Application of Six Detection Methods for Analysis of Paralytic Shellfish Toxins in Shellfish from Four Regions within Latin America.

Andrew D Turner,Dinorah Medina,Fernanda Barrera,Daniel Carrasco,Maria Salhi,Alejandra B Goya,Ignacio Rubilar,Frances Van Dolah,Robert G Hatfield,Maggie Broadwater,Sophie Tarnovius,Ernesto Garcia-Mendoza,Mickael Teixeira Alves,Benjamin A Suarez-Isla

doi:10.3390/md18120616

Abstract

With the move away from use of mouse bioassay (MBA) to test bivalve mollusc shellfish for paralytic shellfish poisoning (PSP) toxins, countries around the world are having to adopt non-animal-based alternatives that fulfil ethical and legal requirements. Various assays have been developed which have been subjected to single-laboratory and multi-laboratory validation studies, gaining acceptance as official methods of analysis and approval for use in some countries as official control testing methods. The majority of validation studies conducted to date do not, however, incorporate shellfish species sourced from Latin America. Consequently, this study sought to investigate the performance of five alternative PSP testing methods together with the MBA, comparing the PSP toxin data generated both qualitatively and quantitatively. The methods included a receptor binding assay (RBA), two liquid chromatography with fluorescence detection (LC-FLD) methods including both pre-column and post-column oxidation, liquid chromatography with tandem mass spectrometry (LC-MS/MS) and a commercial lateral flow assay (LFA) from Scotia. A total of three hundred and forty-nine shellfish samples from Argentina, Mexico, Chile and Uruguay were assessed. For the majority of samples, qualitative results compared well between methods. Good statistical correlations were demonstrated between the majority of quantitative results, with a notably excellent correlation between the current EU reference method using pre-column oxidation LC-FLD and LC-MS/MS. The LFA showed great potential for qualitative determination of PSP toxins, although the findings of high numbers of false-positive results and two false negatives highlighted that some caution is still needed when interpreting results. This study demonstrated that effective replacement methods are available for countries that no longer wish to use the MBA, but highlighted the importance of comparing toxin data from the replacement method using local shellfish species of concern before implementing new methods in official control testing programs.

Highlights

Paralytic shellfish toxins (PSTs) are harmful neurotoxins originating from phytoplankton of the generaGymnodinium, andareAlexandrium that periodically accumulate in shellfish throughParalytic shellfishPyrodinium toxins (PSTs) harmful neurotoxins originating from phytoplankton of the filter feeding.These may result in sickness and even fatalities following human consumption of genera Gymnodinium, Pyrodinium and Alexandrium that periodically accumulate in shellfish through contaminated shellfish products [1,2].The toxins are members of the saxitoxin family, which contain filter feeding
Out of the 349 shellfish samples analysed by pre-column oxidation (PreCOX) liquid chromatography with fluorescence detection (LC-FLD) in this study, total toxicities were found to vary enormously, with 62 samples showing paralytic shellfish poisoning (PSP) < 16 μg STX eq./kg and toxicities reaching a maximum of >400,000 μg STX eq./kg in a mussel sample originating from Argentina
Total PST concentrations generated by the two LC-FLD methods and LC-MS/MS were used to estimate sample toxicities, which could be compared with total PSP toxicities determined by mouse bioassay (MBA)

Summary

Introduction

Paralytic shellfish toxins (PSTs) are harmful neurotoxins originating from phytoplankton of the generaGymnodinium, andareAlexandrium that periodically accumulate in shellfish throughParalytic shellfishPyrodinium toxins (PSTs) harmful neurotoxins originating from phytoplankton of the filter feeding.These may result in sickness and even fatalities following human consumption of genera Gymnodinium, Pyrodinium and Alexandrium that periodically accumulate in shellfish through contaminated shellfish products [1,2].The toxins are members of the saxitoxin family, which contain filter feeding. Paralytic shellfish toxins (PSTs) are harmful neurotoxins originating from phytoplankton of the genera. Paralytic shellfishPyrodinium toxins (PSTs) harmful neurotoxins originating from phytoplankton of the filter feeding. These may result in sickness and even fatalities following human consumption of genera Gymnodinium, Pyrodinium and Alexandrium that periodically accumulate in shellfish through contaminated shellfish products [1,2]. The toxins are members of the saxitoxin family, which contain filter feeding. These may result in sickness and even fatalities following human consumption of over 55 structurally related compounds [3]toxins Toxicityofrelates to the action the toxins on contaminated shellfish products [1,2]. Toxicity to theand action of thewith toxins on doses causing paralysis and death by asphyxiation [4,5]

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Discussion

Conclusion