Date of Award

Spring 5-9-2020

Document Type

Honors Thesis



First Advisor

Dr. Jake Kerby

Second Advisor

Dr. Andrea Liebl

Third Advisor

Beate Wone


Batrachochytrium dendrobatidis, Chytridiomycosis, Serratia marcescens, Genetic engineering

Subject Categories

Animal Diseases | Behavior and Ethology | Biodiversity | Integrative Biology | Microbiology | Other Animal Sciences


The fungal pathogen Batrochochytrium dendrobatidis (Bd) has been threatening amphibian populations across the globe. Recent work has discovered that bacteria isolated from certain populations of amphibians protect hosts from this pathogen. This project focuses on the anti-fungal mechanisms of Serratia marcescens, a species of bacteria isolated from a Costa Rican frog that dramatically inhibited Bd in culture. Wild-type and recombinant S. marcescens was introduced to the microbiomes of a live amphibian host, Acris blanchardi (Blanchard’s Cricket Frog) and then challenged with Bd to examine the protective effects of this bacteria. The experiment includes recombinant S. marcescens with the genetic pathway responsible for the production of prodigiosin interrupted. This work observed significantly greater movement among frogs treated with wild-type Sm when compared to the other bacteria treatments. There were also significant differences in mean mass and snout-vent length (SVL) between the washed and unwashed treatments. In particular, mean SVL was greater in washed frogs compared to unwashed frogs of the wild-type Sm and no bacteria treatments. These efforts will aid in the future conservation of amphibian species worldwide.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.