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Paralytic shellfish toxin

Shu-Fei Zhang, Yong Zhang, Lin Lin, Da-Zhi Wang
Paralytic shellfish toxins (PSTs) are a group of potent neurotoxic alkaloids that are produced mainly by marine dinoflagellates. PST biosynthesis in dinoflagellates is a discontinuous process that is coupled to the cell cycle. However, little is known about the molecular mechanism underlying this association. Here, we compared global protein expression profiles of a toxigenic dinoflagellate, Alexandrium catenella , collected at four different stages of toxin biosynthesis during the cell cycle, using an isobaric tags for relative and absolute quantification (iTRAQ)-based quantitative proteomic approach...
December 7, 2018: Marine Drugs
Jorge I Mardones, Lana Shabala, Sergey Shabala, Juan José Dorantes-Aranda, Andreas Seger, Gustaaf M Hallegraeff
Harmful algal blooms (HAB) are responsible for massive mortalities of wild and aquacultured fish due to noticeable gill damage, but the precise fish-killing mechanisms remain poorly understood. A non-invasive microelectrode ion flux estimation (MIFE) technique was successfully applied to assess changes in membrane-transport processes in a model fish gill cell line exposed to harmful microplankton. Net Ca2+ , H+ , K+ ion fluxes in the rainbow trout cell line RTgill-W1 were monitored before and after addition of lysed cells of this Paralytic Shellfish Toxins (PST) producer along with purified endocellular dinoflagellate PST...
December 2018: Harmful Algae
Barbara C Sendall, Glenn B McGregor
Strains of the freshwater filamentous, benthic cyanobacterium Scytonema crispum Agardh isolated from six sites in subtropical south-east Queensland were characterised using a combination of phenotypic and genetic traits. Morphologically, the strains were consistent with the description of Scytonemataceae sensu stricto, and the description of Scytonema crispum. However, phylogenetic analysis of the 16S rRNA gene, the 16S-23S rRNA operon, and the nifH gene revealed that these strains and three others from outside Australia formed a monophyletic clade distinct from Scytonema and other species in the Scytonemataceae...
December 2018: Harmful Algae
Aletta T Yñiguez, Jennifer Maister, Cesar L Villanoy, Josephine Dianne Deauna, Eileen Peñaflor, Aldwin Almo, Laura T David, Garry A Benico, Ellen Hibay, Irmi Mora, Sandra Arcamo, Jun Relox, Rhodora V Azanza
In contrast to temperate Harmful Algal Blooms (HABs), knowledge on the mechanisms driving tropical HABs are less well studied. The interaction of a seasonal temperature window, cysts (for certain species) and large-scale transport are some of the key processes in temperate HABs. In the Philippines, HABs occur not along long open coastlines, but in embayments that are highly influenced by run-off and stratification. These embayments are typically also the sites of cultured or wild harvest shellfish and other aquaculture activities...
December 2018: Harmful Algae
Paul M D'Agostino, Michael J Boundy, Tim D Harwood, Wayne W Carmichael, Brett A Neilan, Susanna A Wood
To date Paralytic shellfish toxin (PST) variants in cyanobacteria have primarily been characterized using high performance liquid chromatography coupled with fluorescence detection. In this study we re-evaluated the PST profiles of five cyanobacterial cultures (Dolichospermum circinale AWQC131C, Aphanizomenon sp. NH-5, Raphidiopsis raciborskii T3, Scytonema cf. crispum CAWBG524 and CAWBG72) and one environmental sample (Microseria wollei) using hydrophilic interaction liquid chromatography coupled with electrospray ionization tandem mass spectrometry...
November 21, 2018: Toxicon: Official Journal of the International Society on Toxinology
Sabrina Loise de Morais Calado, Gustavo Souza Santos, Juliana Wojciechowski, Valéria Freitas de Magalhães, Helena Cristina Silva de Assis
Paralytic shellfish Toxins (PSTs) or saxitoxins are neurotoxins that block the neural transmission by binding to the voltage-gated sodium channels in the nerve cells. There are >50 analogues described, which could be biotransformed into a molecular form of greater or lesser toxicity. The Alagados Reservoir is used for water supply, and persistent cyanobacterial blooms as well as PSTs concentrations have been found in this water body since 2002. The aims of this study were to quantify the concentrations of PSTs in the water and fish samples from the Alagados Reservoir...
February 15, 2019: Science of the Total Environment
Carla Mellado, Oscar R Chaparro, Cristian Duarte, Paola A Villanueva, Alejandro Ortiz, Nelson Valdivia, Rodrigo Torres, Jorge M Navarro
High latitudes are considered particularly vulnerable to ocean acidification, since they are naturally low in carbonate ions. The edible mussel Mytilus chilensis is a common calcifier inhabiting marine ecosystems of the southern Chile, where culturing of this species is concentrated and where algal blooms produced by the toxic dinoflagellate A. catenella are becoming more frequent. Juvenile Mytilus chilensis were exposed to experimental conditions simulating two environmental phenomena: pCO2 increase and the presence of paralytic shellfish toxins (PST) produced by the dinoflagellate Alexandrium catenella...
October 30, 2018: Science of the Total Environment
Carmela Dell'Aversano, Luciana Tartaglione, Giuseppe Polito, Karl Dean, Mariagrazia Giacobbe, Silvia Casabianca, Samuela Capellacci, Antonella Penna, Andrew D Turner
Paralytic shellfish toxins (PST) and tetrodotoxin (TTX) are naturally-occurring toxins that may contaminate the food chain, inducing similar neurological symptoms in humans. They are co-extracted under the same conditions and thus their combined detection is desirable. Whilst PST are regulated and officially monitored in Europe, more data on TTX occurrence in bivalves and gastropods are needed before meaningful regulations can be established. In this study, we used three separate analytical methods - pre-column oxidation with liquid chromatography and fluorescence detection, ultrahigh performance hydrophilic interaction liquid chromatography (HILIC) tandem mass spectrometry (MS/MS) and HILIC high resolution (HR) MS/MS - to investigate the presence of PST and TTX in seawater and shellfish (mussels, clams) collected in spring summer 2015 to 2017 in the Mediterranean Sea...
January 2019: Chemosphere
Pedro Reis Costa, Ana Catarina Braga, Andrew D Turner
Paralytic shellfish poisoning (PSP) is a severe food-borne illness, caused by the ingestion of seafood containing paralytic shellfish toxins (PST), which are naturally produced by marine dinoflagellates and accumulate in shellfish during algae blooms. Novel PST, designated as hydroxybenzoate analogues (also known as GC toxins), was relatively recently discovered in Gymnodinium catenatum strains worldwide. However, to date, there have been no studies examining their accumulation in shellfish. In this study, mussels ( Mytilus galloprovincialis ) were exposed to G...
October 26, 2018: Toxins
Sarah C Finch, Michael J Boundy, D Tim Harwood
Tetrodotoxin (TTX) is a potent neurotoxin associated with human poisonings through the consumption of pufferfish. More recently, TTX has been identified in bivalve molluscs from diverse geographical environments, including Europe, and is therefore recognised as an emerging threat to food safety. A recent scientific opinion of the EFSA Panel on Contaminants in the Food Chain recognised the need for further data on the acute oral toxicity of TTX and suggested that, since saxitoxin (STX) and TTX had similar modes of action, it was possible that their toxicities were additive so could perhaps be combined to yield one health-based guideline value...
October 23, 2018: Toxins
Virginia Angélica Bianchi, Hendrik Langeloh, Urban Tillmann, Bernd Krock, Annegret Müller, Ulf Bickmeyer, Doris Abele
Multiple toxic and bioactive compounds produced by Alexandrium spp. cause adverse effects on bivalves, but these effects are frequently difficult to attribute to a single compound class. To disentangle the effect of neurotoxic vs lytic secondary metabolites, we exposed blue mussels to either a paralytic shellfish toxin (PST) producing Alexandrium spp. strain, or to an exclusively lytic compound (LC) producing strain, or a strain containing both compound classes, to evaluate the time dependent effects after 3 and 7 days of feeding...
October 11, 2018: Fish & Shellfish Immunology
Alescia Cullen, Paul M D'Agostino, Rabia Mazmouz, Russell Pickford, Susanna Wood, Brett A Neilan
The neurotoxin saxitoxin and related paralytic shellfish toxins are produced by multiple species of cyanobacteria and dinoflagellates. This study investigates the two saxitoxin-producing strains of Scytonema crispum, CAWBG524 and CAWBG72, isolated in New Zealand. Each strain was previously reported to have a distinct paralytic shellfish toxin profile, a rare observation between strains within the same species. Sequencing of the saxitoxin biosynthetic clusters ( sxt) from S. crispum CAWBG524 and S. crispum CAWBG72 revealed the largest sxt gene clusters described to date...
October 19, 2018: ACS Chemical Biology
Ruiwen Cao, Dan Wang, Qianyu Wei, Qing Wang, Dinglong Yang, Hui Liu, Zhijun Dong, Xiaoli Zhang, Qianqian Zhang, Jianmin Zhao
Harmful algae blooms have expanded greatly in recent decades, and their secreted toxins pose a severe threat to human health and marine ecosystems. Saxitoxin (STX) is a main paralytic shellfish poison naturally produced by marine microalgae of the genus Alexandrium . Despite numerous studies have assessed the impacts of STX on marine bivalves, comparative in vivo study on the toxicity of STX on bivalves with distinct accumulation ability (such as oysters and scallops) has been seldom investigated. The aim of this study was to identify whether distinct sensitivity exists between oysters, Crassostrea gigas , and scallops, Chlamys farreri under the same amount of STX exposure using multiple biomarker responses...
2018: Frontiers in Physiology
April L Lukowski, Duncan C Ellinwood, Meagan E Hinze, Ryan J DeLuca, J Du Bois, Sherwood Hall, Alison R H Narayan
The remarkable degree of synthetic selectivity found in Nature is exemplified by the biosynthesis of paralytic shellfish toxins such as saxitoxin. The polycyclic core shared by saxitoxin and its relatives is assembled and subsequently elaborated through the installation of hydroxyl groups with exquisite precision that is not possible to replicate with traditional synthetic methods. Here, we report the identification of the enzymes that carry out a subset of C-H functionalizations involved in paralytic shellfish toxin biosynthesis...
September 19, 2018: Journal of the American Chemical Society
Subhendu Chakraborty, Marina Pančić, Ken H Andersen, Thomas Kiørboe
Many species of phytoplankton produce toxins that may provide protection from grazing. In that case one would expect toxin production to be costly; else all species would evolve toxicity. However, experiments have consistently failed to show any costs. Here, we show that costs of toxin production are environment dependent but can be high. We develop a fitness optimization model to estimate rate, costs, and benefits of toxin production, using PST (paralytic shellfish toxin) producing dinoflagellates as an example...
August 14, 2018: ISME Journal
J Galindo, M Contreras, P Maldonado, F Torrealba, N Lagos, J L Valdés
BACKGROUND: Neosaxitoxin (NeoSTX) and related paralytics shellfish toxins has been successfully used as local anesthetic and muscle relaxants to treat a variety of ailments. The primary mechanism of action of these toxins occurs by blocking voltage-gated sodium channels with compounds such as TTX, lidocaine, or derivatives. However, most of these non-classical sodium channel blockers act with a reduced time effect as well as ensuing neurotoxicity. NEW METHOD: In this report, we show that the use of local NeoSTX injections inactivates the hippocampal neuronal activity reversibly with a by long-term dynamics, without neuronal damage...
August 11, 2018: Journal of Neuroscience Methods
J Naouli, R Abouabdellah, A Bennouna, A Laissaoui, P W Swarzenski, H Ait Bouh, A Mesfioui, M-S Benbrahim, M-Y Dechraoui Bottein
Paralytic shellfish poisoning (PSP) events occur regularly along the Mediterranean and Atlantic coast of Morocco, and have been responsible for several severe cases of human intoxication. Along the southern Atlantic coast of Morocco, aquaculture and intensive artisanal fishing practices have recently been particularly heavily impacted, and toxic species have been observed in increasing intensity and frequency. In the 1990's a regulatory monitoring program was established for the coastal waters off Morocco by the National Institute of Fisheries Research (INRH), to reduce the risk of intoxication with biotoxins...
December 2018: Journal of Environmental Radioactivity
Hongbo Li, Xinwei Wei, Chenlei Gu, Kaiqi Su, Hao Wan, Ning Hu, Ping Wang
Okadaic acid (OA) and saxitoxin (STX) are typical toxins of diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP), respectively, which are highly toxic marine toxins threatening human health and environmental safety. OA is a potent inhibitor of serine/threonine protein phosphatases that can cause cellular death, while STX is an inhibitor of sodium channel that can lead to neurological damage. In this work, a dual functional cardiomyocyte-based biosensor was proposed to detect DSP and PSP toxins by monitoring the viability and electrophysiology of cardiomyocytes...
2018: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Veronica Rey, Ana M Botana, Alvaro Antelo, Mercedes Alvarez, Luis M Botana
Although paralytic shellfish toxins (PSTs) have traditionally been analyzed by liquid chromatography with either pre- or post-column derivatization, and these methods have been validated successfully through inter-laboratory studies, mass spectrometry methods have also been described in literature for use in monitoring programs. However, methods using liquid chromatography coupled with mass spectrometry (LC-MS) need to be improved in terms of sensitivity, analyte recovery and retention time stability because of undesirable matrix effects...
December 15, 2018: Food Chemistry
Natalia Vilariño, M Carmen Louzao, Paula Abal, Eva Cagide, Cristina Carrera, Mercedes R Vieytes, Luis M Botana
Marine biotoxins are produced by aquatic microorganisms and accumulate in shellfish or finfish following the food web. These toxins usually reach human consumers by ingestion of contaminated seafood, although other exposure routes like inhalation or contact have also been reported and may cause serious illness. This review shows the current data regarding the symptoms of acute intoxication for several toxin classes, including paralytic toxins, amnesic toxins, ciguatoxins, brevetoxins, tetrodotoxins, diarrheic toxins, azaspiracids and palytoxins...
August 9, 2018: Toxins
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