Dihydrodinophysistoxin-1 Produced by <i>Dinophysis norvegica</i> in the Gulf of Maine, USA and Its Accumulation in Shellfish

Jonathan R. Deeds; Whitney L. Stutts; Mary Dawn Celiz; Jill MacLeod; Amy E. Hamilton; Bryant J. Lewis; David W. Miller; Kohl Kanwit; Juliette L. Smith; David M. Kulis; Pearse McCarron; Carlton D. Rauschenberg; Craig A. Burnell; Stephen D. Archer; Jerry Borchert; Shelley K. Lankford

doi:10.3390/toxins12090533

Toxins (Aug 2020)

Dihydrodinophysistoxin-1 Produced by <i>Dinophysis norvegica</i> in the Gulf of Maine, USA and Its Accumulation in Shellfish

Jonathan R. Deeds,
Whitney L. Stutts,
Mary Dawn Celiz,
Jill MacLeod,
Amy E. Hamilton,
Bryant J. Lewis,
David W. Miller,
Kohl Kanwit,
Juliette L. Smith,
David M. Kulis,
Pearse McCarron,
Carlton D. Rauschenberg,
Craig A. Burnell,
Stephen D. Archer,
Jerry Borchert,
Shelley K. Lankford

Affiliations

Jonathan R. Deeds: Office of Regulatory Science, United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD 20740, USA
Whitney L. Stutts: Office of Regulatory Science, United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD 20740, USA
Mary Dawn Celiz: Office of Regulatory Science, United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, MD 20740, USA
Jill MacLeod: Maine Department of Marine Resources, West Boothbay Harbor, ME 05475, USA
Amy E. Hamilton: Maine Department of Marine Resources, West Boothbay Harbor, ME 05475, USA
Bryant J. Lewis: Maine Department of Marine Resources, West Boothbay Harbor, ME 05475, USA
David W. Miller: Maine Department of Marine Resources, West Boothbay Harbor, ME 05475, USA
Kohl Kanwit: Maine Department of Marine Resources, West Boothbay Harbor, ME 05475, USA
Juliette L. Smith: Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, VA 23062, USA
David M. Kulis: Department of Biology, Woods Hole Oceanographic Institute, Woods Hole, MA 02543, USA
Pearse McCarron: Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
Carlton D. Rauschenberg: Bigelow Analytical Services, Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
Craig A. Burnell: Bigelow Analytical Services, Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
Stephen D. Archer: Bigelow Analytical Services, Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
Jerry Borchert: Washington State Department of Health, Olympia, WA 98504, USA
Shelley K. Lankford: Washington State Department of Health Public Health Laboratories, Shoreline, WA 98155, USA

DOI: https://doi.org/10.3390/toxins12090533
Journal volume & issue: Vol. 12, no. 9
p. 533

Abstract

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Dihydrodinophysistoxin-1 (dihydro-DTX1, (M-H)−m/z 819.5), described previously from a marine sponge but never identified as to its biological source or described in shellfish, was detected in multiple species of commercial shellfish collected from the central coast of the Gulf of Maine, USA in 2016 and in 2018 during blooms of the dinoflagellate Dinophysis norvegica. Toxin screening by protein phosphatase inhibition (PPIA) first detected the presence of diarrhetic shellfish poisoning-like bioactivity; however, confirmatory analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) failed to detect okadaic acid (OA, (M-H)−m/z 803.5), dinophysistoxin-1 (DTX1, (M-H)−m/z 817.5), or dinophysistoxin-2 (DTX2, (M-H)−m/z 803.5) in samples collected during the bloom. Bioactivity-guided fractionation followed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) tentatively identified dihydro-DTX1 in the PPIA active fraction. LC-MS/MS measurements showed an absence of OA, DTX1, and DTX2, but confirmed the presence of dihydro-DTX1 in shellfish during blooms of D. norvegica in both years, with results correlating well with PPIA testing. Two laboratory cultures of D. norvegica isolated from the 2018 bloom were found to produce dihydro-DTX1 as the sole DSP toxin, confirming the source of this compound in shellfish. Estimated concentrations of dihydro-DTX1 were >0.16 ppm in multiple shellfish species (max. 1.1 ppm) during the blooms in 2016 and 2018. Assuming an equivalent potency and molar response to DTX1, the authority initiated precautionary shellfish harvesting closures in both years. To date, no illnesses have been associated with the presence of dihydro-DTX1 in shellfish in the Gulf of Maine region and studies are underway to determine the potency of this new toxin relative to the currently regulated DSP toxins in order to develop appropriate management guidance.

Published in Toxins

ISSN: 2072-6651 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Medicine
Website: http://www.mdpi.com/journal/toxins/

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