title: Monitoring of brevetoxins in the Karenia brevis bloom-exposed Eastern oyster (Crassostrea virginica).
abstract: Brevetoxin uptake and elimination were examined in Eastern oyster (Crassostrea virginica) exposed to recurring blooms of the marine alga Karenia brevis in Sarasota Bay, FL, over a three-year period. Brevetoxins were monitored by in vitro assays (ELISA, cytotoxicity assay, and receptor binding assay) and LC-MS, with in vivo toxicity of shellfish extracts assessed by the traditional mouse bioassay. Measurements by all methods reflected well the progression and magnitude of the blooms. Highest levels recorded by mouse bioassay at bloom peak were 157 MU/100g. Oysters were toxic by mouse bioassay at levels >or=20 MU/100g for up to two weeks after bloom dissipation, whereas brevetoxins were measurable by in vitro assays and LC-MS for several months afterwards. For the structure-based methods, summed values for the principal brevetoxin metabolites of PbTx-2 (cysteine and cysteine sulfoxide conjugates), as determined by LC-MS, were highly correlated (r(2)=0.90) with composite toxin measurements by ELISA. ELISA and LC-MS values also correlated well (r(2)=0.74 and 0.73, respectively) with those of mouse bioassay. Pharmacology-based cytotoxicity and receptor binding assays did not correlate as well (r(2)=0.65), and were weakly correlated with mouse bioassay (r(2)=0.48 and 0.50, respectively). ELISA and LC-MS methods offer rapid screening and confirmation, respectively, of brevetoxin contamination in the oyster, and are excellent alternatives to mouse bioassay for assessing oyster toxicity following K. brevis blooms.
authors.affiliation: Gulf Coast Seafood Laboratory, U.S. Food and Drug Administration, 1 Iberville Drive, Dauphin Island, AL 36528, USA. steven.plakas@fda.hhs.gov
authors.forename: Steven M
authors.initials: SM
authors.lastname: Plakas
authors.forename: Edward L E
authors.initials: EL
authors.lastname: Jester
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: El Said
authors.forename: Hudson R
authors.initials: HR
authors.lastname: Granade
authors.forename: Ann
authors.initials: A
authors.lastname: Abraham
authors.forename: Robert W
authors.initials: RW
authors.lastname: Dickey
authors.forename: Paula S
authors.initials: PS
authors.lastname: Scott
authors.forename: Leanne J
authors.initials: LJ
authors.lastname: Flewelling
authors.forename: Michael
authors.initials: M
authors.lastname: Henry
authors.forename: Patricia
authors.initials: P
authors.lastname: Blum
authors.forename: Richard
authors.initials: R
authors.lastname: Pierce
mesh_terms: D000818:Animals; D001681:Biological Assay; D002853:Chromatography, Liquid; D049896:Crassostrea / Q000378:metabolism*; D004141:Dinoflagellida / Q000472:pathogenicity*; D004784:Environmental Monitoring; D005506:Food Contamination; D008387:Marine Toxins / Q000032:analysis* / Q000633:toxicity; D013058:Mass Spectrometry; D051379:Mice; D035964:Oxocins / Q000032:analysis* / Q000633:toxicity; D000095702:Polyether Toxins
chemical_list: D008387:Marine Toxins; D035964:Oxocins; C053342:brevetoxin; D000095702:Polyether Toxins