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Occurrence of toxin-producing cyanobacteria blooms in a Brazilian semiarid reservoir
Costa, I. A. S.;Azevedo, S. M. F. O;Senna, P. A. C.;Bernardo, R. R.;Costa, S. M.;Chellappa, N. T.;
Brazilian Journal of Biology , 2006, DOI: 10.1590/S1519-69842006000200005
Abstract: we report the occurrence of cyanobacterial blooms and the presence of cyanotoxins in water samples from the armando ribeiro gon?alves reservoir (06° 08? s and 37° 07? w), located in the state of rio grande do norte, in the semiarid region of northeastern brazil. the cyanobacterial species were identified and quantified during the rainy and dry seasons in the year 2000. cyanotoxins such as microcystins, saxitoxins and cylindrospermopsins were analyzed and quantified using hplc and elisa methods. the mixed toxic blooms of cylindrospermopsis raciborskii, microcystis spp (m. panniformis, m. protocystis, m. novacekii) and aphanizomenon spp (aphanizomenon gracile, a. cf. manguinii, a. cf. issastschenkoi) were persistent and represented 90-100% of the total phytoplankton species. toxic cyanobacterial blooms from the armando ribeiro gon?alves reservoir were analyzed and found to have three phases in relation to the annual cycle. during the rainy season, an intense toxic bloom of cylindrospermopsis raciborskii was recorded along with saxitoxins (3.14 μg.l-1). during the transition period, between the rainy and dry seasons, different species of microscytis occurred and microcystin as high as 8.8 μg.l-1 was recorded. in the dry season, co-dominance of cylindrospermopsis raciborskii, microcystis spp and aphanizomenon spp occurred and the concentrations of saxitoxin remained very low. our results indicate the presence of microcystins (8.8 μg.l-1) and saxitoxins (3.14 μg.l-1) into the crude water, with increasing concentrations from the second fortnight of april to late may 2000. the occurrence of toxic blooms in this reservoir points to a permanent risk of cyanotoxins in supply waters, indicating the need for the implementation of bloom control measures to improve the water quality. exposure of the local population to cyanotoxins through their potential accumulation in fish muscle must also be considered.
Determinación de saxitoxina y sus derivados en moluscos bivalvos:Evaluación y optimización del uso de cromatografía líquida de alta resolución con previa oxidación
Rojas de Astudillo,Luisa; Chang-Yen,Iván; La Barbera-Sánchez,Amelia;
Zootecnia Tropical , 2002,
Abstract: saxitoxin and its derivatives are potent neurotoxins associated with paralytic shellfish poisoning (psp) in humans which are primarily produced by dinoflagellates. to evaluate and optimize the use of high performance liquid chromatography (hplc) with previous oxidation in order to determine saxitoxin and its derivatives, samples of the green mussel (perna viridis) and oysters (crassostrea sp) were collected at six locations in venezuela and at four in trinidad, the latter along the west coast line, in june 2000. the samples were extracted using the aoac bioassay mouse procedure. each extract was oxidized using periodic acid and the oxidation product was injected to the chromatographic column. the method used to hplc in this work was a modification of lawrence et al. (1996). the separation of important pairs of toxins (stx/neo, gtx1,4/gtx2,3) were achieved, but the resolution and height of the peaks of oxidation products of these toxins varied depending on column efficiencies. some samples had presence of psp below permissible levels, which was confirmed by using bioassay mouse method. the results showed that the reaction precolumn method gives prompt information about profile of the toxins, which is independent of matrix of receptor organism, and it is a simple method for monitoring psp in shellfish in the caribbean.
Screening the toxicity and toxin content of blooms of the cyanobacterium Trichodesmium erythraeum (Ehrenberg) in northeast Brasil
Proen?a, LAO;Tamanaha, MS;Fonseca, RS;
Journal of Venomous Animals and Toxins including Tropical Diseases , 2009, DOI: 10.1590/S1678-91992009000200004
Abstract: blooms of the cyanobacterium trichodesmium occur in massive colored patches over large areas of tropical and subtropical oceans. recently, the interest in such events has increased given their role in major nitrogen and carbon dioxide oceanic fluxes. trichodesmium occurs all along the brazilian coast and patches frequently migrate towards the coast. in this paper we screen the toxicity and toxin content of trichodesmium blooms off the coast of bahia state. four samples, collected from february to april 2007, were analyzed. organisms were identified and assessed for toxicity by means of several methods. analogues of microcystins, cylindrospermopsins and saxitoxins were analyzed using hplc. microcystins were also assayed through elisa. results showed dominance of t. erythraeum, which makes up as much as 99% of cell counts. other organisms found in smaller quantities include the dinoflagellates prorocentrum minimum and p. rhathymum. extracts from all samples delayed or interrupted sea urchin larval development, but presented no acute toxicity during a mouse bioassay. saxitoxin congeners and microcystins were present at low concentrations in all samples, occurrences that had not previously been reported in the literature. despite our finding of saxitoxin analogues and microcystins in trichodesmium blooms, these toxins do not represent a potential harm to human health by primary contact. we conclude, based on our results and those reported in the recent literature, which differ from results published in 1963, that although toxins are present, there is no evidence that t. erythraeum blooms represent a threat to humans.
A methodology for optimising the removal of cyanobacteria cells from a brazilian eutrophic water
De Julio, M.;Fioravante, D. A.;De Julio, T. S.;Oroski, F. I.;Graham, N. J. D.;
Brazilian Journal of Chemical Engineering , 2010, DOI: 10.1590/S0104-66322010000100010
Abstract: this work is concerned with optimizing the performance of the coagulation process in terms of the removal of intact cyanobacteria cells and saxitoxins (stx). the evaluation has been carried out through bench-scale jar tests to construct coagulation diagrams for aluminium sulphate, polyaluminium chloride (pacl) and ferric chloride. the test water was taken from a eutrophic surface source, collected at the inlet to the water treatment plant that supplies ponta grossa city, brazil, at a time of high algal activity corresponding to a total of 108833 cells/ml of cyanobacteria. by constructing the coagulation diagram for turbidity, the optimal dose-ph conditions were used in subsequent tests involving both coagulation and sand filtration. in these tests the benefits of adding a cationic synthetic polymer and powdered activated carbon (pac) to the overall treatment were investigated. from the results of the tests, the optimal dosages and ph for each coagulant, polymer and pac were obtained corresponding to the lowest concentrations of cyanobacteria cells, stx and turbidity.
Preparation of Calibration Standards of N1-H Paralytic Shellfish Toxin Analogues by Large-Scale Culture of Cyanobacterium Anabaena circinalis (TA04)
Ryuichi Watanabe,Toshiyuki Suzuki,Yasukatsu Oshima
Marine Drugs , 2011, DOI: 10.3390/md9030466
Abstract: Mouse bioassay is the official testing method to quantify paralytic shellfish toxins (PSTs) in bivalves. A number of alternative analytical methods have been reported. Some methods have been evaluated by a single laboratory validation. Among the different types of methods, chemical analyses are capable of identifying and quantifying the toxins, however a shortage of the necessary calibration standards hampers implementation of the chemical analyses in routine monitoring of PSTs in bivalves. In our present study, we studied preparation of major PST analogues as calibrants by large-scale cultivation of toxic freshwater cyanobacteria Anabaena circinalis TA04. The cells were steadily grown in 10?L bottle for 28 days. The primary N1-H toxins, C1/C2, were produced at a concentration of 1.3?±?0.1 μmol/L. The intracellular and extracellular toxins occupied 80% and 20%, respectively. Over 220 μmol of the toxins was obtained from approximately 200?L of the culture over six months, demonstrating that it is sufficient to prepare saxitoxin analogues. The toxins were chemically converted to six N1-H analogues. Preparation of the analogues was carried out at relatively high yields (50–90%). The results indicate that our preparation method is useful to produce N1-H toxins. In our present study, detailed conditions for preparation of one of the rare N1-H analogues, gonyautoxin-5, were investigated.
Surface Plasmon Spectroscopic Detection of Saxitoxin
Hongxia Chen,Youn Sook Kim,Sam-Rok Keum,Sung-Hoon Kim,Heung-Jin Choi,Jaebeom Lee,Won Gun An,Kwangnak Koh
Sensors , 2007, DOI: 10.3390/s7071216
Abstract: For the surface-optoelectronic study of Saxitoxin sensing, we fabricated self-assembled calix[4]arene derivative monolayers as the recognition-functional interfaces ona gold surface. An interaction study between Saxitoxin and calix[4]arene derivativemonolayers were performed using surface plasmon resonance (SPR) spectroscopy. Amongthree calix[4]arene derivatives, calix[4]arene crown ether SAM showed the highestsensitivity to Saxitoxin. The detection limit of this system is three orders of magnitudelower than that of the mouse bioassay which is the current benchmark for Saxitoxindetection.
Studies in the Use of Magnetic Microspheres for Immunoaffinity Extraction of Paralytic Shellfish Poisoning Toxins from Shellfish
Raymond Devlin,Katrina Campbell,Kentaro Kawatsu,Christopher Elliott
Toxins , 2011, DOI: 10.3390/toxins3010001
Abstract: Paralytic shellfish poisoning (PSP) is a potentially fatal human health condition caused by the consumption of shellfish containing high levels of PSP toxins. Toxin extraction from shellfish and from algal cultures for use as standards and analysis by alternative analytical monitoring methods to the mouse bioassay is extensive and laborious. This study investigated whether a selected MAb antibody could be coupled to a novel form of magnetic microsphere (hollow glass magnetic microspheres, brand name Ferrospheres-N) and whether these coated microspheres could be utilized in the extraction of low concentrations of the PSP toxin, STX, from potential extraction buffers and spiked mussel extracts. The feasibility of utilizing a mass of 25 mg of Ferrospheres-N, as a simple extraction procedure for STX from spiked sodium acetate buffer, spiked PBS buffer and spiked mussel extracts was determined. The effects of a range of toxin concentrations (20–300 ng/mL), incubation times and temperature on the capability of the immuno-capture of the STX from the spiked mussel extracts were investigated. Finally, the coated microspheres were tested to determine their efficiency at extracting PSP toxins from naturally contaminated mussel samples. Toxin recovery after each experiment was determined by HPLC analysis. This study on using a highly novel immunoaffinity based extraction procedure, using STX as a model, has indicated that it could be a convenient alternative to conventional extraction procedures used in toxin purification prior to sample analysis.
Preliminary assessment of the performance of oyster shells and chitin materials as adsorbents in the removal of saxitoxin in aqueous solutions
Silvia P Melegari, William G Matias
Chemistry Central Journal , 2012, DOI: 10.1186/1752-153x-6-86
Abstract: Chitin and OSP were found to be efficient adsorbents with a high capacity to remove STX from aqueous solutions within the concentration limits evaluated (> 50% over 18?h). The rate of STX removal for both adsorbents decreased with contact time, which was likely due to the saturation of the adsorbing sites and suggested that the adsorption occurred through ion exchange mechanisms. Our results also indicated that the adsorption equilibrium was influenced by pH and was not favored under acidic conditions.The results of this study demonstrate the possibility of using these two materials in the treatment of drinking water contaminated with STX. The characteristics of chitin and OSP were consistent with the classical adsorption models of linear and Freundlich isotherms. Kinetic and thermodynamic evaluations revealed that the adsorption process was spontaneous (ΔGads < 0) and favorable and followed pseudo-second-order kinetics.The blooming of cyanobacteria in drinking water reservoirs is an increasingly common problem associated with eutrophication, and several different water treatment processes exist to remove cyanobacteria and cyanotoxins [1]. When cyanobacteria lyse due to natural causes or through the use of algaecides, cyanotoxins are released and solubilized in water [1,2]. When this occurs, the water treatment process must ensure the efficient and consistent removal of cyanotoxins. Appropriate treatment processes exist and have been tested and optimized to remove soluble organic compounds. Such processes include using ozone, activated charcoal, nanofiltration or reverse osmosis, and biodegradation [1-6].Consistent evidence indicates that high doses of powdered activated charcoal work well in the removal of cyanotoxins from aqueous solutions, but this process is slow and expensive due to the large quantities of activated charcoal that must be used [7,8]. Different alternatives for removing cyanotoxins by adsorption and with others techniques have been tested [9-12],
Clinical and epidemiological study of 27 poisonings caused by ingesting puffer fish (Tetrodontidae) in the states of Santa Catarina and Bahia, Brazil
Silva, Claudia Carvalho Pestana;Zannin, Marlene;Rodrigues, Daisy Schwab;Santos, Claudia Regina dos;Correa, Ieda Ana;Haddad Junior, Vidal;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2010, DOI: 10.1590/S0036-46652010000100009
Abstract: puffer fish can be poisonous due to the presence of the potent neurotoxins such as tetrodotoxin (ttx) and saxitoxin (stx) found in its tissues. the authors report 27 human poisonings from ingestion of puffer fish in patients treated at toxicology centers in the states of santa catarina and bahia, brazil, between 1984 and january 2009. poisonings were classified as moderate (52%) and severe (33%), two deaths were observed. early diagnosis is very important to ensure respiratory support.
Paralytic Shellfish Poisoning (PSP) in Margarita Island, Venezuela
La Barbera-Sánchez,Amelia; Soler,Jose Franco; Rojas de Astudillo,Luisa; Chang-Yen,Ivan;
Revista de Biología Tropical , 2004,
Abstract: a severe outbreak of paralytic shellfish poisoning (psp) occurred in manzanillo and guayacán, northwestern coast of margarita island, venezuela, between august and october 1991. a bloom of dinoflagellates including prorocentrum gracile, gymnodinium catenatum and alexandrium tamarense seemed to be responsible for this outbreak. levels of psp toxins in mussels (perna perna) exceeded the international safety limit of saxitoxin, 80 μg stx/100 g meat. psp toxin values varied between 2 548 and 115 μg stx/100 g meat in manzanillo, and between 1 422 and 86 μg stx/100 g meat in guayacán. at both locations, the highest levels were detected in august, when 24 patients exhibited typical symptoms of psp toxicity after consuming cooked mussels (16 required hospitalization). a high pressure liquid chromatographic (hplc) procedure was recently used on the 1991 samples. the major toxin detected in samples of both locations was decarbamoyl saxitoxin (dcstx), but low concentrations of saxitoxin were also found in manzanillo samples. gonyautoxins gtx1, gtx2 and gtx3 were detected only at guayacán, while in both locations, decarbamoylgonyatouxin (dcgtx2,3) toxins were detected. these findings represent the first time that causative toxins of psp in venezuela have been chemically identified, and confirm the presence of dcstx and dcgtx in mussels from the caribbean sea. the presence of dcstx and dcgtx in shellfish is indicative that gymnodinium catenatum was a causative organism for outbreak of psp
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