Date of Award


Degree Type


Degree Name

Master of Science (MS)


Food Science

Committee Chair

Haley Oliver

Committee Member 1

Amanda Deering

Committee Member 2

Charilaos Mousoulis


Transmission pathways of pathogenic bacteria are one of the most relevant fields of research because of its direct impact not only on the public health but also on the economy. Identifying the critical factors for bacteria spreading through the population provide new tools for the prevention of disease and risk management. Clostridium difficile is the primary causative of antibiotic-associated diarrhea in healthcare settings. C. difficile infection (CDI) symptoms range from mild diarrhea to pseudomembranous colitis and can result in death. Awareness of the microorganism is extremely low, and the understanding of it is far from complete. Because of this, the control, prevention, and treatment of the disease is a challenge. It has been demonstrated that C. difficile bacterial spores heavily contaminate surfaces, stating a clear transmission vehicle. However, eradication of these spores from surfaces is still a challenge, mainly because there is not yet a high market demand for this. In this project, a protocol for detection of bacterial spores from environmental surfaces was developed. The proposed method can detect concentrations as low as 100 CFU/ml after enrichment processes. This method can be used for future studies of C. difficile presence on hospital environments and the validation of spore eradication techniques.

In parallel, Listeria monocytogenes is one of the most relevant foodborne pathogens in the ready-to-eat food industry. Despite the relatively low incidence of listeriosis cases in the population, the mortality rate of the disease is as low as 15%, which is significantly higher when compared to other foodborne diseases. Several studies have focused on the risk management and prevention of the disease; however, outbreaks are still prevalent throughout the world. Cross-contamination and temperature abuse of the food products seem to be one of the major causatives for these outbreaks. Here, a new time-temperature monitoring (TTM) sensor for the cold chain management is employed to reduce the consumer exposure to mishandled and potentially contaminated products. The demonstrated wireless sensor is capable of providing real-time data during at least two weeks. In combination with microbial growth models, the use of the sensor will facilitate the identification of potentially highly contaminated products before these reach the consumer.