Western College of Veterinary Medicine
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Item How Does African Swine Fever Virus Evade the cGAS-STING Pathway?(Pathogens, 2024-11) Lin, Can; Zhang, Chenyang; Chen, Nanhua; Meurens, Francois; ZHU, JIANZHONG; Zheng, WanglongAfrican swine fever (ASF), a highly infectious and devastating disease affecting both domestic pigs and wild boars, is caused by the African swine fever virus (ASFV). ASF has resulted in rapid global spread of the disease, leading to significant economic losses within the swine industry. A significant obstacle to the creation of safe and effective ASF vaccines is the existing knowledge gap regarding the pathogenesis of ASFV and its mechanisms of immune evasion. The cyclic GMP–AMP synthase (cGAS)–stimulator of interferon genes (STING) pathway is a major pathway mediating type I interferon (IFN) antiviral immune response against infections by diverse classes of pathogens that contain DNA or generate DNA in their life cycles. To evade the host’s innate immune response, ASFV encodes many proteins that inhibit the production of type I IFN by antagonizing the cGAS-STING signaling pathway. Multiple proteins of ASFV are involved in promoting viral replication by protein–protein interaction during ASFV infection. The protein QP383R could impair the function of cGAS. The proteins EP364R, C129R and B175L could disturb the function of cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). The proteins E248R, L83L, MGF505-11L, MGF505-7R, H240R, CD2v, E184L, B175L and p17 could interfere with the function of STING. The proteins MGF360-11L, MGF505-7R, I215L, DP96R, A151R and S273R could affect the function of TANK Binding Kinase 1 (TBK1) and IκB kinase ε (IKKε). The proteins MGF360-14L, M1249L, E120R, S273R, D129L, E301R, DP96R, MGF505-7R and I226R could inhibit the function of Interferon Regulatory Factor 3 (IRF3). The proteins MGF360-12L, MGF505-7R/A528R, UBCv1 and A238L could inhibit the function of nuclear factor kappa B (NF-Κb).Item Avian influenza virus circulation and immunity in a wild urban duck population prior to and during a highly pathogenic H5N1 outbreak(Veterinary Research, 2024-11) Wight, Jordan; Rahman, Ishraq; Wallace, Hannah; Cunningham, Joshua; Roul, Sheena; Robertson, Gregory J; Russell, Rod; Xu, Wanhong; Zhmendak, Dmytro; Alkie, Tamiru N.; Berhane, Yohannes; Hargan, Kathryn; Lang, Andrew S.Highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b viruses were first detected in St. John’s, Canada in late 2021. To investigate the patterns of avian influenza virus (AIV) infection and immune responses subsequent to the arrival of H5N1, we sampled the wild urban duck population in this area for a period of 16 months after the start of the outbreak and compared these findings to those from archived samples. Antibody seroprevalence was relatively stable before the outbreak (2011–2014) at 27.6% and 3.9% for anti-AIV (i.e., NP) and H5-specific antibodies, respectively. During the winter of 2022, AIV-NP and H5-specific antibody seroprevalence both reached 100%, signifying a population-wide infection event, which was observed again in late February 2023 following a second H5N1 incursion from Eurasia. As expected, population-level immunity waned over time, with ducks seropositive for anti-AIV-NP antibodies for approximately twice as long as for H5-specific antibodies, with the population seronegative to the latter after approximately six months. We observed a clear relationship of increasing antibody levels with decreasing viral RNA loads that allowed for interpretation of the course of infection and immune response in infected individuals and applied these findings to two cases of resampled ducks to infer infection history. Our study highlights the value of applying both AIV surveillance and seroprevalence monitoring to provide a better understanding of AIV dynamics in wild populations, which may be crucial following the global dissemination of clade 2.3.4.4b H5Nx subtypes to assess the threats they pose to both wild and domestic animals, and to humans.Item Upregulation of porcine epidemic diarrhea virus (PEDV) RNA translation by the nucleocapsid protein(Virology, 2024-11) Hao, Lin; Fragoso-Saavedra, Mario; Liu, QiangThe role of coronaviral nucleocapsid (N) protein in regulating viral translation remains poorly understood. Here, we showed that the N protein of porcine epidemic diarrhea virus (PEDV) enhances the translation of both virus-like genomic RNA (gRNA) and messenger RNA. Further characterization of the gRNA translation upregulation showed that the N-terminal domain (NTD) + Linker region plays a major role. The stem-loop 1 in the 5′ untranslated region (UTR) and the budged stem loop in the 3′UTR are required for viral translation upregulation by PEDV N protein. The signaling kinase Akt exists in three isoforms. We found that Akt1 enhances viral gRNA translation upregulation by the N protein dependent on its kinase activity. We further showed an interaction between Akt1 and PEDV N, that is abolished by the NTD + Linker region. This suggested that the enhancing effect of Akt1 on translation upregulation by the N protein does not require interaction between these two proteins.Item Target organ toxicity in Sprague Dawley rats following oral exposure to complex groundwater mixture: Assessment of dose-response relationships using histopathological and biochemical alterations(Regulatory Toxicology and Pharmacology, 2024-11) Boamah, Bright Boafo; Siciliano, Steven; Hogan, Natacha; Hecker, Markus; Hanson, M; Campbell, P; Peters, R; Al-Dissi, Ahmad; Weber, LynnExposure to contaminant mixtures from industrial legacy sites presents unique challenges that require novel approaches such as effects-directed toxicity assessment. This study characterized the target organ toxicity of groundwater from a legacy contaminated pesticide plant in male and female Sprague Dawley rats exposed to low impact (10% v/v) groundwater, high impact (0.01% v/v, 0.1% v/v, 1% v/v, and 10% v/v) groundwater or tap water (control) for 60 days. Rats exposed to high impact (1% and 10%) and 10% low impact groundwater mixture showed statistically significant increases in liver necro-inflammation relative to control. A statistically significant reduction was observed in plasma albumin of exposed rats (except 0.01% high impact) and alpha 2 macroglobulin (all exposed) when compared to the control. All groundwater-exposed rats showed glomerulopathy, but there were sex-specific differences in acute tubular necrosis. Testes showed germinal cell vacuolation, necrosis, reduced seminiferous epithelial height, and Sertoli syndrome in exposed rats, accompanied by reduced plasma testosterone and increased testicular malondialdehyde. Taken together, this sub-chronic oral exposure to groundwater from a contaminated industrial site caused dose-dependent hepatic and testicular toxicity, while nephrotoxicity was both sex-dependent and dose-dependent. This study provides support for the essentiality of using effects-driven approaches in the risk assessment of complex mixtures.Item The distribution of Babesia odocoilei in Ixodes species ticks in Canada: Implications for one health surveillance(Ticks and Tick-borne Diseases, 2024-11) Guillot, Camille; Pelletier, Jerome; Aenishaenslin, Cécile; Coatsworth, Heather; Dibernardo, Antonia; Koffi, Jules K.; Kulkarni, Manisha; Rocheleau, Jean-Philippe; Wilson, Christy; Russell, Curtis; Nelder, Mark; Badcock, Jacqueline; Carr, Justin; Checkley, Sylvia; Clow, Katie M; Cooper, Stephanie; Cork, Susan; Dumas, Ariane; Dergousoff, Shaun; Faraone, Nicoletta; Fraser, Erin; Graham-Derham, Scott; irace cima, alejandra; Iwasawa, Stefan; Jenkins, Emily; Leighton, Patrick; McKay, Roman; Morshed, Muhammad; Pelletier, Roxane; Ripoche, Marion; Rochon, Kateryn; Thivierge, Karine; Voordouw, Maarten; Ogden, Nicholas H; Bouchard, CatherineIxodes scapularis and Ixodes pacificus are vectors of a range of pathogens of public health significance in North America. These ticks transmit pathogens to and from wild animal reservoir host species, but also bite humans and expose them to the pathogens. We describe the geographical and temporal distribution of the pathogen Babesia odocoilei, the causative agent of cervid babesiosis. Ixodes spp. ticks collected through active and passive surveillance were submitted to the National Microbiology Laboratory of the Public Health Agency of Canada for analysis of the presence of B. odocoilei from 2018 to 2021. Generalized linear models were constructed to evaluate the temporal change of B. odocoilei prevalence across Canada. Babesia odocoilei-positive I. scapularis are widespread across south-central and eastern regions of Canada, with an overall prevalence of 12.0 % in both nymphs (CI 95 % : 11.4–12.6) and adults (CI 95 % : 11.9–12.1) collected in passive surveillance and 13.2 % (CI 95 % : 12.9–13.5) and 10.0 % (CI 95 % : 9.8–10.2) in nymphs and adult, respectively, collected in active surveillance. A single I. pacificus tick tested positive in active surveillance out of 29 ticks collected in British Columbia, while no B odocoilei-positive I. scapularis were found in passive surveillance among the 11 adult ticks tested. Although B. odocoilei infection prevalence of adult I. scapularis was significantly higher in 2019 (14.1 %) than in 2018 (7.4 %), it remained stable from 2019 to 2021, suggesting that this pathogen may already be well established in endemic tick populations. The results provided in this article represent, to date, the most comprehensive picture of B. odocoilei distribution and prevalence in ticks in Canada and highlight the interest of maintaining One Health surveillance approaches to give added insight into disease transmission cycles for less well-characterized microorganisms.Item Rearing pigs with play opportunities: the effects on disease resilience in pigs experimentally inoculated with PRRSV(Frontiers, 2024-09-17) Steinerová, Karolína; Harding, John; Parker, Sarah Elizabeth; Wilson, Heather; Nery Finatto, Arthur; Seddon, YolandePositive emotions can reduce disease susceptibility during infectious challenges in humans, and emerging evidence suggests similar effects in farm animals. Because play behaviour may support a positive emotional state in pigs, this study investigates whether rearing pigs with regular intermittent play opportunities enhances disease resilience when challenged with porcine reproductive and respiratory syndrome virus (PRRSV). Litters were assigned to either play (PLY; n = 5 L) or control (CON; n = 4 L) treatments at birth. In PLY, play was promoted with extra space and enrichment items for three hours daily from five days of age (doa). At weaning (25 ± 2 doa; mean ± SD), 28 pigs (14/treatment) were selected for a disease challenge, based on weight, sex, and sow. The pigs were transported to a disease containment facility and at 43 ± 2 doa (day 0 post-inoculation, DPI) inoculated with PRRSV. Skin lesions, blood, rectal temperature, clinical signs, body weight, and behaviour were collected pre- and post-inoculation. Play opportunities for PLY continued every other day until euthanasia of all pigs at 65 ± 2 doa (22 DPI). PLY pigs exhibited fewer skin lesions following transport and throughout the infection compared to CON. Although the viral load did not differ between treatments, PLY pigs had a lower probability of experiencing moderate and severe respiratory distress, with a shorter duration. PLY also performed better throughout the infection, showing higher ADG and greater feed efficiency. The immune response differed as well. PLY pigs had fewer monocytes on 8 DPI than CON, with levels returning to baseline by 21 DPI, whereas CON levels exceeded baseline. Regardless of day of infection, lymphocyte counts tended to be lower in PLY than in CON, and white blood cells and neutrophils were also lower, but only in slow-growing pigs. PLY pigs continued to play during the infection, demonstrating less sickness behaviour and emphasizing the rewarding properties of play. Results suggest that PLY pigs were less affected by PRRSV and developed increased resilience to PRRSV compared to CON. This study demonstrates that rearing pigs in an environment supporting positive experiences through provision of play opportunities can enhance resilience against common modern production challenges, underscoring the value of positive welfare in intensive pig farming.Item Identification of genetic markers of resistance to macrolide class antibiotics in Mannheimia haemolytica isolates from a Saskatchewan feedlot(American Society for Microbiology [Society Publisher], 2024-06-12) Deschner, Darien; Voordouw, Maarten J.; Fernando, Champika; Campbell, John; Waldner, Cheryl L.; Hill, Janet E.Mannheimia haemolytica is a major contributor to bovine respiratory disease (BRD), which causes substantial economic losses to the beef industry, and there is an urgent need for rapid and accurate diagnostic tests to provide evidence for treatment decisions and support antimicrobial stewardship. Diagnostic sequencing can provide information about antimicrobial resistance genes in M. haemolytica more rapidly than conventional diagnostics. Realizing the full potential of diagnostic sequencing requires a comprehensive understanding of the genetic markers of antimicrobial resistance. We identified genetic markers of resistance in M. haemolytica to macrolide class antibiotics commonly used for control of BRD. Genome sequences were determined for 99 M. haemolytica isolates with six different susceptibility phenotypes collected over 2 years from a feedlot in Saskatchewan, Canada. Known macrolide resistance genes estT, msr(E), and mph(E) were identified in most resistant isolates within predicted integrative and conjugative elements (ICEs). ICE sequences lacking antibiotic resistance genes were detected in 10 of 47 susceptible isolates. No resistance-associated polymorphisms were detected in ribosomal RNA genes, although previously unreported mutations in the L22 and L23 ribosomal proteins were identified in 12 and 27 resistant isolates, respectively. Pangenome analysis led to the identification of 79 genes associated with resistance to gamithromycin, of which 95% (75 of 79) had no functional annotation. Most of the observed phenotypic resistance was explained by previously identified antibiotic resistance genes, although resistance to the macrolides gamithromycin and tulathromycin was not explained in 39 of 47 isolates, demonstrating the need for continued surveillance for novel determinants of macrolide resistance.Item Outcomes of surgically treated sialoceles in 21 cats: A multi-institutional retrospective study (2010–2021)(Wiley, 2024-07-31) Marti, Laura G.; Del Carpio, Laura-Isabela; Goldschmidt, Stephanie; Gagnon, Dominique; Shmon, Cindy; Sterman, Allyson A.; Scharf, Valery F.; MacPhail, Catriona M.; Maki, Lynn; Arzi, BoazAbstract Objective: To report the outcomes of cats that underwent surgical correction for sialoceles. Study design: Multi-institutional retrospective cohort study. Animals: Twenty-one client-owned cats. Methods: Medical records were examined of cats diagnosed with sialocele, which underwent surgical intervention over an 11-year period at one of10 referral hospitals. The data collected included signalment, clinical signs, diagnostic imaging, histopathology, surgical procedures performed, and post-operative complications. Results: The most common presenting complaints for cats with sialocele included dysphagia and ptyalism. Only two cats had a recent history of trauma, and one was diagnosed with a concurrent sialolith. Most displayed visible tis-sue swelling, with ranulae being most common. Surgical treatment consisted of sialoadenectomy and/or marsupialization. Intraoperative complications occurred in three cats, and postoperative complications in five cats. No recurrence or development of contralateral sialoceles were reported during the follow-up period (30–968 days). Conclusion: The majority of cats did not have a clear underlying cause for developing a sialocele. The sublingual and mandibular salivary glands were presumed to be the most commonly affected. Mandibular and sublingual sialoadenectomy and/or marsupialization provided resolution of clinical signs to the 21 cats that underwent these procedures. Clinical significance: Sialocele, although rare, should remain a differential diagnosis when managing cats with relevant clinical signs. Surgical intervention appears to offer resolution of signs with apparently low over-all risk of complication or short-term recurrence. In cats it is necessary to evaluate whether sialoadenectomy is necessary, or whether marsupialization alone should be attempted as a less invasive first-line surgical intervention.Item Antimicrobial Disc Diffusion Testing - A Visual Guide(2024-05-29) Rubin, Joseph E; Weerasooriya, Gayani; Madalagama Appuhamilage, Roshan PriyanthaItem Course Notes - Veterinary Bacteriology and Mycology(2024) Rubin, Joseph EWelcome to microbiology! In this 3-credit unit course we will cover the microbiology of bacterial and fungal organisms of importance to veterinary medicine. This content of this course lies somewhere in between basic microbiology and clinical infectious disease; although we will discuss some fundamental microbiological concepts, material will be presented from the clinician’s perspective where possible.Item Laboratory Procedures Manual(2024-03-01) Madalagama Appuhamilage, Roshan Priyantha; Rubin, Joseph E.The development of this laboratory manual was a collaboration between Drs. M.A.R. Priyantha and J.E. Rubin. This manual is intended to serve as a foundational guide to the microbiological techniques and principles required for diagnostic and research microbiology. These materials were developed specifically for the regional labs within the Department of Animal Production and Health and the Veterinary Research Institute of Sri Lanka.Item Participant Consent Form(2023) Monique, MayerItem Supplemental Table 1(2023) Williams, Alison; Mayer, Monique; Sukut, Sally; Dickinson, Ryan; MacDonald, Valerie; Gagnon, JeromeItem Contouring the canine optic apparatus using the optic plane(2022) Walther, Eric; Mayer, MoniqueItem Contouring the canine optic apparatus using the optic plane(2022) Walther, EricItem 2021 Videocast by Dr. Hiroo Suami: Anatomical Studies of the Lymphatic System - Comparative Anatomy between Canine and Humans(University of Saskatchewan Pressbooks, 2021-08-24) Suami, HirooItem Radiation safety practices among Canadian equine veterinary workers during diagnostic procedures with portable X-ray equipment(Canadian Veterinary Journal, 2020) Belotta, Alexandra F.; Mayer, Monique N.; Waldner, Cheryl L.; Robinson, Kate; Sidhu, Narinder; Carmalt, James; Bell, Chris D.; Koehncke, Niels K.