Distinguished Speaker Seminar Series in Infectious Diseases
Jonathan Auguste and Bryan Hsu
The Center for Emerging, Zoonotic and Arthropod-borne Pathogens (CeZAP) introduces the CeZAP Distinguished Speaker Seminar Series in Infectious Diseases. This university wide seminar series at Virginia Tech invites outstanding scientists nationally to give presentations to CeZAP and broader university community on topics of current interest in the broad area of infectious diseases. Diversity of seminar topics is essential to meeting the purpose of the Distinguished Speaker Seminar Series in Infectious Diseases. Each spring, nominations for nationally distinguished speakers for the seminar series for the following academic year will be solicited from CeZAP affiliated faculty. The seminar coordinators (Drs. Jonathan Auguste and Bryan Hsu) will coordinate the selection of speakers, and the CeZAP faculty nominators will serve as the host for the national speakers. We expect to host at least one nationally distinguished speaker each month, and the remaining speakers will feature our own CeZAP affiliated faculty.
FALL 2022 SCHEDULE
Seminar Date & Time:
Thursdays at 12:30pm starting August 25, 2022
In person in Fralin Hall Auditorium
August 25, 2022:
Jonathan Auguste, Ph.D. Assistant Professor, Department of Entomology, CALS
Title: "Enemy of my Enemy: Employing an insect-specific virus in the fight against Zika virus"
Vaccination remains critical for viral disease outbreak prevention and control, but conventional vaccine development typically involves trade-offs between safety and immunogenicity. ZIKV recently caused immense economic and health impacts throughout the Americas, and re-emergence poses a significant threat. Here, we created a chimeric virus expressing ZIKV prM and E proteins on an Aripo virus (ARPV; an ISFV) backbone. In vitro safety studies showed that after infection of mammalian cells with ARPV/ZIKV, the virus did not replicate nor cause cytopathic effects. Additionally, ARPV/ZIKV did not produce ZIKV E protein in mammalian cells but production did occur in insect cells. ARPV/ZIKV also demonstrated exceptional safety when administered at high doses intracranially to suckling mice. Protective efficacy was evaluated by subcutaneous immunization of 4-week-old immune -competent (C57BL/6J) and -compromised (IFN-αβR-/-) mouse models. ARPV/ZIKV-vaccinated mice were completely protected from viremia, weight loss, and mortality after being challenged with a lethal dose of ZIKV. ARPV/ZIKV immunization also prevented in utero ZIKV transmission in gravid IFNAR-/- mice. Vaccinated dams and their embryos exhibited no morbidity post-challenge, and no detectable ZIKV was present in placental, spleen, or brain tissues. To further study the correlates of protection post-vaccination we characterized the cell-mediated response to ARPV/ZIKV immunization. Splenocytes derived from vaccinated mice demonstrated ZIKV-specific CD4+ and CD8+ responses, and significant cytokine production post-antigen exposure. Furthermore, transcriptomic studies on murine macrophages exposed to ARPV/ZIKV indicated robust PRR, B-cell receptor, Th1 and Th2 polarization, and antigen presentation signaling. Vaccine efficacy studies in Rag1-/-, Tcra-/-, and muMt-/- mice, and T-cell depletion and passive transfer studies in IFNAR-/- mice, show both humoral and cell-mediated responses are significant contributors to ARPV/ZIKV-induced protection. Altogether, chimeric insect-specific flaviviruses are a promising new platform to restrict flavivirus emergence via vaccine development.
September 1, 2022: Virtual Seminar Zoom: https://virginiatech.zoom.us/j/89419666443
Maria Elena Bottazzi, Ph.D. Associate Dean, National School of Tropical Medicine, Baylor College of Medicine
TItle:"Academic Creativity, Strategic Alliances and Diplomacy: Behind the scenes of a COVID-19 vaccine sutable for global access"
Host: Kylene Kehn-Hall, Ph.D.
For the last two decades, the National School of Tropical Medicine and its Center for Vaccine Development in Houston, Texas has operated with the mission to develop and test new low-cost and effective vaccines against emerging and neglected tropical diseases, build capacity for vaccine development locally and with foreign nations and guide and influence vaccine policy and advocacy. This approach relies on the need for international diplomacy, solidarity, and cooperation. This presentation will provide a behind the scenes vignette and an overview of the vaccine development process and will highlight the case study of Corbevax, a COVID-19 vaccine, suitable for global access.
September 8, 2022:
David Riglar, Ph.D., Sir Henry Dale Research Fellow, Faculty of Medicine, Imperial College London
Title: "Using synthetic biology to combat the double-edged-sword of spatially varying host-microbiome interactions"
The mammalian gut microbiome plays a critical, but poorly understood, role in the triggering, maintenance and response to inflammation-linked conditions including infection, inflammatory bowel disease and colorectal cancer. Spatial dynamics in both microbial abundance and gene expression are likely to be important factors in disease outcome, however, methods to resolve microbial function in the context of the gut's varying longitudinal, radial, and inflammatory microenvironments are limited. Because of this, care must be taken so that spatio-temporal dynamics do not lead to unexpected variation in a range of analyses.
We have previously demonstrated the power of synthetic memory circuits to engineer living bacterial probes as recorders for exposure to inflammatory conditions within the mammalian gut. Here, I will discuss further developments to engineered biosensors and their combination with advanced 3D imaging approaches to investigate the functional biogeography of the healthy and inflamed gut.
September 15, 2022:
Luis Escobar Ph.D. Assistant Professor, Department of Fish and Wildlife Conservation, CNRE
Title: "Linkages Between Climate Change, Zoonotic Diseases and Wild Life"
Climate change is the most important current threat to human being and biodiversity. Although substantial data exist on the negative effects of climate change, consequences are increasing due negligent inaction. Floods, heatwaves, and spread of infectious diseases increase in magnitude and rise inequity in low Human Development Index countries. Climate change impacts amplify the harms to health driven by the COVID-19 pandemic, and could trigger new pandemics originating in wild life. This talk will present research on climate change and fish and wildlife diseases and their connections with food security.
September 22, 2022:
ID IGEP Research Rotation Presentations
September 29, 2022:
Hanh Lam, Ph.D. Associate Professor of Biological Sciences, COS
Title: "Probing host- microbe interactions for pathogen specific antimicrobials"
Pseudomonas aeruginosa is one of the ESKAPE pathogens that frequently “escapes” antimicrobial drugs and is one of the most common causes of healthcare-associated infections worldwide. The Type III secretion system (T3SS) is a major virulence determinant associated with acute Pseudomonas infection. T3SS is required for virulence in a number of pathogens but largely absent from commensals, making it an ideal target of antimicrobial development. Among four effector proteins secreted out from the T3SS, the ExoU phospholipase is a known marker of highly virulent strains and antibiotic resistance. Our lab investigates the mechanisms of host cell death caused by P. aeruginosa ExoU phospholipase and develops inhibitors of bacterial phospholipase and the T3SS using an interdisciplinary approach.
October 6, 2022: Virtual Seminar Zoom: https://virginiatech.zoom.us/j/89419666443
Matha Clokie Ph.D. Professor, University of Leicester
Title: "The use of phages to remove intestinal pathogens from poultry and swine"
Host: Bryan Hsu, Ph.D.
Antibiotics are frequently used to treat bacterial infections in poultry, but are increasingly acknowledged as being problematic as they drive antimicrobial resistance. Worryingly, multi-antibiotic resistant bacterial strains from many bacterial species have entered the human food chain and are difficult to treat. Consequently, alternatives to antibiotics are needed to treat and prevent diseases in poultry and prevent carriage of human bacterial pathogens. Bacteriophages (phages for short) could provide an effective alternative or compliment. Phages are viruses that target and kill bacteria with extreme specificity to a bacterial species or subspecies. They are incredibly abundant and genetically diverse. Phages are present in food we eat, in the natural environment and they play important roles in maintaining gut health in animals.
I will show how phages have been used to prevent and treat problematic bacterial infections caused by bacteria such as Salmonella. I will present studies that have shown phages can be used at different stages from pre to post slaughter to control the spread of harmful bacteria within the food chain. I will then present data on our current research, on using phages to reduce Salmonella colonisation in swine and poultry. To date, we have isolated a large phage set, that can lyse the most dominant subgroups of Salmonella worldwide and I will share insights form analysing the genomes of these phages within the context of all known Salmonella phages using a graph-based system that we developed. I will show how our recent trials have been conducted, and how delivering phages via feed significantly reduces Salmonella colonisation in poultry. In summary, I will show how phages have the potential to provide natural, safe and much needed means to prevent and treat diseases and improve animal welfare and food safety within the poultry industry.
October 13, 2022:
Brian Kvitko, Ph.D. Associate Professor, University of Georgia
Title: "A new paradigm for bacterial necrotrophs: chemical warfare"
Host: Ann Stevens, Ph.D.
October 20, 2022:
ID IGEP Research Rotation Presentations
October 27, 2022: Hybrid Seminar Zoom: https://virginiatech.zoom.us/j/89419666443
Leda Kobziar, Ph.D. Associate Professor, University of Idaho
Title: “Catching, Counting, and Considering the Microbial Life Transported by Wildfire Smoke Plumes”Host: David Schmale Ph.D.
November 3, 2022: Hybrid Seminar Zoom: https://virginiatech.zoom.us/j/89419666443
Gregory Glass, Ph.D. Professor, University of Florida
Title: "Nuances and hidden implications in disease dynamics"
Host: Luis Escobar, Ph.D.
Within the scientific enterprise it is estimated approximately 1.8 million publications are generated per year. At the same time, there are reports that more than half of all studies do not produce results that are repeatable either by the initial group or by other research teams. Various reasons have been proposed for these observations, with inappropriate activity being rare (but the most common reason for retractions). Today, we focus on the failure of repeatable results by distinguishing between reproducible and replicable results.
We focus on why lack of replicable results (new data, new research groups), which are key to scientific validation, are especially troublesome. We propose that, as scientific fields try to better integrate their findings within the broader scientific community, this challenge will become even more critical. We suggest that though technical proficiency may be satisfactory (good reproducibility), the choices of methods produce results that are extremely sensitive to those methods and can produce misunderstandings in the wider context. This generates incorrect directions for future studies.
I will provide several case studies related to pathogen/disease systems to demonstrate the consequences.
November 10, 2022:
Kevin Lahmers DVM, Ph.D, DACVP Clinical Associate Professor, Virginia-Maryland College of Veterinary Medicine
Title: "The story of Theileria orientalis, a rapidly emerging pathogen of cattle, and Haemaphysalis longicornis, its exotic tick vector"
Host: Margie Lee, Ph.D.
November 17, 2022:
ID IGEP Research Rotation Presentations
December 1, 2022:
John Aggrey, Ph.D. Postdoctoral Associate, Department of Science, Technology, and Society, CLAHS
Title: "Invisible Visibilities: Risk INfrastructure and Epidemiological Obfuscation in Peidemics"
Host: Kiyah Duffy
Risk communication and community engagement (RCCE) are essential for curbing emerging infectious disease (EID) epidemics. However, the biomedical framing of RCCE renders it inadequate in identifying evolving risk factors amidst the complexity, uncertainty, and changing nature of EID epidemics. I argue that the opacity of evolving risk factors that influence the dynamics of the epidemic constitutes epidemiological obfuscation. Drawing from an analysis of CDC and WHO documents on emergency risk communication and community engagement and insights from multi-sited qualitative interviews in Ghana during the 2014-2016 Ebola outbreak, I examine the risk infrastructure in EID epidemics to suggest that the muddle of evolving risk factors contributes to the shaping of people's response to EID epidemics and the epidemic process which sustains the longevity of epidemics.