Paralytic Shellfish Toxins and Cyanotoxins in the Mediterranean: New Data from Sardinia and Sicily (Italy).

Antonella Lugliè,Maria Grazia Giacobbe,Anna Maria Bazzoni,Elena Riccardi,Anna Milandri,Silvia Pulina,Nicola Sechi,Bachisio Mario Padedda,Cecilia Teodora Satta,Daniela Stacca,Pasqualina Farina,Maria Antonietta Mariani,Tiziana Caddeo,Silvia Pigozzi,Milena Bruno

doi:10.3390/microorganisms5040072

Abstract

Harmful algal blooms represent a severe issue worldwide. They affect ecosystem functions and related services and goods, with consequences on human health and socio-economic activities. This study reports new data on paralytic shellfish toxins (PSTs) from Sardinia and Sicily (Italy), the largest Mediterranean islands where toxic events, mainly caused by Alexandrium species (Dinophyceae), have been ascertained in mussel farms since the 2000s. The toxicity of the A. minutum, A. tamarense and A. pacificum strains, established from the isolation of vegetative cells and resting cysts, was determined by high performance liquid chromatography (HPLC). The analyses indicated the highest toxicity for A. pacificum strains (total PSTs up to 17.811 fmol cell−1). The PSTs were also assessed in a strain of A. tamarense. The results encourage further investigation to increase the knowledge of toxic species still debated in the Mediterranean. This study also reports new data on microcystins (MCs) and β-N-methylamino-l-alanine (BMAA) from a Sardinian artificial lake (Lake Bidighinzu). The presence of MCs and BMAA was assessed in natural samples and in cell cultures by enzyme-linked immunosorbent assay (ELISA). BMAA positives were found in all the analysed samples with a maximum of 17.84 µg L−1. The obtained results added further information on cyanotoxins in Mediterranean reservoirs, particularly BMAA, which have not yet been thoroughly investigated.

Highlights

Harmful algal blooms (HABs) are recognized as one of the major threats in aquatic ecosystems worldwide [1,2,3,4]
The results from this study encourage further investigation to increase the knowledge of toxic species still debated in the Mediterranean region and on cyanotoxins not investigated enough in this geographical area, as well as worldwide
The present work has revealed the highest toxicity of A. pacificum among the analysed strains and has documented the presence of paralytic shellfish toxins (PSTs) in a Mediterranean strain of A. tamarense, highlighting the need for the further investigation of A. tamarense strains from different geographical areas in the Mediterranean Sea

Summary

Introduction

Harmful algal blooms (HABs) are recognized as one of the major threats in aquatic ecosystems worldwide [1,2,3,4]. A major negative aspect of HABs is the production of toxic compounds which impact on human health [8,9], both directly (e.g., during work and recreational outdoor activities) and indirectly (e.g., ingesting contaminated seafood). In this regards, dinoflagellates and cyanobacteria are the most important representatives of harmful classes in marine and freshwater ecosystems, respectively. PSP outbreaks have harmful effects on human health as well as important economic implications for aquaculture and shellfish farms, the impairment of tourism and recreational activities, alteration of marine trophic structure and the death of marine mammals, fishes and seabirds [11]. The member states of the European Union must ban mussel harvesting if PSTs in shellfish exceed the limit of 800 μg STXeq kg−1 in any edible part (2004/853/EC)

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Results

Conclusion