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https://www.readbyqxmd.com/read/28433693/cyanotoxins-which-detection-technique-for-an-optimum-risk-assessment
#1
Virginie Gaget, Melody Lau, Barbara Sendall, Suzanne Froscio, Andrew R Humpage
The presence of toxigenic cyanobacteria (blue-green algae) in drinking water reservoirs poses a risk to human and animal health worldwide. Guidelines and health alert levels have been issued in the Australian Drinking Water Guidelines for three major toxins, which are therefore the subject of routine monitoring: microcystin, cylindrospermopsin and saxitoxin. While it is agreed that these toxic compounds should be monitored closely, the routine surveillance of these bioactive chemicals can be done in various ways and deciding which technique to use can therefore be challenging...
April 10, 2017: Water Research
https://www.readbyqxmd.com/read/28409869/single-and-combined-effects-of-microcystins-and-saxitoxins-producer-cyanobacteria-on-the-fitness-and-antioxidant-defenses-of-cladocerans
#2
Aloysio da S Ferrão-Filho, Daniel Abreu S de Silva, Taissa A de Oliveira, Valéria Freitas de Magalhães, Stephan Pflugmacher, Eduardo Mendes da Silva
Cyanobacteria produce different toxic compounds that affect animal life, among them hepatotoxins and neurotoxins. As cyanobacteria are able to produce a variety of toxic compounds at the same time, organisms may be, generally, subjected to their combined action. In the present study, we demonstrate the effects of single and combined hepatotoxic (microcystins) and neurotoxic (saxitoxins) producer cyanobacteria on cladocerans. Animals were exposed to two strains of cyanobacteria isolated from the same environment (Funil Reservoir, RJ), either in single or combined exposures...
April 14, 2017: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/28370934/synthesis-and-identification-of-key-biosynthetic-intermediates-for-the-formation-of-the-tricyclic-skeleton-of-saxitoxin
#3
Shigeki Tsuchiya, Yuko Cho, Renpei Yoshioka, Keiichi Konoki, Kazuo Nagasawa, Yasukatsu Oshima, Mari Yotsu-Yamashita
Saxitoxin (STX) and its analogues are potent voltage-gated sodium channel blockers biosynthesized by freshwater cyanobacteria and marine dinoflagellates. We previously identified genetically predicted biosynthetic intermediates of STX at early stages, Int-A' and Int-C'2, in these microorganisms. However, the mechanism to form the tricyclic skeleton of STX was unknown. To solve this problem, we screened for unidentified intermediates by analyzing the results from previous incorporation experiments with (15) N-labeled Int-C'2...
March 31, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28366387/the-physiological-adaptations-and-toxin-profiles-of-the-toxic-alexandrium-fundyense-on-the-eastern-bering-sea-and-chukchi-sea-shelves
#4
Masafumi Natsuike, Hiroshi Oikawa, Kohei Matsuno, Atsushi Yamaguchi, Ichiro Imai
Abundant cyst distributions of the toxic dinoflagellate Alexandrium fundyense (previous A. tamarense north American clade) were recently observed on the north Chukchi Sea shelf and on the eastern Bering Sea shelf, suggesting that A. fundyense is both highly adapted to the local environments in the high latitude areas and might cause toxin contamination of plankton feeders. However, little is known about the physiological characteristics and toxin profiles of A. fundyense in these areas, which are characterized by low water temperatures, weak sunlight, and more or less permanent ice cover during winter...
March 2017: Harmful Algae
https://www.readbyqxmd.com/read/28364328/use-of-three-monitoring-approaches-to-manage-a-major-chrysosporum-ovalisporum-bloom-in-the-murray-river-australia-2016
#5
Adam Crawford, Jon Holliday, Chester Merrick, John Brayan, Mark van Asten, Lee Bowling
An unusual bloom of Chrysosporum ovalisporum (basionym Aphanizomenon ovalisporum) occurred for the first time in the Murray River and distributary rivers in New South Wales, Australia, from mid-February to early June 2016. At its greatest extent, it contaminated a combined river length of ca. 2360 km. Chrysosporum ovalisporum usually comprised >99% of the total bloom biovolume at most locations sampled, which at times exceeded 40 mm(3) l(-1). The origins of the bloom were most likely reservoirs on the upper Murray River, with cyanobacterial-infested water released from them contaminating the river systems downstream...
April 2017: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/28359039/spatiotemporal-patterns-of-paralytic-shellfish-toxins-and-their-relationships-with-environmental-variables-in-british-columbia-canada-from-2002-to-2012
#6
Stephen Finnis, Nikolas Krstic, Lorraine McIntyre, Trisalyn A Nelson, Sarah B Henderson
BACKGROUND: Harmful algal blooms produce paralytic shellfish toxins that accumulate in the tissues of filter feeding shellfish. Ingestion of these toxic shellfish can cause a serious and potentially fatal condition known as paralytic shellfish poisoning (PSP). The coast of British Columbia is routinely monitored for shellfish toxicity, and this study uses data from the monitoring program to identify spatiotemporal patterns in shellfish toxicity events and their relationships with environmental variables...
March 27, 2017: Environmental Research
https://www.readbyqxmd.com/read/28349851/first-report-of-neurotoxic-effect-of-the-cyanobacterium-cylindrospermopsis-raciborskii-on-the-motility-of-trematode-metacercariae
#7
K C Lopes, A S Ferrão-Filho, E G N Santos, C P Santos
Cylindrospermopsis raciborskii (Woloszynska) is a photosynthetic cyanobacterium that can produce cytotoxic (cylindrospermopsin) and neurotoxic cyanotoxins (saxitoxins). In Brazil the strains of C. raciborskii are reported to produce only saxitoxins (STX) and their effect on fish parasites has not been tested to date. The fish Poecilia vivipara Bloch and Schneider is a common host for the trematode Pygidiopsis macrostomum Travassos off the coast of Rio de Janeiro, and this fish-parasite interaction is a model for behavioural and ecotoxicological studies...
March 28, 2017: Journal of Helminthology
https://www.readbyqxmd.com/read/28282935/multiple-stressors-at-the-land-sea-interface-cyanotoxins-at-the-land-sea-interface-in-the-southern-california-bight
#8
Avery O Tatters, Meredith D A Howard, Carey Nagoda, Lilian Busse, Alyssa G Gellene, David A Caron
Blooms of toxic cyanobacteria in freshwater ecosystems have received considerable attention in recent years, but their occurrence and potential importance at the land-sea interface has not been widely recognized. Here we present the results of a survey of discrete samples conducted in more than fifty brackish water sites along the coastline of southern California. Our objectives were to characterize cyanobacterial community composition and determine if specific groups of cyanotoxins (anatoxins, cylindrospermopsins, microcystins, nodularins, and saxitoxins) were present...
March 9, 2017: Toxins
https://www.readbyqxmd.com/read/28245621/detection-of-cyanotoxins-in-algae-dietary-supplements
#9
Audrey Roy-Lachapelle, Morgan Solliec, Maryse F Bouchard, Sébastien Sauvé
Algae dietary supplements are marketed worldwide as natural health products. Although their proprieties have been claimed as beneficial to improve overall health, there have been several previous reports of contamination by cyanotoxins. These products generally contain non-toxic cyanobacteria, but the methods of cultivation in natural waters without appropriate quality controls allow contamination by toxin producer species present in the natural environment. In this study, we investigated the presence of total microcystins, seven individual microcystins (RR, YR, LR, LA, LY, LW, LF), anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine in 18 different commercially available products containing Spirulina or Aphanizomenon flos-aquae...
February 25, 2017: Toxins
https://www.readbyqxmd.com/read/28241803/predator-cues-reduce-intraspecific-trait-variability-in-a-marine-dinoflagellate
#10
Sylke Wohlrab, Erik Selander, U John
BACKGROUND: Phenotypic plasticity is commonplace and enables an organism to respond to variations in the environment. Plastic responses often modify a suite of traits and can be triggered by both abiotic and biotic changes. Here we analysed the plastic response towards a grazer of two genotypes of the marine dinoflagellate Alexandrium fundyense, evaluated the similarity of this response and discuss potential strain-specific trade-offs. We compared the expression of the known inducible defensive traits paralytic shellfish toxin content, and chain length...
February 27, 2017: BMC Ecology
https://www.readbyqxmd.com/read/28235579/dolichospermum-and-aphanizomenon-as-neurotoxins-producers-in-some-russian-freshwaters
#11
Ekaterina Chernova, Sergey Sidelev, Iana Russkikh, Ekaterina Voyakina, Olga Babanazarova, Roman Romanov, Anton Kotovshchikov, Hanna Mazur-Marzec
Last decades, cyanobacterial blooms have been commonly reported in Russia. Among the boom-forming species, potential toxin producers have been identified. The aim of this paper was to study the presence of neurotoxic compounds - saxitoxins and anatoxin-a - in water bodies from different regions of Russia. We also made attempts to identify the neurotoxin-producing genera. The good convergence of the results obtained by light microscopy, PCR and LC-MS/MS analyses indicated the presence of active neurotoxin producing species in all investigated water bodies...
February 21, 2017: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/28230783/acute-toxicities-of-the-saxitoxin-congeners-gonyautoxin-5-gonyautoxin-6-decarbamoyl-gonyautoxin-2-3-decarbamoyl-neosaxitoxin-c-1-2-and-c-3-4-to-mice-by-various-routes-of-administration
#12
Andrew I Selwood, Craig Waugh, David T Harwood, Lesley L Rhodes, John Reeve, Jim Sim, Rex Munday
Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs). The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required...
February 21, 2017: Toxins
https://www.readbyqxmd.com/read/28224710/extended-low-dose-exposure-to-saxitoxin-inhibits-neurite-outgrowth-in-model-neuronal-cells
#13
Katie O'Neill, Ian F Musgrave, Andrew Humpage
The potent neurotoxin saxitoxin (STX) belongs to a group of structurally related analogues produced by both marine and freshwater phytoplankton. The toxins act by blocking voltage-gated sodium channels stopping the inflow of sodium ions and the generation of action potentials. Exposure from marine sources occurs as a result of consuming shellfish which have concentrated the toxins, and freshwater exposure can occur from drinking water although there have been no acute poisonings from the latter source to date...
April 2017: Basic & Clinical Pharmacology & Toxicology
https://www.readbyqxmd.com/read/28208628/variable%C3%A2-cyanobacterial%C3%A2-toxin%C3%A2-and%C3%A2-metabolite%C3%A2-profiles%C3%A2-across%C3%A2-six%C3%A2-eutrophic%C3%A2-lakes%C3%A2-of%C3%A2-differing%C3%A2-physiochemical%C3%A2-characteristics
#14
Lucas J Beversdorf, Chelsea A Weirich, Sarah L Bartlett, Todd R Miller
Future sustainability of freshwater resources is seriously threatened due to the presence  of  harmful  cyanobacterial  blooms,  and  yet,  the  number,  extent,  and  distribution  of  most  cyanobacterial toxins-including "emerging" toxins and other bioactive compounds-are poorly  understood.  We  measured  15  cyanobacterial  compounds-including  four  microcystins  (MC),  saxitoxin (SXT), cylindrospermopsin (CYL), anatoxin-a (ATX) and homo-anatoxin-a (hATX), two  anabaenopeptins (Apt), three cyanopeptolins (Cpt), microginin (Mgn), and nodularin (NOD)-in  six freshwater lakes that regularly experience noxious cHABs...
February 10, 2017: Toxins
https://www.readbyqxmd.com/read/28202362/effects-of-crude-extracts-of-a-saxitoxin-producer-strain-of-the-cyanobacterium-cylindrospermopsis-raciborskii-on-the-swimming-behavior-of-wild-and-laboratory-reared-guppy-poecilia-vivipara
#15
Karina C Lopes, Aloysio da S Ferrão-Filho, Everton G N Dos Santos, Rodolfo A Cunha, Cláudia P Santos
The cyanobacterium Cylindrospermopsis raciborskii is an invasive species in water supply reservoirs worldwide, which can produces cylindrospermopsins and saxitoxins. In the wild, guppy (Poecilia vivipara) can be exposed to cyanotoxins, but those born and reared in laboratory are free of this contact. The aim of this paper was to comparatively measure the locomotor activity of 'wild' and 'lab' P. vivipara before and after exposure to crude extracts of two different cultures of C. raciborskii (CYRF-01), a saxitoxin-procucer strain...
February 12, 2017: Toxicon: Official Journal of the International Society on Toxinology
https://www.readbyqxmd.com/read/28186342/development-and-validation-of-a-high-throughput-online-solid-phase-extraction-liquid-chromatography-tandem-mass-spectrometry-method-for-the-detection-of-gonyautoxins1-4-and-gonyautoxins2-3-in-human-urine
#16
Rebecca Coleman, Sharon W Lemire, William Bragg, Alaine Garrett, Geovannie Ojeda-Torres, Rebekah Wharton, Elizabeth Hamelin, Jerry Thomas, Rudolph C Johnson
Paralytic shellfish toxins (PSTs), including gonyautoxins and saxitoxins, are produced by multiple species of microalgae and dinoflagellates, and are bioaccumulated by shellfish and other animals. Human exposure to PSTs typically occurs through ingestion of recreationally-harvested contaminated shellfish and results in non-specific symptomology. Confirmation of exposure to PSTs has often relied on the measurement of saxitoxin, the most toxic congener; however, gonyautoxins (GTXs), the sulfated carbamate derivatives of saxitoxin, may be present in shellfish at higher concentrations...
February 10, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28106838/molecular-characterization-of-voltage-gated-sodium-channels-and-their-relations-with-paralytic-shellfish-toxin-bioaccumulation-in-the-pacific-oyster-crassostrea-gigas
#17
Floriane Boullot, Justine Castrec, Adeline Bidault, Natanael Dantas, Laura Payton, Mickael Perrigault, Damien Tran, Zouher Amzil, Pierre Boudry, Philippe Soudant, Hélène Hégaret, Caroline Fabioux
Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized...
January 19, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28073548/cyanobacteria-and-cyanotoxins-in-fishponds-and-their-effects-on-fish-tissue
#18
Damjana Drobac, Nada Tokodi, Jelena Lujić, Zoran Marinović, Gordana Subakov-Simić, Tamara Dulić, Tamara Važić, Sonja Nybom, Jussi Meriluoto, Geoffrey A Codd, Zorica Svirčev
Cyanobacteria can produce toxic metabolites known as cyanotoxins. Common and frequently investigated cyanotoxins include microcystins (MCs), nodularin (NOD) and saxitoxins (STXs). During the summer of 2011 extensive cyanobacterial growth was found in several fishponds in Serbia. Sampling of the water and fish (common carp, Cyprinus carpio) was performed. Water samples from 13 fishponds were found to contain saxitoxin, microcystin, and/or nodularin. LC-MS/MS showed that MC-RR was present in samples of fish muscle tissue...
May 2016: Harmful Algae
https://www.readbyqxmd.com/read/28073529/seasonality-and-toxin-production-of-pyrodinium-bahamense-in-a-red-sea-lagoon
#19
E Banguera-Hinestroza, W Eikrem, H Mansour, I Solberg, J Cúrdia, K Holtermann, B Edvardsen, S Kaartvedt
Harmful algal blooms of the dinoflagellate Pyrodinium bahamense have caused human and economic losses in the last decades. This study, for the first time, documents a bloom of P. bahamense in the Red Sea. The alga was recurrently present in a semi-enclosed lagoon throughout nearly 2 years of observations. The highest cell densities (10(4)-10(5)cellsL(-1)) were recorded from September to beginning of December at temperatures and salinities of ∼26-32°C and ∼41, respectively. The peak of the bloom was recorded mid-November, before a sharp decrease in cell numbers at the end of December...
May 2016: Harmful Algae
https://www.readbyqxmd.com/read/28073526/prevalence-of-algal-toxins-in-alaskan-marine-mammals-foraging-in-a-changing-arctic-and-subarctic-environment
#20
Kathi A Lefebvre, Lori Quakenbush, Elizabeth Frame, Kathy Burek Huntington, Gay Sheffield, Raphaela Stimmelmayr, Anna Bryan, Preston Kendrick, Heather Ziel, Tracey Goldstein, Jonathan A Snyder, Tom Gelatt, Frances Gulland, Bobette Dickerson, Verena Gill
Current climate trends resulting in rapid declines in sea ice and increasing water temperatures are likely to expand the northern geographic range and duration of favorable conditions for harmful algal blooms (HABs), making algal toxins a growing concern in Alaskan marine food webs. Two of the most common HAB toxins along the west coast of North America are the neurotoxins domoic acid (DA) and saxitoxin (STX). Over the last 20 years, DA toxicosis has caused significant illness and mortality in marine mammals along the west coast of the USA, but has not been reported to impact marine mammals foraging in Alaskan waters...
May 2016: Harmful Algae
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