title: Rapid Extraction and Identification of Maitotoxin and Ciguatoxin-Like Toxins from Caribbean and Pacific Gambierdiscus Using a New Functional Bioassay.
abstract: BACKGROUND
  Ciguatera is a circumtropical disease produced by polyether sodium channel toxins (ciguatoxins) that enter the marine food chain and accumulate in otherwise edible fish. Ciguatoxins, as well as potent water-soluble polyethers known as maitotoxins, are produced by certain dinoflagellate species in the genus Gambierdiscus and Fukuyoa spp. in the Pacific but little is known of the potential of related Caribbean species to produce these toxins.
  
  
  METHODS
  We established a simplified procedure for extracting polyether toxins from Gambierdiscus and Fukuyoa spp. based on the ciguatoxin rapid extraction method (CREM). Fractionated extracts from identified Pacific and Caribbean isolates were analysed using a functional bioassay that recorded intracellular calcium changes (Ca2+) in response to sample addition in SH-SY5Y cells. Maitotoxin directly elevated Ca2+i, while low levels of ciguatoxin-like toxins were detected using veratridine to enhance responses.
  
  
  RESULTS
  We identified significant maitotoxin production in 11 of 12 isolates analysed, with 6 of 12 producing at least two forms of maitotoxin. In contrast, only 2 Caribbean isolates produced detectable levels of ciguatoxin-like activity despite a detection limit of >30 pM. Significant strain-dependent differences in the levels and types of ciguatoxins and maitotoxins produced by the same Gambierdiscus spp. were also identified.
  
  
  CONCLUSIONS
  The ability to rapidly identify polyether toxins produced by Gambierdiscus spp. in culture has the potential to distinguish ciguatoxin-producing species prior to large-scale culture and in naturally occurring blooms of Gambierdiscus and Fukuyoa spp. Our results have implications for the evaluation of ciguatera risk associated with Gambierdiscus and related species.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Lewis
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Marco
authors.initials: M
authors.lastname: Inserra
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Irina
authors.initials: I
authors.lastname: Vetter
authors.affiliation: National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Fisheries & Habitat Research, 101 Pivers Island Road, Beaufort, NC, 28516, United States of America.
authors.forename: William C
authors.initials: WC
authors.lastname: Holland
authors.affiliation: National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Fisheries & Habitat Research, 101 Pivers Island Road, Beaufort, NC, 28516, United States of America.
authors.forename: D Ransom
authors.initials: DR
authors.lastname: Hardison
authors.affiliation: National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Fisheries & Habitat Research, 101 Pivers Island Road, Beaufort, NC, 28516, United States of America.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Tester
authors.affiliation: National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Fisheries & Habitat Research, 101 Pivers Island Road, Beaufort, NC, 28516, United States of America.
authors.forename: R Wayne
authors.initials: RW
authors.lastname: Litaker
mesh_terms: D000818:Animals; D001681:Biological Assay; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D002922:Ciguatoxins / Q000302:isolation & purification*; D004141:Dinoflagellida / Q000737:chemistry*; D006801:Humans; D008387:Marine Toxins / Q000302:isolation & purification*; D035964:Oxocins / Q000302:isolation & purification*; D010140:Pacific Ocean; D013050:Spectrometry, Fluorescence; D000095702:Polyether Toxins
chemical_list: D002922:Ciguatoxins; D008387:Marine Toxins; D035964:Oxocins; C020394:maitotoxin; D000095702:Polyether Toxins