Co-occurrence of ciguatoxin-like and Paralytic Shellfish-like toxins in Trichodesmium isolates from New-Caledonian lagoon.

Titre: 
Co-occurrence of ciguatoxin-like and Paralytic Shellfish-like toxins in Trichodesmium isolates from New-Caledonian lagoon.
Auteurs: 
Kerbrat AS, Peyraud-Thomas C, Darius HT, Pauillac S, Chinain M, Laurent D
Type de communication: 
Communication orale
Conférence: 
Congrès Ciguatéra et Biotoxines associées (Nouméa, Nouvelle-Calédonie)
Année: 
10/2008

The marine pelagic cyanobacteria Trichodesmium spp. are widespread in the New Caledonian lagoon and are seasonally observed during the hot season. Often implicated in ecosystem damage, blooms of these Oscillatoriales are suspected to be a potential source of toxins in the ciguatera food chain and were reported to contain a type of neurotoxins commonly associated with Paralytic Shellfish toxins. In the present study, toxicity experiments were conducted on both lipid- and water-soluble extracts of freeze-dried mat-forming samples of these cyanobacteria. Lipid-soluble fractions revealed a ciguatoxin-like activity in both in vivo (mouse bioassay test) and in vitro (neuroblastoma toxicity test and receptor binding assay using tritiated brevetoxin-3) assays. Moreover, water-soluble fractions also exhibited neurotoxicity in mice bioassay with paralytic symptoms similar to those produced by anatoxin-a. Comparable toxicities have also been observed with some benthic filamentous cyanobacteria within the Oscillatoriales order. This study provides an unprecedent evidence of the toxicity of Trichodesmium species of New Caledonian lagoon and of its possible link with ciguatera fish poisoning.
Workshop international Ciguatéra et biotoxines associées (Nouméa, 27-31 octobre 2008)