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The okadaic acid (OA)-group toxins, including OA, dinophysistoxin-1 (DTX1), dinophysistoxin-2 (DTX2), and dinophysistoxin-3 (DTX3), cause diarrheic shellfish poisoning in humans. To manage OA-group toxins more strictly, Korean regulations were recently revised to consider OA, DTX1, DTX2, and DTX3 combined. Thus, our study characterized the occurrence of OA, DTX1, DTX2, and DTX3 in seafood distributed across South Korea, and a risk assessment of seafood consumption was conducted. Two hundred and seventeen samples from 16 bivalve and 7 non-bivalve species collected from three representative coastal areas in 2021 were analyzed via liquid chromatography-tandem mass spectrometry. OA, DTX1, and DTX3 were detected in 2.3%, 4.1%, and 9.2% of the examined samples, with positive mean levels of 11.3, 16.4, and 40.9 µg/kg, respectively. DTX2 was not detected in any of the samples. At least one OA-group toxin was detected in the bivalve samples, including blood clams, pan shells, hard clams, mussels, and scallops, whereas none were detected in non-bivalves. The estimated acute exposure to OA-group toxins through the intake of seafood in the Korean population and consumer groups was low, ranging from 24.7 to 74.5% of the recommended acute reference dose (ARfD) of 0.33 μg OA equivalents/kg body weight. However, for the scallop consumers aged 7–12 years, acute exposure to OA-group toxins exceeded the ARfD, indicating a possible health risk. These results suggest that including DTX3 in the new regulatory limits is appropriate to protect Korean seafood consumers from exposure to OA-group toxins. [ABSTRACT FROM AUTHOR]

Recent studies have reported on the occurrence of tetrodotoxin (TTX), a sodium channel-blocking neurotoxin commonly found in pufferfishes, in various marine gastropods in tropical and temperate shallow marine environments, raising concern for potential seafood poisoning as the sea snails are consumed. The intertidal beaches and rocky shores of Jeju Island include numerous subtropical and temperate gastropods including mud snails, which are commonly exploited as seafood. Accordingly, surveillance of TTX-bearing gastropods in intertidal Jeju Island is necessary to ensure seafood safety. In this study, we first screened TTX in 15 gastropod species from the Jeju coast using TTX-specific competitive ELISA. The ELISA indicated that mud snail Nassarius livescens contained a certain level of TTX in their muscle and visceral mass, whereas 14 species of gastropods were free from TTX. Accordingly, the levels of TTX and its analogues were determined in 30 individuals of N. livescens using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The LC–MS/MS applied in this study showed a quantification limit (method detection/quantification limit [MDL/MQL]) of 18–19 µg/kg and 56–57 µg/kg, respectively, indicating that the LC–MS/MS was sensitive enough to detect a small quantity of TTX in the tissues. The TTX levels in the muscle ranged from below the detection limit to 3006.9 µg/kg, and those in the viscera ranged from below the detection limit to 1457.2 µg/kg. The detection frequency of TTX in mud snails was 83.3% in muscle and 70.0% in visceral mass, indicating that most N. livescens contained TTX. The LC–MS/MS also revealed several TTX analogues in the tissues, including epiTTX, anhydroTTX, deoxyTTX, dideoxyTTX, trideoxyTTX, and norTTX. [ABSTRACT FROM AUTHOR]

Perna Viridis has become a common dish in daily life. Consumption of Perna Viridis, which is contaminated with diarrhetic shellfish poisoning (DSP) toxins can cause food poisoning in humans. Therefore, there is an urgent need for a rapid and accurate method to identify Perna Viridis contaminated with DSP toxins. In this study, a non-destructive method based on near-infrared spectroscopy (NIS) is proposed to detect DSP toxin-laden Perna Viridis. Spectral data of Perna Viridis were collected in the range of 950–1700 nm for DSP toxin-laden and non-laden (non-DSP) samples. The second derivative (D2) spectral preprocessing method was used to reduce the influence of noise and light scattering. A support vector machine (SVM) model based on Bayesian optimization (BO-SVM) was constructed as a classifier for the detection of the DSP toxin-laden Perna Viridis. The average accuracy for the D2-BO-SVM classifier in detecting DSP toxin-laden Perna Viridis in 50 random tests reached 99.97%. The recognition performance of the D2-BO-SVM model was analyzed to solve the problems of different ratios of training and test datasets, small sample datasets, and unbalanced class datasets in practical applications. The experimental results show that the D2-BO-SVM model was found to be superior to BO-SVM, D2-Standard SVM, and Standard SVM. These results suggest that the combination of NIS and artificial intelligence models has great potential for the detection of the DSP toxin-laden Perna Viridis. This study provides a new method for detecting the quality and safety of shellfish, which is of great practical importance for ensuring the safety of shellfish for consumers. [ABSTRACT FROM AUTHOR]

Ammonia–nitrogen is a common stress factor for aquatic organisms in their habitation environment, which is enriched in water due to high-density farming and environmental pollution. Ammonia nitrogen can enter fish body through gill, epidermis, digestive tract, and other tissues, causing fish ammonia poisoning. In the present study, juvenile blunt snout bream (average weight, 45 ± 5 g) were exposed to high concentrations of ammonia–nitrogen stress (25.0 ± 0.5 mg/L) for six different treatment times (0, 3, 6, 12, 24, 48, and 72 h); the tissue ultrastructure, mRNA levels of antioxidation system, and apoptosis patterns were studied. The antioxidant systems of malondialdehyde (MDA), catalase (CAT), acid phosphatase (ACP), and reduced glutathione (GSH) in various tissues were highly transcripted at 6 or 12 h (hpt) after treatment under high ammonia–nitrogen, which may play a role in preventing cells from being attacked by highly toxic reactive oxygen species (ROS). After 24 hpt, the antioxidant capacity threshold is breached, followed by the decline of antioxidant enzyme activity. Thus, with the prolonging of high ammonia–nitrogen processing time, ammonia–nitrogen stress caused irreversible damage of organs (gill, liver, and kidney). Furthermore, the expression of caspase-3 apoptotic pathway was highly induced in different tissues, implying the apoptotic system is activated, which causes extensive cell apoptosis in different tissues as shown using TUNEL analysis. In conclusion, we observed that, in response to acute ammonia–nitrogen stress, blunt snout bream enhances antioxidant capacity and cell apoptosis. [ABSTRACT FROM AUTHOR]

Although tunas represent a significant part of the global fish economy and a major nutritional resource worldwide, their microbiome still remains poorly documented. Here, we conducted an analysis of the taxonomic composition of the bacterial communities inhabiting the gut, skin, and liver of two most consumed tropical tuna species (skipjack and yellowfin), from individuals caught in the Atlantic and Indian oceans. We hypothesized that each organ harbors a specific microbial assemblage whose composition might vary according to different biotic (sex, species) and/or abiotic (environmental) factors. Our results revealed that the composition of the tuna microbiome was totally independent of fish sex, regardless of the species and ocean considered. Instead, the main determinants of observed diversity were (i) tuna species for the gut and (ii) sampling site for the skin mucus layer and (iii) a combination of both parameters for the liver. Interestingly, 4.5% of all amplicon sequence variants (ASV) were shared by the three organs, highlighting the presence of a core-microbiota whose most abundant representatives belonged to the genera Mycoplasma, Cutibacterium, and Photobacterium. Our study also revealed the presence of a unique and diversified bacterial assemblage within the tuna liver, comprising a substantial proportion of potential histamine-producing bacteria, well known for their pathogenicity and their contribution to fish poisoning cases. These results indicate that this organ is an unexplored microbial niche whose role in the health of both the host and consumers remains to be elucidated. [ABSTRACT FROM AUTHOR]

Species within the dinoflagellate genus Dinophysis can produce okadiac acid and dinophysistoxins leading to diarrhetic shellfish poisoning. Since the first report of D. ovum from the Gulf of Mexico in 2008, reports of other Dinophysis species across US have increased. Members of the D. cf. acuminata complex (D. acuminata, D. acuta, D. ovum, D. sacculus) are difficult to differentiate due to their morphological similarities. Dinophysis feeds on and steals the chloroplasts from the ciliate, Mesodinium rubrum, which in turn has fed on and captured the chloroplasts of its prey, the cryptophyte Teleaulax amphioxeia. The objective of this study was to generate de novo transcriptomes for new isolates of these mixotrophic organisms. The transcriptomes obtained will serve as a reference for future experiments to assess the effect of different abiotic and biotic conditions and will also provide a useful resource for screening potential marker genes to differentiate among the closely related species within the D. cf. acuminata-complex. The complete comprehensive detailed workflow and links to obtain the transcriptome data are provided. [ABSTRACT FROM AUTHOR]

Okadaic acid (OA), a lipophilic phycotoxin distributed worldwide, causes diarrheic shellfish poisoning and even leads to tumor formation. Currently, the consumption of contaminated seafood is the most likely cause of chronic OA exposure, but there is a serious lack of relevant data. Here, the Sprague-Dawley rats were exposure to OA by oral administration at 100 µg/kg body weight, and the tissues were collected and analyzed to assess the effect of subchronic OA exposure. The results showed that subchronic OA administration disturbed colonic mucosal integrity and induced colitis. The colonic tight junction proteins were disrupted and the cell cycle of colonic epithelial cells was accelerated. It is inferred that disruption of the colonic tight junction proteins might be related to the development of chronic diarrhea by affecting water and ion transport. Moreover, the accelerated proliferation of colonic epithelial cells indicated that subchronic OA exposure might promote the restitution process of gut barrier or induce tumor promoter activity in rat colon. [ABSTRACT FROM AUTHOR]

Recently, suspected ciguatera fish poisoning (CFP) cases caused by the consumption of moray eels, popular seafood for locals and tourists, have been reported in Viet Nam. However, little is known about ciguatoxins (CTXs) in these marine fish. In May 2020, 119 specimens of six moray eel species were collected for CTX detection from Ly Son Island (site 1), Ninh Hai Coast (site 2), Phu Quy Island (site 3), and Spratly Islands (site 4), where suspected CFP from moray eel consumption have occurred. CTX-1B was detected by liquid chromatography–mass spectrometry (LC/MS) analysis in 12 specimens belonging to four Gymnothorax species: (G. fimbriatus, G. flavimarginatus, G. javanicus, and G. undulatus), accounting for about 10% of the total specimens. Remarkably, CTX-1B levels detected in all toxic specimens were beyond the safety threshold of 10 pg/g CTX-1B equivalent. The highest occurrence was observed at site 4 (15.6%) (n = 45), followed by site 1 (10.0%) (n = 40) and site 2 (6.3%) (n = 16); whereas no CTX-1B was detected in any specimens (n = 18) from site 3. These results, for the first time, report the presence of CTX-1B, indicating a CFP risk in Viet Nam from consumption of moray eels. [ABSTRACT FROM AUTHOR]

Ciguatoxins are marine compounds that share a ladder-shaped polyether structure produced by dinoflagellates of the genus Gambierdiscus and Fukuyoa, and include maitotoxins (MTX1 and MTX3), ciguatoxins (CTX3C) and analogues (gambierone), components of one of the most frequent human foodborne illness diseases known as ciguatera fish poisoning. This disease was previously found primarily in tropical and subtropical areas but nowadays, the dinoflagellates producers of ciguatoxins had spread to European coasts. One decade ago, the European Food Safety Authority has raised the need to complete the toxicological available data for the ciguatoxin group of compounds. Thus, in this work, the in vivo effects of ciguatoxin-related compounds have been investigated using internationally adopted guidelines for the testing of chemicals. Intraperitoneal acute toxicity was tested for maitotoxin 1 at doses between 200 and 3200 ng/kg and the acute oral toxicity of Pacific Ciguatoxin CTX3C at 330 and 1050 ng/kg and maitotoxin 1 at 800 ng/kg were also evaluated showing not effects on mice survival after a 96 h observation period. Therefore, for the following experiments the oral subchronic doses were between 172 and 1760 ng/kg for gambierone, 10 and 102 ng/kg for Pacific Ciguatoxin CTX3C, 550 and 1760 ng/kg for maitotoxin 3 and 800, 2560 and 5000 ng/kg for maitotoxin 1. The results presented here raise the need to reevaluate the in vivo activity of these agents. Although the intraperitoneal lethal dose of maitotoxin 1 is assumed to be 50 ng/kg, without chemical purity identifications and description of the bioassay procedures, in this work, an intraperitoneal lethal dose of 1107 ng/kg was obtained. Therefore, the data presented here highlight the need to use a common procedure and certified reference material to clearly establish the levels of these environmental contaminants in food. [ABSTRACT FROM AUTHOR]

Okadaic acid (OA) is an important marine lipophilic phycotoxin with various pathological properties, responsible for diarrheal shellfish poisoning events in human beings over the world. However, to date no mechanism can well explain the toxicity and symptom of OA, even diarrhea. Here, to reveal the toxic mechanism of OA to mammals, we analyzed the metabolism of OA in rat and the effects of OA exposure on the composition and function of gut bacteria using a multi-omics strategy and rRNA high-throughput technology. We found that OA exerted great effects on gut bacteria, mainly featured in heavy fluctuation of dominant genera and significant changes in the mapped bacterial function genes, including not only virulence genes of pathogenic bacteria, but also bacterial metabolism genes. In the feces of the OA-exposed group, we detected dinophysistoxin-2 (DTX-2), lespedezaflavanone F and tolytoxin, suggesting that OA could be transformed into other metabolites like DTX-2. Other metabolic biomarkers such as N-Acetyl-a-neuraminic acid, N,N-dihydroxy-l-tyrosine, nalbuphine, and coproporphyrin I and III were also highly correlated with OA content, which made the toxicity of OA more complicated and confusing. Spearman correlation test demonstrated that Bacteroides and Romboutsia were the genera most related to OA transformation, suggesting that Bacteroides and Romboutsia might play a key role in the complicated and confusing toxicity of OA. In this study, we found for the first time that OA may be converted into other metabolites in gut, especially DTX-2. This finding could not only help to reveal the complex toxicity of OA, but also have important significance for clarifying the transportation, metabolism, and environmental fate of OA in the food chain. [ABSTRACT FROM AUTHOR]

Marine fishes have been used in the determinations and corroborations of biogeographic hypotheses, as in the southwest Gulf of Mexico (GOM), where the warm-temperate and tropical ichthyofaunas of the Carolinian and Caribbean provinces mix. The objective of this study was to determine if the arrangement of the lagoon-estuarine ichthyofauna of the southwest GOM corresponds to a previous biogeographic hypothesis based on coastal marine ichthyofauna. Based on peer-reviewed and specialized literature, an ichthyofauna distribution database of 15 coastal lagoons distributed from southern Texas, USA, to Campeche, Mexico, was constructed and used to determine beta diversity, taxonomic diversity, and the geographical segregation of lagoons. A database of 115 species was obtained, more than expected for the lagoon systems of the southwest GOM. The lagoon ichthyofauna of the southwest of the GOM did not follow the traditional biogeographic hypothesis; instead, it was segregated into three sections: northern section within the Carolinian Province, central section with major Caribbean influence, and southern section within the Caribbean Province. [ABSTRACT FROM AUTHOR]

Diarrhetic shellfish-poisoning (DSP) toxins such as okadaic acid and dinophysistoxins harm the human gastrointestinal tract, and therefore, their levels are regulated to an upper limit of 160 μg per kg tissue to protect consumers. Rodents are used routinely for risk assessment and studies concerning mechanisms of toxicity, but there is a general move toward reducing and replacing vertebrates for these bioassays. We have adopted insect larvae of the wax moth Galleria mellonella as a surrogate toxicology model. We treated larvae with environmentally relevant doses of okadaic acid (80–400 μg/kg) via intrahaemocoelic injection or gavage to determine marine toxin-related health decline: (1) whether pre-exposure to a sub-lethal dose of toxin (80 μg/kg) enhances susceptibility to bacterial infection, or (2) alters tissue pathology and bacterial community (microbiome) composition of the midgut. A sub-lethal dose of okadaic acid (80 μg/kg) followed 24 h later by bacterial inoculation (2 × 105Escherichia coli) reduced larval survival levels to 47%, when compared to toxin (90%) or microbial challenge (73%) alone. Histological analysis of the midgut depicted varying levels of tissue disruption, including nuclear aberrations associated with cell death (karyorrhexis, pyknosis), loss of organ architecture, and gross epithelial displacement into the lumen. Moreover, okadaic acid presence in the midgut coincided with a shift in the resident bacterial population over time in that substantial reductions in diversity (Shannon) and richness (Chao-1) indices were observed at 240 μg toxin per kg. Okadaic acid-induced deterioration of the insect alimentary canal resembles those changes reported for rodent bioassays. [ABSTRACT FROM AUTHOR]

The consumption of contaminated shellfish with okadaic acid (OA) group of toxins leads to diarrhoeic shellfish poisoning (DSP) characterized by a set of symptoms including nausea, vomiting and diarrhoea. These phycotoxins are Ser/Thr phosphatase inhibitors, which produce hyperphosphorylation in cellular proteins. However, this inhibition does not fully explain the symptomatology reported and other targets could be relevant to the toxicity. Previous studies have indicated a feasible involvement of the nervous system. We performed a set of in vivo approaches to elucidate whether neuropeptide Y (NPY), Peptide YY (PYY) or serotonin (5-HT) was implicated in the early OA-induced diarrhoea. Fasted Swiss female mice were administered NPY, PYY(3–36) or cyproheptadine intraperitoneal prior to oral OA treatment (250 µg/kg). A non-significant delay in diarrhoea onset was observed for NPY (107 µg/kg) and PYY(3–36) (1 mg/kg) pre-treatment. On the contrary, the serotonin antagonist cyproheptadine was able to block (10 mg/kg) or delay (0.1 and 1 mg/kg) diarrhoea onset suggesting a role of 5-HT. This is the first report of the possible involvement of serotonin in OA-induced poisoning. [ABSTRACT FROM AUTHOR]

The predominant constituents of the essential oil from I C. tomentosa i were I i -humulene (14.6%), humulene epoxide-II (12.9%), I i -eudesmol (7.0%), manool oxide (8.4%), I i -caryophyllene (9.5%) and I i -chamigrene (5.3%). The phytoconstituents now obtained are similar to those reported in several other I Callicarpa i leaf essential oils such as I C. bodinieri i , I C. candicans i , I C. formosana i , I C. longifolia i , I C. petelotii i , I C. rubella i , and I C. sinuata i , where oxygenated and hydrocarbon sesquiterpenoids have been reported as the major chemical classes [[3]]. Eighteen sesquiterpene hydrocarbons (44.4%), 19 oxygenated sesquiterpenes (35.9%), one oxygenated diterpene (8.4%), and two diterpene hydrocarbons (2.0%) were identified in the essential oil. [Extracted from the article]

Although thin and pale as an Apple pencil, he ate constantly and seemed much more interested in food than math. "What's wrong with you, Crocker? "Step one, stop gabbing", said Waffle as he headed for the math lounge, most likely to raid the seminar cookies. I'm a grad student in math, or at least I was a grad student in math. In second grade, my teacher, Mrs. Snyderman, nicknamed me Professor Crocker because I was so much stronger mathematically than my peers. [Extracted from the article]

Bivalve molluscs can acquire marine biotoxins by filter-feeding upon certain toxin-producing microalgae. The two most common syndromes observed in temperate coastal waters have been diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP). While DSP is a non-fatal gastrointestinal syndrome, PSP is a neurological syndrome which can lead to death by respiratory paralysis in high intoxication scenarios. In Portugal, the presence of both DSP and PSP toxins leads to recurrent seasonal bans of bivalve harvesting. On a few occasions, the bans were not placed in time, not properly disseminated to the public or were disregarded by recreational harvesters. Several cases of poisonings have been studied in collaboration between health authorities and the laboratory in charge of the biotoxin monitoring programme. Some of the outbreaks have even called the attention of the local media. In several of these recorded cases, a common trait has emerged throughout the years: bivalve harvest had often been done during very low tides attributed to either new or full moons. These tides expose intertidal bivalves more widely, increase harvesting time, and allow picking of larger-sized specimens. In some occasions, the consumers were extremely unfortunate because a noxious coincidence had occurred: larger-sized specimens were available but had attained the highest toxin content of the toxic season. This review alerts that despite costly monitoring programmes have been perfected through the years, human poisonings still take place due to the rapid increase in toxin levels and/or disrespect of harvest bans. [ABSTRACT FROM AUTHOR]

Vibrio parahemolyticus is a halophilic bacterium which causes widespread seafood poisoning pathogenicity. Although the incidence of disease caused by V. parahemolyticus was stepwise increased, the pathogenic mechanism remained unclear. Herein, the difference of V. parahemolyticus's metabonomic which on blood agar and seawater beef extract peptone medium was detected via nuclear magnetic resonance and 55 metabolites were identified. Among them, 40 kinds of metabolites were upregulated in blood agar group, and 12 kinds were downregulated. Nine pathways were verified by enrichment analysis which were predicted involved in amino acids and protein synthesis, energy metabolism, DNA and RNA synthesis and DNA damage repair. We supposed that the metabolic pathway obtained from this study is related to V. parahemolyticus pathogenicity and our findings will aid in the identification of alternative targets or strategies to treat V. parahemolyticus-caused disease. [ABSTRACT FROM AUTHOR]

Histamine food poisoning is a major safety concern related to seafood consumption worldwide. Morganella psychrotolerans is a novel psychrotolerant histamine-producer. In this study, the histamine production behaviors of M. psychrotolerans and two other major histamine-producers, mesophilic Morganella morganii and psychrotrophic Photobacterium phosphoreum, were compared in seafood products, and histamine accumulation by M. psychrotolerans was characterized at various pH and temperature levels in culture broth. The growth of M. psychrotolerans and P. phosphoreum increased similarly at 4 °C in canned tuna, but M. psychrotolerans produced much higher levels of histamine than P. phosphoreum. Histamine accumulation by M. psychrotolerans was induced at lower environmental pH condition at 4 and 20 °C. The optimal temperature and pH for producing histamine by crude histidine decarboxylase of M. psychrotolerans were 30 °C and pH 7, respectively. The activity of the crude HDC extracted from M. psychrotolerans cells at 10 °C retained 45% of the activity at 30 °C. Histidine decarboxylase gene expression of M. psychrotolerans was induced by low pH conditions. These results suggest that M. psychrotolerans are also a very important histamine-producer leading to histamine poisoning associated with seafood below the refrigeration temperature. [ABSTRACT FROM AUTHOR]

High bioavailability of man-made pollutants in marine environments raises serious concern regarding the safety of seafood. In the present study, the presence, trophic transfer, and risks of polycyclic aromatic hydrocarbons (PAHs), and potentially toxic elements (PTEs) in 170 benthic marine organisms (87 prawn; 28 crab; 55 fish) from the Persian Gulf were investigated. Among investigated species, E. coioides displayed the lowest level of metal pollution index (MPI), while P. armatus and P. semisulcatus showed the highest level of MPI and total PAHs, respectively. Principal component biplot exhibited a significant association of PTEs (except Hg) and PAHs in less motile benthic species. The results of trophic transfer investigation revealed that PTEs (except Hg) and PAHs were not biomagnified in the studied organisms through diet. However, Hg biomagnification factors greater than 1 indicated trophic transfer of mercury. In order to gain nutritional benefits of seafood, consumption of two fish/prawn meals/week for adults (except vulnerable groups such as pregnant women) and one fish/prawn meals/week for children is recommended. However, lifelong consumption of crabs (P. armatus) may threaten human health. In addition, the maximum allowable fish consumption rate (CRlim) for studied fish is 120 g fish/day for adults and 30 g fish/day for children. In the case of prawns, the safe dose is 30 and 10 g prawns/day for adults and children, respectively. [ABSTRACT FROM AUTHOR]

The lipophilic phycotoxin okadaic acid (OA) occurs in the fatty tissue and hepatopancreas of filter-feeding shellfish. The compound provokes the diarrhetic shellfish poisoning (DSP) syndrome after intake of seafood contaminated with high levels of the DSP toxin. In animal experiments, long-term exposure to OA is associated with an elevated risk for tumor formation in different organs including the liver. Although OA is a known inhibitor of the serine/threonine protein phosphatase 2A, the mechanisms behind OA-induced carcinogenesis are not fully understood. Here, we investigated the influence of OA on the β-catenin-dependent Wnt-signaling pathway, addressing a major oncogenic pathway relevant for tumor development. We analyzed OA-mediated effects on β-catenin and its biological function, cellular localization, post-translational modifications, and target gene expression in human HepaRG hepatocarcinoma cells treated with non-cytotoxic concentrations up to 50 nM. We detected concentration- and time-dependent effects of OA on the phosphorylation state, cellular redistribution as well as on the amount of transcriptionally active β-catenin. These findings were confirmed by quantitative live-cell imaging of U2OS cells stably expressing a green fluorescent chromobody which specifically recognize hypophosphorylated β-catenin. Finally, we demonstrated that nuclear translocation of β-catenin mediated by non-cytotoxic OA concentrations results in an upregulation of Wnt-target genes. In conclusion, our results show a significant induction of the canonical Wnt/β-catenin-signaling pathway by OA in human liver cells. Our data contribute to a better understanding of the molecular mechanisms underlying OA-induced carcinogenesis. [ABSTRACT FROM AUTHOR]

The polyether toxin, okadaic acid, causes diarrhetic shellfish poisoning in humans. Despite extensive research into its cellular targets using rodent models, we know little about its putative effect(s) on innate immunity. We inoculated larvae of the greater wax moth, Galleria mellonella, with physiologically relevant doses of okadaic acid by direct injection into the haemocoel (body cavity) and/or gavage (force-feeding). We monitored larval survival and employed a range of cellular and biochemical assays to assess the potential harmful effects of okadaic acid. Okadaic acid at concentrations ≥ 75 ng/larva (≥ 242 μg/kg) led to significant reductions in larval survival (> 65%) and circulating haemocyte (blood cell) numbers (> 50%) within 24 h post-inoculation. In the haemolymph, okadaic acid reduced haemocyte viability and increased phenoloxidase activities. In the midgut, okadaic acid induced oxidative damage as determined by increases in superoxide dismutase activity and levels of malondialdehyde (i.e. lipid peroxidation). Our observations of insect larvae correspond broadly to data published using rodent models of shellfish-poisoning toxidrome, including complementary LD50 values: 206–242 μg/kg in mice, ~ 239 μg/kg in G. mellonella. These data support the use of this insect as a surrogate model for the investigation of marine toxins, which offers distinct ethical and financial incentives. [ABSTRACT FROM AUTHOR]

Radioactive contamination from the Fukushima disaster has undermined the seafood caught around the area. Approximately 20 % of general consumers are reported to avoid seafood from Fukushima, even though it has not been found to exceed the Japanese criteria of radioactivity since April 2015. Based on a survey of more than 2000 domestic consumers in Japan, this study investigated the characteristics of those who boycotted safe marine products from the devastated region, using conjoint analysis with a latent class model. The attributes (levels) included price, three prefectural origins (including Fukushima and adjacent prefectures), six local origins, and two ecolabels targeting white fish meat. The latent class model divided participants into three classes: boycotters (27.5 %), consumers devaluing cod (41.0 %), and ordinary consumers (31.5 %). Boycotters neither believed the radioactive test results from any entity nor bought seafood frequently. Furthermore, they tended not to recognize the Marine Stewardship Council, earned more, and were relatively older than the average. [ABSTRACT FROM AUTHOR]

In annual surveys conducted during the period 2012-2015, concentrations of the toxic or essential elements B, Se, Cd, Sn, Cs, Hg, Pb, Al, Cr, Mn, Fe, Ni, Cu, Zn, and As were analyzed in brown meat of edible crab (Cancer pagurus), and filets of cod (Gadus morhua) and halibut (Hippoglossus hippoglossus) in one of the most important commercial crab fishing areas in Norway, at Mausund in Frøya municipality in Sør-Trøndelag, Norway. Concentrations of the elements were analyzed in sediments in 2015. Several salmon farms are located in this area. Samples were extracted by HNO3 and analyzed using inductively coupled plasma mass spectroscopy (ICP-MS). Crab, cod, and halibut were caught in a total of five locations. One of these locations was in the proximity of a salmon farm. In edible crabs, the mean ranks were significantly different between two locations only for Sn (p = 0.034). When all data were pooled, the mean ranks statistics showed significant difference between all years for the elements Se (p = < 0.001), Cs (p = 0.005), Mn (p = 0.002), Zn (p = 0.006), and As (p = 0.001) in edible crab. The study showed elevated levels of Cd in edible crabs in 2012, 2013, 2014, and 2015, with the highest levels in 2015. In cod, there were significant differences between locations for the elements B (p = 0.003), and Pb (p = 0.04), as well as between the years for the elements B, Sn, Cs, Hg, Cr, and As (p = < 0.01). The study showed elevated level of Pb in cod in 2013. Halibut showed no significant differences between years or locations for any elements. The Cd, Hg, and Pb values of the sediments in this study indicate that local geogenic sources cannot be considered a major cause of high values in local biota. [ABSTRACT FROM AUTHOR]

The positioning of fishes within a riverscape is dependent on the proximity of complementary habitats. In this study, foraging and non-foraging habitat were quantified monthly over an entire year for a rainbow trout ( Oncorhynchus mykiss) population in an isolated, headwater stream in southcentral New Mexico. The stream follows a seasonal thermal and hydrologic pattern typical for a Southwestern stream and was deemed suitable for re-introduction of the native and close relative, Rio Grande cutthroat trout ( O. clarkii virginalis). However, uncertainty associated with limited habitat needed to be resolved if repatriation of the native fish was to be successful. Habitat was evaluated using resource selection functions with a mechanistic drift-foraging model to explain trout distributions. Macroinvertebrate drift was strongly season- and temperature-dependent (lower in winter and spring, higher in summer and fall). Models identified stream depth as the most limiting factor for habitat selection across seasons and size-classes. Additionally, positions closer to cover were selected during the winter by smaller size-classes (0, 1, 2), while net energy intake was important during the spring for most size-classes (0, 1, 2, 3). Drift-foraging models identified that 81% of observed trout selected positions that could meet maintenance levels throughout the year. Moreover, 40% of selected habitats could sustain maximum growth. Stream positions occupied by rainbow trout were more energetically profitable than random sites regardless of season or size-class. Larger size-classes (3, 4+) were energetically more limited throughout the year than were smaller size-classes. This research suggests that habitat in the form of deep pools is of paramount importance for rainbow trout or native cutthroat trout. [ABSTRACT FROM AUTHOR]

The peacock hind Cephalopholis argus (family Serranidae), locally known as ' roi', was introduced from French Polynesia to Hawaii in the mid-twentieth century as a food fish. However, because of its association with ciguatera fish poisoning, it is rarely fished for food. Previous research indicates that roi could have a negative impact on native reef fish assemblages because of their high densities and prey consumption rates. However, it is unclear whether roi add to the cumulative mortality of prey (predation hypothesis), or whether predation is instead compensatory (doomed surplus hypothesis). This study experimentally assessed the effects of roi on reef fish populations through a long-term (5.5 year) predator removal experiment. A Before-After-Control-Impact study design was used to assess changes in fish assemblages following the removal of roi on 1.3 ha of patch reef. Increases in the density of prey-sized fish (<15 cm TL) were observed 18 months after roi removal. However, those effects did not translate into sustained increases in prey. While increases in potential competitors, wrasses (family Labridae), particularly the piscivorous ringtail wrasse Oxycheilinus unifasciatus, were observed on roi-free reefs, the fish assemblage did not diverge substantially in composition. Native reef fish appeared to resist the potential negative impacts of predation by roi, possibly through a refuge in size for some fish families. Management to protect intact fish assemblage size-structure could serve to bolster native resistance to invading species. In considering the threats facing coral reefs, and the possible solutions, roi removal alone will not likely replenish native fishery resources. [ABSTRACT FROM AUTHOR]

Benzothiazoles are high production volume chemicals widely used in many industrial and household applications. However, information on their occurrence in aquatic organisms is very limited, although a high level of bioaccumulation is expected. In this study and for the first time, a method was developed involving subcritical water extraction followed by solid-phase microextraction coupled to gas chromatography-ion trap-tandem mass spectrometry for the determination of five benzothiazoles in seafood. The repeatability and reproducibility of the method were under 21% (%RSD, n = 5, 100 ng g (dw)), while method detection limits and method quantification limits were between 0.5 and 10 ng g (dw) and 1 and 50 ng g (dw), respectively. Ten widely consumed fish and shellfish species from the county of Tarragona (Catalonia, Spain) were selected in order to estimate dietary exposure and to assess the human health risks. The most frequently determined compounds were benzothiazole and 2-(methylthio)-benzothiazole, with squid being the species which showed the highest level of benzothiazole (82 ng g (dw)). In terms of human exposure, the current concentrations of benzothiazoles found in fish and shellfish could not be compared to threshold values because of the lack of toxicological data. [ABSTRACT FROM AUTHOR]

Marine biotoxins regularly occur along the coast, with several consequences for the environment as well as the food industry. Monitoring of these compounds in seawater is required to assure the safety of marine resources for human consumption, providing a means for forecasting shellfish contamination events. In this study, an analytical method was developed for the detection of ten lipophilic marine biotoxins in seawater: azaspiracids 1, 2, 3, 4 and 5, classified as azaspiracid shellfish poisoning toxins, and pectenotoxin 2, okadaic acid and the related dinophysistoxin 1, yessotoxin and homoyessotoxin, classified as diarrheic shellfish poisoning toxins. The method is based on the application of solid-liquid ultrasound-assisted extraction and solid-phase extraction, followed by high-performance liquid chromatography coupled with high-resolution mass spectrometry. The limits of detection of this method are in the range of nanograms per litre and picograms per litre for most of the compounds, and recoveries range from 20.5% to 97.2%. To validate the effectiveness of this method, 36 samples of surface water from open coastal areas and marinas located along the Catalan coast on the Mediterranean Sea were collected and analysed. Eighty-eight per cent of these samples exhibited okadaic acid in particulate and aqueous phases in concentrations ranging from 0.11 to 560 μg/g and from 2.1 to 1780 ng/L respectively. Samples from open coastal areas exhibited higher concentrations of okadaic acid in particulate material, whereas in samples collected in sportive ports, the particulate material exhibited lower levels than the aqueous phase. [ABSTRACT FROM AUTHOR]

The distribution of the toxic elements As, Cd, and Pb in nine different types of seafood from Shenzhen, China, was investigated by using inductively coupled plasma mass spectrometry (ICP-MS). The results revealed that the concentrations of arsenic (As) in fish ( Lutjanus erythropterus, Paralichthys olivaceus) and in bivalve ( Meretrix meretrix) and cadmium (Cd) in scallop ( Argopecten irradians) exceed the limits established by food safety regulations in China and EU (European Union). Furthermore, the bioavailability of As, Cd, and lead (Pb) in mice after 20-day oral ingestion of Crassostrea rivularis was investigated, and the total rate of absorption of toxic elements in samples from the liver and kidney tissues and blood was determined. The results of this in vivo trial indicated that the oral bioavailability of As, Cd, and Pb was approximately 0.33, 0.45, and 0.74%, respectively. [ABSTRACT FROM AUTHOR]

The major beds of oyster along the central-west coast of India are exposed to different anthropogenic activities and are severely exploited for human consumption. In this viewpoint, tissues of oyster Crassostrea madrasensis, C. gryphoides and Saccostrea cucullata were analyzed for Cu, Ni, Cd and Pb concentrations (dry weight) from Chicalim Bay, Nerul Creek and Chapora Bay in pre-monsoon, monsoon and post-monsoon seasons. A higher concentration of Cu (134.4-2167.9 mg kg) and Cd (7.1-88.5 mg kg) was found, which is greater than the recommended limits in all the three species (and sites). Moreover, significant ( p < 0.05) variations were observed for all the metals concentrations among the species, seasons and sites. The high concentrations of Cd and Cu in tissues of edible oyster pose a threat to human health. Therefore, continuous monitoring, people awareness and a stringent government policy should be implemented to mitigate the metal pollution along the studied sites. [ABSTRACT FROM AUTHOR]

The aims of the present study were to obtain the seafood dietary patterns of coastal residents, to determine the concentrations of heavy metals, and to evaluate the possible health risks caused by seafood intake. The daily food intakes of 24 types of seafood were collected from 738 participants from Xiamen, a southern Chinese coastal city, using food frequency questionnaire (FFQ) and dietary history method. One hundred and fifty-six samples of 14 types of highest intake seafood were collected from local markets for lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), and arsenic (As) determination. Health risks via seafood consumption were evaluated by calculating the target hazard quotient (THQ) and the total hazard index (HI) for carcinogenic and non-carcinogenic effects recommended by the US Environmental Protection Agency. The results showed that the seafood daily intake of Xiamen residents was 61.5 (2.14, 115) g/day. The concentrations of Pb, Cd, Cr, Hg, and As in seafood were ND-0.45 mg/kg, ND-0.19 mg/kg, ND-0.80 mg/kg, ND-0.70 mg/kg, and 0.32-16.9 mg/kg, respectively. Concentrations of Cd and As in some samples were higher than national limitation standards. Consumption of 14 common types of seafood would not pose non-carcinogenic risk. However, some types, such as sparuslatus, oyster, and porphyra tenera, would form a carcinogenic risk. Regardless of a carcinogenic or non-carcinogenic risk, As posed the highest risk on humans. The observed HI value for non-carcinogenic effect of all metals in all seafood reached 0.69-2.20, and the metal orders of risk can be listed as As > Hg > Cr > Cd > Pb, reiterating the risk of As is a matter of concern in seafood from Xiamen markets. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus is a causative agent of human serious seafood-borne gastroenteritis disease and even death. Shrimps, often eaten raw or undercooked, are an important reservoir of the bacterium. In this study, we isolated and characterized a total of 400 V. parahaemolyticus strains from commonly consumed fresh shrimps ( Litopenaeus vannamei, Macrobrachium rosenbergii, Penaeus monodon, and Exopalaemon carinicauda) in Shanghai fish markets, China in 2013-2014. The results revealed an extremely low occurrence of pathogenic V. parahaemolyticus carrying two major toxic genes ( tdh and trh, 0.0 and 0.5 %). However, high incidences of antibiotic resistance were observed among the strains against ampicillin (99 %), streptomycin (45.25 %), rifampicin (38.25 %), and spectinomycin (25.50 %). Approximately 24 % of the strains derived from the P. monodon sample displayed multidrug resistant (MDR) phenotypes, followed by 19, 12, and 6 % from the E. carinicauda, L. vannamei, and M. rosenbergii samples, respectively. Moreover, tolerance to heavy metals of Cr and Zn was observed in 90 antibiotic resistant strains, the majority of which also displayed resistance to Cu (93.3 %), Pb (87.8 %), and Cd(73.3 %). The pulsed-field gel electrophoresis (PFGE)-based genotyping of these strains revealed a total of 71 distinct pulsotypes, demonstrating a large degree of genomic variation among the isolates. The wide distribution of MDR and heavy-metal resistance isolates in the PFGE clusters suggested the co-existence of a number of resistant determinants in V. parahaemolyticus population in the detected samples. This study provided data in support of aquatic animal health management and food safety risk assessment in aquaculture industry. [ABSTRACT FROM AUTHOR]

The diatom Nitzschia bizertensis was recently discovered in Bizerte Lagoon (Tunisia, SW Mediterranean Sea), where it was shown to produce the amnesic shellfish poisoning toxin, domoic acid (DA). This diatom was previously found to be widespread in both time and space throughout the lagoon. The present study was carried out to test the hypothesis that N. bizertensis is able to survive after being filtered and ejected as biodeposits (faeces plus pseudofaeces) by mussels. N. bizertensis cultures (strains BD4 and BD8), at natural bloom concentrations, were fed to mussels ( Mytilus sp.). The stomach contents (after 1 h) and biodeposits (after 48 h) were observed for the presence and viability of N. bizertensis cells. Light microscopy revealed intact and partial cells of N. bizertensis in both the stomach contents and biodeposits of the mussels. Incubation of the biodeposits resulted in the regrowth of N. bizertensis. This provides evidence that transplanted mussels have the potential to serve as vectors for the transport of N. bizertensis. Furthermore, cells regrown from the biodeposits contained DA, but at levels lower than those in pre-filtered cells (up to 11.9 fg cell). Thus, regrown cells remain toxigenic. The results suggest that one must guard against spreading N. bizertensis and other DA producers via the transfer of shellfish from contaminated to pristine areas. [ABSTRACT FROM AUTHOR]

The "final list of introduced harmful algal species" by Marampouti et al. ([1]) contains species that are not harmful, and no species is an indisputably validated introduction (see details in the Appendix S1 as Supplementary Material). Marampouti et al. ([1]) offer a "final list of introduced harmful algal species" encompassing fifteen species of dinoflagellates, four diatoms, and one raphidophyte. The authors list the "origin" (Supplementary Material), presumably the natural range of the species, according to their definition of invasive alien species. [Extracted from the article]

A bloom of D. acuminata complex was detected in early March 2008 in the shellfish farming area of Baía Sul, southern Brazil. Cell density reached up to 4.7 × 10 cells/L at the surface by March 31st, quickly decreasing (<4.0 × 10 cells/L) 1-2 weeks later as salinity increased (>32) in all sampling stations. On average, commercial-sized mussels, Perna perna, accumulated 11-fold higher okadaic acid (OA) levels in the digestive glands (DG) (maximum 2422 ng/g) compared to those of oysters, Crassostrea gigas (maximum 271 ng/g). Moreover, 50 % of the mussel DG extracts tested ( n = 42) produced acute toxic effects as assessed by mouse bioassay, whereas all oyster samples produced negative results ( n = 17). In parallel, juvenile oysters, Crassostrea brasiliana and C. gigas, and juvenile mussels, P. perna, exposed to a laboratory-simulated D. acuminata complex bloom (1350-13,750 cells/L) accumulated 7.5, 23.4, and 51.1 ng OA/g in whole bodies (22.7, 66.1, and 183.3 ng OA/g in visceral tissues), respectively. Toxin levels in the whole bodies dropped to similarly low average levels in all bivalve species (3.6, 3.7, and 1.3 ng/g, respectively) after 168 h of depuration. Mussels, therefore, detoxified OA at faster rates (0.023/h) than oysters C. gigas (0.010/h) and C. brasiliana (0.004/h). [ABSTRACT FROM AUTHOR]

With the increasing number of outbreaks of food-borne diseases caused by okadaic acid (OA) and its analogue dinophysistoxin-1 (DTX-1), two key diarrhetic shellfish poison (DSP) toxins, OA and DTX-1, have become a serious threat to public health and have attracted significant public attention in China. The aim of our study was to monitor OA and DTX-1 contamination in commercially available seafood and to provide references for tracking these toxins and preventing disease outbreaks. From 2010 to 2012, 40 species were collected from six coastal cities of four inland seas in China. An enzyme-linked immunosorbent assay (ELISA) and a lateral flow immunochromatographic (LFIC) test strip were used to analyse the samples, and the results were further confirmed using a commercially available ELISA kit. The monitoring results indicated that 23 of 40 species were positive for contamination. In addition, 14 of the positive species were determined to be inedible because the content of OA and DTX-1 was above the regulatory limit. Simultaneously, we verified that the digestive glands of shellfish tended to accumulate toxin, in contrast to the flesh. The highest concentrations of OA and DTX-1 were recorded in Scapharca broughtonii, which was collected from Qing Dao, in relation to the other analysed species. Moreover, the Arca family as well as Mytilus galloprovincialis were severely contaminated by OA and its analogue. The above results indicate that some of the commercially available seafood from the coastal cities in China may be inedible due to serious marine toxin contamination. The results of this study might play an important role in protecting consumer health and safety screening of marine products. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus, an emerging food and waterborne pathogen, is a leading cause of seafood poisoning worldwide. Surface proteins can directly participate in microbial virulence by facilitating pathogen dissemination via interactions with host factors. Screening and identification of protective antigens is important for developing therapies against V. parahaemolyticus infections. Here, we systematically characterized a novel immunogenic enolase of V. parahaemolyticus. The enolase gene of V. parahaemolyticus ATCC33847 was cloned, sequenced, and expressed in Escherichia coli BL21. Enzymatic assays revealed that the purified recombinant V. parahaemolyticus enolase protein catalyzes the dehydration of 2-phospho- d-glycerate to phosphoenolpyruvate. Western blot analysis showed that V. parahaemolyticus enolase was detectable in the extracellular, outer membrane (OM) and cytoplasmic protein fractions using antibodies against the recombinant enolase. Surface expression of enolase was further confirmed by immunogold staining and mass spectrometry (liquid chromatography-tandem mass spectrometry) analysis of OM protein profiles . Notably, V. parahaemolyticus enolase was identified as a human plasminogen-binding protein with the enzyme-linked immunosorbent assay. The values obtained for adherence and inhibition suggest a role of surface-exposed enolase in epithelial adherence of V. parahaemolyticus. We further showed that enolase confers efficient immunity against challenge with a lethal dose of V. parahaemolyticus in a mouse model. To our knowledge, this is the first study to demonstrate the plasminogen-binding activity of enolase that is an adhesion-related factor of V. parahaemolyticus. Our findings collectively imply that enolase plays important roles in pathogenicity, supporting its utility as a novel vaccine candidate against V. parahaemolyticus infection. [ABSTRACT FROM AUTHOR]

Domoic acid (DA) is a neurotoxin produced by different algae, including pennate diatoms, principally from the genus Pseudo-nitzschia, and it is the main cause of amnesic shellfish poisoning. Determination of this toxin in seawater samples is fundamental to define the real contamination risks for aquatic species. We have developed two very sensitive instrumental methods using hydrophilic interaction liquid chromatography coupled using tandem mass spectrometry in positive and negative polarity modes. Instrumental detection limits were 9 pg mL for positive and 19 pg mL for negative ionisation. A procedural method based on solid-phase extraction for the determination of dissolved DA present in seawater has been developed, and an extraction procedure was employed for the determination of the toxin in the particulate fraction. DA quantification was performed using the internal standard method to account for signals fluctuations and random errors during sample treatment. To our knowledge, this is the first study to use this quantification method for DA determination. Trueness, extraction yield, matrix effects, repeatability and procedural detection limits were evaluated during method validation. Procedural detection limits of 0.3 pg mL (positive mode) and 0.6 pg mL (negative mode) were found for the dissolved fraction, and absolute limits of 0.4 pg (positive mode) and 6.0 pg (negative mode) for particulate samples were obtained. The most sensitive method in positive mode was applied to define DA occurrence in the Venice Lagoon. Trace concentrations of domoic acid ranging from 1.5 to 16.2 pg mL were found for the first time in the Venetian environment. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Matrix reference materials are an essential component for the validation and quality control of analytical methodologies for the quantitation of marine biotoxins in shellfish. Given the potential advantages of reference materials in powder form, a study was conducted to assess the feasibility for the production of a freeze-dried oyster tissue reference material containing a range of important paralytic shellfish poisoning toxins. One bulk sample of a wet oyster tissue homogenate was generated following mass culturing of toxic Alexandrium and oyster feeding experiments. The bulk tissue was used to prepare untreated wet frozen aliquots with the remainder being freeze-dried and processed into appropriately-sized powder samples. A pre-column oxidation LC-FLD analysis was used to confirm the absence of any chromatographic artefacts resulting from the processing and to confirm acceptable homogeneity of the tissues. Excellent stability over both the short-term (1 month) and long-term (1 year) of the freeze-dried material was demonstrated as compared with the stability of the untreated wet tissue. A post-column oxidation LC-FLD method was used to confirm the absence of toxin epimerisation in freeze-dried tissues which were observed in the wet tissues. Overall the work showed the feasibility of an approach to produce a homogenous freeze-dried oyster matrix material with enhanced stability in comparison to the untreated wet tissue. The potential for use of the process for preparation of large scale production batches of a freeze-dried CRM for paralytic shellfish poisoning toxins has therefore been demonstrated. [ABSTRACT FROM AUTHOR]

Monitoring programs for harmful algal blooms (HABs) typically rely on time-consuming manual methods for identification and enumeration of phytoplankton, which make it difficult to obtain results with sufficient temporal resolution for early warning. Continuous automated imaging-in-flow by the Imaging FlowCytobot (IFCB) deployed at Port Aransas, TX has provided early warnings of six HAB events. Here we describe the progress in automating this early warning system for blooms of Karenia brevis. In 2009, manual inspection of IFCB images in mid-August 2009 provided early warning for a Karenia bloom that developed in mid-September. Images from 2009 were used to develop an automated classifier that was employed in 2011. Successful implementation of automated file downloading, processing and image classification allowed results to be available within 4 h after collection and to be sent to state agency representatives by email for early warning of HABs. No human illness (neurotoxic shellfish poisoning) has resulted from these events. In contrast to the common assumption that Karenia blooms are near monospecific, post-bloom analysis of the time series revealed that Karenia cells comprised at most 60-75 % of the total microplankton. [ABSTRACT FROM AUTHOR]

Mercury is a toxic metal shown to have harmful effects on human health. Several studies have reported high blood mercury concentrations as a risk factor for autism spectrum disorders (ASDs), while other studies have reported no such association. The goal of this study was to investigate the association between blood mercury concentrations in children and ASDs. Moreover, we investigated the role of seafood consumption in relation to blood mercury concentrations in Jamaican children. Based on data for 65 sex- and age-matched pairs (2-8 years), we used a General Linear Model to test whether there is an association between blood mercury concentrations and ASDs. After controlling for the child's frequency of seafood consumption, maternal age, and parental education, we did not find a significant difference ( P = 0.61) between blood mercury concentrations and ASDs. However, in both cases and control groups, children who ate certain types of seafood (i.e., salt water fish, sardine, or mackerel fish) had significantly higher (all P < 0.05) geometric means blood mercury concentration which were about 3.5 times that of children living in the US or Canada. Our findings also indicate that Jamaican children with parents who both had education up to high school are at a higher risk of exposure to mercury compared to children with at least one parent who had education beyond high school. Based on our findings, we recommend additional education to Jamaican parents regarding potential hazards of elevated blood mercury concentrations, and its association with seafood consumption and type of seafood. [ABSTRACT FROM AUTHOR]

In recent years, mussels have already become commercially important seafood species worldwide. Mussels accumulate a wide range of metals in their soft tissue. Thus, the determination of accumulated concentrations of heavy metals, such as Pb, Cd, Hg, and As, in mussels is essential because of their usage as seafood and the potential adverse effects of their consumption on human health. In this review, these issues are presented and discussed using the Mediterranean mussel Mytilus galloprovincialis as an example. M. galloprovincialis is very efficient at converting low value victuals into high quality animal protein. The production of M. galloprovincialis in Mediterranean countries has been increasing rapidly, but Spain is still the largest producer of mussels. Only China has a larger production of these mussels than Spain. M. galloprovincialis is a filter feeding animal and accumulates a wide range of metals from their environment. The metal concentrations in the soft tissue of M. galloprovincialis are indicators of marine ecosystems contamination. In the same time, the bioaccumulation of heavy metals remains an issue concerning the consumption of mussels. Thereby, the Cd, Pb, Hg, and As concentration measurement in mussel soft tissue as a seafood have become significant. A review of literature data revealed large variations in the Cd, Pb, Hg, and As concentrations in M. galloprovincialis from their endemic areas, e.g., Mediterranean, Adriatic, and Black Sea, and the concentrations of these toxic metals were generally in the following order: As > Pb > Cd > Hg. The guidelines on heavy metals for seafood safety set by different countries and associations are reviewed. Comparison of the published data with European legislation showed that the levels of the heavy metals generally did not exceed the existing limits in all the mussels analyzed, excluding mussels from hot spots, such as lagoons and harbors, in the Mediterranean, Adriatic, and Black Sea. [ABSTRACT FROM AUTHOR]

Blooms of Ostreopsis spp. have been recently reported along the Mediterranean coasts of Spain, France, Italy, and Greece posing serious risks to human health. Occurrence of Ostreopsis spp. may result in palytoxin contamination of seafood and, in order to prevent sanitary risks, the need exists to develop efficient extraction procedures to be coupled to rapid and sensitive monitoring methods of palytoxin-like compounds in seafood. In the present study, the best conditions for both extraction of palytoxin from seafood and palytoxin quantification by using liquid chromatography tandem mass spectrometry (LC-MS/MS) were investigated. Three seafood matrices (mussels, sea-urchins, and anchovies) were selected and five different extraction systems were tested, namely: the official protocol for extraction of lipophilic toxins and various aqueous methanol or acetonitrile solutions (MeOH/HO 1:1, MeOH/HO 8:2, MeCN/HO 8:2 and MeOH 100%). Extraction with MeOH/HO 8:2 provided the best results in terms of accuracy and matrix interference on LC-MS/MS detection of palytoxin. Accuracy and intra-day reproducibility ( n = 3) were evaluated for all the selected matrices but only for mussels at three spiking concentration levels, including the provisional limit proposed by the Community Reference Laboratory for marine biotoxins (250 μg kg). Limits of quantitation of palytoxin in mussels, sea-urchins and anchovies tissues were calculated using matrix-matched standards; taking into account extraction efficiency of MeOH/HO 8:2, they resulted to be 228, 343, and 500 μg kg, respectively. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Methylmercury (MeHg) is a neurotoxic contaminant and one of the main sources of exposure in humans is seafood consumption. It is thus of interest to assess precisely MeHg exposure. The objective of this study was to estimate MeHg daily intake in exposed individuals using two different approaches, a food questionnaire and toxicokinetic modeling, and compare the complementary and use of each method. For this purpose, a group of 23 fishermen from northern Quebec provided blood and hair samples and answered a standard food questionnaire focusing on seafood consumption. A published and validated toxicokinetic model was then used to reconstruct MeHg daily intakes from mercury (Hg) measurements in biological samples. These intakes were compared to those estimated using a standard food questionnaire on seafood consumption. Daily intakes of MeHg from seafood (mean/median (range)) estimated from hair concentrations with the toxicokinetic-based approach were 6.1/5.2 (0.0-19) μg/day. These intake values were on average six times lower than those estimated using a food questionnaire, that is, 49/32 (7.2-163) μg/day. No correlation was found between the toxicokinetic-based and the questionnaire estimates of MeHg daily intakes. Most of the MeHg intakes estimated with the food questionnaire (21/23) exceeded the US EPA RfD of 0.1 μg/kg bw/day, whereas only a small proportion (6/23) of modeled estimates exceeded the RfD. This study shows that human health risk estimates strongly depend on the chosen approach. [ABSTRACT FROM AUTHOR]

Mercury is an environmental contaminant and may occur as methylmercury in marine organisms. Methylmercury is considered as having higher toxicity than the inorganic form; therefore, it is important to differentiate the mercury species in order to evaluate the potential risk for seafood consumers. In the largest study of the German market to date, 536 marine foods from the state of Baden-Württemberg (southwestern Germany) were analyzed using gas chromatography with atomic emission detection. Methylmercury was found at levels ranging from non-detectable (below 6 μg/kg) up to 567 μg/kg. The average, median, 90th, 95th, and 99th percentile contents were 38, 22, 78, 117, and 316 μg/kg, respectively. The average methylmercury proportion of total mercury was 70%. Based on a daily total fish and seafood consumption of 30 g according to the German National Nutrition Survey II, the methylmercury exposure was estimated to range between 5 μg/week (median) and 67 μg/week (99th percentile), which was below the provisional tolerable weekly intake (PTWI) established by the Joint FAO/WHO Expert Committee on Food Additives. The risk of methylmercury for the German fish consumer was judged to be rather low, being restricted to the unlikely worst-case scenario of daily consumption of highly contaminated fish, which could exceed the PTWI. In conclusion, the previous opinions that the benefits of the moderate fish consumption appear to outweigh the risks associated with methylmercury exposure were confirmed by our survey. [ABSTRACT FROM AUTHOR]

There is a growing awareness by consumers and food safety authorities regarding the possible presence of parasites or parasite-related potentially hazardous substances in seafood. Anisakis simplex is among the most frequently occurring parasites in wild-caught marine fish. Except for various visual inspection techniques and PCR-based methods for the detection of more or less intact worms or parasite DNA, respectively, there are at present no validated methods for the quantification of A. simplex proteins in processed fish products. This work describes the development and validation of a sandwich enzyme-linked immunosorbent assay (ELISA) for the quantification and analysis of proteins from A. simplex in seafood products. The ELISA is based on a polyclonal rabbit anti- A. simplex antibody for capture and a biotinylated conjugate of the same antibody for detection. The ELISA is specific for A. simplex and does not cross-react with other species. Recoveries ranged from 72-101% in typical food matrixes, while intra- and inter-assay precisions were <11 and <25%, respectively. With a limit of detection of 1.1 μg A. simplex protein/g of sample, the sensitivity of the A. simplex sandwich ELISA appears to be sufficient to detect even low levels in seafood products. [ABSTRACT FROM AUTHOR]

The paralytic shellfish poisoning toxins (PSTs) were, as their name suggests, discovered as a result of human poisoning after consumption of contaminated shellfish. More recently, however, the same toxins have been found to be produced by freshwater cyanobacteria. These organisms have worldwide distribution and are common in our sources of drinking water, thus presenting another route of potential human exposure. However, the regulatory limits for PSTs in drinking water are considerably lower than in shellfish. This has increased the need to find alternatives to the mouse bioassay, which, apart from being ethically questionable, does not have a limit of detection capable of detecting the PSTs in water at the regulated concentrations. Additionally, the number of naturally occurring PSTs has grown substantially since saxitoxin was first characterised, markedly increasing the analytical challenge of this group of compounds. This paper summarises the development of chromatographic, toxicity, and molecular sensor binding methodologies for detection of the PSTs in shellfish, cyanobacteria, and water contaminated by these toxins. It then summarises the advantages and disadvantages of their use for particular applications. Finally it recommends some future requirements that will contribute to their improvement for these applications. [ABSTRACT FROM AUTHOR]

Seafood containing heavy metals as a result of environmental contamination causes toxicity in human beings. To evaluate such kind of contamination, our study targeted the analysis of metals such as lead, copper, cadmium, mercury, and arsenic in muscle tissue of the fish. The fish commonly consumed such as Brama brama (Pomfret), Rachycentron canadus (Surmai/King Fish), Rastrelliger kanagurta (Mackerel), Eleutheronema tetradactylum (Ravas/Indian salmon), and Metapenaeus monoceros (Brown Prawn) were collected from four different docks in the city. The heavy metals in tissue samples of fish were estimated using voltammeter and cold vapor atomic absorption spectrophotometer. Heavy metal concentration in the tissues varied significantly depending upon the locations from where the fish were collected. Although the concentration of arsenic, copper, cadmium, and lead were in normal range, the concentration of mercury was found to exceed the daily permissible levels (1 μg/g) as a food source for human consumption. We have analyzed heavy metals from different locations in Mumbai—Versova dock, Sassoon dock, Navi Mumbai dock, and Mazgaon dock. [ABSTRACT FROM AUTHOR]

The article presents a report which investigates an incidence of large foodborne outbreak caused by Vibrio mimicus occurred after a dinner reception at an academic institution in Chiang Mai, Thailand on November 2004. It discusses the conducted questionnaire survey on the dining guests who attended the dinner reception, in which clinical symptoms of gastrointestinal disease were observed in 306 dining guests among the 403 respondents. It states that the probable cause of the outbreak was the served undercooked seafood as relative to the investigation. Furthermore, it notes that the prolonged time interval between food preparation and serving as well as the temperature at which the food was managed were favourable for the growth of the microorganisms.

Each year, there are many cases of seafood poisoning in humans worldwide. Among the various toxins isolated that contribute to these poisonings, the chlorosulpholipids are particularly intriguing because of their structural and stereochemical complexity. The mechanism of biological activity remains unknown and, although chlorosulpholipids are associated with membranes in the organisms from which they are isolated, little is understood about their role within biological membranes. The lack of availability of the natural products has impaired more in-depth biochemical studies. So far, none of the chlorosulpholipids have been obtained from total synthesis, and efficient routes to their synthesis would be desirable for the preparation of material for pharmacological characterization and proper evaluation of the risk to human health. Despite the notable advances in the science of organic synthesis, reliable methods for stereoselective construction of polychlorinated acyclic substrates are lacking, although some preliminary investigations have appeared. Here we report the synthesis of a chlorosulpholipid cytotoxin, leading to confirmation of the proposed structure and the discovery of unanticipated reactivity of polychlorinated hydrocarbons. The concise synthetic approach should enable the preparation of material in sufficient quantities to facilitate biological studies. [ABSTRACT FROM AUTHOR]

This study aimed to adopt MPN-PCR (most probable number-polymerase chain reaction) for rapid detection of the quantity of Vibrio parahaemolyticus in seafood. V. parahaemolyticus in seafood could be quantitated by MPN statistics according to PCR products. The sensitivity of MPN-PCR was 100 times higher than that of direct PCR. Of 225 seafood samples from Qingdao, 165 were positive for the presence of V. parahaemolyticus, with an MPN value of >719 per gram, and about 41.5% of samples were positive for tdh gene-possessing cells. Eighty muscle tissues from the 225 seafood samples were investigated by direct PCR and MPN-PCR, but no V. parahaemolyticus was detected. The MPN-PCR test could be completed in less than 16 h from the time of sample preparation. It was rapid, sensitive, and reliable for comprehensive detection and quick quantitative determination of V. parahaemolyticus in seafood and it revealed the potential risk of illness associated with their consumption. [ABSTRACT FROM AUTHOR]