Paralytic Shellfish Toxins (paralytic + shellfish_toxin)

Distribution by Scientific Domains


Selected Abstracts


PRODUCTION OF PARALYTIC SHELLFISH TOXINS BY APHANIZOMENON SP.

JOURNAL OF PHYCOLOGY, Issue 4 2002
LMECYA 31 (CYANOBACTERIA)
We examined intracellular and extracellular paralytic shellfish toxins (PST) in a strain of Aphanizomenon sp. (LMECYA31) isolated from a Portuguese freshwater reservoir throughout the growth cycle and under different conditions affected by temperature and nitrate and phosphate availability. PST concentrations and compositions were greatly influenced by cell density, growth stage, and temperature and nutrients conditions. On a per-cell basis results showed (1) the enhancement of PST cell quota after the end of exponential growth phase in nutrient replete batch cultures, (2) the absence of a PST increment at late growth stages under phosphate limitation, (3) a rise in PST maximum cell quota under nitrate depletion, and (4) the enhancement of toxin production at higher temperatures. The relative proportion of the four toxins detected, neoSTX, dcSTX, STX and GTX5, also changed within and between culture settings. While growing under phosphate rich media cells produced mainly GTX5 and neoSTX, whereas under phosphate limitation the proportion of STX and dcSTX increased substantially with culture age. Large amounts of extracellular toxins were found in the culture medium, increasing during culture time. Extracellular toxin composition in each culture was fairly constant and always similar to the intracellular composition found at late stages of growth. This further supported other research that indicates that PSTs are released to the water through cell lysis, and a significant concentration of PST may be expected to remain in the water upon the collapse of a toxic bloom or after cells removal by water treatment. [source]


41 Incidence of paralytic shellfish toxin in bivalve mollusc tissue from the oregon coast

JOURNAL OF PHYCOLOGY, Issue 2003
R. C. Everroad
Saxitoxin and domoic acid sequestration by bivalve molluscs occurs periodically along the Oregon coast, presumably as a result of harmful algal blooms (HABs). Since 1958 and more continuously since 1979, the Oregon Shellfish Program (OSP) has assayed toxin levels in these molluscs as part of a monitoring program for paralytic (PSP) and amnesic (ASP) shellfish poisoning. We have created a working data base for all PSP sampling by the OSP between 1958 and 2001 and have examined the data for spatial and temporal trends in the appearance of toxin in shellfish, amount of toxin, and apparent duration of toxic events. In this report, we examine the data from the five stations with the longest record of continuous sampling (1979,2000) for evidence of correlation with El Niño events, upwelling, and/or a pattern of increasing frequency or intensity of toxic events. We also compare the pattern of appearance of toxin at open coast stations with the timing of first appearance of toxin in shellfish at adjacent estuarine stations. This is an important analysis because, in Oregon, shellfish closures due to PSP occur frequently in mussel beds on the open coast and the source of toxin-producing organisms is unknown. [source]


First report of saxitoxin in Finnish lakes and possible associated effects on human health

ENVIRONMENTAL TOXICOLOGY, Issue 3 2005
Jarkko Rapala
Abstract This study is the first report of saxitoxin in cyanobacterial blooms in Finland. Bloom samples (n = 50) were collected from Finnish freshwater sites during summer months of 2002 and 2003. These samples were screened for the presence of paralytic shellfish toxins (PSTs) using the Jellett rapid PSP screening test. Samples testing positive for PSTs (n = 7) were further analyzed with saxiphilin- and voltage-gated sodium channel [3H]-STX,binding radioreceptor assays and liquid chromatography using fluorescence and mass spectrometric analysis. The results indicated that saxitoxin (STX) was the only PST analogue in the samples and that it was present in high concentrations, as much as 1 mg L,1. Microscopic analysis revealed that 95%,100% of the phytoplankton in the positive samples consisted of Anabaena lemmermannii. The trophic status of lakes in which STX-containing blooms were found varied from oligotrophic to hypertrophic. All the lakes had high nitrogen-to-phosphorus ratios. In some instances, samples had been collected from sites where swimmers had reported adverse health effects, and in three such cases, reported adverse health effects were associated with sites from which samples testing positive for STX had been received. Symptoms of fever, eye irritation, abdominal pains, and skin rash were reported in children aged 2,10 years after exposure to the water. These were not the adverse human symptoms typical of STX poisoning; rather, they represented acute effects often reported following recreational exposure to cyanobacterial blooms. © 2005 Wiley Periodicals, Inc. Environ Toxicol 20: 331,340, 2005 [source]


Effects of the toxic dinoflagellate, Alexandrium fundyense on three species of larval fish: a food-chain approach

JOURNAL OF FISH BIOLOGY, Issue 1 2008
J. C. Samson
Sublethal behavioural effects of exposure to paralytic shellfish toxins (PST; saxitoxin and its derivatives) from the toxic dinoflagellate Alexandrium fundyense were investigated in newly settled winter flounder Pseudopleuronectes americanus, larval sheepshead minnow Cyprinodon variegatus and larval mummichog Fundulus heteroclitus through an A. fundyense,copepod,fish food chain. Consumption of as few as six to 12 toxin-containing copepods was lethal to the fishes. After consuming fewer toxin-containing copepods, all three fish species exhibited sublethal effects from vector-mediated exposure. Prey-capture ability of mummichogs was reduced in larvae that had consumed toxic copepods, Coullana canadensis. After consuming toxic C. canadensis or mixed copepods, mummichog larvae had reduced swimming performance. Swimming activity was also significantly reduced in winter flounder after consuming toxic copepods, including time spent in motion and distance travelled. Prey capture and predator avoidance were reduced in first-feeding sheepshead minnow larvae that had consumed toxic dinoflagellate cells. Adverse effects on prey capture or predator avoidance may reduce larval survival and facilitate the transmission of PST through the food web. This study provides baseline information on sublethal effects of PST exposure on fishes using a novel food-chain approach with zooplankton as vectors. [source]


PRODUCTION OF PARALYTIC SHELLFISH TOXINS BY APHANIZOMENON SP.

JOURNAL OF PHYCOLOGY, Issue 4 2002
LMECYA 31 (CYANOBACTERIA)
We examined intracellular and extracellular paralytic shellfish toxins (PST) in a strain of Aphanizomenon sp. (LMECYA31) isolated from a Portuguese freshwater reservoir throughout the growth cycle and under different conditions affected by temperature and nitrate and phosphate availability. PST concentrations and compositions were greatly influenced by cell density, growth stage, and temperature and nutrients conditions. On a per-cell basis results showed (1) the enhancement of PST cell quota after the end of exponential growth phase in nutrient replete batch cultures, (2) the absence of a PST increment at late growth stages under phosphate limitation, (3) a rise in PST maximum cell quota under nitrate depletion, and (4) the enhancement of toxin production at higher temperatures. The relative proportion of the four toxins detected, neoSTX, dcSTX, STX and GTX5, also changed within and between culture settings. While growing under phosphate rich media cells produced mainly GTX5 and neoSTX, whereas under phosphate limitation the proportion of STX and dcSTX increased substantially with culture age. Large amounts of extracellular toxins were found in the culture medium, increasing during culture time. Extracellular toxin composition in each culture was fairly constant and always similar to the intracellular composition found at late stages of growth. This further supported other research that indicates that PSTs are released to the water through cell lysis, and a significant concentration of PST may be expected to remain in the water upon the collapse of a toxic bloom or after cells removal by water treatment. [source]