FISHING FOR PHYCOTOXINS IN SHELLFISH
Toxic contamination is the main reason for health authorities to ban harvesting and sale of aquacultured shellfish. As it can cause major economic damage to this industry, adequate testing for shellfish toxins is crucial. In Europe, the broad spectrum mouse or rat bioassay is the only official detection method for such toxins. This method is expensive and occasionally produces false positive and false negative results. It requires killing animals and is simply unable to cope with the number of toxin groups that must be detected according to new European Union regulations. The nine partners of the Specific Targeted Research Project DETECTOX aim to develop a fast, versatile biosensor employing surface plasmon resonance (SPR) technology. This new tool will detect shellfish toxins with better accuracy, greater ease and lower cost, helping to protect human health and safeguard the shellfish industry.
DANGERS OF THE DEEP
Shellfish poisoning is caused by phycotoxins produced by certain naturally occurring marine phytoplankton. These microalgae have been increasing in abundance worldwide and several new toxins have been identified in European seas, possibly carried by ballast waters in ships or due to shellfish farming, nutrient enrichment, climate change, or a decrease in algae predators. Meanwhile, many new toxin derivatives have been identified, but only a few of their structures are known. These bioactive toxins are thermo-resistant, so normal cooking, freezing or smoking cannot destroy them. It is virtually impossible to prevent their occurrence in the aquatic environment.
Several acceptable alternatives to the current bioassay exist to detect shellfish toxins, including enzyme-linked immunosorbent assay (ELISA) and HPLC followed by photometric detection. DETECTOX will develop an SPR-based biosensor, which offers advantages in terms of accuracy, rapidity, and robustness. The three-year STREP focuses on five main types of lipophilic phycotoxins that pose a serious health hazard to humans when present above certain limits in bivalve molluscs, echinoderms, tunicates or marine gastropods. It will acquire and purify them for use as reference standards in calibrating the biosensor. It will then produce polyclonal antibodies for the toxins by immunisation of sheep, rabbits and mice, for use as binding molecules in the assay. Having produced an optimised biosensor chip, it will be compared with accepted methods.
The new multi-channel SPR biosensor will feature a simplified sample preparation technique able to deal with larger batch sizes and ready to reuse immediately after previous usage. It will be capable of quickly detecting a range of toxins in the same extract, calculating concentrations immediately after the analytical cycle ends. It will be usable in laboratories and at on-site locations, such as on ships or in markets, and will not necessitate the killing of animals.
Throughout the project, DETECTOX will disseminate its findings to the scientific community, forming links with other related Commission food safety projects, and to end-users and regulatory and industrial decisionmakers. It will create an online database for marine phycotoxins. The new test could be adapted for use in detecting other, more lethal, but less prevalent, shellfish toxins. In addition to the improved quality and safety of aquacultured seafood, better toxin detection will contribute to the wider knowledge required to enhance problem-management strategies.
List of Partners
- Universidade de Santiago de Compostela (Spain)
- Xenosense (UK)
- Centre National de la Recherche Scientifique (France)
- Queen's University Belfast (UK)
- Asociación Nacional de Fabricantes de Conservas de Pescados y Mariscos (Anfaco) (Spain)
- Ege University (Turkey)
- National Reference Laboratory on Marine Biotoxins (Greece)
- European Community Reference Laboratory of Marine Biotoxins (Spain)
- Full title:
- Development of an SPRbased biosensor for the detection of lipophilic phycotoxins in shellfish residues
- Contract n°:
- EC Scientific Officer:
- Maria Spulber, Maria.Spulber@ec.europa.eu
- EU contribution:
- € 802,847
- Specific Targeted Research Project