Fluorescent probe could detect toxins in seafood

Scientists at the University of California at San Diego claim that a fluorescent probe could provide a tool for real-time toxin screening in shellfish and help put an end to seafood-related food poisoning, as reported by Chemistry World.

It is often thought that symbiotic bacteria play a key role in the biosynthesis of toxins from dinoflagellates, which are organisms commonly found in sea water that can, at times, be toxic. But this toxin-bacteria interaction has not been confirmed until now. Michael Burkart and colleagues at the University of California at San Diego have used their findings to develop a fluorescence microscopy tool to screen shellfish for toxin-producing dinoflagellates.

Burkart's team fluorescently labeled a protein that is taken up by the marine cells responsible for biosynthesizing the toxin okadaic acid. In-vivo studies clearly show that the samples producing the toxin glow fluorescent blue under the microscope. The samples that provide a positive response to the probe also show signs of symbiotic bacteria in the cell walls, confirming the toxin-bacteria association.

Using this information, Burkhart's assay is able to select mussels that contain live toxin producing dinoflagellates at different stages of infection by counting the number of cells that fluoresce. Imaging shellfish during dinoflagelate infection detects okadaic acid much quicker than present techniques, which can only detect the dinoflagellates once they have been fully absorbed into the shellfish tissue.

Burkhart says that if this method can be applied to an automated system, then it could prove to be a useful screening tool for the aquafarming industry.