A precise and powerful technique for detecting toxins in shellfish is a step closer to being accepted as a worldwide standard after validation by New Zealand’s IRL Measurement Standards Laboratory (MSL) and endorsement from the United States Food and Drug Administration (FDA).
Based on an analytical chemistry technique called LCMS, the test was developed by Nelson-based Cawthron in 2000 out of research it had been conducting since the early 1980s. MSL encouraged Cawthron to come up with the chemical test after an outbreak of shellfish poisoning in New Zealand in 1993 caused by people eating shellfish contaminated with a class of natural toxins called brevetoxins. Cawthron became the first laboratory in the world approved to use the test.
The test provides a more efficient, accurate and sensitive method of detecting toxins in shellfish, says Cawthron’s technical manager Paul McNabb, and leads to fewer product recalls. The existing testing method required by international regulators is a mouse bioassay which is a laborious process involving mice of specified body weight and the use of large amounts of chemicals which can be dangerous and difficult to handle. There is no standardised mouse bioassay protocol and the test is not validated, meaning results can vary considerably.
However, it has been challenging for Cawthron to get its test accepted by international regulatory authorities despite its proven efficacy and the growing global concern about live animal testing.
“The European Union in particular has been a sticking point,” says McNabb. “Despite the ethical issues around using live animals in testing and the fact that the test is working really well in New Zealand, it’s been a slow process to have the LCMS system accepted as the new standard.”
Enter IRL’s MSL, which recognised the need for validation and the potential for New Zealand to make a significant contribution to a global issue. It handed the task to Cawthron and the Virtual Institute for Metrology in Chemistry and Biology (VIMC), an IRL-led initiative which combines New Zealand experts into a single web-centred organisation.
Head of the VIMC, Dr Laly Samuel from IRL, says the initiative is a way of linking geographically scattered centres of excellence in New Zealand and the Measurement Standards Laboratory and connecting them to other user laboratories and trade and regulatory users of analytical results.
The validation is already adding weight to the test on the international stage with researchers at the FDA now advocating its use as a total replacement for the mouse bioassay around the world.
Robert Dickey, supervisor of the FDA’s Chemical Hazards Research Unit, says alternative testing methods will be welcomed by the international scientific community.
“As an international, collaborative effort, we must move away from live animal testing where it is manifestly and demonstrably unnecessary and indeed, inferior, to alternative methods. It is past time that support be granted to this final transition to modern public health protection measures.”
Apart from solving ethical issues, McNabb says the key advantage of the LCMS test is that it can be validated and verified. “This is significant for international trade because in a trade dispute over a mouse bioassay result it can’t be established whether or not the result is wrong. However, if the test is based on metrology, we can find out why something certified as safe here in New Zealand has produced a different result in another country.”
Dr Samuel says validation of the test by the VIMC will help New Zealand set a new global standard in preventing shellfish poisoning.
“It will help our industry maintain its reputation for food safety and confirm that New Zealand is a world leader in this field.”