Vibrio in Oysters: Exploring the Impact of Harvesting Practices
Faculty Mentor
Dr John Carroll
Location
Russell Union Ballroom
If Other was choses above, please indicate your topic area here:
Seafood and Sustainability in Aquaculture
Type of Research
On-going
Session Format
Poster Presentation
College
College of Science & Mathematics
Department
Biology
Abstract
The rapid growth of oyster aquaculture in the Southeastern United States necessitates the validation of post-harvest processing strategies to mitigate the risk of Vibrio spp. infection. This study investigated the efficiency of three cooling methods - Direct Ice Burial, Indirect Ice Cooling, and Ambient Control- on the prevalence and abundance of V. cholerae, V. parahaemolyticus, and V. vulnificus in cultured oysters (Crassostrea virginica) harvested in Georgia. Additionally, the study examined the safety of the different re-submersion periods for oyster safety.
Internal temperature profiles confirmed that while Direct Ice Burial achieved the most rapid cooling (< 10° C in 7.3 ± 1.2 min), the Indirect Ice Cooling protocol successfully reached the safety threshold in 73.7 ± 17.2 min, well within the 2-hour regulatory window. Microbiological analysis (N=270) revealed that V. cholerae prevalence was significantly influenced by seasonality (P=0.0039) and cooling method (P=0.0014). Samples subjected to ambient temperature abuse were significantly more likely to harbor V. cholerae (OR = 6.32) and V. parahaemolyticus (P=0.0287) compared to cooled samples. Importantly, there was no significant difference in pathogen control between Direct and Indirect cooling (P=0.50), validating the use of indirect icing as a viable industry alternative.
A distinct seasonal divergence was observed in the efficacy of tidal resubmersion. A significant interaction between month and submersion (P=0.0129) was detected in September. In this late-season window, extending re-submersion to 14 days from day 10 resulted in a secondary re-infection, characterized by elevated V. cholerae detection and the emergence of V. vulnificus. These findings suggest that physiological exhaustion may compromise host immunity in late summer, rendering the standard depuration interval ineffective. This study recommends the use of indirect icing protocols, but cautions that re-submersion strategies must be seasonally adaptive to prevent pathogen resurgence.
Program Description
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Start Date
4-23-2026 10:00 AM
End Date
4-23-2026 12:00 PM
Recommended Citation
Yasar, Samin, "Vibrio in Oysters: Exploring the Impact of Harvesting Practices" (2026). GS4 Student Scholars Symposium. 55.
https://digitalcommons.georgiasouthern.edu/research_symposium/2026/2026/55
Vibrio in Oysters: Exploring the Impact of Harvesting Practices
Russell Union Ballroom
The rapid growth of oyster aquaculture in the Southeastern United States necessitates the validation of post-harvest processing strategies to mitigate the risk of Vibrio spp. infection. This study investigated the efficiency of three cooling methods - Direct Ice Burial, Indirect Ice Cooling, and Ambient Control- on the prevalence and abundance of V. cholerae, V. parahaemolyticus, and V. vulnificus in cultured oysters (Crassostrea virginica) harvested in Georgia. Additionally, the study examined the safety of the different re-submersion periods for oyster safety.
Internal temperature profiles confirmed that while Direct Ice Burial achieved the most rapid cooling (< 10° C in 7.3 ± 1.2 min), the Indirect Ice Cooling protocol successfully reached the safety threshold in 73.7 ± 17.2 min, well within the 2-hour regulatory window. Microbiological analysis (N=270) revealed that V. cholerae prevalence was significantly influenced by seasonality (P=0.0039) and cooling method (P=0.0014). Samples subjected to ambient temperature abuse were significantly more likely to harbor V. cholerae (OR = 6.32) and V. parahaemolyticus (P=0.0287) compared to cooled samples. Importantly, there was no significant difference in pathogen control between Direct and Indirect cooling (P=0.50), validating the use of indirect icing as a viable industry alternative.
A distinct seasonal divergence was observed in the efficacy of tidal resubmersion. A significant interaction between month and submersion (P=0.0129) was detected in September. In this late-season window, extending re-submersion to 14 days from day 10 resulted in a secondary re-infection, characterized by elevated V. cholerae detection and the emergence of V. vulnificus. These findings suggest that physiological exhaustion may compromise host immunity in late summer, rendering the standard depuration interval ineffective. This study recommends the use of indirect icing protocols, but cautions that re-submersion strategies must be seasonally adaptive to prevent pathogen resurgence.
