RESUMO
Marine pelagic diazotrophic cyanobacteria of the genus Trichodesmium (Oscillatoriales) are widespread throughout the tropics and subtropics, and are particularly common in the waters of New Caledonia. Blooms of Trichodesmium are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain several types of paralyzing toxins. The toxicity of water-soluble extracts of Trichodesmium spp. were analyzed by mouse bioassay and Neuroblastoma assay and their toxic compounds characterized using liquid chromatography coupled with tandem mass spectrometry techniques. Here, we report the first identification of palytoxin and one of its derivatives, 42-hydroxy-palytoxin, in field samples of Trichodesmium collected in the New Caledonian lagoon. The possible role played by Trichodesmium blooms in the development of clupeotoxism, this human intoxication following the ingestion of plankton-eating fish and classically associated with Ostreopsis blooms, is also discussed.
Assuntos
Acrilamidas/toxicidade , Venenos de Cnidários/toxicidade , Cianobactérias/química , Piranos/toxicidade , Acrilamidas/isolamento & purificação , Animais , Bioensaio/métodos , Linhagem Celular Tumoral , Cromatografia Líquida , Venenos de Cnidários/isolamento & purificação , Feminino , Humanos , Masculino , Camundongos , Neuroblastoma/patologia , Piranos/isolamento & purificação , Espectrometria de Massas em Tandem , Testes de ToxicidadeRESUMO
Marine pelagic cyanobacteria Trichodesmium are widespread in the New Caledonia lagoon. Blooms of these Oscillatoriales are suspected to be a potential source of toxins in the ciguatera food chain and were previously reported to contain certain types of paralysing toxins. In the present study, toxicity experiments were conducted on lipid- and water-soluble extracts of freeze-dried samples of these cyanobacteria. Lipid-soluble fractions revealed a ciguatoxin-like activity in both in vivo (mouse bioassay) and in vitro (mouse neuroblastoma cells assay and receptor binding assay using tritiated brevetoxin-3) assays. The water-soluble fractions tested on mice exhibited neurotoxicity with paralytic symptoms. These toxicities have also been observed with benthic filamentous cyanobacteria within the Oscillatoriales order, also collected in New Caledonia. This study provides an unprecedented evidence of the toxicity of Trichodesmium species from the New Caledonia lagoon. This survey also demonstrates the possible role of these cyanobacteria in ciguatera fish poisoning.
Assuntos
Toxinas Bacterianas/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Ciguatoxinas/toxicidade , Cianobactérias/química , Ecossistema , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Animais , Toxinas Bacterianas/química , Toxinas Bacterianas/isolamento & purificação , Linhagem Celular Tumoral , Ciguatoxinas/isolamento & purificação , Toxinas de Cianobactérias , Feminino , Masculino , Toxinas Marinhas/química , Toxinas Marinhas/isolamento & purificação , Camundongos , Microcistinas/química , Microcistinas/isolamento & purificação , Neurotoxinas/toxicidade , Nova Caledônia , Testes de ToxicidadeRESUMO
We report the first identification of homoanatoxin-a from benthic marine cyanobacteria (Hydrocoleum lyngbyaceum) samples collected in Lifou (Loyalty Islands, New Caledonia), where cases of giant clams (Tridacna maxima) intoxications were recorded during a severe ciguatera fish poisoning outbreak. Homoanatoxin-a was also detected in extracts of giant clams harvested in the surroundings of the contaminated area suggesting the possible link between these poisoning events and the occurrence of potentially neurotoxic Hydrocoleum.
