Masters Thesis Defense: Mark Stoops

The Masters Thesis Defense of Mark Stoops is presented by the University of North Carolina at Chapel Hill’s Department of Earth, Marine and Environmental Sciences. This event will be held on Wednesday, November 3rd at 10:00 am. This event will be held in person and will also be streamed online. The physical location of the event is off campus on the coast in room 222 at the Institute of Marine Sciences, 3431 Arendell Street, Morehead City, NC. To watch online join via Zoom Meeting ID 942 4010 6524 .

Title: The effects of time to temperature on North Carolina oysters: implications for Vibrio-associated risk

Abstract:V. vulnificus and V. parahaemolyticus bacteria can accumulate in oysters and are a leading cause of disease from consumption of raw or undercooked seafood. It is common practice for shellfish destined for raw consumption to experience periods of ambient exposure after harvest before they are cooled using ice slurries or mechanical refrigeration. Time spent at ambient temperatures may provide opportunity for pathogenic species of V. vulnificus and V. parahaemolyticus to multiply to dangerous levels. In this study, we monitored the growth of V. vulnificus and V. parahaemolyticus in both ambient exposure and cold storage experiments and found a significant increase in V. vulnificus after 48 hours of ambient exposure, as well as slow inactivation rates in cold storage. A secondary objective of this study was to examine oyster mantle fluid as an alternative matrix to whole oyster homogenate. Current Vibrio monitoring assays rely on the use of composite samples of whole oyster meats as a standard matrix, while the use of mantle fluid has the potential to improve the frequency of monitoring, cost effectiveness, assay efficiency, and ease of use. Our study shows that there is not a significant difference between V. vulnificus and V. parahaemolyticus concentrations between homogenate, mantle fluid, and oyster tissue. Taken together, this work furthers our understanding of current shellfish regulations in North Carolina and provides an initial body of work for evaluating mantle fluid as an alternative matrix.