), pen environment (<italic>n</italic> = 2), essential oil supplementation (<italic>n</italic> = 1), grass feeding (<italic>n</italic> = 1), therapeutic versus subtherapeutic antimicrobial use (<italic>n</italic> = 1), feeding wet distiller grains with solubles (<italic>n</italic> = 1), nutritional supplementation (<italic>n</italic> = 1) and processing plant type (<italic>n</italic> = 1). Results were included irrespective of their quality of evidence.</p></sec><sec><title>Discussion</title><p>Comparability issues arising throughout the review process were related to data aggregation, hierarchical structures, study design, and inconsistent data reporting. Findings from articles were often temporally specific in that resistance was associated with AMR outcomes at sampling times closer to exposure compared to studies that sampled at longer intervals after exposure. Resistance was often nuanced to unique gene and phenotypic resistance patterns that varied with species of enterococci. Intrinsic resistance and interpretation of minimum inhibitory concentration varied greatly among enterococcal species, highlighting the importance of caution when comparing articles and generalizing findings.</p></sec><sec><title>Systematic Review Registration</title><p>[<ext-link xlink:href="http://hdl.handle.net/1880/113592" ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink">http://hdl.handle.net/1880/113592</ext-link>]</p></sec>