Theses and Dissertations

Issuing Body

Mississippi State University


Donaldson, R. Janet

Date of Degree


Document Type

Graduate Thesis - Open Access


Biological Sciences

Degree Name

Master of Science


College of Arts and Sciences


Department of Biological Sciences


Listeria monocytogenes is an enteric pathogen that can replicate within bile, yet this capability differs between strains. This project analyzed whether the pathogenic potential of the strain affects the ability to resist bile. We tested this hypothesis by examining the effect of bile on the morphology of a virulent strain (EGD-e) and an avirulent strain (HCC23) under aerobic and anaerobic conditions. Our data showed that exposure to bile greatly impacted the growth of HCC23. Additionally, scanning electron microscopy and transmission electron microscopy analyses indicated that bile affects the cell envelope of EGD-e and HCC23 differently. Our results suggest that differences exist in the ability of EGD-e and HCC23 to survive and replicate in the presence of bile. We propose that the virulence capability of L. monocytogenes directly correlates to its ability to resist the detergent properties of bile.