Donaldson, Janet R.
Thornton, Justin A.
Date of Degree
Graduate Thesis - Open Access
Master of Science
College of Arts and Sciences
Department of Biological Sciences
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.
Wright, Morgan Layne, "The Effect of Oxygen on Bile Resistance in Listeria Monocytogenes" (2015). Theses and Dissertations MSU. 4364.