New way to detect fish poison ciguatera
Imagine eating a piece of fish that looks, smells and tastes completely normal, but a few hours ater you're stuck in the toilet, vomiting and with tingling in your arms and legs. Well, this can happen if the fish you eat is contaminated with ciguatera toxin. This affects fish in tropical waters that eat a dinoflagellate species of algae that make the toxin. It affects between 20-60 thousand people every year and is the most common form of food poisoning caused by a natural toxin.Testing fish for the toxin has up until now been a lengthy and time consumingprocess, involving injecting purified samples into mice, and watching to see ifthey become ill. Now Kentaro Yogi and his colleagues in Japan have developeda much faster and effective way of testing for the toxin, which has also allowedthem to identify 15 different forms of the toxin present in fish species caught in different areas, as well as identifying differences in the dinoflagellates responsible for producing the toxin.The team used liquid chromatography tandem mass spectrometry to analyse thetoxins, which were extracted and purified in a similar way to the mouse bioassaymethod. The peaks obtained from the analysis were compared with known referencesamples of the toxins and they accurately showed the separate toxins found. Theteam believe that with the production of more reference samples of the various toxins from extraction from natural sources and through synthetic chemistry, this method of detection could become widespread and would improve the speed and accuracy of testing for this unpleasant toxin.