Vibrio in oysters and clams in North Carolina
The role of salinity and temperature in Vibrio concentrations in oysters
In a collaborative project that included the University of North Carolina at Charlotte, the University of North Carolina at Chapel Hill - Institute of Marine Sciences, and the North Carolina Division of Marine Fisheries, oysters were continuously collected from sites in coastal North Carolina for over two years. An easy-to-read matrix tool was developed to estimate the number of V. vulnificus cells in water and oysters in NC. This tool can be used by anyone by simply measuring the temperature and salinity of the water in which the oysters are harvested.
An inexpensive thermometer and salinity meter (refractometer) can be purchased from the following links:
To use the following tool, simply measure the temperature and salinity of the water covering or around the oysters you wish to harvest. Next, simply find the point on the chart where the salinity (bottom of graph) and temperature (left side of graph) meet.
V. vulnificus in oysters
V. vulnificus in water
For example, if the measured temperature was 24 degrees celsius, and the salinity was 20 parts per thousand, the intersection of those two lines would be in the yellow region of the graph. Indicating that there are likely ~3000 V. vulnificus cells per gram of oyster meat.
For further details and methods, please refer to the publication in Applied and Environmental Microbiology
Brittney Phippen, Mezrop Ayrepetyan, Tiffany Williams, Leigh Robertson
Kelsey Jesser, Justin Hart, Denene Blackwood, Mary-Jo Weiss, Katie Dugan
Patti Fowler, Shannon Jenkins, Paul Moore, Mike Millard, Timmy Moore, Phil Piner, Steve Murphy
BA Froelich, B Phippen, P Fowler, RT Noble, and JD Oliver; Differences in total Vibrio spp. V. vulnificus, and V. parahaemolyticus abundance between clams and oysters in North Carolina, 2017, Applied and Environmental Microbiology, 83:2
Froelich, BA; Ayrapetyan, M; Fowler, P; Oliver, JD; and Noble, RT; 2015; The development of a matrix tool for the prediction of potentially pathogenic Vibrio species in oysters harvested from North Carolina; Applied and Environmental Microbiology; 81(3), 1111-1119
TC Williams, BA Froelich, B Phippen, P Fowler, RT Noble, and JD Oliver; Different abundance and correlational patterns exist between total and presumed pathogenic Vibrio vulnificus and V. parahaemolyticus in shellfish and waters along the North Carolina coast; 2017; FEMS Microbiology Ecology; 93:6
Vibrio vulnificus and Vibrio parahaemolyticus in North Carolina oysters and clams, Invited Presentation to the 1st Oyster Symposium, presented by Oyster South, January 2017
The state of Vibrio research in North Carolina; Invited Presentation to the Southern California Coastal Water Research Project, December 2016
Clams and oysters have different Vibrio concentrations despite being harvested from the same site; Presented at the 2016 UNC Water Microbiology Conference, Chapel Hill, NC, May 2016
Differences in Vibrio vulnificus and Vibrio parahaemolyticus ecology between clams and oysters collected from the same location, Presented at the 2016 International Conference on Vibrio; Roscoff, France
JD Oliver, BA Froelich, RT Noble, B Phippen; A long term study on the interaction of Vibrio vulnificus and V. parahaemolyticus with oysters and clams; Presented at the 11th International Conference on Molluscan Shellfish Safety; Galway, Ireland, 2017
TC Williams, BA Froelich, B Phippen, P Fowler, RT Noble, and JD Oliver; Long-term assessment of V. vulnificus clinical and environmental genotype distributions in environmental samples from the North Carolina coast; Presented at the 2016 International Conference on Vibrio, Roscoff, France
B.A. Froelich, M. Ayrapetyan, P. Fowler, J.D. Oliver, and R.T. Noble; 2015; Risk matrix tools for predicting pathogenic Vibrio spp. in oysters harvested from North Carolina; Presented at the 2015 National Institute of Food and Agriculture, United States Department of Agriculture, Washington, D.C.
B.A. Froelich, M. Ayrapetyan, P. Fowler, R.T. Noble, and J.D. Oliver; 2014; The development of a decision matrix tool for predicting pathogenic Vibrio spp. in oysters harvested from North Carolina, USA; Presented at Vibrio 2014, Edinburgh, Scotland