Predavanje prof. dr. Aurelie Tubaro

Shellfish poisonings represent a sanitary and economic problem all over the world. Virus and bacteria are mainly responsible for seafood poisonings, but, sometimes, toxins produced by dinoflagellate unicellular algae can contaminate shellfish and provoke human intoxications. The incidence of shellfish algal poisoning is around 7.5 % of all the marine food borne disease in USA and they can be life threatening.

According to the main symptoms, these intoxications can be classified as Paralytic Shellfish Poisoning (PSP), Diarrhoetic Shellfish Poisonings (DSP), Neurotoxic Shellfish Poisoning (NSP), Amnesic Shellfish Poisoning (ASP), Azaspiracid Shellfish Poisoning (AZA). Coral reef fishes are the vectors of another algal poisoning , the Ciguatera Fish Poisoning (CFP).

PSP is the most serious disease, with an average mortality rate of about 6 % worldwide. Saxitoxin and related compounds are responsible of this poisoning characterized by paraestaesiae in mounth and in lips, dizzinezz and, in the most severe cases, paralysis that can lead to death, when respiratory muscles are involved. The microalgae responsible for the production of PS toxins are dinoflagellates: Alexandrium ssp., Gymnodinium catenatum, Pyrodinium bahamense var. compressa.

Toxins of the okadaic acid group have been to know to cause a syndrome named diarrhoeic shellfish poisoning due to the dominating symptom: its symptoms are similar to that of a bacteria enterotoxin poisoning. Although not life threatening, this poisoning is particularly spread in Europe. The diarrhogenic toxins are produced by several Dinophysis species and by Prorocentrum lima. The microalgae responsible for the DSP contamination in Adriatic Sea is Dinophysis fortii.

Non diarrhogenic lipophilic toxins, such as yessotoxins (YTXs), can be detected together with okadaic acid during the usual monitoring programs for DSP. Although no human intoxication has been ascribed to YTXs so far, their toxicity is not completely clarified. Studies are in progress to determine the potential toxicological risk of this class of toxins, that represented the main problem in Adriatic Sea in the last years.