Bacterial genomics reveal the complex epidemiology of an emerging pathogen in Arctic and boreal ungulates

Northern ecosystems are currently experiencing unprecedented ecological change, largely driven by a rapidly changing climate. Pathogen range expansion, and emergence and altered patterns of infectious disease, are increasingly reported in wildlife at high latitudes. Understanding the causes and consequences of shifting pathogen diversity and host-pathogen interactions in these ecosystems is important for wildlife conservation, and for indigenous populations that depend on wildlife. Among the key questions are whether disease events are associated with endemic or recently introduced pathogens, and whether emerging strains are spreading throughout the region. In this study, we used a phylogenomic approach to address these questions of pathogen endemicity and spread for Erysipelothrix rhusiopathiae, an opportunistic multi-host bacterial pathogen associated with recent mortalities in arctic and boreal ungulate populations in North America. We isolated E. rhusiopathiae from carcasses associated with large-scale die-offs of muskoxen in the Canadian Arctic Archipelago, and from contemporaneous mortality events and/or population declines among muskoxen in northwestern Alaska and caribou and moose in western Canada. Bacterial genomic diversity differed markedly among these locations; minimal divergence was present among isolates from muskoxen in the Canadian Arctic, while in caribou and moose populations, strains from highly divergent clades were isolated from the same location, or even from within a single carcass. These results indicate that mortalities among northern ungulates are not associated with a single emerging strain of E. rhusiopathiae, and that alternate hypotheses need to be explored. Our study illustrates the value and limitations of bacterial genomic data for discriminating between ecological hypotheses of disease emergence, and highlights the importance of studying emerging pathogens within the broader context of environmental and host factors

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

IntroductionAntimicrobial 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 Enterococcus spp. applicable to the Canadian farm-to-fork beef continuum.MethodsFive databases (MEDLINE, BIOSIS, Web of Science, Embase, and CAB Abstracts) were searched for articles published from January 1984 to March 2022, using a priori 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, in vivo research, describing an intervention or exposure, and specific to Enterococcus spp.ResultsOut 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 (n = 16), raised without antimicrobials (n = 6), metal supplementation (n = 4), probiotics supplementation (n = 3), pen environment (n = 2), essential oil supplementation (n = 1), grass feeding (n = 1), therapeutic versus subtherapeutic antimicrobial use (n = 1), feeding wet distiller grains with solubles (n = 1), nutritional supplementation (n = 1) and processing plant type (n = 1). Results were included irrespective of their quality of evidence.DiscussionComparability 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.Systematic Review Registration[http://hdl.handle.net/1880/113592

Iqaluktutiaq Voices: Local Perspectives about the Importance of Muskoxen, Contemporary and Traditional Use and Practices + Supplementary Appendices S1–S5 (See Article Tools)

Understanding human-wildlife relationships and interactions is crucial to implementing policies and practices related to wildlife and public health that are locally relevant and adapted to local communities and needs. With the goal of informing a community-based participatory muskox health surveillance system in the community of Iqaluktutiaq (Cambridge Bay) on Victoria Island, Nunavut, Canada, we explored the importance of muskoxen for community residents, their relevance for local food security, and the relationships and interactions between Iqaluktutiamiut and muskoxen. We investigated these themes through individual interviews of 30 community members identified as muskox experts by local organizations. Results were finalized and refined with 26 interviewees in feedback sessions. For Iqaluktutiaq residents, muskoxen have nutritional, economic, sociocultural, and environmental importance. The decline of muskoxen documented locally has a multidimensional impact on the community, with negative effects on all the domains explored, from food security to the integrity of the cultural system. Descriptions of subsistence and commercial harvesting and butchering practices are an asset for the successful implementation of participatory muskox health surveillance activities (e.g., hunter-based sampling), as well as for interpretation of derived data (e.g., local knowledge on muskox diseases). Knowledge of specific harvesting practices that might increase exposure to zoonotic agents is also relevant for designing targeted strategies to mitigate public health risks. This research underlines how careful examination of the human-wildlife context through local perspectives can benefit wildlife health surveillance, public health, and wildlife co-management outcomes.Comprendre les relations et interactions entre les humains et la faune est essentiel à la mise en oeuvre de politiques et de pratiques liées à la faune et à la santé publique pertinentes du point de vue local et adaptées aux communautés et aux besoins de l’endroit. Dans le but d’informer un système communautaire participatif de surveillance de la santé des boeufs musqués dans la communauté canadienne d’Iqaluktutiaq (Cambridge Bay) sur l’île Victoria, au Nunavut, nous avons étudié l’importance du boeuf musqué pour les résidents de la région, leur importance en matière de sécurité alimentaire locale, ainsi que les relations et les interactions entre les Iqaluktutiamiut et le boeuf musqué. Nous avons étudié ces thèmes au moyen d’entrevues individuelles auprès de 30 membres de la communauté considérés comme des experts du boeuf musqué par des organisations locales. Les résultats ont été finalisés et affinés dans le cas de 26 interviewés ayant participé à des séances de commentaires. Pour les résidents d’Iqaluktutiaq, les boeufs musqués revêtent une importance nutritionnelle, économique, socioculturelle et environnementale. Le déclin du boeuf musqué, documenté localement, a des incidences multidimensionnelles sur la communauté, dont des effets négatifs sur tous les domaines explorés, allant de la sécurité alimentaire à l’intégrité du système culturel. La description de la chasse de subsistance et des pratiques commerciales d’abattage et de dépeçage est un atout pour la mise en oeuvre réussie d’activités participatives de surveillance de la santé des boeufs musqués (comme l’échantillonnage en fonction des chasseurs) et pour l’interprétation des données dérivées (comme les connaissances locales sur les maladies des boeufs musqués). La connaissance des pratiques d’abattage susceptibles d’accroître l’exposition aux agents zoonotiques est également pertinente à la formulation de stratégies ciblées visant à atténuer les risques pour la santé publique. Cette recherche fait ressortir à quel point l’examen approfondi du contexte des relations entre les humains et la faune grâce aux perspectives locales peut profiter à la surveillance de la santé de la faune, à la santé publique et à la cogestion de la faune

Antimicrobial Resistance in Escherichia coli Recovered from Feedlot Cattle and Associations with Antimicrobial Use.

The objectives of this study were to estimate the prevalence of antimicrobial resistance (AMR) and to investigate the associations between exposures to antimicrobial drugs (AMDs) and AMR in fecal non-type specific Escherichia coli (NTSEC) recovered from a large population of feedlot cattle. Two-stage random sampling was used to select individually identified cattle for enrollment, which were sampled at arrival and then a second time later in the feeding period. Advanced regression techniques were used to estimate resistance prevalences, and to investigate associations between AMD exposures in enrolled cattle and penmates and AMR identified in NTSEC recovered from the second sample set. Resistance was most commonly detected to tetracycline, streptomycin, and sulfisoxazole, and was rarely identified for critically important AMDs. All cattle were exposed to AMDs in feed, and 45% were treated parenterally. While resistance prevalence generally increased during the feeding period, most AMD exposures were not significantly associated with AMR outcomes. Exposures of enrolled cattle to tetracycline were associated with increased resistance to tetracycline and trimethoprim sulfa, while beta-lactam exposures were associated with decreased likelihood of detecting streptomycin resistance. Pen-level AMD exposure measures were not associated with resistance outcomes. These findings suggest that tetracycline treatment of feedlot cattle can be associated with modest increases in risk for recovery of resistant NTSEC, but the numerous treatments with an advanced macrolide (tulathromycin) were not associated with detectable increases in resistance in NTSEC. All cattle were exposed to in-feed treatments of tetracycline and this could limit the ability to identify the full impact of these exposures, but these exposures varied for enrolled cattle varied, providing an opportunity to evaluate a dose response. While AMD exposures were not associated with detectably increased risks for resistance to critically important AMDs, rare resistance outcomes and infrequent exposure to other important AMDs (e.g., cephalosporins) limited our ability to rigorously investigate questions regarding factors that can influence resistance to these important AMDs