Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Donaldson, Janet R.

Committee Member

Thornton, Justin A.

Committee Member

Jordan, Heather

Date of Degree

8-14-2015

Document Type

Graduate Thesis - Open Access

Major

Biological Sciences

Degree Name

Master of Science

College

College of Arts and Sciences

Department

Department of Biological Sciences

Abstract

Listeria monocytogenes is a Gram-positive facultative anaerobe that is the causative agent of the disease listeriosis and is responsible for nearly 20% of all food-related deaths in the United States. The ability of this bacterium to cause infections is proposed to correlate to its ability to resist the bactericidal properties of bile acids found in bile. Bile resistance mechanisms have exhibited increased activity under anaerobic conditions. Therefore, we hypothesized that limited oxygen could enhance the bile resistance of L. monocytogenes. Upon survival analysis, viability for virulent strains F2365, EGD-e, and 10403S increased upon 10% porcine bile extract under anaerobic conditions. However, avirulent strain HCC23 depicted no difference in bile resistance. The proteomic analysis revealed increased expression of proteins associated with DNA repair and virulence factors under anaerobic conditions in a strain dependent manner. Therefore, oxygen availability may contribute to bile resistance through the regulation of the SOS response.

URI

https://hdl.handle.net/11668/20120

Comments

anaerobiosis||acidity||bile||proteomics||stress responses

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