Date of Graduation


Document Type


Degree Name

Master of Science in Food Science (MS)

Degree Level



Food Science


Steven C. Ricke

Committee Member

Steven L. Foley

Second Committee Member

Young Min Kwon


Biological sciences, Food safety, Microbiology, Salmonella


This thesis consists of four research parts: a literature review that covers Salmonella spp., one of the more prominent foodborne pathogens that represents a major risk to humans (chapter 1). Understanding the growth of Salmonella serovars and strains is an important basis for more in depth research. In this case we studied a) the aerobic and anaerobic growth responses of multiple strains from six different serovars, b) how the spent media from different serovars, more importantly S. Heidelberg, affect the growth of S. Typhimurium, and c) determined whether or not two different serovars undergo competitive interactions when they were grown together (chapter 2). Growth responses of four Salmonella serovars, Heidelberg, Kentucky, Typhimurium, and Enteritidis in enrichment and non-enrichment media were compared to determine the effectiveness of a non-selective enrichment media, such as Luria Bertani broth over selective enrichment methods (chapter 3). Since antimicrobial resistance continues to be one of the major concerns about Salmonella, and consumers are demanding more natural antimicrobials we studied the effectiveness of five essential oils against Salmonella Heidelberg. Besides being one of the top five Salmonella enterica serovars associated with human infections, S. Heidelberg is the primary focus for our research (chapter 4). Given that Salmonella enterica are important facultative intracellular pathogens that are widely known to be isolated from poultry and to cause infections in humans, understanding the ability of this pathogen to attach and invade different cell types is of great importance. We studied the adhesion and invasion of four different strains to chicken macrophage (HD11), and human epithelial (Caco-2) cells (chapter 5).