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Elucidating the involvement of catalase in the oxidative stress-induced antibiotic susceptibility, physiology, and virulence of Acinetobacter baumannii
Get PDFAcinetobacter baumannii is a Gram-negative opportunistic pathogen that has a high incidence of infection among individuals with compromised immune systems. Currently, 80% of all hospital-acquired A. baumannii infections are multidrug-resistant to at least three different families of antibiotics, including last-line treatments. Therefore, there is an urgent need for effective therapeutic strategies which requires a thorough understanding of bacterial mechanisms of resistance. Infections caused by A. baumannii are difficult to eradicate, not only due to its extensive antibiotic resistance, but also due to its ability to adapt and persist against harsh environmental and host stressors; a prominent one being oxidative stress via the generation of reactive oxygen species (e.g., H2O2). A. baumannii is known to employ protective enzymes such as catalases to degrade hydrogen peroxide to water and oxygen. Mutants with single- and double-deletions of the catalase genes katG and katE, and their respective complements, were subjected to phenotypic assays and omics analysis to help us elucidate the overall contribution of this oxidative stress response in A. baumannii.
The catalase mutants exhibited reduced fitness in rich medium, which was exacerbated when supplemented with H2O2. They also displayed differential antibiotic susceptibilities that were presumed to be mediated by the resistance-nodulation-division (RND) efflux pumps. Further assessment of overall efflux activity and expression profile of the RND efflux pump-encoding genes inferred alternative antibiotic resistance mechanism(s), most likely secondary to oxidative stress. Moreover, as H2O2 is generated by the innate immune cells as a pathogen containment and clearing strategy, we were prompted to examine bacterial virulence with a macrophage survivability assay. While the absence of catalases KatG and KatE sensitized A. baumannii to oxidative stress, their involvement in the virulence of this bacterium proved to be complicated. Catalase mutants showed a surprising persistence and possibly adaptive response in phagocytic macrophages. Transcriptomic and genomic sequencing data revealed differential expression of several genes associated with information storage and processing, virulence determinants, and biomolecules transport and metabolism. Together, these observations demonstrated the complex involvement of catalases beyond their primary function of ROS detoxification. Additionally, we also created visualization tools of fluorescence plasmids to aid in the research and study of A. baumannii.October 202
We’re here too: child health information-seeking experiences and preferences of Red River Métis families – a qualitative study
Get PDFBackground
Red River Métis families need access to meaningful and appropriate resources when their children are sick. At the invitation of the Manitoba Métis Federation (MMF) to partner in this research, our aim was to understand Red River Métis parents’ experiences and preferences for seeking child health information when their child is acutely ill, to inform the adaptation of existing parent resources.
Methods
A qualitative descriptive approach underpinned by a participatory paradigm guided this study. Semi-structured interviews were conducted with 19 Red River Métis parents and Elders via Zoom or telephone. An inductive thematic analysis approach was used to explore patterns and themes across the data.
Results
Analysis generated four themes: (1) We’re here too; (2) We are not all the same; (3) Finding trustworthy information; and (4) Information needs to be widely available. Red River Métis pride was prominent in the results. Parents provided tangible ways to modify existing parent resources, including adding information on how to access Elders, healers and/or traditional medicines and showing different family structures, transport, living situations, Métis names, and incorporating Métis languages. While most parents reported looking for child health information online, they also stressed the need to provide multiple options, including information sheets, recognizing that parents seek information in different contexts. Parents also emphasized the importance of accessible, safe spaces to find child health information, including local schools, community centres, healthcare organizations and the MMF.
Conclusion
There is a lack of child health information created specifically for Red River Métis families. The development of this information can support their information needs and preferences and the ongoing efforts to revitalize Red River Métis culture and language. Study findings will inform the adaptation and dissemination of existing child health resources to ensure they reflect Red River Métis parents’ information needs and preferences. This research is a critical step in addressing an identified need for Red River Métis families to have culturally relevant and meaningful child health resources, and in the pursuit of equitable care for all children in Canada
Evaluation of silver diamine fluoride at arresting carious lesions in irradiated tooth structures.
No full textObjectives: For oncologic patients undergoing head and neck radiotherapy (HNRT), the rapid and chronic progression of radiation-related caries (RRCs) signifies an abrupt deterioration in oral health. This study investigated the in vitro effectiveness of silver diamine fluoride (SDF) at arresting carious lesions in irradiated teeth, and compared to the preventive topical therapy being clinically implemented at the Dental Oncology Program at the Northeast Cancer Centre of Health Sciences North.
Methods: Randomly assigned extracted tooth samples were subjected to in vitro irradiation comparable to typical HNRT treatment protocols, followed by a series of controlled chemical pH cycling to mimic artificial lesions. Experimental groups (N = 15) comprised of: controls (N = 10); positive control subjected to in vitro irradiation only; and treatment applications of: SDF; and nano medical hydroxyapatite remineralization paste with topical neutral fluoride gel (mHAP+F).
Results: Baseline Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy identified characteristic hydroxyapatite (HAp) functional groups: hydroxyl; carbonate (CO32-); and phosphate (PO43-). pH cycling suggested water removal, and relative CO32- and PO43- loss. It was clear from X-ray Photoelectron Spectroscopy survey analyses of major minerals that SDF altered enamel microstructure simply with application; fluorapatite (FAp) formation at 10 and 100nm, with calcium fluoride at 30nm. While mHAP+F, which inundated the surface with calcium at baseline, remained unchanged and formed increased FAp across profile depths. Interestingly, Scanning Electron Microscopy images of both treatments demonstrated restoration of surface destruction associated with irradiated and demineralized enamel. This restoration remained evident with pH cycling. Energy-Dispersive X-ray Spectroscopy spectra confirmed large, bright clusters of variously sized silver precipitates on the surface of group SDF. Additional analysis verified atomic percentage (At.%) F after mHAP+F application. 3-way ANOVA comparison showed a significant interaction of At.%Ag and O between group and with condition (<0.0001). Mechanical properties were investigated with Vickers hardness, demonstrating SDF significantly increased surface hardness. However, when comparing between groups, there was no significant difference. Findings of Micro-Computed Tomography indicated no difference in Relative Enamel Density.
Conclusion: SDF has equal in vitro benefits in the prevention and arresting RRCs as current mHAP+F treatment. This research provides evidence worthy of the recommendation for further investigations and future clinical studies.May 202
Macroalgae distribution among varying glacial fjords as an indicator of light and nutrient availability
Get PDFArctic macroalgae (kelp) are critical primary producers, contributing significantly to a wide variety of ecosystem services. Kelp extent has been predicted to increase due to decreasing sea ice cover that increases light reaching the coastal ocean. However, climate change-induced factors, such as increasing coastal turbidity and glacier melt, could also impact kelp growth in the Arctic. This thesis examines the role that light and nutrient availability play in understanding kelp cover and depth extent. This study used GoPro videos to determine kelp cover and depth extent as well as macroalgae samples to determine the nutritive state of kelp within two Greenlandic fjords. Results reveal significant turbidity and nutrient gradients throughout the fjords. Where light was limited due to glacial discharge and resuspension of sediments, kelp growth at depth was limited; and where there was increased light availability, kelp cover was greater. Additionally, kelp located nearest the marine-terminating glacier had greater nitrogen concentration than kelp located further from the marine-terminating glacier or the land-terminating glacier, revealing the influence of estuarine circulation on nutrient availability. Where light and nutrients were abundant, kelp biomass and subsequent production was greatest. Additionally, we concluded that sea urchin grazing provided an additional influence with light on kelp depth extent and distribution in both shallow and deep waters. These results are necessary and important to consider when assessing kelp distribution and change, both now and into the future.May 202
Queering autism: Heteronormative barriers to autism identification
Get PDFAutistic people are everywhere and not limited by any intersection including race, religion, country or culture. Many of us experience social oppression and disadvantage. In this autoethnography, I explore some of my experiences navigating being “different”, even in today’s culture. This analysis highlights key areas where culture can have a negative impact on autistic people. From a transfeminist disability studies framework, utilizing queer theory and the neurodiversity paradigm, I explore the positive impacts of queering autism within my own life. Through personal accounts of queering, I highlight how some heteronormative barriers can be reduced in one’s personal life, with the potential also to be applied more broadly within culture. Implications of queering autism broadly include an application within the medical and psychological fields and government autism program changes. Utilizing autoethnographic accounts and stories from within my community, I discuss the barriers to autism identification among those with numerous identities that do not align with stereotypical white cis male-centred autism concepts within culture that have also had impacted me throughout my lifespan. The stories told advocate for inclusive research and increased funding to share the stories of marginalized voices, policy changes and community education initiatives. I conclude with the importance of queering autism to increase access to autism self-identity, particularly among autistic people who are not cisgender males.October 202
Late-life mental health, substance use and addiction service needs in Manitoba
Get PDFAdults ages 65+ may experience mental health or substance use / addiction (‘SUA’) challenges that can endanger their quality of life, health, and longevity. Yet mental health and/or SUA services are often unavailable or inaccessible for adults 65+, which can perpetuate unmet needs. Services become more accessible when they reflect the needs and priorities of intended users; however, few studies have engaged individuals who use and deliver late-life mental health and/or SUA services to better understand their needs and priorities. The primary objective of this mixed-methods research was to describe the mental health and SUA service needs and priorities of adults 65+ and those who deliver services to adults 65+. A secondary objective was to explore adults’ 65+ SUA literacy (i.e., knowledge of how to recognize and manage SUA problems and find and access SUA services and information). Six adults 65+ who had tried to access services participated in two virtual focus groups, and six service leaders and providers participated in a separate two-part focus group series, to discuss service and research needs, and define and set service priorities. Using reflexive thematic analysis, four main themes described adults’ 65+ experiences of services: 1. “What you need just isn’t there”; 2. “Where do I go?”: Knowing about and finding services; 3. “Roadblocks” along pathways to services; 4. COVID-19 “forced” new ways of connecting with people and services. Four additional themes reflected service leader and provider perspectives. Priority-setting was achieved with each group using a modified nominal group technique. Emergent priorities were then built into an online survey for validation with a convenience sample of community-living adults 65+ (n = 138). Respondents selected protection and advocacy services for older adults as a top priority, followed by more involvement of caregivers in treatments and care teams. The survey was also used to examine differences between respondents’ SUA and mental health literacy (analyzed using a paired samples t-test), and sociodemographic and psychosocial predictors of SUA literacy (analyzed using hierarchical linear regression). Low to moderate SUA literacy (M = 3.1, SD = 0.97) among the adult 65+ sample was significantly lower than their mental health literacy, t(137) = -3.30, p = .001, and both older age and limited SUA lived experience were significant predictors of lower SUA literacy. Findings inform future selection, funding, and delivery of services that are targeted to the needs of aging populations and recommend clarifying pathways into them.Liquor Gaming and Cannabis Authority of Manitoba
Research Manitoba
University of ManitobaFebruary 202
Keystone Agricultural Producers Roll Over Tractor Training Course
Get PDFTractor rollovers, many of which impact inexperienced drivers, contribute significantly to the fatality rate of the agricultural industry. Keystone Agricultural Producers and their partners developed the Roll-Over Training Tractor (ROTT) as a tool to improve the efficacy of teaching about tractor rollovers. The ROTT is a one-third scale electric tractor modeled based off the design of a commercial tractor. This machine is piloted using a remote control. It has a live video feed using the Reolink app from a camera mounted above the rear axle. The ROTT was intended to be used at the University of Manitoba (UofM) Glenlea Research Station. There is currently no adequate course to demonstrate typical rollover scenarios using the ROTT. The objective of the project undertaken by Team 1 was to design the ROTT Demonstration Course which includes stations to simulate sideways and backwards rollovers.
Technical specifications were developed with the client to ensure that the design of the ROTT Demonstration Course fulfilled the project problem statement. The solution developed includes two stations: the Incremental Slope Station and Silage Bunker Station. The Incremental Slope Station is intended to induce a side rollover. It will be implemented as an addition to an existing slope at the UofM Glenlea Research Station. The slope of this addition will begin at 30° and will increase to 45° at 1° every 6ft. The ROTT will be driven along this slope until it rolls over sideways and is caught by the side support wheels. The process of piloting the tractor and viewing the live feed of the rollover will provide experience for students that will allow them to adequately assess if a slope will risk a tractor rollover. The ROTT will be retrofitted with spikes and a centre rod on the bucket such that a 3.11 slug mass can be carried. The Incremental Slope Station can then be run with an added mass on the front. This will demonstrate the effect of a displaced centre of gravity on the angle that induces a tractor rollover. The Silage Bunker Station is a to-scale model of a concrete silage bunker. It is designed such that when the ROTT drives on the silage packed at 45° (+, -0°), a back rollover will be induced. The course was designed to require little maintenance. Drawings and a Bill of Materials are included for the construction of each station, the spikes, and centre rod. Evaluation approaches were developed to assess whether the proposed design solution fulfils each of the technical specifications. Due to the ROTT being inoperable, using a test slope to verify rollover angles was not possible. It is recommended that tests will be administered after construction is completed in the summer of 2024
HIV phylogenetic clusters point to unmet hiv prevention, testing and treatment needs among men who have sex with men in kenya
Get PDFAbstract Background The HIV epidemic in Kenya remains a significant public health concern, particularly among gay, bisexual, and other men who have sex with men (GBMSM), who continue to bear a disproportionate burden of the epidemic. This study’s objective is to describe HIV phylogenetic clusters among different subgroups of Kenyan GBMSM, including those who use physical hotspots, virtual spaces, or a combination of both to find male sexual partners. Methods Dried blood spots (DBS) were collected from GBMSM in Kisumu, Mombasa, and Kiambu counties, Kenya, in 2019 (baseline) and 2020 (endline). HIV pol sequencing was attempted on all seropositive DBS. HIV phylogenetic clusters were inferred using a patristic distance cutoff of ≤ 0.02 nucleotide substitutions per site. We used descriptive statistics to analyze sociodemographic characteristics and risk behaviors stratified by clustering status. Results Of the 2,450 participants (baseline and endline), 453 (18.5%) were living with HIV. Only a small proportion of seropositive DBS specimens were successfully sequenced (n = 36/453; 7.9%), likely due to most study participants being virally suppressed (87.4%). Among these sequences, 13 (36.1%) formed eight distinct clusters comprised of seven dyads and one triad. The clusters mainly consisted of GBMSM seeking partners online (n = 10/13; 76.9%) and who tested less frequently than recommended by Kenyan guidelines (n = 11/13; 84.6%). Conclusions Our study identified HIV phylogenetic clusters among Kenyan GBMSM who predominantly seek sexual partners online and test infrequently. These findings highlight potential unmet HIV prevention, testing, and treatment needs within this population. Furthermore, these results underscore the importance of tailoring HIV programs to address the diverse needs of GBMSM in Kenya across different venues, including both physical hotspots and online platforms, to ensure comprehensive prevention and care strategies
Design and implementation of a structured illumination hyperspectral imaging microscope
No full textWe designed and implemented a hyperspectral microscope with structured illumination using the Olympus IX73 microscope as its basic platform. This system, which was designed and built in our Integrated Computational Optical Imaging Laboratory, combines two Digital Micromirror Devices (DMD) to compensate for the angular dispersion introduced by the blazed grating structure of the original DMD that was used to produce the structured illumination.
Our hyperspectral microscope uses a supercontiuum laser illumination that can be spectrally filtered for desired wavelength ranges using an acoustic-optic filter. The system is controlled using LabVIEW, that allows for synchronous and asynchronous control of 1) illumination laser source, 2) acousto-optic filter, 3) spatial light modulator (DMD) and 4) camera. This LabView-based system control enables the implementation of a wide variety of image acquisition modes.
Our microscope’s hyperspectral modality uses a wavelength-scanning configuration, where the supercontiuum laser illumination is filtered using an acousto-optic filter to produce very narrowband light for to acquire different hyperspectral images.
Our system could be an excellent platform for implementing different types of hyperspectral data acquisition to implement, e.g., super-resolution microscopy and compressed sensing. The use of a DMD-based spatial light modulator allows for very fast spatial light modulation.October 202
Scoping review on the link between economic growth, decent work, and early childhood caries
Get PDFBackground
Early Childhood Caries (ECC) is a prevalent chronic non-communicable disease that affects millions of young children globally, with profound implications for their well-being and oral health. This paper explores the associations between ECC and the targets of the Sustainable Development Goal 8 (SDG 8).
Methods
The scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. In July 2023, a search was conducted in PubMed, Web of Science, and Scopus using tailored search terms related to economic growth, decent work sustained economic growth, higher levels of productivity and technological innovation, entrepreneurship, job creation, and efforts to eradicate forced labor, slavery, and human trafficking and ECC all of which are the targets of the SDG8. Only English language publications, and publications that were analytical in design were included. Studies that solely examined ECC prevalence without reference to SDG8 goals were excluded.
Results
The initial search yielded 761 articles. After removing duplicates and ineligible manuscripts, 84 were screened. However, none of the identified studies provided data on the association between decent work, economic growth-related factors, and ECC.
Conclusions
This scoping review found no English publication on the associations between SDG8 and ECC despite the plausibility for this link. This data gap can hinder policymaking and resource allocation for oral health programs. Further research should explore the complex relationship between economic growth, decent work and ECC to provide additional evidence for better policy formulation and ECC control globally