Thesis
A mechanism for inter-epizootic plague persistence
Washington State University
Master of Science (MS), Washington State University
2014
Handle:
https://hdl.handle.net/2376/100202
Abstract
Yersinia pestis, the causative agent of the bubonic plague is responsible for several pandemics in human history. Sylvatic plague cycles in wild rodent populations and is transmitted by flea bite. These cycles are characterized by an epizootic period defined by rampant death of susceptible hosts and risk of human disease and an inter-epizootic period that supports persistence of the bacterium. Periods of persistence are not fully understood; however persistence of the plague bacterium in a telluric reservoir has been speculated. In this study we have explored the possibility of an alternate protozoan host for Y. pestis in the environment that could better explain the possibility of a telluric reservoir as a mechanism for plague persistence. We have assessed the ability of several Y. pestis and Y. pseudotuberculosis to survive and replicate inside the amoeba Acanthamoeba castellanii. We have observed that Y. pestis and Y. pseudotuberculosis can survive in A. castellanii trophozoites and cysts for up to 1 week post infection. Furthermore, we have observed that both the type III secretion system and the transcriptional regulator PhoP are important for intracellular survival in the model tested. Additionally, we have found that Y. pestis resided within spacious vacuoles inside A. castellanii. This presents the first report of the ability of the plague bacterium to survive within an amoeba host. This study highlights alternative mechanisms of plague maintenance and persistence during inter epizootic episodes, which can lead to establishment of improved detection methods to predict disease emergence.
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Details
- Title
- A mechanism for inter-epizootic plague persistence
- Creators
- Jennifer Santos
- Contributors
- Viveka Vadyvaloo (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Veterinary Medicine, College of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525102201842
- Language
- English
- Resource Type
- Thesis