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PubMed2001

Biomarkers of sublethal stress in the soft-sediment bivalve Austrovenus stutchburyi exposed in-situ to contaminated sediment in an urban New Zealand harbour.

In this study, a suite of sublethal stress biomarkers were analysed in the sediment-dwelling bivalve, Austrovenus stutchburyi, with a view to using them as pollution monitoring tools. Shellfish were transplanted from a relatively uncontaminated site to four sites in a different harbour with different levels of contaminants in the sediment, where they were exposed in-situ for 2 and 8 weeks. A range of sublethal stress biomarkers were selected on the basis of their potential to provide ecologically relevant information (adenylate energy charge, total adenylate nucleotide pool, glycogen and RNA). Adenylate energy charge was lower at contaminated sites after 2 weeks, but recovered after 8 weeks, whereas total adenylate nucleotide pool was depressed after 8 weeks at these sites. Glycogen and RNA were found to be significantly higher at the uncontaminated site after both 2 and 8 weeks. These data suggest the potential application of biomarkers in coastal pollution monitoring.

Adenine Nucleotides↗

PubMed2003

Monitoring of DSP toxins in small-sized plankton fraction of seawater collected in Mutsu Bay, Japan, by ELISA method: relation with toxin contamination of scallop.

Monitorings were conducted on DSP toxins in mid-gut gland of scallop (mouse assay), cell numbers of toxic dinoflagellate species of Dinophysis, and diarrhetic shellfish poisoning (DSP) toxins in small-sized (0.7-5 microm) plankton fraction of seawater collected from surface (0 m) and 20 m depth at a station in Mutsu Bay, Aomori Prefecture, Japan, in 2000. A specific enzyme-linked immunosorbent assay (ELISA) was employed for the analysis of DSP toxins in small-sized plankton fraction using a mouse monoclonal anti-okadaic acid antibody which recognizes okadaic acid, dinophysistoxin-1, and dinophysistoxin-3. DSP toxins were detected twice in the mid-gut gland of scallops at 1.1-2.3 MU (mouse units) g(-1) on 26 June and at 0.6-1.2 MU g(-1) on 3 July, respectively. Relatively high cell densities of D. fortii were observed on 26 June and 11 September, and may only contribute to the bivalve toxicity during late June to early July. D. acuminata did not appear to be responsible for the toxicity of scallops in Mutsu Bay in 2000. ELISA monitoring of small-sized plankton fraction in seawater could detect DSP toxins two weeks before the detection of the toxin in scallops, and could do so two weeks after the loss of the bivalve toxicity by mouse assay. On 17 July, toxic D. fortii was detected at only small number, <10 cells l(-1), but DSP toxins were detected by the ELISA assay, suggesting a presence of other toxic small-sized plankton in seawater. For the purpose of reducing negative impacts of DSP occurrences, monitorings have been carried out hitherto on DSP toxins of bivalve tissues by mouse assay and on cell densities of "toxic" species of Dinophysis. Here we propose a usefulness of ELISA monitoring of plankton toxicity, especially in small-sized fraction, which are possible foods of mixotrophic Dinophysis, as a practical tool for detecting and predicting DSPs in coastal areas of fisheries grounds of bivalve aquaculture.

Animals↗

PubMed2001

PSP toxins from Aphanizomenon flos-aquae (cyanobacteria) collected in the Crestuma-Lever reservoir (Douro river, northern Portugal).

The presence of paralytic shellfish poisoning (PSP) toxins in cultures of Aphanizomenon flos-aquae, isolated from the Crestuma-Lever reservoir, was found by reversed phase high performance liquid chromatography employing two isocratic elution systems for the separation of PSP toxins. With the first isocratic elution protocol, the presence of apolar toxins as saxitoxin, decarbamoyl saxitoxin and neosaxitoxin not detected. On the other hand, GTX4, GTX1 and GTX3 as well as Cs toxins were present either in the Aphanizomenon flos-aquae cells collected directly from the bloom or in the other toxic isolates priorly cultivated in laboratory conditions.

Bacterial Toxins↗

PubMed2001

Non-selective retention of PSP toxins by the mussel Mytilus galloprovincialis fed with the toxic dinoflagellate Alexandrium tamarense.

Mussels, Mytilus galloprovincialis, were contaminated by paralytic shellfish poisoning (PSP) toxins by being fed with the toxic dinoflagellate Alexandrium tamarense. Temporal variations in the toxin content and the profile of mussels during the feeding experiment were monitored by high-performance liquid chromatography (HPLC). The toxin profile of mussels was compared with that of A. tamarense to clarify the mechanism of uptake of toxins in mussels. The prominent toxins in mussels and A. tamarense were N-sulfocarbamoyl toxins (C1,2) and carbamate toxins, gonyautoxin-1,4 (GTX1,4). The toxin profiles of both mussels and A. tamarense were almost constant throughout the experimental period. There were no remarkable differences in the toxin proportion between mussel and A. tamarense. These results indicate that mussels do not selectively accumulate particular toxins.

Animals↗

PubMed2002

Comparison of oral and intraperitoneal toxicity of yessotoxin towards mice.

Currently, yessotoxin is regulated among the toxins in the diarrhetic shellfish poisoning (DSP) complex. Yessotoxin is equally acutely toxic towards mice upon intraperitoneal injections as those algal toxins giving diarrhea, but is not diarrheagenic. Its presence in mussels may therefore lead to overestimation of risk of DSP in consumers when the standard mouse bioassay is used. Arguments are presented for the use of analytical methods instead of the mouse bioassay for the diarrheagenic DSP toxins and yessotoxin. Yessotoxin was found to be more than ten times less toxic to mice via the oral route, compared with intraperitoneal injections. Even at 10mg/kg body weight, the highest dose ever tested orally, yessotoxin did not kill the mice. By means of light microscopy of several organs, moderate changes were only observed in the heart. Ultrastructural studies revealed swelling of heart muscle cells leading to separation of the organelles. Effects were most pronounced close to the capillaries. The pathological changes were clearly dose dependent, and the lowest oral dose where any effects were seen was 2.5mg yessotoxin per kg.

Administration, Oral↗

PubMed2002

Post-mortem analysis of samples from a human victim of a fatal poisoning caused by the xanthid crab, Zosimus aeneus.

After ingestion of a specimen of the crab Zosimus aeneus (Xanthidae), an East Timorese adult male died within several hours. Xanthid crabs are known to harbour paralytic shellfish toxins (PSTs), tetrodotoxin and palytoxin. A post-mortem examination did not find any obvious pathological abnormalities. This absence of pathologies is more often associated with PSTs and tetrodotoxin intoxication. A second, yet uneaten specimen of Z. aeneus from the same meal, contained a significant amount of PSTs and these same toxins were identified in the gut contents, blood, liver and urine of the victim. Metabolism of the PSTs occurred with the ingested crab harbouring gonyautoxin 2, gonyautoxin 3 and saxitoxin (STX) whereas neoSTX, decarbamoylSTX and STX dominated the PSTs in the victim's urine. The PST composition in the gut contents, in both their identity and proportion, was intermediate between the eaten crab and the urine suggesting that toxin conversion commenced in the victim's gut. The dose consumed by the victim was calculated to be between 1 and 2 microg STX equivalents/kg based upon the concentration in the remains of the cooked crab. The victim's meal did not consist solely of the toxic crab eaten and the possibility of other food items acting in a synergistic manner with the consumed PSTs cannot be discounted.

Adult↗

PubMed2002

DSP toxin profile in the coastal waters of the central Adriatic Sea.

A monitoring program, carried out in 1996 and 1997, has confirmed that toxic compounds, other than the most frequently detected toxins okadaic acid (OA) and dinophysistoxin-1 (DTX-1), are involved in DSP phenomena in the Adriatic Sea. Toxicity was assessed by the mouse bioassay; the content and the nature of the toxic components were established through fluorometric HPLC analysis combined with mass spectrometry. A rare pectenotoxin-2 (PTX-2) derivative, 7-epi-pectenotoxin-2 seco acid (7-epi-PTX-2SA), was the exclusive contaminant of samples collected from the central Adriatic in 1996. Contrary to its marked oral toxicity, intraperitoneally 7-epi-PTX-2SA displayed no toxic effects, hampering its detection by the mouse bioassay. In 1997, its concentration and frequency of appearance were lower than in 1996, with concomitant occurrence of OA, DTX-2, and a new unidentified component related to the DSP toxic group of compounds. This is the first report on the occurrence of DTX-2 in Adriatic mussels. A survey of the phytoplankton community in the surrounding seawater has established the presence of Prorocentrum micans and several potentially toxic species from the Dinophysis genus. A case of unexplained toxicity, associated with the occurrence of Gonyaulax polyedra, suggested possible shellfish contamination with yessotoxin (YTX).

Animals↗

PubMed2003

A potential vector of domoic acid: the swimming crab Polybius henslowii Leach (Decapoda-brachyura).

The swimming crab Polybius henslowii may play an important role in the movement of the amnesic shellfish toxin, domoic acid (DA), through the marine food chain. High DA concentrations have been determined in crab samples harvested along the Portuguese coast during the summer of 2002, reaching a level of 323.1 microg DA/g crab tissue. Toxin distribution in the different crab organs showed levels as high as 571.6 microg DA/g in the visceral tissues. Levels of toxin 4-12 times lower were detected in the remaining tissues. This crab might be a prominent vector of the toxin to higher trophic levels, including fishes, sea birds and even humans. In Portugal P. henslowii is commercialised during the summer in some local markets. DA concentrations were found close to the legal limit of 20 microg/g in samples purchased at Figueira da Foz market. The crabs are boiled prior to reaching the consumers. The cooking process was evaluated. Determination of toxin losses during the cooking process showed a toxin reduction higher than 50%. DA was determined by HPLC-UV and confirmed by spectra acquired with diode-array detector.

Animals↗

PubMed1998

Occurrence of okadaic acid-producing Prorocentrum lima on the Sanriku coast, northern Japan.

Prorocentrum lima was found to be distributed on the surface of the algae, Sargassum confusum and Carpopeltis flabellata collected at the Sanriku coast, northern Japan. Chemical analysis of cultured cells revealed that Sanriku strains of P. lima produce okadaic acid, a toxin responsible for diarrhetic shellfish poisoning. The Sanriku strain grew well in T1 medium at 15 degrees C at which tropical strains do not grow, indicating that it is a local strain which adapts to cooler environments.

Adaptation, Biological↗

PubMed1999

Confirmation of domoic acid production of Pseudo-nitzschia multiseries isolated from Ofunato Bay, Japan.

Production of domoic acid (DA), the responsible toxin for amnesic shellfish poisoning, was examined for 44 strains of Pseudo-nitzschia spp. isolated from Ofunato Bay, Japan. Only one strain which was identified as Pseudo-nitzschia multiseries produced DA in a level comparable to Canadian strains. No significant DA was detected in the rest of the strains, indicating that toxic P. multiseries does not bloom in a high density in the bay.

Canada↗

PubMed2000

An ultrasensitive competitive binding assay for the detection of toxins affecting protein phosphatases.

An ultrasensitive assay is described for microcystin-LR and other substances (microcystins, nodularin, okadaic acid, calyculin A, tautomycin) which block the active site of protein phosphatases (PP) 1 and 2A. The assay is based on competition between the unknown sample and [125I]microcystin-YR for binding to the catalytic subunit of PP2A. The PP2A-bound [125I]microcystin-YR was stable (half-time of dissociation = 1.8 h), allowing non-bound [125I]microcystin-YR to be removed by Sephadex G-50 size-exclusion chromatography. Compared to current assays based on inhibition of protein phosphatase activity the present assay was more robust against interference (from fluoride, ATP, histone, and casein), and had an even better sensitivity. The detection limit was below 50 pM (2.5 fmol) for nodularin and microcystin-LR, and below 200 pM (10 fmol) for okadaic acid. The method was used successfully to detect extremely low concentrations of either microcystin or nodularin in drinking water or seawater, and okadaic acid in shellfish extract.

Bacterial Toxins↗

PubMed2000

Multiple organ damage caused by a new toxin azaspiracid, isolated from mussels produced in Ireland.

A new type of food poisoning resulting from ingestion of mussels produced in Ireland occurred in the Netherlands in 1995 and then reoccurred in Ireland in 1997. As the causative agent, azaspiracid, was isolated in pure form and revealed to have a structure entirely unlike other known algal toxins, in vivo studies with mice were carried out to elucidate the pathological injuries caused by the toxin. By per os administration, the toxin caused necrosis in the lamina propria of the small intestine and in lymphoid tissues such as thymus, spleen and the Peyer's patches. Both T and B lymphocytes were injured. Additionally a fatty change was observed in the liver. These injuries distinctly differed from those caused by the representative diarrhetic shellfish toxin, okadaic acid.

Administration, Oral↗

PubMed2003

Fish tissue quality in the lower Mississippi River and health risks from fish consumption.

Between 1990 and 1994, samples of three shellfish species (i.e. blue crab, Callinectes sapidus;crayfish, Procambarus acutis; and river shrimp, Macrobrachium ohionii) and 16 fish species and were collected at six sites along the lower Mississippi River by the Louisiana Department of Environmental Quality, Office of Water Resources in coordination with the US Environmental Protection Agency. The fish species included: bigmouth buffalo (Ictiobus cyanellus); blue catfish (Ictalurus furcatus); carp (Cyprinus carpio); channel catfish (Ictalurus punctatus); cobia (Rachycentron canadum); flathead catfish (Pylodictis olivaris); freshwater drum (Aplodinotus grunniens); largemouth bass (Micropterus salmoides); long nose gar (Lepisosteus osseus); red drum (Sciaenops ocellatus); red snapper (Lutjanus campechanus); smallmouth buffalo (Ictiobus bubalus); spotted gar (Lepisosteus oculatus); striped bass (Morone saxatilis); white bass (Morone chrysops); and white crappie (Pomoxis annularis). Organic compound and heavy metal concentrations were measured in 161 composite fish tissue samples where each composite included three to 10 individual fish. Nineteen chemicals, found at measurable levels in sample tissues, were used in calculations of lifetime excess cancer and non-cancer risks due to fish consumption. We calculated: 574 chemical-specific cancer risks; 41 total cancer risks; and 697 margins of exposure based on a consumption rate of one 8-ounce meal per week (0.032 kg/day), a body weight of 70 kg and reported cancer potency factors and reference doses. We identified nine species of concern (blue catfish, carp, channel catfish, cobia, crayfish, flathead catfish, red drum, spotted gar and striped bass) based on total cancer risk greater than 10(-4) or margin of exposure greater than 1, and whether or not samples collected in subsequent years resulted in lower risks. The compounds primarily responsible for the elevated risks were aldrin, dieldrin, alpha-benzene hexachloride, gamma-benzene hexachloride, heptachlor epoxide, arsenic and mercury.

Animals↗

PubMed1997

Long-term decline of radiocesium concentration in seafood from the Ligurian sea (northern Italy) after Chernobyl.

The activity of 137Cs, 134Cs and 40K in tissues from fish, molluse and shellfish of the Ligurian sea was measured during 1987-1988. The mean annual concentrations in 1987 were 5.92 +/- 4.1 Bq/kg (wet tissue) for 137Cs and 2.7 +/- 1.5 Bq/kg for 134Cs and 2.46 +/- 1.82 and 0.33 +/- 0.57 Bq/kg respectively in 1988. The mean value of 40K activity was 138.6 +/- 22.1 Bq/kg. Contamination was significantly higher in the littoral area up to 1000 m from the coast (8.39 +/- 7.6 and 1.74 +/- 2.08 Bq/kg respectively versus 2.91 +/- 1.87 and 0.58 +/- 0.59 Bq/kg respectively in the open sea). The common octopus (Octopus vulgaris) had the highest radioactivity values and could be utilized as an indicator of radioactivity pollution. There were no significant differences regarding the trophic level, the seafood phylum, or the east and west Ligurian sea areas. Long-term reduction in the sea habitat was estimated at about 200 days for 137Cs and 110 days for 134Cs, reflecting differences in the physical half-life of these radionuclides. These values were lower than those found in terrestrial foodstuff and could have reflected dilution of the contaminants in the open sea. The effective dose equivalent for the Ligurian population of radiocesium originating from seafood was estimated at 1.3 microSv in 1987 and 0.5 microSv in 1988. These va ues represent 0.8 and 0.3% respectively of the annual dose (180 microSv/year) due to 40K intake with the diet.

Analysis of Variance↗

PubMed1983

Epidemic hepatitis A from cockles.

Early in 1981, cases of hepatitis possibly associated with the consumption of cockles were reported mainly from south-east England. A case-control study was undertaken in 19 local authority districts. Between Nov. 1, 1980, and April 30, 1981, 424 cases of infective jaundice were formally notified and case-finding yielded 26 additional cases. 42.6% of those with hepatitis and 17.5% of the controls reported consumption of cockles. There was a statistically significant association between infective jaundice and the consumption of cockles but not other sea foods. The cockles had probably been insufficiently processed and stricter controls on treatment of such shellfish are needed.

Adolescent↗

PubMed1988

Pelagic paralysis.

Three conditions that may occur after consumption of seafood--puffer fish poisoning, ciguatera, and paralytic shellfish poisoning--are caused by a group of poisons that block voltage-gated sodium channels in myelinated and non-myelinated nerves. The conditions cannot be distinguished clinically and so constitute an entity for which the name pelagic paralysis is proposed. Variations in the clinical features can be accounted for by large differences in the amount of toxin present in the seafood.

Animals↗

PubMed2002

Ion trap MS(n) for identification of gliotoxin as the cytotoxic factor of a marine strain of Aspergillus fumigatus Fresenius.

When cultured in a marine solid medium, a strain of Aspergillus fumigatus (Fresenius) isolated from a shellfish-farming area in the Loire estuary (France) produced a highly cytotoxic exudate. To identify the origin of this activity, a cytotoxicity test on KB cells was used to monitor the purification of the exudate, together with electrospray/ion trap/mass spectrometry (ESI/IT/MS(n)) to detect and identify the toxic compound. After three purification stages, a comparison of fullscan analyses of the last six fractions showed that a monocharged compound at m/z 349 was present only in the active fraction, corresponding to the sodium adduct of gliotoxin [C(13)H(14)N(2)O(4)S(2)+Na](+). Isotopic distribution determination showed that the m/z 349 product possessed two sulphur atoms and multi-stage fragmentation confirmed the hypothesis. MS/MS analysis exhibited the characteristic gliotoxin loss of the disulphide intracyclic bridge. MS(3) analysis revealed four main ions and confirmed the identity of the m/z 349 ion. This study points out that the combined use of a KB cells bioassay and ESI/IT/MS(n) allows a fast and very specific detection and elucidation of unidentified cytotoxic products in natural samples. This method does not require total purification, and it allowed us to report the first detection of gliotoxin production in marine conditions.

Animals↗

PubMed1987

A theoretical discourse on the pharmacology of toxic marine ingestions.

The known and theoretical pharmacology of poisons involved in toxic marine ingestions has assisted in the development of specific therapeutics for these afflictions. The clinical manifestations of several toxic marine ingestions have suggested toxins/cogeners that may be involved in the poisoning process, providing direction for the development of diagnostic laboratory tests, including those for cyclic ethers. Future investigations should involve utilization of acetaminophen and indomethacin for chronic ciguatera fish poisoning, and the evaluation of the role of polycyclic ethers in the temperature sensation reversal phenomenon of both ciguatera and neurotropic shellfish poisoning.

Animals↗