Location: Infectious Bacterial Diseases Research
2024 Annual Report
Objectives
Objective 1: Develop vaccines that prevent disease or mitigate disease spread with an emphasis on platforms that allow for extended antigen release and remote delivery for livestock and wildlife species.
Subobjective 1.A: Assess the potential of a polyanhydride delivery platform to enhance BCG availability and immunogenicity in order to promote protective anti-mycobacterial responses.
Subobjective 1.B: Evaluate the immune response of WTD to encapsulated lyophilized BCG delivered in oral vaccine delivery units (VDUs).
Objective 2: Improve current diagnostic tests for bovine TB and develop novel, next generation diagnostics which are amenable to remote or continuous disease surveillance and can be incorporated into precision livestock management.
Sub-objective 2.A: Assess the sensitivity and specificity of a fluorescence polarization assay (FPA) to detect serum antibodies against synthetic M. bovis antigens.
Subobjective 2.B: Develop a battery-free, self-contained sensor for the detection of biological IFN-' in vivo that could be used as a diagnostic platform.
Objective 3: To enable the rational-design of intervention strategies, using transcriptomic approaches,define the immunopathogenesis of bovine tuberculosis at the tissue and cellular level by analyzing gene expression of peripheral immune responses and those responses involved in granuloma formation and maintenance.
Subobjective 3.A: Characterize the presence of key T cell subsets and transcription factors in granulomas from BCG-vaccinated vs. non-vaccinated animals following experimental infection with M. bovis.
Subobjective 3.B: Characterize the gene transcription profiles of Mycobacterium bovis-specific T cells in the periphery following M. bovis infection or vaccination.
Approach
Characterize and compare cytokine and biomarker expression (immune responses) at the cellular level in lungs and lymph nodes of Mycobacterium bovis-infected cattle. Comparing responses between tissues, as well as over time, will aid in understanding the host response to M. bovis within the environment where host and pathogen interact (granuloma). We aim to improve the specificity of diagnostic tests by developing diagnostic reagents from proteins found in M. bovis but not in non-tuberculous mycobacteria, thus avoiding cross-reactivity elicited by environmental mycobacteria that contributes to false positive results on cattle tuberculosis diagnostic tests. Similarly, we aim to identify proteins/genes expressed by M. bovis in vivo that may be considered as potential diagnostic test targets and to use genomics/transcriptomics to characterize genes/gene profiles of M. bovis-infected vs non-infected cattle. These data will aid diagnosis and provide insight into the immunopathogenesis of bovine tuberculosis. In terms of vaccine evaluation, we aim to examine duration of immunity to experimental infection provided by the vaccine M. bovis BCG in white-tailed deer and examine the effects of oral BCG vaccination on deer-to-deer transmission of virulent M. bovis. In cattle, we aim to determine the efficacy of simultaneous administration of parenteral M. bovis BCG and a mucosally delivered bacterial-vectored subunit vaccine against aerosol M. bovis infection in neonatal calves.
Progress Report
Over 100 years ago, in 1917, USDA initiated a bovine tuberculosis (bTB) eradication program that is still in place today. Although significant progress has been made, eradication has proved elusive. Obstacles to eradication include, 1) lack of rapid and accurate diagnostic tests to detect animals infected with Mycobacterium bovis (M. bovis; the cause of tuberculosis in animals), and 2) infected wildlife acting as a source of infection for cattle.
Research activities of ARS scientists in Ames, Iowa, provide direct support for the USDA bTB eradication program, specifically, through development of more sensitive diagnostics, efficacious vaccines, and improved animal disease models to enhance the capability to detect, prevent and control bTB.
In support of Objective 1, and in collaboration with other USDA scientists at Ft. Collins, Colorado, ARS scientists in Ames, Iowa developed an edible alginate sphere that contained a liquid form of the human TB vaccine, BCG. In 2022-2023, they delivered these alginate spheres orally to white-tailed deer and monitored their immune responses to BCG, demonstrating that BCG in alginate spheres induced an immune response similar to previous studies using subcutaneously injected vaccine. In March – May 2024 the edible alginate spheres were coated with a suitable attractant for white-tailed deer and deployed at specific farms in Michigan in a pilot project to test the feasibility of vaccinating wild deer against tuberculosis. Collaborators with the Michigan Department of Natural Resources (MDNR) and USDA Wildlife Services (WS) are collecting samples that are being analyzed by ARS scientists in Ames, Iowa.
In support of Objective 2, banked serum samples from M. bovis infected cattle are being prepared for analysis using the fluorescent polarization assay, a novel means of tuberculosis diagnosis in cattle, which uses fluorescent probes to detect antigen specific antibody in a rapid, highly specific fashion.
In support of Objective 3, ARS scientists in Ames, Iowa continue to analyze tissue samples from tuberculous cattle for gene expression of key immune system genes at both the tissue level and at the level of the blood. Several key immune system factors have been identified in tissue and manuscripts are being prepared and submitted. Samples of blood are being prepared to be processed to look at wide array of immune system factor genes at the molecular level.
Accomplishments
1. Prolonged virus shedding and antibody responses in SARS-CoV-2 (COVID) infected deer. SARS-CoV-2 (COVID) is known to infected humans and animals, although the range of susceptible animal hosts is unknown. As part of Animal Health Emergency Response Research, ARS scientists in Ames, Iowa, in 2020 conducted critical research on the susceptibility of various animal species to the COVID virus. Results indicated that white-tailed deer were susceptible to COVID and that wild deer had a high prevalence of infection. There was a need to characterize how long deer remain infected and test positive on antibody tests to allow interpretation of field sample data and understand disease prevalence in white-tailed deer. Data demonstrated that deer shed virus for long periods of time and can remain antibody positive for at least 320 days. This information allows understanding of the epidemiology of the COVID virus in the only known wildlife reservoir in the U.S. This work is of interest to wildlife officials, public health personnel, and researchers with an interest in the COVID virus.
2. Persistence of the COVID virus in elk. SARS-CoV-2 (COVID) is known to infect humans and animals. The range of susceptible animal hosts is unknown, although white-tailed deer are known to be susceptible. As part of the Animal Health Emergency Response Research, ARS scientists in Ames, Iowa evaluated the susceptibility of elk to the COVID virus. Results demonstrated that elk become infected and develop antibody responses after infection with the virus, but do not shed significant amounts of virus and are unlikely to transmit disease to other animals. The virus could be detected after 3 weeks in elk even though there was no evidence of virus shedding. This data helps understand the epidemiology of COVID in elk and provides information for analysis of surveillance data. Persistence of virus in elk could have both public and animal health implications in areas where human-elk interactions occur and transmission between elk and humans is possible. This work will be of interest to wildlife officials, public health personnel, and researchers with an interest in the COVID virus.
Review Publications
Sacco, R.E., Mena, I., Palmer, M.V., Durbin, R.K., Garcia-Sastre, A., Durbin, J.E. 2022. An intranasal recombinant NDV-RSV F opt vaccine is safe and reduces lesion severity in a colostrum-deprived calf model of RSV infection. Scientific Reports. 12(1). Article 22552. https://doi.org/10.1038/s41598-022-26938-w.
Hadi, S.A., Brenner, E.P., Palmer, M.V., Waters, W.R., Thacker, T.C., Vilcheze, C., Larsen, M.H., Jacobs, W.R., Sreevatasan, S. 2022. Mycobacterium bovis strain Ravenel is attenuated in cattle. Pathogens. 11(11). Article 1330. https://doi.org/10.3390/pathogens11111330.
Kudva, I.T., Biernbaum, E.N., Cassmann, E.D., Palmer, M.V. 2023. Bovine rectoanal junction in vitro organ culture model system to study Shiga toxin-producing Escherichia coli adherence. Microorganisms. 11(5). Article 1289. https://doi.org/10.3390/microorganisms11051289.
Palmer, M.V., Thacker, T.C., Kanipe, C.R., Boggiatto, P.M. 2021. Heterogeneity of pulmonary granulomas in cattle experimentally infected with Mycobacterium bovis. Frontiers in Veterinary Science. 8. https://doi.org/10.3389/fvets.2021.671460.
Palmer, M.V., Kanipe, C.R., Lehman, K.A., Thacker, T.C., Putz, E.J., Boggiatto, P.M. 2023. Vaccination of white-tailed deer with Mycobacterium bovis bacillus calmette-guérin (BCG): effect of Mycobacterium avium ssp. paratuberculosis infection. Microorganisms. https://doi.org/10.3390/microorganisms11102488.
Boggiatto, P.M., Kanipe, C.R., Putz, E.J., Olsen, S.C., Palmer, M.V. 2023. Wildlife immune responses to Mycobacterium bovis and to bacille of calmette-guerin. Journal of Immunology. https://doi.org/10.4049/jimmunol.2300323.
O'Brien, D.J., Thacker, T.C., Salvador, L.C., Duffiney, A.G., Robbe-Austerman, S., Camacho, M.S., Lombard, J.E., Palmer, M.V. 2023. The devil you know and the devil you don’t: current status and challenges of bovine tuberculosis eradication in the United States. Irish Veterinary Journal. https://doi.org/10.1186/s13620-023-00247-8.
Boggiatto, P.M., Buckley, A.C., Cassmann, E.D., Seger, H., Olsen, S.C., Palmer, M.V. 2024. Persistence of viral RNA in North American elk experimentally infected with an ancestral strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Scientific Reports. 14. Article 11171. https://doi.org/10.1038/s41598-024-61414-7.
Boggiatto, P.M., Kanipe, C.R., Palmer, M.V. 2021. Enhanced detection of Mycobacterium bovis-specific T cells in experimentally-infected cattle. Frontiers in Veterinary Science. https://doi.org/10.3389/fvets.2021.676710.
Wilson-Welder, J.H., Han, S., Bayles, D., Alt, D.P., Kanipe, C.R., Garrison, K., Mansfield, K., Olsen, S.C. 2024. Correlation of lesion severity with bacterial changes in Treponeme-associated hoof disease from free-roaming wild elk (Cervus canadensis). Animal Microbiome. 6. Article 20. https://doi.org/10.1186/s42523-024-00304-9.