Growth and survival differences of Vibrio vulnificus and Vibrio parahaemolyticus strains during cold storage.

Vibrio vulnificus and Vibrio parahaemolyticus are the most common Vibrio species associated with seafood illness in the United States. Our study was conducted to determine if strain-to-strain differences exist in the growth and survival of 8 different V. vulnificus and V. parahaemolyticus strains at low temperatures. By day 10, V. vulnificus strain 515-4C2 had significantly higher counts (P < 0.05) (1.97 log CFU/g) compared with strains 3315, 1007, 29306 at 5 degrees C, which reached nondetectable levels. At 8 degrees C, strain 515-4C2 had significantly higher counts (P < 0.05) (2.23 log CFU/mL) compared with 1007, 33815, 541(O) 49C, which reached nondetectable levels. At 10 degrees C, only V. vulnificus strain 33815 reached nondetectable levels. At 5 degrees C, V. parahaemolyticus strain 541(O) 57C had the highest counts (5.28 log CFU/g) by day 10 while strain 33847 had significantly lower counts (3.46 log CFU/g). After 10 d at 8 degrees C, V. parahaemolyticus strain M350A had the highest counts (7.97 log CFU/mL) while strain 541(O) 57C had the lowest counts (4.80 log CFU/mL). At 10 degrees C, V. parahaemolyticus strain NY477 had significantly higher counts (P < 0.05) with 8.31 log CFU/mL compared with strain 33847, which had the lowest counts (6.77 log CFU/mL). Our research has shown that various V. vulnificus and V. parahaemolyticus strains vary in their ability to survive and grow at refrigeration temperatures.