Oyster aquaculture is a growing industry that contributes to the production of sustainable seafood. Oysters may accumulate microbial human pathogens during filter feeding and, as they are often eaten raw, there are seafood safety concerns associated with their consumption. The current FDA-approved testing methods for these species in oysters are time consuming and/or require extensive resources to conduct, which limits the ability to investigate Vibrio at the farm level. To improve understanding of Vibrio at a finer scale, simple and inexpensive biphasic assays have been developed that produce results in approximately 24 hours (Fig. 1). These assays can be performed by oyster farmers without specialized equipment, improving knowledge of Vibrio abundances at specific sites and providing opportunities to test practices that reduce these potential pathogens, leading to increased safety for the consumer.
This project, funded by a two-year grant, seeks to 1) expand the use of Vp and Vv biphasic assays to oyster farms in the northern Gulf of Mexico (GoM), 2) assess the assays for specificity, ruggedness, and comparability to FDA-approved methods, and 3) develop a proficiency test for participating growers. This presentation will provide a one-year update on these objectives. To date, a laboratory has been established at one commercial GoM farm. Vp assays are rugged, performing statistically the same with different lots of reagents. Testing on mantle fluid demonstrates that Vp levels are stable with refrigeration for up to 3 days (Fig. 2), indicating it can be used for proficiency testing. Use of mantle fluid provides a real-world robust challenge that incorporates diverse natural strains and competing bacteria while avoiding “dangerous goods” shipping status required for laboratory inoculated pathogens.