Browsing by Author "Checkley, Sylvia L."

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    Characterization and Comparison of Antimicrobial Resistance Phenotypes and Genotypes in Enterococcus spp. Isolated from Cattle Feces, Poultry Feces, and Beef and Poultry Retail Meats in Alberta, Canada, Related to Surveillance
    (2020-12-15) Rogers, Lindsay A; Checkley, Sylvia L.; Cork, Susan C.; McAllister, Tim A.; Zaheer, Rahat; Liljebjelke, Karen
    Enterococcus spp. are ubiquitous in the gastrointestinal tracts of animals and the environment and are important nosocomial pathogens. The use of antimicrobials in food producing animals along with the ability of enterococci to acquire antimicrobial resistance leads to concern about the contamination of retail meat products with antimicrobial resistant Enterococcus spp. from food production animals. The concern is that the antimicrobial resistant enterococci from retail meats may transfer to the human population and cause disease. In addition, increased resistant enterococci and genes in the environment may increase overall risk their transfer to humans. The objective of this thesis was to contribute to the surveillance of Enterococcus spp. from food animal production through a scoping review and the characterization of enterococcal isolates from surveillance in Alberta, Canada using whole genome sequencing. The scoping review followed PRISMA and JBI guidelines and included 57 articles, of which 87.7% identified E. faecium and the majority included isolates from human clinical or commensal samples. Significant findings from the articles included the increasing prevalence of vancomycin-resistant enterococci in hospitals and the importance of surveillance for enterococci in humans, animals, and the environment. E. faecium (n=107) and E. faecalis (n=132) were isolated from research and surveillance samples previously collected from beef cattle feces, broiler poultry feces, and beef and poultry retail meats in Alberta, Canada. Antimicrobial susceptibility and whole genome sequencing with comparative genomics were performed on the isolates. The odds of multiclass resistance in E. faecium was about 3 times that of E. faecalis after adjusting for sample source and clustering (OR 3.09; 95% CI: 1.48, 6.48). In contrast, a higher number of virulence genes were found in E. faecalis as compared to E. faecium. Generally antimicrobial resistance genotype showed good sensitivity and specificity for use as a presumptive predictor of the corresponding phenotype. Comparative genomic analyses showed distinct clustering within sample source for E. faecium, but not for E. faecalis. Overall, this work supports the usefulness of whole genome sequencing for surveillance of Enterococcus spp. and further characterizes a population of E. faecium and E. faecalis isolates from surveillance programs in Alberta, Canada.
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    Climate Change and Range Expansion of Protostrongylid Nematodes in the Canadian Arctic
    (2018-09-19) Kafle, Pratap; Kutz, Susan; Checkley, Sylvia L.; Massolo, Alessandro; Lejeune, Manigandan
    Through this doctoral research, I aimed to determine the diversity, distribution and abundances of protostrongylids in muskoxen and caribou from several sites in Subarctic and Arctic Canada and investigate the northward range expansion of Umingmakstrongylus pallikuukensis and Varestrongylus eleguneniensis in relation to Arctic warming. I first developed morphological keys to differentiate the first stage larvae (L1) of U. pallikuukensis, V. eleguneniensis and Parelaphostrongylus andersoni. This enabled me to identify L1 to the species level and determine the intensity of infections. Secondly, I analyzed over 1600 muskox and caribou fecal samples, and 40 muskox lung samples to determine the diversity, distribution and abundance patterns of protostrongylids. I found that the diversity and abundance of protostrongylids varied geographically. Both U. pallikuukensis and V. eleguneniensis had expanded their ranges and increased in abundance on Victoria Island between 2013 and 2017, with U. pallikuukensis expanding its range faster than V. eleguneniensis. I also detected P. andersoni in the Dolphin and Union caribou herd. In the third part of the study, I determined the important life cycle parameters for U. pallikuukensis and V. eleguneniensis through lab experiments. I demonstrated that V. eleguneniensis has higher thermal requirements for larval development inside the intermediate host, a shorter prepatent and patent period, and lower fecundity than U. pallikuukensis. Based on these findings I hypothesized that higher thermal requirements and lower fecundity might be limiting the rate and extent of range expansion for V. eleguneniensis. Finally, to map the thermal niches of U. pallikuukensis and V. eleguneniensis from 1980 through to 2017, I parametrized a process-based mechanistic model (Degree-day model) using data derived from the lab experiments, the literature, and high-resolution temperature data from a regional climate model. Models indicated a substantial expansion in the zones of climatic suitability for both parasites during the study period with the realized niches of both parasites lagging behind the expansion of their thermal niches. This work contributes to the field of Arctic parasitology by providing simple and effective diagnostic tools for protostrongylids, and adding to the present knowledge on diversity, distribution, abundance as well as ecology of protostrongylid nematodes. Finally, by using a multifaceted approach to investigate the patterns of parasite emergence in the Arctic, this study contributes to the overall understanding of disease emergence in a rapidly changing ecosystem.
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    Exploring Antimicrobial Resistance in Escherichia coli: A Scoping Review Protocol Comparing Antibiotic-free and Conventionally Raised Beef Cattle in North America
    (2023-07-10) Sanguinetti, Verónica María; Davies, Willow-Bethany O.; Ganshorn, Heather; Checkley, Sylvia L.
    Escherichia coli is a gram-negative bacterium commonly found in the human and animal gastrointestinal tract. Beef cattle are considered reservoirs, although some strains can trigger diarrhea in newborn calves. Certain strains, such as Shiga toxin-producing E. coli (STECs), pose health risks in humans and animals [2]. Antibiotic resistance in E. coli is a significant concern in human and veterinary medicine, as it can lead to treatment challenges and transmission to other bacteria [3]. Canada and the United States Drug-Resistant Index score lie among the lowest ten countries, and this can be associated with the wide use of narrow-spectrum penicillin [4]. Strains encode accessory resistance and are likely resistant to multiple antibiotic classes [5]. Evidence suggests that E. coli can be resistant to more than one antimicrobial drug, and the most common resistance phenotypes are older drugs such as tetracycline, sulfonamide, streptomycin, and ampicillin [6]. Antibiotic-free beef cattle certifications have been implemented to address antimicrobial resistance concerns in the food chain [7]. However, the evidence regarding the prevalence of resistant bacteria in antibiotic-free production systems is limited. Antimicrobial resistance in Escherichia coli represents a significant One Health issue, highlighting the urgent need to explore alternatives, such as limiting the use of antibiotics in beef cattle production to therapeutic treatments, to mitigate the spread of resistant strains and safeguard human and animal health [8]. Objectives The objective of this study is to lead a scoping review to define the range of existing research in the area, individualize research gaps and suggest areas important for future research studies about Antimicrobial Resistance in Escherichia coli of Antibiotic-free and Conventionally Raised Beef Cattle from North America. Methods This scoping review has been designed following the JBI Reviewer’s Manual [9] and the PRISMA ScR guidelines for scoping reviews [1] to report it and the search question was constructed using the PICO framework. We will search the literature for peer-reviewed articles using the following databases: CAB Abstracts, BIOSIS Previews, Environmental Complete, the Web of Science’s Science Citation Index and Emerging Sources Citation Index. The grey literature search will include a search of ProQuest Dissertations and the websites of relevant government departments, agencies, and industry groups. Two independent reviewers will screen the articles at the title, abstract, and full-text levels.
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    Exploring Antimicrobial Resistance in Escherichia coli: A Scoping Review Protocol Comparing Antibiotic-free and Conventionally Raised Beef Cattle in North America
    (Veterinary Medicine, Libraries and Cultural Resources, University of Calgary, 2023-06-20) Sanguinetti, Veronica Maria; Davies, Willow-Bethany O.; Ganshorn, Heather; Checkley, Sylvia L.
    Escherichia coli is a gram-negative bacterium commonly found in the human and animal gastrointestinal tract. Antibiotic resistance in E. coli is a significant concern in human and veterinary medicine, as it can lead to treatment challenges and transmission to other bacteria [3]. Antibiotic-free beef cattle certifications have been implemented to address antimicrobial resistance concerns in the food chain [7]. Objectives: To define the range of existing research in the area, individualize research gaps and suggest areas important for future research studies about Antimicrobial Resistance in Escherichia coli of Antibiotic-free and Conventionally Raised Beef Cattle from North America. Methods: This scoping review has been designed following the JBI Reviewer’s Manual and the PRISMA ScR guidelines for scoping reviews. The search question was constructed using the PICO framework. We will search the literature for peer-reviewed articles using the following databases: CAB Abstracts, BIOSIS Previews, Environmental Complete, the Web of Science’s Science Citation Index and Emerging Sources Citation Index. The grey literature search will include a search of ProQuest Dissertations and the websites of relevant government departments, agencies, and industry groups. Two independent reviewers will screen the articles at the title, abstract, and full-text levels.
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    Identification and Distribution of Tick Species in Cattle in Eastern Bhutan
    (2020-11-04) Namgyal, Jamyang; Cork, Susan Catherine; Checkley, Sylvia L.; Lysyk, Timothy J.; Ribble, Carl S.; Russell, Margaret L.; Cork, Susan Catherine
    Tick infestation is the most reported parasitological problem in cattle in Bhutan. Its negative impacts on the health and production of cattle affect the livelihoods of resource-poor subsistence farmers. However, the current knowledge of tick species diversity, infestation prevalence, geographic distribution, and farmers’ perception on tick prevention and control practices is limited. Therefore, the objectives of this research were to 1) determine the presence, diversity and infestation prevalence of tick species in cattle in two districts of eastern Bhutan using a targeted field survey; 2) model the habitat suitability of selected tick species identified in these two districts using the MaxEnt modeling approach; and 3) assess the knowledge, attitude, and practices (KAP) of ticks and tick-borne diseases (TBDs) among cattle farmers in a selected area of eastern Bhutan. In May and June 2019, 3600 live adult ticks were collected from 240 cattle and morphologically identified to the species level. In June 2019, 246 cattle owners were interviewed using a structured questionnaire. Four genera and six species of ticks were found. These were Rhipicephalus microplus (Canestrini) (70.2%), Rhipicephalus haemaphysaloides Supino (18.8%), Haemaphysalis bispinosa Neumann (8.2%), Haemaphysalis spinigera Neumann (2.5%), Amblyomma testudinarium Koch (n=7), and an unidentified species of Ixodes (n=1). For all tick species except A. testudinarium and Ixodes sp., the high altitude northeastern part and the low altitude southernmost part of the study area were predicted as areas with a very low probability of tick(s) presence. The KAP study identified only 52% of the farmers with adequate knowledge about ticks as vectors of diseases and 36% with a favorable attitude toward tick control programs. The findings from this research are expected to guide the planning and implementation of effective tick prevention and control measures in Bhutan.
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    Improved Wildlife Health and Disease Surveillance through the Combined Use of Local Knowledge and Scientific Knowledge
    (2018-07-30) Tomaselli, Matilde; Checkley, Sylvia L.; Kutz, Susan; Elkin, Brett; Ribble, Carl Steven; Gerlach, S. Craig
    Effective health and disease surveillance of wildlife populations is necessary for evidence-based wildlife management and conservation, as well as for the protection of human and animal health. Wildlife surveillance, however, is often challenging to undertake due to numerous limitations associated with gathering and interpreting field data from free-ranging populations. This thesis illustrates a novel approach to wildlife health surveillance which overcomes these limitations by capitalizing on the experiential-based knowledge of resource users documented with participatory methods and applied in combination with conventional surveillance methods. This participatory approach was developed and applied in – and with the active participation of – the community of Cambridge Bay in the Canadian Arctic to improve veterinary surveillance of muskoxen (Ovibos moschatus). In the North, harvesting muskoxen improves food security, the local economy and is connected to local indigenous culture and traditions. In Cambridge Bay, an accurate understanding of muskoxen health was urgently needed due to local concerns of possible declines and disease emergence. A participatory surveillance program composed of different activities which drew on both local knowledge and scientific knowledge was developed. Semi-structured interviews of key informants applied participatory epidemiology techniques to document local knowledge on muskox health, while scientific knowledge was generated by testing samples collected through collaboration with hunters, field investigations, and available archives. Local knowledge of key informants proved critical for filling historic and contemporary knowledge gaps on muskox health, including data on demography, morbidity, mortality and body condition, highlighting its potential to serve as an early warning system for detecting changes in wildlife health. Local knowledge informed the design of targeted scientific studies, and when combined the two knowledge systems reduced the overall uncertainty of the surveillance output. Participation of local resource users throughout the study enabled development of a surveillance adapted to the local context and needs, including customization of surveillance interventions. In addition to producing important information for Cambridge Bay and the local muskox population, this thesis develops the field of participatory wildlife surveillance by illustrating the broader applicability of this approach for enhancing the capacity for health surveillance of other wildlife species, both harvested and not, and in other settings.
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    Indigenous Knowledge and Biomarkers of Physiological Stress Inform Muskox Conservation in a Rapidly Changing Arctic
    (2020-12-11) Di Francesco, Juliette; Kutz, Susan J.; Checkley, Sylvia L.; Gerlach, S. Craig; Mastromonaco, Gabriela F.; Cooke, Steven J.; Pavelka, Mary Susan McDonald
    Glucocorticoids play a key role in energy regulation and are mediators of the physiological stress response in mammals. Their concentrations are commonly measured in wildlife to understand the effects of environmental changes and anthropogenic disturbances, but their use is associated with multiple challenges and there is a need for species-specific validation. Muskoxen (Ovibos moschatus) are an essential part of the Arctic ecosystem, where they have a strong economic, nutritional, and sociocultural value for Indigenous communities. Recent population declines and mortality events suggest that muskoxen may be threatened by the multiple environmental changes and associated stressors to which they are increasingly exposed. Overall, I sought to establish fecal glucocorticoid metabolites (FGM) and qiviut (woolly undercoat) cortisol as biomarkers of physiological stress in muskoxen, and to apply these tools together with Indigenous knowledge (IK) to explore potential causes and patterns of physiological stress in wild muskoxen. Through two repeated pharmacological challenges in captive muskoxen, I showed that qiviut cortisol and FGM levels accurately reflect long-term (over the period of the hair’s growth) and short-term changes in circulating cortisol, respectively. I also demonstrated that changes in circulating cortisol are not reflected in qiviut in the absence of growth and highlighted variations across body regions, significant differences in qiviut segments over time, and differences between shed and unshed qiviut. Additionally, I documented IK which provided novel insights on the potential stressors of muskoxen and their specific importance. Finally, I identified important factors influencing qiviut cortisol (sex, geographical location, season, and year), and found associations between qiviut cortisol and marrow fat and lungworm intensity. Findings were interpreted in part collaboratively with IK holders. This work has advanced our understanding of glucocorticoid deposition and stability in hair, and of the limitations and challenges associated with hair glucocorticoid interpretation. It has highlighted the multiple benefits of incorporating IK in wildlife endocrinology studies and provided a framework for doing so. Finally, identifying factors associated with qiviut cortisol is a key step to simultaneously investigating the causes and consequences, both at the individual and population levels, of physiological stress in muskoxen.
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    Investigating Perceptions of Well Water Quality in Rural Alberta
    (2019-07-17) Munene, Abraham; Hall, David C.; Checkley, Sylvia L.; Lockyer, Jocelyn M.; Massolo, Alessandro
    Adequate access to safe drinking water is important in maintaining public health. Over 400,000 rural Albertans use well water for domestic purposes. The current policy on the management of private water wells requires well owners be responsible for their own water well management and well water quality. Therefore, the decision of when to test well water, what to test for, and what treatments to use to safeguard or improve water quality, lies with well owners. The purpose of this thesis was to 1. Describe the perceptions, knowledge, and beliefs rural Albertan residents have of well water quality and whether they associate livestock farming with water well contamination. 2. Identify the barriers faced by water well owners with respect to implementing well water stewardship practices. 3. Identify factors associated with water well stewardship practices (i.e., testing and treatment). A mixed methods study was completed which included a systematic review, interviews with well owners, a questionnaire survey of well owners, and collection of well water samples to assess for microbiological indicators of drinking water contamination. Thematic analyses were used to understand factors shaping perceptions of well water quality and identify factors influencing water testing behaviour as viewed through the lens of the Health Belief Model. Descriptive statistics and logistic regression analyses were used to understand the characteristics of well owners, well use, well stewardship practices, as well as investigate associations between independent variables and well stewardship practices. Barriers to treatment included a lack of awareness of what treatments to use. Increased education and awareness may be important to increase the adoption of well stewardship practices. Several factors were found to influence perceptions of well water quality. Furthermore, well owners described issues such as low perceived susceptibility to water well contamination and logistical barriers when submitting water samples for testing.
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    Investigation of the Co-occurrence of Zinc and Copper Resistance and Antimicrobial Resistance in Escherichia coli from Beef Cattle Production Systems
    (2020-09-21) Guardado Servellón, Fernando Joaquín; Liljebjelke, Karen A.; Checkley, Sylvia L.; Turner, Raymond Joseph; Harrison, Joe J.
    The present set of studies was directed towards determining the relationship between zinc (Zn) and copper (Cu) resistance and antimicrobial resistance in Escherichia coli from beef cattle production systems. First, a spectrophotometric assay was developed to properly assess the resistance levels of both Zn and Cu in Escherichia coli. The method was standardized for E. coli and it displayed a good linear dynamic range (R2>0.95), and precision (RSD< 35% in all but three Zn concentrations). The MIC for the E. coli reference strain (ATCC 25922) were 2.78 mol/ml and 8.41 mol/ml for Zn and Cu respectively. In the second study, we determined antimicrobial phenotypes and the Zn and Cu resistance levels for E. coli isolates from environmental samples obtained from W.A Ranches. The samples analyzed had a low prevalence of antimicrobial resistance as 31/39 isolates were susceptible to all the antimicrobials tested using the disc diffusion method. The most common resistance was ampicillin (4/39) and amoxicillin-clavulanic acid (4/39), with one isolate being resistant to doxycycline. All the isolates resistant to ampicillin were also resistant to amoxicillin-clavulanic acid. The isolates were then tested for Zn and Cu resistance using the assay developed. Seven of the eight isolates with resistant or intermediate antimicrobial resistance patterns showed higher optical density (OD) in the Zn and Cu resistance spectrophotometric assay when compared to the reference strain. Fisher’s exact test was conducted to compare antimicrobial-resistant (all antimicrobials) and susceptible isolates in their resistance to Zn and Cu, with the results showing that the antimicrobial-resistant isolates are also more likely to have a higher resistance to Zn (p value<0.001) and Cu (p value=0.013) as indicated by higher absorbance units (AU). A Principal Component Analysis showed the clustering of 6/8 antimicrobial-resistant isolates based on the Zn and Cu resistance meaning that resistance to these metals might be an indicator of antimicrobial resistance.
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    Modeling of Antimicrobial-Resistant Enterococci Exposure Risks in Canadian Beef Cattle Production System Using Existing Data
    (2024-04-17) Strong, Kayla; Checkley, Sylvia L.; Checkley, Sylvia L.; Kastelic, John Patrick; Otto, Simon James G.; Reid-Smith, Richard; Waldner, Cheryl Lynne; Lhermie, Guillaume; Noyes, Noelle
    Antimicrobial resistance occurs when microbes change, and antimicrobials previously used to treat them are no longer effective. Antimicrobial resistance presents a global risk to health and food safety, with previously treatable infections becoming increasingly costly and challenging. Antimicrobial resistance is a quintessential One Health issue, given its impact and drivers across human, animal, and environmental health, and requires transdisciplinary interpretations and solutions. This thesis considers methods of risk interpretation using a case study of antimicrobial-resistant Enterococcus spp. within Canadian beef production systems. Five objectives were considered: (1) to identify factors associated with antimicrobial-resistant enterococci within Canadian beef production systems; (2) to construct an integrated assessment model for interpretation of factors potentially associated with antimicrobial-resistant enterococci; (3) to construct a risk profile for interpretation of risks associated with antimicrobial-resistant enterococci in Canadian beef; (4) to construct a Bayesian model for interpretation of enterococci resistance within beef production; and (5) to describe integrated strengths and weaknesses of modeling approaches. Factors assessed for association with antimicrobial-resistant Enterococcus spp. within Canadian beef production systems included antimicrobial and nutritional supplement administration to cattle, environmental factors, and type of processing plant. Resistance trends were often nuanced to unique gene and phenotypic resistance. Patterns varied by species of enterococci. When data were available, the integrated assessment model utilized crude odds ratios extracted from identified factors. Limited data for baseline seeding and factor inclusion limited the model's interpretability. Recommendations and best practices are proposed for future model applications. The risk profile was developed to meet the Codex 77 guidelines and demonstrated the scarce evidence of enterococci resistance transference from beef products, and limited human pathogenicity of enterococci from foodborne consumption. The risk profile highlighted the need for Canadian surveillance studies of enterococci in food products for more informed decision-making. The Bayesian model incorporated available evidence with current estimates of enterococci resistance trends, integrating expert opinion within the model. The model suggests that less than 0.3% of beef products carry antimicrobial-resistant E. faecalis. Individual models and risk discussions uniquely fill niches in resistance discussions and interpretations but were insufficient for providing a holistic interpretation required by stakeholders across the production chain. Drawing findings from multiple reports supported a better understanding and enhanced decision-making.
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    Perceptions of Risk Factors and Mitigating Strategies for Water Related Zoonotic Diseases on Small-Scale Integrated Farms in Vietnam
    (2016) Le, Quynh Ba; Hall, David Clement; Cork, Susan Catherine; Schaetzl, Hermann; Checkley, Sylvia L.; Ribble, Carl Steven; Russell, Margaret Leora; Armstrong, Glen Douglas; Fenwick, Stanley Gordon
    Small-scale integrated (SSI) farming is a common agricultural model in Vietnam. However, SSI farmers use contaminated water, have no access to hygienic latrines, and have very limited awareness about water quality or environmental sanitation. There are potential interactions in the context of this model that may result in transmission of water-related zoonotic diseases (WRZD). The government of Vietnam plans to restructure the agriculture system by 2020. Study of the model in the context of water and public health can contribute to shaping the future of Vietnam’s agriculture system. I used a cross-sectional study to develop a socioeconomic profile of SSI farmers, examine their perceptions of risk factors for transmitting WRZD, assess basic microbial and related quality of water used on their farms, and explore factors that are associated with on-farm water quality as well as SSI farmers’ engagement in strategies to reduce transmission of WRZD. Data were collected from 600 SSI farms in two provinces in North and South Vietnam. The typical profile of the participating SSI farmers was a 45 year old married individual with two children, seven years of formal education, low income (c. $1200 p.a.), and nine years farming experience. Most SSI farmers had basic awareness of avian influenza prevention, but very limited awareness of WRZDs such as Escherichia coli (E. coli). Water on the majority of SSI farms had unacceptable levels of E. coli and was significantly associated with SSI farmers’ characteristics and perceptions (e.g., years of farming, number of poultry on a farm, and perceived self-efficacy in managing livestock). SSI farmers’ characteristics and perceptions (e.g., education, income, and perceived self-efficacy in managing livestock) influenced their engagement in strategies to reduce transmission of WRZD. Future research and policies in Vietnamese agriculture need to consider a transdisciplinary approach (e.g., EcoHealth) to increase SSI farmers’ awareness of water public health and their engagement in mitigating strategies for WRZD transmission. Consideration for the health of farmers, animals, and the environment should be interwoven with livestock production and be an equally important part of a holistic integrated SSI farming model.