Browsing by Author "Marasco, Kaitlin"
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- ItemOpen AccessFactors Associated with Antimicrobial Resistant Enterococci in North American Beef Cattle: A Scoping Review Protocol(2021-07-05) Strong, Kayla; Marasco, Kaitlin; Invik, Jesse; Ganshorn, Heather; Reid-Smith, Richard; Waldner, Cheryl; Otto, Simon; Chapman, Brennan; Checkley, SylviaIntroduction: Enterococcus spp. is a commensal gram-positive bacterium routinely found in humans and bovines' intestinal tracts; however, it can lead to infection when found outside the intestinal tract.1 There is increasing difficulty in treating Enterococcal infections due to a rise in resistance, particularly multidrug resistance.2 The rise of antimicrobial resistance is a One Health problem resulting from antimicrobial use in human health, animal health, and the environment.3 This research focuses on the connection between animal and human health, and considers the epidemiology of antimicrobial resistance within the North American beef cattle production system. The research will identify factors associated with antimicrobial resistance in Enterococcus spp. from cow-calf operations up to but not including human beef consumption. This project is a component of the broader iAM.AMR initiative. Objectives: The primary objective is to identify what factors increase or decrease the prevalence of antimicrobial resistance in Enterococcus spp. within the North American Beef Cattle Industry, from cow-calf operations to the retail setting. The results will populate a component of an integrated assessment model as a component of the Integrated Assessment Model on Antimicrobial Resistance (iAM.AMR) project, built using Analytica software (Educational Professional license, Lumina) Methods: A double-blinded scoping review following PRISMA guidelines will examine five databases (MEDLINE, BIOSIS Previews, the Web of Science Science Citation Index and Emerging Sources Citation Index, Embase, and CAB Abstracts). The search will consider Enterococcus spp., Antimicrobials, Resistance, beef cattle, and search term variants. Articles identified will be screened at three primary stages: bibliography, title and abstract, and full text. The authors will exclude articles published before 1984 (Enterococcus spp. was designated a species in 1984), journals specific to a livestock species that is not beef cattle, and non-English articles. Articles that are solely In vitro, specific to fermented meat, opinion-based, or not applicable to the North American context will also be excluded. Articles will be included if there is an intervention identified and the AMR impact of the intervention measured. Article information will be charted in an excel spreadsheet. Following the charting process, authors will identify articles to be included in the iAM.AMR Collection of Epidemiologically Derived Associations with Resistance (CEDARS) database. These articles must have an extractable "factor" associated with AMR Enterococcus spp, presented as an odds ratio or prevalence comparison (in text or graph) specific to an "intervention" and "control." The study must use non-selective media and have the total (N) provided for the intervention and control. Relevant data will be collected and coded into an Access (V2103, Microsoft) database. Meta-analysis will occur if two articles examine the same factor and are comparable in the research design and study population.
- ItemOpen AccessToxicity Assessment and Effects of Molecular Structure of Naphthenic Acids on Mode of Toxic Action in Lymnaea stagnalis(2017) Marasco, Kaitlin; Wildering, Willem; Chua, Gordon; Turner, Ray; Vijayan, Matt; Smits, JuditNaphthenic acids (NAs) are a diverse group of carboxylic acids often associated with the toxicity of tailings, a petrochemical waste product generated by oil sands mining. NAs can be found in the acid extractable organic fraction (AEO) of the liquid component of tailings, oil sands process-affected water (OSPW). To assess the potential toxicity of AEO and individual NAs, a hatching bioassay using imaging and computer analysis was developed using the pond snail Lymnaea stagnalis. AEO dose-dependently decreased Lymnaea hatching percentage as well as delayed hatching at 25-50 mg/L AEO. This study also aimed to assess the effect different NA molecular architectures may have on NA toxicity. Varying degrees of hatching success and hatch time delays were observed following exposure of Lymnaea embryos to individual model NAs with diverse molecular structures. Molecular shape and dipole architecture of NAs may be an important factor in the ability of certain NAs to insert in biological membranes, indicating a possible relationship between NA structure and the degree of severity of NA toxicity. Finally, this study explored the hypothesis that the mechanism of NA toxicity is due to “narcosis” (which involves plasma membrane disruption via insertion of NAs’ hydrophobic alkyl tail) and may work in conjunction with PLA2-mediated fatty acyl hydrolysis. While the data did not support this hypothesis, it uncovered evidence for a hitherto unrecognized biological action of NAs; the binding of fatty acid-binding proteins.