Discovery Park Undergraduate Research Internship Program

"Examination of the persistence, movement, and possible internalization of Listeria monocytogenes in cantaloupe (Cucumis melo)"

About the Project

Project Time & Type:
Summer 2012 - DURI
Research area(s):
Plant biology, microbiology, food safety
Project Description:
Listeria monocytogenes is a human pathogenic bacterium that is an increasing public health concern for the fresh produce industry. In the fall of 2011, a total of 146 people from 28 states were infected with Listeria monocytogenes that resulted in 30 deaths. This multistate outbreak of listeriosis was linked to whole cantaloupes that originated from Jensen Farms in Colorado. The focus of this project is to better understand the interactions the bacterium has with the plant that may have contributed to the contamination of the melons. Classical microbiological techniques will be utilized to determine the growth and persistence of 4 strains of Listeria monocytogenes that were implicated in the Jensen Farms outbreak using 4 different cultivars of cantaloupe. In addition, the possible internalization of the bacterium within the plant tissue will be examined using immunocytochemical techniques previously developed in our lab. Together, this will provide information into the ability of the bacterium to survive within the plant. This study will also provide insight into the possibility that the mature cantaloupe fruit could harbor internalized Listeria monocytogenes cells that would be protected from various sanitization treatments and serve as a vehicle of transmission of the bacterium to consumers.
Expected Student Contributions:
The DURI student will be trained and work closely with a Post-Doctoral Research Associate throughout the project. The student will learn basic microbiological techniques such as growing cultures, serial dilutions, and plating plant tissue samples contaminated with Listeria monocytogenes for enumeration of the bacterium. The student will also learn histological based techniques such as tissue fixation, paraffin embedding, and sectioning of the tissue. In addition, the student will learn immunocytochemical techniques for the localization of the bacteria within the plant tissue using fluorescence microscopy.
Related Website(s):
Desired Qualifications:
Coursework in biology, microbiology, or food microbiology is mandatory. Previous experience working in a lab and an interest in microbiology, food safety, botany, and/or microscopy is desired and would be beneficial, but not required.
Estimated Weekly Hours:
Department awards independent research credits for this project?

Professor in Charge

Oliver, Haley
Department of Food Science

Student Supervisor

Amanda Deering
Postdoctoral Research Associate

Cooperating Faculty

Robert Pruitt
Botany and Plant Pathology/Agriculture