Persistent low concentrations of diarrhetic shellfish toxins in green mussels Perna viridis from the Johor Strait, Singapore: first record of diarrhetic shellfish toxins … (original) (raw)

Accumulation, transformation and breakdown of DSP toxins from the toxic dinoflagellate Dinophysis acuta in blue mussels, Mytilus edulis

Toxicon : official journal of the International Society on Toxinology, 2016

Okadaic acid (OA), dinophysistoxins (DTX) and pectenotoxins (PTX) produced by the dinoflagellates Dinophysis spp. can accumulate in shellfish and cause diarrhetic shellfish poisoning upon human consumption. Shellfish toxicity is a result of algal abundance and toxicity as well as accumulation and depuration kinetics in mussels. We mass-cultured Dinophysis acuta containing OA, DTX-1b and PTX-2 and fed it to the blue mussel, Mytilus edulis under controlled laboratory conditions for a week to study toxin accumulation and transformation. Contents of OA and DTX-1b in mussels increased linearly with incubation time, and the net toxin accumulation was 66% and 71% for OA and DTX-1b, respectively. Large proportions (≈50%) of both these toxins were transformed to fatty acid esters. Most PTX-2 was transformed to PTX-2 seco-acid and net accumulation was initially high, but decreased progressively throughout the experiment, likely due to esterification and loss of detectability. We also quantifi...

Simultaneous occurrence of diarrhetic and paralytic shellfish poisoning toxins in Spanish mussels in 1993

Natural Toxins, 1996

Mussel aquaculture is an important industry for the Galician Ri as, located in northwestern Atlantic coast of Spain. Since 1976 this region has been seriously affected by incidents of paralytic and diarrhetic shellfish poisoning (PSP and DSP). A particularly bad epidode occurred in 1993, when the toxic event lasted for an unusually long period. Many people were stncken 111 with unusual symptoms. In this paper we report on the chemical analysis of toxic 1993 mussel samples, using the techniques of liquid chromatography and capillary electrophoresis coupled with mass spectrometry. These analyses revealed a very complex toxin profile, with both PSP and DSP toxins present. Two DSP toxins, okadaic acid and D W , were observed, while the primary PSP toxins were 61 and the decarbamoylated derivatives of saxitoxin, Glxp and GTX3. Small amounts of saxitoxin and other as yet unidentified PSP toxins were observed.

Toxin Profiles of Okadaic Acid Analogues and Other Lipophilic Toxins in Dinophysis from Japanese Coastal Waters

Toxins, 2018

The identification and quantification of okadaic acid (OA)/dinophysistoxin (DTX) analogues and pectenotoxins (PTXs) in Dinophysis samples collected from coastal locations around Japan were evaluated by liquid chromatography mass spectrometry. The species identified and analyzed included Dinophysis fortii, D. acuminata, D. mitra (Phalacroma mitra), D. norvegica, D. infundibulus, D. tripos, D. caudata, D. rotundata (Phalacroma rotundatum), and D. rudgei. The dominant toxin found in D. acuminata was PTX2 although some samples contained DTX1 as a minor toxin. D. acuminata specimens isolated from the southwestern regions (Takada and Hiroshima) showed characteristic toxin profiles, with only OA detected in samples collected from Takada. In contrast, both OA and DTX1, in addition to a larger proportion of PTX2, were detected in D. acuminata from Hiroshima. D. fortii showed a toxin profile dominated by PTX2 although this species had higher levels of DTX1 than D. acuminata. OA was detected a...

Efficient isolation of the rare diarrhoeic shellfish toxin, dinophysistoxin-2, from marine phytoplankton

Toxicon, 1999

The rare diarrhoeic shell®sh poisoning (DSP) toxin, dinophysistoxin-2 (DTX-2), which is an okadaic acid (OA) isomer, has been isolated from a marine phytoplankton biomass that consisted mainly of Dinophysis acuta. Using a large double plankton net (length 5.9 m), bulk phytoplankton samples were collected o the south±west coast of Ireland and extracted with methanol and chloroform. Liquid chromatography coupled with ionspray mass spectrometry and tandem mass spectrometry (LC±MS, LC±MS±MS) showed the sample contained DTX-2 and OA, at a concentration of 80 pg/cell and 60 pg/cell, respectively. Flash chromatography using silica, sephadex LH20 and C 18 -silica, followed by preparative reversed-phase LC, separated DTX-2 from OA. The eciency of the separation procedures was substantially improved by the use of a bioscreen to detect DSP toxins in eluate fractions and the application of a new derivatisation procedure for the chromatographic elucidation of toxin pro®les with¯uorimetric detection (LC±FLD). Thus, 1/1000th aliquots of eluate fractions were assayed using protein phosphatase-2A for the presence of inhibitory compounds. Positive fractions were further analysed for DSP toxins by LC±FLD following derivatisation using the hydrazine reagent, luminarine-3. The identity and purity of the free isolated DTX-2 was con®rmed using¯ow injection analysis Toxicon 37 (1999) 343±357

Further Studies on the Analysis of DSP Toxin Profiles in Galician Mussels

Journal of Agricultural and Food Chemistry, 1999

Further studies on mussel samples from Galicia, Spain, have revealed the presence of okadaic acid (OA), dinophysistoxin 2 (DTX2), and the fatty acid acyl esters of both of these toxins as the "DTX3" complex. Measurements were performed with an improved in situ method for the formation of 9-anthryldiazomethane (ADAM) derivatives followed by liquid chromatography with fluorescence detection. Base hydrolysis of DTX3 toxins gave free OA and DTX2, which were determined following ADAM derivatization. Results were confirmed by liquid chromatography/mass spectrometry analyses, and in most of the samples, free DTX2 was the most abundant toxin. However, the OA/DTX2 ratio in the DTX3 conjugated form was different, with OA being the most abundant in all cases. This difference could be due to different rates of metabolism of OA and DTX2 to the acyl esters or due to contamination of the shellfish by the two toxins at different points in time, resulting in less acyl ester formation for one toxin versus the other. The second possibility would be reasonable if two different source organisms were producing the toxins.

Toxic marine dinoflagellates in Singapore waters that cause seafood poisonings

Clinical and experimental pharmacology and …, 2002

1. The present paper reviews the toxic dinoflagellates found in Singapore waters that produce toxins that can accumulate through marine food chains to cause seafood poisonings. 2. Singapore waters contain dinoflagellate species linked to three types of seafood poisoning: paralytic shellfish poisoning, diarrhetic shellfish poisoning (DSP) and ciguatera. 3. Paralytic shellfish poisoning and DSP occur by eating bivalve shellfish contaminated with saxitoxins and okadaic acid analogues, respectively. Shellfish accumulate these toxins from filter feeding on a number of species of (mostly) planktonic dinoflagellates. 4. In contrast, benthic species of dinoflagellates of the genus Gambierdiscus produce the ciguatoxins that are bioaccumulated into finfish to cause ciguatera. 5. Paralytic shellfish poisoning and DSP are the major concern for local and regionally produced seafood. To the best of our knowledge, ciguatera poisoning in Singapore only originates from imported reef fish.

First report of diarrheic shellfish toxins in mollusks from Buenos Aires Province (Argentina) associated with Dinophysis spp.: evidence of okadaic acid, dinophysistoxin-1 and their acyl- derivatives

Resumen: Primer reporte de toxinas diarreicas de moluscos en bivalvos de la Provincia de Buenos Aires (Argentina) asociado con Dinophysis spp.: evidencia de Ácido Okadaico, Dinophysistoxina-1 y sus acyl-derivados. En enero de 2010, los dinoflagelados productores de toxinas Dinophysis acuminata y D. caudata (10 3 cells·l -1) fueron detectados en Mar Azul durante un monitoreo rutinario de fitoplancton realizado en aguas costeras de la Provincia de Buenos Aires, Argentina. Mesodesma mactroides (almeja amarilla) y Donax hanleyanus (berberecho) del intermareal de Mar Azul, que son parte de la dieta de los habitantes del lugar y de turistas, dieron resultado positivo para toxinas lipofílicas mediante bioensayo ratón. Este trabajo está focalizado en la detección de Toxinas Diarreicas de Moluscos (DSP) en muestras colectadas durante el evento de toxicidad usando un HPLC-FLD con procedimiento de derivatización precolumna. Los datos evidenciaron contaminación de los moluscos con toxinas DSP y...