Tetrodotoxins Occurrence in Non-Traditional Vectors of the North Atlantic Waters (Portuguese Maritime Territory, and Morocco Coast).

Marisa Silva,Amparo Alfonso,Manfred Kaufmann,Meryem Hassouani,Vitor Vasconcelos,Luis M Botana,Brahim Sabour,Ana Isabel Neto,Inés Rodríguez,Aldo Barreiro

doi:10.3390/toxins11060306

Abstract

Tetrodotoxin (TTX) is a potent alkaloid typically from tropical ecosystems, but in the last decade its presence has been more pronounced in the temperate waters of the Atlantic. In its last scientific opinion, the European Food Safety Authority (EFSA) stressed the need for data regarding TTX prevalence in European waters. To address EFSA’s concerns, benthic organisms such as mollusks, crustaceans, echinoderms and fish with different feeding habits were collected along the Portuguese continental coast, islands (São Miguel, Azores, and Madeira) and the northwestern Moroccan coast. A total of 165 samples were analyzed by ultra high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) and ultra high performance chromatography mass spectrometry (UHPLC-MS/MS). Geographical tendencies were detected as follows, by descending order: S. Miguel Island (Azores), Moroccan coast, Madeira Island and Portuguese continental coast. The toxin amounts detected were significant, above the Dutch limit value established in 2017, showing the importance and the need for continuity of these studies to gain more knowledge about the prevalence of these toxins, unraveling new vectors, in order to better assess human health risk. This work represents a general overview of new TTX bearers (7) most of them in gastropods (Patella depressa, Nucella lapillus, Onchidella celtica and Aplysia depilans), followed by echinoderms (Echinus esculentus and Ophidiaster ophidianus) and puffer fish Sphoeroides marmoratus.

Highlights

Tetrodotoxin (TTX) is an extremely potent alkaloid typical from warm ecosystems that over recent years became more frequent in temperate waters [1,2,3]
A total of 165 samples collected from 25 different sampling points (Figure 1) were screened using the techniques of ultra high performance chromatography mass mass spectrometry (UHPLC-MS/MS)
The primary aim of this work was to search for new vectors for TTXs off the Portuguese coast, islands and the northwestern coast of Morocco using UHPLC-HRMS and UHPLC-MS/MS

Summary

Introduction

Tetrodotoxin (TTX) is an extremely potent alkaloid typical from warm ecosystems that over recent years became more frequent in temperate waters [1,2,3]. TTX is a crystalline weakly basic heterocyclic molecule with six hydroxyl groups, a pyridine ring with additional fused ring systems and a guanidinium group, positively charged at a physiological pH, with a molecular formula of C11 H17 O8 N3 (Table 1) [1]. This powerful alkaloid exhibits its action by binding selectively and extracellularly to receptor-site 1 of voltage-gated sodium channels (Nav s), once it mimics the sodium hydrated cation, occluding the outer pore. The rise of water temperature together with anthropological intervention aided the migration and establishment of this neurotoxin typically from tropical ecosystems, the Pacific and Indian oceans, into European waters, where it has become more prevalent in the last decade [13,14,15,16,17]

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