B16001: A study to identify the causative agent(s) responsible for atypical responses in the DSP MBA from cockles and other relevant shellfish material using LC-MS

Study Duration: May 2003 to October 2003

Contractor: Laboratory of the Government Chemist (LGC)

Since 2001, the algal biotoxin monitoring programme has detected atypical positive responses to the diarrhetic shellfish poisoning (DSP) mouse bioassay (MBA) from a number of cockles (and a few mussels) harvested around the coast of England, Wales and Northern Ireland. The FSA commissioned LGC to undertake a study to try to detect, and possibly identify, the causal agent(s) responsible for atypical responses to the DSP MBA.

Crude shellfish extracts will be initially screened using liquid chromatography-mass spectometry (LC-MS), LC-fourier transform ion cyclotron resonance (LC-FTICR) and a type of LC-MS known as LC-MSⁿ. Sophisticated separation technologies will then be used in combination with these detection methods to look for metabolites or related compounds of some known toxins and to see if any unusual signals stand out as being unique to the samples causing the atypical responses in the MBA.

Since 2001, the algal biotoxin monitoring programme has detected atypical positive responses in the test for diarrhetic shellfish poisoning (DSP) for some cockle (and a few mussel) samples harvested from around the coast of England, Wales and Northern Ireland.

The FSA commissioned LGC (Laboratory of the Government Chemist) to undertake a study to try to detect, and possibly identify, the causal agent(s) responsible for atypical responses to the test. The study used liquid chromatography-mass spectrometry (LC-MS) to look for metabolites or related compounds of some known toxins and to see if any unusual signals stood out as being unique to the samples causing the atypical responses in the test.

No fragments of four known DSP toxins (okadaic acid, spirolides, pectenotoxin and gymnodimine) were detected in any of the atypical extracts examined. A number of other candidate fragments were found that generally had a higher mass than the known DSP toxins tested. However, there were not enough data to draw any firm conclusions about whether these fragments caused the atypical results.

More work would be required to prove or disprove whether there is an association between these fragments and the atypical response. Consideration is being given to what further work should be undertaken to identify the agent causing this response.

Final report is available from the FSA Library and Information centre.
To obtain a copy, please contact the Enquiry Desk, Dr Elsie Widdowson Library and Information Services, Food Standards Agency Tel: 020 7276 8181/8182 or email: library&info@foodstandards.gsi.gov.uk