Decontamination of paralytic shellfish toxins in cultured shellfish using marine bacteria

Shellfish poisoning incidents are a chronic problem world-wide and have been reported in the literature for hundreds of years. The most dangerous of the marine biotoxins, paralytic shellfish toxiris (PSTs), deserve particular attention because of their high acute toxicity and potential lethality. This group of structurally-related compounds (~24) is produced by certain marine algae of the genera Gymnodinuim, Alexandrium and Pyrodinium. Upon ingestion of these algae, PSTs accumulate in the digestive glands of filter-feeding molluscan shellfish. Human consumption of contaminated shellfish can lead to paralytic shellfish poisoning (PSP), and to date there are no known antidotes or effective medical treatments for this condition. The proposed project is a continuation of an AquaNet (NCE) grant (2003-2006) aimed at isolating and characterizing unique marine bacteria with the ability to metabolize and destroy PSTs. We screened more than 70 promising isolates and selected 4 with the highest ability to breakdown PSTs in vitro, converting them into non-toxic by-products as confirmed by high-performance liquid chromatography and the mouse bioassay. Within this proposal, we plan to incorporate the PST-degrading bacteria into a commercializable probiotic product to be used in the detoxification of contaminated mussels. This commercialization strategy seems feasible because our probiotic product will easily interface with the already existing infrastructure throughout Atlantic Canada that is used for coliform depuration of shellfish in man-made seawater tanks according to Canadian Food Inspection Agency (CFIA) specifications (CFIA, http://www.inspection.gc.ca/english/anima/fispoi/manman/cssppccsm/chap 10-1e.shtml).