Electronic Theses and Dissertations

Identifier

975

Date

2013

Date of Award

11-25-2013

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Biology

Committee Chair

Matthew J Parris

Committee Member

Michael Ferkin

Committee Member

David Freeman

Committee Member

Stephan Schoech

Abstract

Due to the displacement of natural habitats by anthropogenic landscapes (e.g. agricultural fields), the use of agrochemicals (e.g. pesticides) has increased exponentially and non-target organisms such as amphibians are often at risk of exposure through direct overspray, runoff, or spraydrift. Because agricultural landscapes are encroaching on amphibian habitats, interactions likely occur between environmental pressures such as disease and contamination. Accordingly, I assessed the effects of pesticides on the amphibian pathogen Batrachochytrium dendrobatidis (Bd) host-pathogen interactions. As Bd-infected individuals have been found in agricultural-adjacent landscapes, pesticides can potentially alter host-pathogen interactions. In chapter two I demonstrated that pesticides can kill Bd outside of hosts. Chapters three and four demonstrated that pesticides differentially affect Bd in hosts post-infection. Chapter five demonstrated that a fungicide used in chapters one and three causes trophic cascades in aquatic systems, potentially negating the ameliorative effects of the pesticide on Bd both within and outside of hosts. Collectively, the work from my dissertation suggests that pesticides may alter host-pathogen dynamics in amphibians.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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