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• First application of a qPCR assay for Dinophysis spp. in the Northwestern Adriatic Sea. • Application of qPCR assay to single Dinophysis cells and environmental samples. • rDNA copy number variation among Dinophysis spp. individuals.is provided. • High sensitivity of qPCR assay for potential future application to phytoplankton monitoring. Several Dinophysis species can produce potent lipophilic toxins that pose a risk to human health when contaminated seafood is consumed, especially filter-feeding bivalve mussels. In the mussel farms of the Northwestern Adriatic Sea, seawater and seafood are regularly monitored for the presence of Dinophysis species and their associated toxins, but the current methodological approaches, such as light microscopy determinations, require a long time to make results available to local authorities. A molecular qPCR-based assay can be used to quantify various toxic Dinophysis species in a shorter timeframe. However, this approach is not currently employed in official testing activities. In this study, field samples were collected monthly or bi-weekly over one year from various mussel farms along the Northwestern Adriatic coast. The abundance of Dinophysis species in the seawater was determined using both traditional microscopy and qPCR assays. In addition, the concentration of lipophilic toxins for DSP in mussel flesh was quantified using LC-MS/MS focusing on the okadaic acid group. Dinophysis spp. site-specific single cells were isolated and analysed by qPCR yielding a mean rDNA copy number per cell of 1.21 × 104 ± 1.81 × 103. The qPCR assay gave an efficiency of 98 % and detected up to 10 copies of the rDNA target gene. The qPCR and light microscopy determinations in environmental samples showed a significant positive correlation (Spearman r s = 0.57, p -value < 0.001) with a ratio of 2.24 between the two quantification methods, indicating that light microscopy estimates were generally 44.6 % lower than those obtained by the qPCR assay. The qPCR approach showed several advantages such as rapidity, sensitivity and efficiency over conventional microscopy analysis, showing its potential future role in phytoplankton monitoring under the Official Controls Regulations for shellfish. [ABSTRACT FROM AUTHOR]

4- tert butylphenol (4-tBP), a toxic environmental pollutant estrogen, received widespread attention due to its widespread presence, environmental persistence, and toxic effect. Common carp (Cyprinus carpio L.) is the most important freshwater economic animal in China and is also a model animal for the study on molecular mechanisms of poisoning. Head kidney is a target organ attacked by environmental pollutants. Here, we established a common carp 4-tBP poisoning model. The results showed that exposure to 4-tBP resulted in mitochondrial damage, endoplasmic reticulum damage, and apoptotic damage in head kidneys of common carps using microstructure and ultrastructure observations, as well as TUNEL kit methods. Furthermore, we found at transcriptional level from three perspectives that 4-tBP induced apoptosis in common carp head kidney cells: Hippo pathway, mitochondrial pathway, and ER stress. Hippo pathway formed a complex network, in which LATS1 was a core gene. It's noteworthy that Hippo pathway triggered mitochondrial pathway through YAP/NR4A1/Bcl-2 and YAP/BIRC5/Caspase-9 pathways under 4-tBP-induced apoptosis. PERK-eIF2α-ATF4-Caspase-3 pathway was involved in 4-tBP-induced apoptosis via ER stress. Moreover, miR-203a mediated 4-tBP-induced apoptosis through targeting MST1, MAP4K4, and NR4A1. In addition, 4-tBP disrupted balance between oxidants and antioxidants, and caused oxidative stress, and oxidative stress mediated ER stress under 4-tBP-caused apoptosis via via H 2 O 2 -PERK-eIF2α-ATF4-Caspase-3 pathway. miR-203a and oxidative stress participated in 4-tBP-induced apoptosis in common carp head kidney cells. For the first time, we found that Hippo pathway took part in molecular mechanism of fish poisoning, which needs to be investigated in the future. Our research provided foundational knowledge for exploring toxic effects of estrogen on fish and provided new insights into a theoretical basis for safety risk assessment for humans and fish, which deserves further profound exploration in the future. Moreover, the insights we generated help inform new strategies for preventing toxic injury in fish. [Display omitted] • Apoptosis: miR-203a, Hippo and mitochondria pathways, oxidative stress, and ER stress. • Hippo pathway took part in molecular mechanism of apoptosis via a complex network. • Mitochondria partook in Hippo pathway-mediated apoptosis via YAP/NR4A1/Bcl-2 and YAP/BIRC5/Caspase-9 pathways. • Oxidative stress triggered ER stress-mediated apoptosis via H 2 O 2 -PERK-eIF2α-ATF4-Caspase-3 pathway. • SAV1, MOB1, NF2, and Bik were involved in molecular mechanism of animal poisoning. [ABSTRACT FROM AUTHOR]

• Species-specific responses to turbulence in 6-d culturing experiments. • Turbulence slowed growth but increased toxin content in D. acuminata strains. • Turbulence stimulated growth but decreased toxin content of the D. caudata strain. • Turbulence promoted leaking of toxins extracellularly in the D. ovum strain. • No measurable effect on the ingestion rates of Dinophysis spp. on prey. Dinophysis , a mixotrophic dinoflagellate that is known to prey on the ciliate Mesodinium rubrum , and retain its chloroplasts, is responsible for diarrhetic shellfish poisoning (DSP) in humans and has been identified on all U.S. coasts. Monocultures of Dinophysis have been used to investigate the growth of Dinophysis species in response to variations in environmental conditions, however, little is known about the roles of system stability (turbulence) and mixotrophy in the growth and toxicity of Dinophysis species in the U.S.. To begin to address this gap in knowledge, culturing experiments were conducted with three species (four strains) of Dinophysis , that included predator-prey co-incubation (Dinophysis spp.+ M. rubrum) and prey-only (M. rubrum) flasks. Cultures were investigated for effects of low or high turbulence on Dinophysis spp. growth, feeding, and amounts of intra- and extracellular toxins: okadaic acid and derivatives (diarrhetic shellfish toxins, DSTs) and pectenotoxins (PTXs). Turbulence did not have a measurable effect on the rates of ingestion of M. rubrum prey by Dinophysis spp. for any of the four strains, however, effects on growth and particulate and dissolved toxins were observed. High turbulence (ε = 10−2 m2s−3) significantly slowed growth of both D. acuminata and D. ovum relative to still controls, but significantly stimulated growth of the D. caudata strain. Increasing turbulence also resulted in significantly higher intracellular toxin content in D. acuminata cultures (DSTs and PTXs), but significantly reduced intracellular toxin content (PTXs) in those of D. caudata. An increase in turbulence appeared to promote toxin leakage, as D. ovum had significantly more extracellular DSTs found in the medium under high turbulence when compared to the still control. Overall, significant responses to turbulence were observed, whereby the three strains from the " Dinophysis acuminata complex" displayed a stress response to turbulence, i.e., decreasing growth, increasing intracellular toxin content and/or increasing toxin leakage, while the D. caudata strain had an opposite response, appearing stimulated by, or more tolerant of, high turbulence. As turbulence increases... [Display omitted] [ABSTRACT FROM AUTHOR]

Tetrodotoxins (TTXs) were investigated in two local pufferfish species, Diodon hystrix and Arothron hispidus , from Mozambican coast. TTX and analogues 4-epiTTX, 4,9-anhydroTTX, 11-deoxyTTX, and 11-norTTX-6-(R/S)-ol were found in both species and high level of TTX was found in A. hispidus (9522.0 μg TTX kg−1) than in D. hystrix (350.9 μg TTX kg−1). The distribution of TTX and their analogues in A. hispidus was intestine > liver > skin ≫ muscle > gonads. This is the first report of TTXs in Mozambican coast. [Display omitted] • First report of Tetrodotoxins occurrence in the local pufferfish species from Mozambique. • Pufferfishes presented Tetrodotoxins level above recommended limit in Europe and Japan. • Need of setting-up a program for Tetrodotoxins surveillance in seafood from Mozambique. [ABSTRACT FROM AUTHOR]

High alkalinity is the most important limiting factor in carbonate-type saline–alkali water aquaculture, and fish growth is slow and survival is low in highly alkaline environments. Selenium-enriched (Se-enriched) Lactobacillus plantarum (L. plantarum) has antioxidant and anti-inflammatory properties and can regulate the balance of the gut flora. However, the physiological regulatory mechanism of Se-enriched L. plantarum on common carp under high alkalinity stress is still unclear. In the present study, 360 common carp were randomly divided into a control group, a high alkalinity group, and a Se-enriched L. plantarum and high alkalinity group and fed for 56 days. High alkalinity stress induced growth inhibition in common carp. Histopathology revealed atrophy of the intestinal villi and damage to the intestinal microvilli and tight junction complexes. Serological parameters showed that the serum ammonia and LPS contents were significantly increased. Gut microbial disruption under high alkalinity stress increased the abundance of Bacteroidota (LPS-producing bacteria), Providencia sp. (ammonia-producing bacteria) and Vibrio (pathogenic bacteria) and significantly decreased the expression of the tight junction proteins Zonula occludens-1 (ZO-1) and Occludin, disrupting the gut barrier. However, Se-enriched L. plantarum decreased the abundance of Bacteroidota Providencia sp. and Vibrio , increased the expression of the tight junction proteins ZO-1 and Occludin, and alleviated intestinal damage caused by high alkalinity while reducing the content of lipopolysaccharides (LPS) and ammonia in the serum. In addition, metabolomic analysis of serum revealed that high alkalinity stress activated autophagy, glucocorticoids and mineralocorticoid receptor agonists/antagonists, ABC transporters, the phosphatidylinositol signalling system, and the Mammalian Target of Rapamycin (mTOR) signalling pathway and significantly increased creatine content and riboflavin. Se-enriched L. plantarum treatment significantly decreased the creatine and D-alanine contents. In summary, this study revealed that Se-enriched L. plantarum can alleviate the harmful effects of high alkalinity on common carp by regulating the balance of the intestinal microbiota, improving intestinal barrier function, reducing the amount of harmful substances entering the bloodstream, and regulating blood metabolites. This study demonstrates the physiological regulatory mechanism of Se-enriched L. plantarum in alleviating high alkalinity stress and provides ideas and a theoretical basis for the protection against high alkalinity poisoning of fish in saline–alkali waters. [Display omitted] • Se-enriched L. plantarum alleviate high alkalinity stress-induced intestinal damage. • Se-enriched L. plantarum reduce LPS content by improving intestinal barrier function under high alkalinity stress. • Se-enriched L. plantarum reduce blood ammonia by regulating creatine under high alkalinity stress. [ABSTRACT FROM AUTHOR]

During the development and senescence of harmful algal blooms (HAB), most of the algae cells not ingested by grazers or filter-feeding organisms sink to the bottom, making sediments important reservoirs of algae toxins. In this study, lipophilic marine toxins were determined in the sediments collected from depths ranging from 5 to 145 m depth in the marine protected area of Arrábida (southwest Portuguese coast). Sediments were characterized in terms of granulometry, water and organic matter content. The toxins were determined by liquid chromatography with tandem mass spectrometry. Okadaic acid (OA), dinophysistoxin-2 (DTX2), and azaspiracid-2 (AZA2), reaching concentrations up to 3.4, 1.3, and 0.13 ng/g, respectively, were found. A trend in the occurrence of DTX2 and AZA2 with sediment water and organic matter content was observed, as well as with AZA2 and depth. This study highlights the need to further investigate sediment deposition of toxins and their availability for bottom-dwelling organisms and its contamination. • First record of lipophilic marine toxins in sediments from Portugal • OA, DTX-2 and AZA-2 were determined. • Sediment water content, organic matter and depth may influence toxins levels. [ABSTRACT FROM AUTHOR]

Okadaic acid (OA), as a diarrhetic shellfish poisoning, can increase the risk of acute carcinogenic or teratogenic effects for the ingestion of OA contaminated shellfish. At present, much effort has been made to graft immunoassay onto a paper substrate to make paper-based sensors for rapid and simple detection of shellfish toxin. However, the complicated washing steps and low protein fixation efficiency on the paper substrate need to be further addressed. A novel paper-tip immunosensor for detecting OA was developed combined with smartphone and naked eye readout. The trapezoid paper tip was consisted of quantitative and qualitative detection zones. To improve the OA antigen immobilization efficiency on the paper substrate, graphene oxide (GO)-assisted protein immobilization method was introduced. Meanwhile, Au nanoparticles composite probe combined with the lateral flow washing was developed to simplify the washing step. The OA antigen-immobilized zone, as the detection zone Ⅰ, was used for quantitative assay by smartphone imaging. The paper-tip front, as the detection zone Ⅱ, which could qualitatively differentiate OA pollution level within 45 min using the naked eye. The competitive immunoassay on the paper tip exhibited a wide linear range for detecting OA (0.02–50 ng∙mL−1) with low detection limit of 0.02 ng∙mL−1. The recovery of OA in spiked shellfish samples was in the range of 90.3 %–113.%. These results demonstrated that the proposed paper-tip immunosensor could provide a simple, low-cost and high-sensitivity test for OA detection without the need for additional large-scale equipment or expertise. We anticipate that this paper-tip immunosensor will be a flexible and versatile tool for on-site detecting the pollution of marine products. [Display omitted] • A novel paper-tip immunosensor for detecting okadaic acid was developed combined with smartphone and naked eye readout. • The paper-tip immunosensor was served as a carrier for immunoreaction separation and rapid detection. • Utilizing GO to improve the efficiency of protein immobilization on paper and simplify the washing step. • The paper-tip immunosensor is expected to be a flexible and versatile tool for on-site detecting shellfish toxins. [ABSTRACT FROM AUTHOR]

• The impact of microplastics on marine benthic dinoflagellates was studied. • PS had limited effect on the growth of P. lima , but enhanced OA and EPS production. • Genes related to toxin and carbohydrate synthesis, and metabolism were upregulated. • Increased DSP toxins may strengthen the threat of benthic dinoflagellates. Microplastics are well known as contaminants in marine environments. With the development of biofilms, most microplastics will eventually sink and deposit in benthic environment. However, little research has been done on benthic toxic dinoflagellates, and the effects of microplastics on benthic dinoflagellates are unknown. Prorocentrum lima is a cosmopolitan toxic benthic dinoflagellate, which can produce a range of polyether metabolites, such as diarrhetic shellfish poisoning (DSP) toxins. In order to explore the impact of microplastics on marine benthic dinoflagellates, in this paper, we studied the effects of polystyrene (PS) on the growth and toxin production of P. lima. The molecular response of P. lima to microplastic stress was analyzed by transcriptomics. We selected 100 nm, 10 μm and 100 μm PS, and set three concentrations of 1 mg L −1, 10 mg L −1 and 100 mg L −1. The results showed that PS exposure had limited effects on cell growth, but increased the OA and extracellular polysaccharide content at high concentrations. After exposure to PS MPs, genes associated with DSP toxins synthesis, carbohydrate synthesis and energy metabolism, such as glycolysis, TCA cycle and pyruvate metabolism, were significantly up-regulated. We speculated that after exposure to microplastics, P. lima may increase the synthesis of DSP toxins and extracellular polysaccharides, improve the level of energy metabolism and gene expression of ABC transporter, thereby protecting algal cells from damage. Our findings provide new insights into the effects of microplastics on toxic benthic dinoflagellates. [ABSTRACT FROM AUTHOR]

• Structure elucidation and optimization were accomplished using spectral data and the DFT technique. • Solute-Solvent interactions reported on UV–Visible investigation, using TD-DFT, comprehension of stability, and biological activity. • Multiwave function analysis, such as ELF, LOL, and RDG, were performed to better understand surface electron density, delocalization, localized orbital, and weak interaction. • The FMO, MEP, and Hirshfeld charges of the molecule, as well as one electron transport pathway, were discovered. • The antioxidant activity and anti-inflammatory impact were investigated, and the in-vitro bioassay results were verified. Eremostachys vicaryi Benth. Ex Hook. f. (Labiatae), a Pakistani (Baluchistan) herbal medicinal plant commonly known as "Stagh," which has a sharp taste and smell. It acts as an antiseptic and antimicrobial agent and is used for fish poisoning, treating skin diseases, and holding a cooling effect. Following the assessment of the plant extract's cytotoxic and phytotoxic assays using phytochemical screening, the antioxidant and anti-inflammatory properties of the pure ingredients that were separated from the ethyl acetate soluble fractions have been evaluated. The bioassay-guided fractionation and purification of E. vicaryi B. crude methanol extract yielded two isoflavones (1–2) that showed promising antioxidative activities with DPPH and cytochrome-c-reduction assays. Compounds 1 and 2 have shown considerable anti-inflammatory efficacy, 1 being a good inhibitor of the superoxide within the living system. Initial assumptions on the one-electron transfer process indicated that Compound 1 has a smaller ionization potential value compared to Compound 2 and so has greater antioxidant potential than its predecessor, isoflavone. Moreover, the anti-inflammatory and antioxidant activity of isoflavones was also probed by first-principles calculations. Based on the findings, it has been concluded that the crude extract of E. vicaryi B. and its organic components exhibit noteworthy phytotoxic and cytotoxic properties. The isolated pure isoflavones 1 and 2 showed significant antioxidant and anti-inflammatory activities. Solute-solvent interactions were studied and reported for both compounds. An analysis was conducted on the UV–Vis electronic transition for different solvents. Using a Multiwave function analyzer the topological findings such as ELF, LOL, and RDG were done to comprehend the surface electron density, delocalization, localized orbital, and weak interaction in the compounds. The antioxidant activity is evaluated by radical methods using DPPH, and cytochrome-c-reduction assays using ascorbic acid as a standard. Through cell-based respiratory burst testing, the anti-inflammatory activity of standard indomethacin was examined. The ground state geometries of isoflavones and reference compounds were optimized by Density Functional Theory- (DFT) by computing various electronic properties. In-vitro bioassay results were validated by first-principles calculations. [ABSTRACT FROM AUTHOR]

Paralytic shellfish toxins (PSTs) produced by some marine dinoflagellates can cause severe human intoxication via vectors like bivalves. Toxic dinoflagellate Gymnodinium catenatum produce a novel group of hydroxybenzoate PSTs named GC toxins, but their biokinetics in bivalves haven't been well examined. In this experiment, we analyzed PSTs in bay scallops Argopecten irradians exposed to G. catenatum (strain MEL11) to determine their accumulation, elimination, anatomical distribution, and biotransformation. To our surprise, up to 30% of the PSTs were accumulated in the adductor muscle of scallops at the end of the experiment, and the toxicity of adductor muscle exceeded the regulatory limit of 800 μg STXeq/kg in only 6 days. High concentration of toxins in the adductor muscle are likely linked to the rapid transfer of GC toxins from viscera to other tissues. Moreover, most GC toxins in scallops were found rapidly transformed to decarbamoyl toxins through enzyme-mediated hydrolysis, which was further supported by the in vitro incubation experiments. Our study demonstrates that GC toxins actively participate in toxin distribution and transformation in scallops, which may increase the risks of food poisoning associated with the consumption of scallop adductor muscle. The negative impacts of harmful algal blooms (HABs) have become a global environmental concern under the joint effects of cultural eutrophication and climate change. Our study, targeted on the biokinetics of paralytic shellfish toxins in scallops exposed to Gymnodinium catenatum producing unique GC toxins, aims to elucidate potential risks of seafood poisoning associated with GC toxins. The findings of this study will help us to understand the roles of GC toxins in seafood poisoning, and to develop effective management strategies against toxic algal blooms and phycotoxins. [Display omitted] • Gymnodinium catenatum producing GC toxins were fed to scallop Argopecten irradians. • Up to 30% of PSTs ingested by scallops were accumulated in the adductor muscle. • Biokinetic model indicated a high PST transfer rate from viscera to adductor muscle. • Most GC toxins undergo enzymatic hydrolysis to form decarbamoyl toxins in scallops. • GC toxins will affect scallop toxicity through tissue transfer and transformation. [ABSTRACT FROM AUTHOR]

• Okadaic acid (OA) is the predominant DSP toxin in Slovenian mussels. • The period with the highest risk of human intoxication is from September to November. • OA is strongly associated with the abundance of Dinophysis fortii in seawater. • Introduction of the LC-MS/MS method has improved the management of aquaculture activities. This article presents the first results on shellfish toxicity in the Slovenian sea (Gulf of Trieste, Adriatic Sea) since the analytical methods for the detection of biotoxins (PSP, ASP, DSP and other lipophilic toxins) in bivalve molluscs were included in the national monitoring program in 2013. In addition to toxins, the composition and abundance of toxic phytoplankton and general environmental characteristics of the seawater (surface temperature and salinity) were also monitored. During the 2014–2019 study period, only lipophilic toxins were detected (78 positive tests out of 446 runs), of which okadaic acid (OA) predominated in 97 % of cases, while dinophysistoxin-2 and yessotoxins only gave a positive result in one sampling event each. The number of samples that did not comply with the EC Regulation for the OA group was 17 or 3.8 % of all tests performed, all of which took place from September to November, while a few positive OA tests were also recorded in December, April, and May. This toxicity pattern was consistent with the occurrence pattern of the five most common DSP-producing dinoflagellates, which was supported by the development of warm and thermohaline stratified waters: Dinophysis caudata, D. fortii, D. sacculus, D. tripos and Phalacroma rotundatum. The strong correlation (r = 0.611, p < 0.001) between D. fortii , reaching abundances of up to 950 cells L −1, and OA suggests that D. fortii is the main cause of OA production in Slovenian waters. Strong interannual variations in OA and phytoplankton dynamics, exacerbated by the effects of anthropogenic impacts in this coastal ecosystem, reduce the predictability of toxicity events and require continuous and efficient monitoring. Our results also show that the introduction of the LC-MS/MS method for lipophilic toxins has improved the management of aquaculture activities, which was not as accurate based on mouse bioassays. [ABSTRACT FROM AUTHOR]

Histamine intoxications result when histamine-metabolizing enzymes are compromised or overwhelmed by dietary histamine in the human body. This can occur either due to metabolic enzyme deficiencies, such as in histamine intolerance to wines, aged cheese and other foods or from high concentrations of histamine following ingestion of decomposed fish. The presence of histamine in decomposed fish and fish products results from bacterial decarboxylation of free L-histidine following product mishandling. Consequently, histamine intoxications from mishandled fish, commonly referred to as scombrotoxin fish poisoning (SFP) or scombroid poisoning, require high levels of free L-histidine only found in certain species of pelagic fish. Differential diagnosis is required of clinicians since dietary histamine intoxications produce the same symptoms typical of release of endogenous histamine due to IgE -mediated seafood allergies or anisakiasis. Although high levels of dietary histamine are responsible for SFP, histamine has important physiological functions and tends to exert toxic effects only at doses beyond the physiological range. Endogenous histamine is essential to local immune responses, regulation of gastric acid secretion in the gut, and neurotransmission in the central nervous system. Scombrotoxins, postulated to explain histamine's augmented toxicity in scombrotoxic fish, are a milieu of histamine and other bioactives. Since time-and-temperature abuse is required to produce high levels of histamine in fish, management consists of ensuring proper handling by identifying hazards and critical control points (HACCP) and maintaining a "cold chain" from catch to consumption. Reference methods for detecting histamine have received increased attention and the European Commission has validated a popular precolumn dansylation-based HPLC method through inter-laboratory collaboration and studied method equivalence with the AOAC fluorescence method 977.13 recognized by Codex Alimentarius. Much progress has been made during the last decade in the development and validation of rapid screening methods for detecting histamine in food and especially in fish products. These include many innovative sensors and several validated commercial test kits, many of them based on a recombinant form of the enzyme histamine dehydrogenase (HD). • Scombrotoxin fish poisoning is also known as scombroid poisoning and histamine fish poisoning. • Scombrotoxin fish poisoning is a common cause of food poisoning worldwide. • Dietary histamine in decomposed fish is formed by bacterial enzymes and is due to mishandling. • Scombrotoxins are bioactives postulated to augment the toxicity of dietary histamine. • Many new rapid screening methods for histamine detection have been developed and validated. [ABSTRACT FROM AUTHOR]

Scombrotoxin fish poisoning (SFP) is caused by the ingestion of certain fish species with elevated concentrations of histamine due to decomposition. In fall 2019, the U.S. Food and Drug Administration (FDA) was notified of 51 SFP cases including two hospitalizations from 11 states through the FDA consumer complaint system or directly from state partners. A case patient was defined as an individual who experienced a histamine-type reaction after consumption of tuna imported from Vietnam and an illness onset between 14 August and 24 November 2019. A traceback investigation was initiated at 19 points of service to identify a common tuna source. The FDA and state partners collected 34 product samples throughout the distribution chain, including from a case patient's home, points of service, distributors, and the port of entry. Samples were analyzed for histamine by sensory evaluation and/or chemical testing. Case patients reported exposure to tuna imported from Vietnam. The traceback investigation identified two Vietnamese manufacturers as the sources of the tuna. Twenty-nine samples were confirmed as decomposed by sensory evaluation and/or were positive for elevated histamine concentrations by chemical testing. Both Vietnamese companies were placed on an import alert. Seven U.S. companies and one Vietnamese company initiated voluntary recalls. The FDA released public communication naming the U.S. importers to help suppliers and distributors identify the product and effectuate the foreign company's recall. This SFP outbreak investigation highlights the complexities of the federal outbreak response, specifically related to imported food. Cultural considerations regarding imported foods should be addressed during outbreak responses when timing is critical. Collaboration with countries where confidentiality agreements are not in place can limit information sharing and the speed of public health responses. An outbreak of scombrotoxin fish poisoning was linked to imported tuna. Sensory evaluation and chemical testing were used to analyze samples of imported tuna. Traceback, laboratory, and epidemiologic data were used to protect public health. This study highlights challenges associated with SFP outbreaks linked to imported foods. [ABSTRACT FROM AUTHOR]

Prorocentrum lima (CSIRCSMCRI005) was isolated from the coastal seawater of Thonithurai, Tamil Nadu, India. Morphology of the isolate was studied using light microscopy (LM) and scanning electron microscopy (SEM) while phylogenetic analyses of the internal transcribed spacer region (ITS1-5.8s-ITS2), 18S rDNA, and large subunit (LSU) rDNA were also carried out. Growth of the isolate was studied, and okadaic acid (OA) production was examined using liquid chromatography with electrospray ionization and quadrupole time of flight mass spectroscopy (LC-ESI-Q-ToF-MS). Morphological features observed including oval cell shape with a broad middle region, narrow anterior and round posterior end, large central pyrenoid with starch sheath, smooth thecal surface, and V-shaped periflagellar area consisting of eight platelets matched with the description of the type species and those reported elsewhere. The ITS, 18S, and LSU sequence phylogenetic analysis revealed that the isolate was closely related to other strains reported from the pacific. The growth rate (μ) was 0.05 div. day−1. P. lima CSIRCSMCRI005 produced okadaic acid and related esters. The production of free and total OA was 20.12 ± 4.77 and 22.30 fg cell−1, respectively. The findings of this study contribute useful information concerning the regional risk of diarrheic shellfish poisoning in the North East Indian Ocean and the global distribution and toxic potential of Prorocentrum lima. Further studies on the ecophysiology of this strain will be helpful. This manuscript reports the detailed morphological, phylogenetic, and toxicological characterization of this species from the Bay of Bengal and the North Indian Ocean as a whole. [Display omitted] • This is the first detailed report on Prorocentrum lima from the North Indian Ocean. • Morphological and molecular characteristics of this strain have been studied. • Production of total and free okadaic acid per cell has been estimated. • The presence of toxic Prorocentrum lima may bring concern for Indian seafood safety. [ABSTRACT FROM AUTHOR]

The mucilage phenomenon observed in the Sea of Marmara in 2021, has raised public concern about seafood safety. Mediterranean mussels serve as a vehicle in food chain, enabling the transfer of pollutants. Farmed and wild mussels were collected from 4 different stations throughout the fishing season. Biotoxins causing amnesic, paralytic, or diarrhetic shellfish poisonings (ASP, PSP, or DSP) were examined during monthly samplings. Potential health risks posed by cadmium, lead and arsenic were assessed. Health risks were evaluated considering 150 g/week mussel consumption, accounting for the different age groups of consumers (50, 60, 70 kg). Estimated Weekly Intake calculations of metals were determined to be lower than Provisional Tolerable Weekly Intake at all age groups throughout the sampling period in all stations. Target Hazard Quotient Cd of mussels captured from Istanbul Strait was always determined <1, while it was equal to 1 for 50 kg individuals in Gelibolu samples. All THQ As were >1. Target carcinogenic Risk was evaluated for Pb and iAs, which were found to be negligible and acceptable, respectively. No biotoxins responsible for ASP, PSP, or DSP were detected. Hg levels were under detectable limits. Excluding Cd, the results did not reveal any risks associated with mussel consumption during mucilage. [Display omitted] • Marine mucilage raises seafood safety concerns among the public. • Mussels have a high consumption potential and are bio-indicators of pollution. • No toxin formation causing ASP, DSP and PSP was observed in wild or farmed mussels. • Of toxic metals, Cd may pose health risk considering total hazard quotient. [ABSTRACT FROM AUTHOR]

Brevetoxins were confirmed in urine specimens from patients diagnosed with neurotoxic shellfish poisoning (NSP) after consumption of gastropods that were recreationally harvested from an area previously affected by a Karenia brevis bloom. Several species of gastropods (Triplofusus giganteus , Sinistrofulgur sinistrum , Cinctura hunteria , Strombus alatus , Fulguropsis spirata) and one clam (Macrocallista nimbosa) from the NSP implicated gastropod collection area (Jewfish Key, Sarasota Bay, Florida) were examined for brevetoxins using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA). All gastropods and the clam were contaminated with brevetoxins. Composite B-type toxin concentrations in gastropods ranged from 1.1 to 198 μg BTX-3 equiv./g by ELISA, levels likely capable of causing NSP in consumers. Several brevetoxin metabolites previously characterized in molluscan shellfish were identified in these gastropods. Brevetoxin analog profiles by ELISA were similar in the gastropod species examined. This work documents the occurrence of NSP through consumption of a type of seafood not typically monitored in Florida to protect human health, demonstrating the need to better assess and communicate the risk of NSP to gastropod harvesters in Karenia brevis endemic areas. • Gastropods transfer brevetoxins to humans during Karenia brevis blooms. • BTX-3 is a useful marker for brevetoxin exposure in gastropods. • Biomarkers of brevetoxin exposure in oyster and clam are present in gastropods. • A need to better communicate the risk of NSP to recreational gastropod harvesters. [ABSTRACT FROM AUTHOR]

Ocean organisms live in competitive environments that demand the production of poisons and toxins. In some cases, these substances have been used in the pharmaceutical industry for human disease treatments. Most fish poisons generally have potent cytolytic activity, probably through cardiovascular and neuromuscular effects. In the case of marine stingrays, the injuries made by their tail venom apparatus are caused by the mechanical penetration of their sting and a subsequent venom release. This study focused on the evaluation of substances with cytotoxic activity in the epithelium that covers the venom apparatus from the marine stingray Hypanus dipterurus. To demonstrate the above, the hemolytic, proteolytic and cytotoxic capacities of H. dipterurus epithelium substances were determined. Discs impregnated with epithelial extract were used on blood agar plates. The proteolytic activity was analyzed using casein as substrate and for gelatin the liquefaction activity test. To determine the cytotoxicity degree of the extracts, the proliferation and cell viability MTT bioassay was implemented on human cervical carcinoma cells (HeLa). The results showed that no hemolytic or proteolytic activity existed against casein associated with the epithelial extract, but gelatin hydrolysis and cytotoxic activity against the HeLa cell line were observed. This study concludes that the substances found in the epithelium covering the H. dipterurus stingray venom apparatus are a mixture of various proteins, among which, glycosylated anionic proteins represent a potential source of molecules with cytotoxic and hydrolytic activity. • Hemolytic, proteolytic and cytotoxic capacities of Hypanus dipterurus epithelium substances were determined. • No hemolytic or proteolytic activity existed against casein associated with the Hypanus dipterurus epithelium extract. • Hydrolysis and cytotoxic activity against the HeLa cell line were observed from Hypanus dipterurus epithelium extract. • Hypanus dipterurus venom apparatus contained a mixture of several proteins, including a glycosylated anionic protein. [ABSTRACT FROM AUTHOR]

Histamine poisoning occurs when fish containing high amount of histamine are consumed. Because histamine is thermally stable, control of histamine-forming bacteria in seafood is an appropriate strategy for preventing the formation of histamine. One prevention method is the use of gamma irradiation on the histamine formers. To understand the effect of gamma irradiation on the histamine-forming bacteria, laboratory isolates of the prolific histamine formers Morganella morganii, Klebsiella variicola, and Proteus vulgaris were exposed to various doses of gamma radiation in nutrient broth and tuna muscle spiked with histamine formers. None of the test bacteria survived in tuna muscle irradiated at 2.0 kGy. K. variicola was highly sensitive to gamma irradiation and was eliminated at a dose of 1.5 kGy. Histamine production also was reduced significantly as the radiation dose increased. These results suggest that gamma irradiation can effectively eliminate histamine-forming bacteria and reduce the threat of histamine poisoning from seafood. Histamine-forming bacteria are highly susceptible to low levels of gamma irradiation. Prolific histamine formers in tuna meat were eliminated by irradiation at 2.0 kGy. Irradiation at 1.5 kGy reduced the level of histamine formers in tuna meat by 4 to 5 log CFU. Histamine formation in tuna meat can be controlled by low levels of gamma irradiation. [ABSTRACT FROM AUTHOR]

In April 2017, an outbreak of histamine fish poisoning causing illness in nine victims associated with consumption of milkfish surimi products (fish ball) occurred in Kaohsiung City, southern Taiwan. Of the two suspected frozen milkfish surimi samples, one sample contained 91.06 mg/100 g of histamine, levels that are greater than the potential hazard action level (50 mg/100 g) in most illness cases. Moreover, 28 frozen milkfish surimi samples from retail stores were collected and tested to determine the occurrence of histamine. One (3.6%) of 28 commercial surimi samples had histamine levels greater than the U.S. Food and Drug Administration (FDA) guideline for decomposition of 5 mg/100 g for scombroid fish and/or products. Thirteen histamine-producing bacterial strains isolated from suspected and commercial surimi samples were identified as prolific histamine formers, able to produce 98.4 to 121.8 mg/100 mL of histamine in Trypticase soy broth supplemented with 1.0% l-histidine. In addition, milkfish surimi was inoculated with Raoultella ornithinolytica at 5.0 log CFU/g and stored at 4, 15, 25, and 37°C to investigate bacterial growth and formation of histamine. The histamine contents quickly increased to more than 50 mg/100 g in samples stored at 37 and 25°C within 12 and 24 h, respectively, as well those stored at 15°C within 96 h. To our knowledge, this is the first report in Taiwan to demonstrate that milkfish surimi products could cause histamine intoxication. This is the first report that milkfish surimi product causes histamine intoxication. High histamine (91.06 mg/100 g) content was found in one suspected surimi sample. Thirteen prolific histamine forms were found in suspected commercial surimi samples. At 15°C for 3.5 days, R. ornithinolytica–contaminated surimi had hazardous levels of histamine. [ABSTRACT FROM AUTHOR]

Extensive application of organophosphorus pesticides such as phenthoate results in its abundance in ecosystems, particularly in waterbodies, thereby providing the impetus to assess its role in aquatic organisms. However, the impact of phenthoate on marine algal physiological and proteomic response is yet to be explored despite its biological significance. In this study, we thus ought to investigate the impact of phenthoate in the marine dinoflagellate Prorocentrum lima , which is known for synthesizing okadaic acid (OA), the toxin responsible for diarrhetic shellfish poisoning (DSP). Our results showed that P. lima effectively absorbed phenthoate in seawater, with a reduction efficiency of 90.31% after 48 h. Surprisingly, the provision of phenthoate (100 and 1000 µg/L) substantially reduced the OA content of P. lima by 35.08% and 60.28% after 48 h, respectively. Meanwhile, phenthoate treatment significantly reduced the oxidative stress in P. lima. Proteomic analysis revealed that the expression level of seven crucial proteins involved in endocytosis was upregulated, suggesting that P. lima could absorb phenthoate via the endocytic signaling pathway. Importantly, phenthoate treatment resulted in the downregulation of proteins such as polyketide synthase (PKS)− 2, Cytochrome P450 (CYP450)− 1, and CYP450–2, involved in OA synthesis, thereby decreasing the OA biosynthesis by P. lima. Our results demonstrated the potential role of P. lima in the removal of phenthoate in water and exemplified the crucial proteins and their possible molecular mechanisms underpinning the phenthoate remediation by P. lima and also the regulatory role of phenthoate in restricting the OA metabolism. Collectively, these findings uncovered the synergistic mechanisms of phenthoate and P. lima in remediating phenthoate and reducing the toxic impact of P. lima. [Display omitted] • Prorocentrum lima effectively removes phenthoate from seawater. • Phenthoate reduces the synthesis of OA in Prorocentrum lima. • Phenthoate alleviates oxidative stress in Prorocentrum lima. [ABSTRACT FROM AUTHOR]

• Ciguatera poisoning (CP) is a common form of seafood poisoning. • CP is caused by ciguatoxins produced by the benthic dinoflagellate Gambierdiscus spp. • Models can be useful tools to study and monitor CP. • Grazing is vital in ciguatoxin (CTX) transfer into marine food webs. • Herein a conceptual model is described for CTX transfer into Caribbean food webs. Ciguatera poisoning (CP) is the most common form of phycotoxin-borne seafood poisoning globally, affecting thousands of people on an annual basis. It most commonly occurs in residential fish of coral reefs, which consume toxin-laden algae, detritus, and reef animals. The class of toxins that cause CP, ciguatoxins (CTXs), originate in benthic, epiphytic dinoflagellates of the genera, Gambierdiscus and Fukuyoa , which are consumed by herbivores and detritivores that facilitate food web transfer. A number of factors have hindered adequate environmental monitoring and seafood surveillance for ciguatera including the low concentrations in which the toxins are found in seafood causing illness (sub-ppb), a lack of knowledge on the toxicity equivalence of other CTXs and contribution of other benthic algal toxins to the disease, and the limited availability of quantified toxin standards and reference materials. While progress has been made on the identification of the dinoflagellate taxa and toxins responsible for CP, more effort is needed to better understand the dynamics of toxin transfer into reef food webs in order to implement a practical monitoring program for CP. Here, we present a conceptual model that utilizes empirical field data (temperature, Gambierdiscus cell densities, macrophyte cover) in concert with other published studies (grazing rates and preference) to produce modeling outputs that suggest approaches that may be beneficial to developing monitoring programs: 1) targeting specific macrophytes for Gambierdiscus and toxin measurements to monitor toxin levels at the base of the food web (i.e., toxin loading); and 2) adjusting these targets across sites and over seasons. Coupling this approach with other methodologies being incorporated into monitoring programs (artificial substrates; FISH probes; toxin screening) may provide an "early warning" system to develop strategic responses to potential CP flare ups in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Derris trifoliata is mainly found in mangrove area in tropical regions and the plant extract is traditionally used for fishing by poisoning. This is the first case report of rotenone poisoning in a child from ingesting Derris trifoliata seed. The child developed altered consciousness, vomiting, hypotension, metabolic acidosis, and acute kidney injury. Species identification of this case requires the collaborative efforts of various agencies. She survived from the poisoning with no neurological sequelae. [Display omitted] • This is the first documented incident of rotenone poisoning from Derris trifoliata in Malaysia. • Clinical features: central nervous system and respiratory depression, metabolic acidosis, shock, acute kidney injury. • Timely and appropriate supportive management is essential to improve the clinical outcome. • Collaborative effort of various agencies for the identification of toxic plant is recommended. • Public awareness on the dangers of foraging and consuming unidentified wild plants needs to be increased. [ABSTRACT FROM AUTHOR]

Ciguatera poisoning (CP) occurs as a result of consuming seafood that has bioaccumulated toxins produced by dinoflagellates (primarily Gambierdiscus) in tropical, coastal ecosystems. The impacts of CP can be long-lasting for affected individuals and communities, especially in places like the Hawaiian Islands, where fish provide sustenance and have important financial and cultural value. This study used anonymous online surveys (n = 106) and targeted interviews (n = 20) to address data gaps on the prevalence, distribution, and impacts of CP among fishers and fish consumers in Hawaiʻi. Survey results indicated that few individuals (22%) reported their CP cases to the Department of Health, despite the fact that most impacted respondents (67%) experienced symptoms lasting more than a week and some (10%) were affected for more than a year. Certain locations (e.g., north shore of Kauaʻi) and species (e.g., uku - Aprion virescens and knifejaw - Oplegnathus punctatus) emerged as being highly problematic, though they have received little research, monitoring, or management attention historically. Interview data revealed common interests and themes among affected individuals, including a desire for more data on the environmental drivers, factors affecting individual CP response variability, and increased education and awareness, particularly for vulnerable populations. This study offers essential information for managers crafting policy and outreach materials to mitigate the risk of CP in Hawaiʻi and provides baseline information that can be used to inform future studies in Hawaiʻi and throughout the region. [Display omitted] [ABSTRACT FROM AUTHOR]

• Prey availability can influence the detection of Dinophysis spp. cells by the imaging FlowCytobot (IFCB). • Alternating use of light scattering and fluorescence triggering methods is a good practice to monitor non constitutive mixotrophs with an IFCB. • Two Dinophysis spp. blooms: one in June–July, the second in September were detected during field deployment. • Size of Mesodinium spp. and time-lag between Dinophysis spp. bloom and presence of Mesodinium spp. influences Dinophysis spp. autofluorescence. The Imaging FlowCytobot (IFCB) is a field-deployable imaging-in-flow cytometer that is increasingly being used to monitor harmful algae. The IFCB acquires images of suspended particles based on their chlorophyll- a fluorescence and/or the amount of light they scatter (side scattering). The present study hypothesized that fluorescence-based image acquisition would undercount Dinophysis spp., a genus of non-constitutive mixotrophs, when prey is limited. This is because Dinophysis spp. acquire plastids via ingestion of their ciliate prey Mesodinium spp., and lose photosynthetic capacity and autofluorescence in the absence of prey. Even small blooms of Dinophysis spp. can be highly toxic and result in diarrhetic shellfish poisoning (DSP), highlighting the importance of accurately detecting low abundances. To explore this, laboratory experiments were conducted to determine optimal IFCB settings for a fed culture of Dinophysis acuminata , and an existing time series of IFCB observations collected in Puget Sound (Washington, U.S.A) was used to compare Dinophysis spp. abundance estimates from samples triggered via side scattering versus fluorescence in relation to Mesodinium spp. abundance. This study introduces a quantitative approach for optimizing the detection of target harmful algae which can be repeated across multiple IFCBs and demonstrates the effects of IFCB calibration on Dinophysis spp. detection. The laboratory experiments showed that IFCB settings for fluorescence-based image acquisition need to be fairly sensitive to accurately detect D. acuminata cells. A poorly calibrated IFCB can miss a significant proportion of D. acuminata abundance whatever the method used to trigger the image acquisition. Field results demonstrated that the physiological status of Dinophysis spp. can influence their detection by the IFCB when triggering on fluorescence. This was observed during a 7-day period when the IFCB failed to detect Dinophysis spp. cells when triggering on fluorescence while cells were still detected using the side scattering triggering method as well as observed by microscopy. During this period, Mesodinium spp. was not detected, IFCB-derived autofluorescence level of individual cells of Dinophysis spp. was low, and less than 50 % of Dinophysis spp. cells exhibited autofluorescence under the microscope. Together, this indicates that the unique feeding ecology of Dinophysis spp. may affect their detection by the IFCB when cells are starved. [ABSTRACT FROM AUTHOR]

Brevetoxins (PbTxs) are emerging marine toxins that can lead to Neurotoxic Shellfish Poisoning in humans by the ingestion of contaminated seafood. Recent reports on brevetoxin detection in shellfish in regions where it has not been described before, arise the need of updated guidelines to ensure seafood consumers safety. Our aim was to provide toxicological data for brevetoxin 3 (PbTx3) by assessing oral toxicity in mice and comparing it with intraperitoneal administration. We followed an Up-and-Down procedure administering PbTx3 to mice and registering clinical signs, neuromuscular function, histopathology, and blood changes. Neuromuscular dysfunction like seizures and ataxia, as well as loss of limb strength were observed at 6 h. Performance and clinical signs largely improved at 24 h, time at which no blood biochemical or histological alterations were detected independently of the administration route. However, PbTx3 oral administration results in lower toxicity than intraperitoneal administration. Mortality was only observed at 4000 μg/kg bw PbTx3 administered via oral, but we still found toxicity clinical signs at low toxin doses. We could stablish an oral Lowest-Observable-Adverse-Effect-Level for PbTx3 of 100 μg/kg bw and an oral No-Observable-Adverse-Effect-Level of 10 μg/kg bw in mice. The data here reported should be considered in the evaluation of risks of PbTxs for human health. • Brevetoxin 3 oral Lowest-Observable-Adverse-Effect-Level is 100 μg/kg bw. • Brevetoxin 3 oral No-Observable-Adverse-Effect-Level is 10 μg/kg bw. • Brevetoxin 3 intraperitoneal LD 50 875 μg/kg in mice. [ABSTRACT FROM AUTHOR]

• French Polynesia is a biodiversity hotspot for Gambierdiscus species. • Gambierdiscus polynesiensis is the main source of ciguatoxins in French Polynesia. • Herbivores and omnivores can be as toxic as carnivores in French Polynesia. • French Polynesia has a long-term epidemiological surveillance program on CP. • Cultural ramifications of CP have strong implications for risk management strategies. Ciguatera Poisoning (CP) is a seafood poisoning highly prevalent in French Polynesia. This illness results from the consumption of seafood contaminated with ciguatoxins (CTXs) produced by Gambierdiscus , a benthic dinoflagellate. Ciguatera significantly degrades the health and economic well-being of local communities largely dependent on reef fisheries for their subsistence. French Polynesia has been the site of rich and active CP research since the 1960′s. The environmental, toxicological, and epidemiological data obtained in the frame of large-scale field surveys and a country-wide CP case reporting program conducted over the past three decades in the five island groups of French Polynesia are reviewed. Results show toxin production in Gambierdiscus in the natural environment may vary considerably at a temporal and spatial scale, and that several locales clearly represent Gambierdiscus spp. "biodiversity hotspots". Current data also suggest the "hot" species G. polynesiensis could be the primary source of CTXs in local ciguateric biotopes, pending formal confirmation. The prevalence of ciguatoxic fish and the CTX levels observed in several locales were remarkably high, with herbivores and omnivores often as toxic as carnivores. Results also confirm the strong local influence of Gambierdiscus spp. on the CTX toxin profiles characterized across multiple food web components including in CP-prone marine invertebrates. The statistics, obtained in the frame of a long-term epidemiological surveillance program established in 2007, point towards an apparent decline in the number of CP cases in French Polynesia as a whole; however, incidence rates remain dangerously high in some islands. Several of the challenges and opportunities, most notably those linked to the strong cultural ramifications of CP among local communities, that need to be considered to define effective risk management strategies are addressed. [ABSTRACT FROM AUTHOR]

A puffer fish poisoning case was reported from the coastal city of Veraval in the Gujarat state of India with patient reporting symptoms of giddiness, vertigo, aphasia and heaviness of head following consumption of cooked fish. Treatment was purely symptomatic and supportive. The patient was discharged from the hospital in a stable condition after 4 days. The suspected fish species was later identified using DNA (Deoxyribonucleic Acid) sequencing as Arothron stellatus with 100% identity. Arothron stellatus, also known as Stellate Puffer, is a demersal marine fish usually found in the Indian Ocean. [Display omitted] • There is lack of official data regarding puffer fish poisoning in India. • A puffer fish poisoning incident occurred in the coastal city of Veraval in India. • Treatments were symptomatic and supportive for the patient. • The fish was later identified as Stellate Puffer, Arothron stellatus. [ABSTRACT FROM AUTHOR]

• Cyanide fishing is a destructive technique that persists in Indo-Pacific coral reefs. • Coral reef fish poisoned by cyanide are traded live in premium markets. • While illegal, there is little legal enforcement against cyanide fishing. • Non-invasive, non-destructive and reliable cyanide detection methods are needed. • To develop effective testing platforms 5 key research topics must be addressed. Indo-Pacific coral reefs face an unprecedented level of anthropogenic pressure. Cyanide fishing is a highly destructive method employed to capture live fish from Indo-Pacific coral reefs and supply the live fish food trade in Asia and the global marine aquarium trade. To allow the development and implementation of an effective and reliable testing platform to screen live reef fish for cyanide poisoning, without their sacrifice, and thus contribute to the ban of this practice from Indo-Pacific coral reefs, the following research topics must be urgently addressed: 1) selection of a suitable model species; 2) standardization of experimental methodologies; 3) exclude the possibility that the target compound(s) being monitored to detect live reef fish illegally collected using cyanide originate from other sources than cyanide poisoning; 4) clarification of the excretion physiology and cyanide pharmacokinetics in marine fish; and 5) evaluate interspecific differences in excretion physiology and cyanide pharmacokinetics in marine fish. [ABSTRACT FROM AUTHOR]

Okadaic acid (OA) is a lipophilic phycotoxin that accumulates in the hepatopancreas and fatty tissue of shellfish. Consumption of highly OA-contaminated seafood leads to diarrhetic shellfish poisoning which provokes severe gastrointestinal symptoms associated with a disruption of the intestinal epithelium. Since the molecular mechanisms leading to intestinal barrier disruption are not fully elucidated, we investigated the influence of OA on intestinal tight junction proteins (TJPs) in differentiated Caco-2 cells. We found a concentration- and time-dependent deregulation of genes encoding for intestinal TJPs of the claudin family, occludin, as well as zonula occludens (ZO) 1 and 2. Immunofluorescence staining showed concentration-dependent effects on the structural organization of TJPs already after treatment with a subtoxic but human-relevant concentration of OA. In addition, changes in the structural organization of cytoskeletal F-actin as well as its associated protein ZO-1 were observed. In summary, we demonstrated effects of OA on TJPs in intestinal Caco-2 cells. TJP expressions were affected after treatment with food-relevant OA concentrations. These results might explain the high potential of OA to disrupt the intestinal barrier in vivo as its first target. Thereby the present data contribute to a better understanding of the OA-dependent induction of molecular effects within the intestinal epithelium. • Exposure of differentiated Caco-2 cells to okadaic acid (OA) induces cytotoxicity. • Intestinal TJPs were affected by OA concentration- and time-dependently. • OA regulates TJPs on gene and protein expression levels. • OA affects TJPs expression after treatment with food-relevant concentrations. • OA destroys the TJP networks resulting in loss of intestinal epithelial function. [ABSTRACT FROM AUTHOR]

• High abundance of Amphidomataceae in Argentinean 2015spring bloom communities at the shelf front. • 31 new Argentinean strains of Azadinium dalianense and Az. spinosum are characterized. • Majority of strains revealed a new non-toxigenic ribotype of Az. spinosum. • A single Argentinean Az. spinosum strain of a different ribotype produced only AZA-2. Azaspiracids (AZA) are the most recently discovered group of lipophilic marine biotoxins of microalgal origin, and associated with human incidents of shellfish poisoning. They are produced by a few species of Amphidomataceae, but diversity and occurrence of the small-sized dinophytes remain poorly explored for many regions of the world. In order to analyze the presence and importance of Amphidomataceae in a highly productive area of Argentinean coastal waters (El Rincón area, SW Atlantic), a scientific cruise was performed in 2015 to sample the early spring bloom. In a multi-method approach, light microscopy was combined with real-time PCR molecular detection of Amphidomataceae, with chemical analysis of AZA, and with the establishment and characterization of amphidomatacean strains. Both light microscopy and PCR revealed that Amphidomataceae were widely present in spring plankton communities along the El Rincón area. They were particularly abundant offshore at the shelf front, reaching peak densities of 2.8 × 105 cells L−1, but no AZA were detected in field samples. In total, 31 new strains were determined as Az. dalianense and Az. spinosum , respectively. All Az. dalianense were non-toxigenic and shared the same rRNA sequences. The large majority of the new Az. spinosum strains revealed for the first time the presence of a non-toxigenic ribotype of this species, which is otherwise the most important AZA producer in European waters. One of the new Az. spinosum strains, with a particular slender shape and some other morphological peculiarities, clustered with toxigenic strains of Az. spinosum from Norway and, exceptionally for the species, produced only AZA-2 but not AZA-1. Results indicate a wide diversity within Az. spinosum, both in terms of sequence data and toxin profiles, which also will affect the qualitative and quantitative performance of the specific qPCR assay for this species. Overall, the new data provide a more differentiated perspective of diversity, toxin productivity and occurrence of Amphidomataceae in a poorly explored region of the global ocean. [ABSTRACT FROM AUTHOR]

Abstract Naturally-occurring saxitoxins periodically accumulate in shellfish giving rise to Paralytic Shellfish Poisoning. For decades a mouse bioassay has been used for public health protection, but in 2019 a pre-column oxidation LC-FLD method became the official reference method in the European Union. Laboratories are now required to use this method for regulatory monitoring, which will prove challenging. This paper reviews the development, validation and implementation of the method, having been used for over twelve years, successfully providing effective controls against human poisonings without resorting to contingency bioassay. The review describes the work conducted to refine, semi-automate and standardise the method, as well as modifications to cope with new analogues and shellfish species. Approaches for qualitative screening, semi-quantitation and full quantitation are also highlighted, as well as faster chromatography, quality assurance tools and interlaboratory studies. Recommendations for those laboratories new to the method are also described. Highlights • Pre-column oxidation LC-FLD method becomes EU reference method for PSP toxin determination Jan 2019. • Review of work conducted to develop, validate and implement the method into official control programmes. • Refinements, semi-automation and standardisation described. • Approaches for qualitative, semi-quantitative and full quantitation highlighted. • Recommendations for validating and implementing the method. [ABSTRACT FROM AUTHOR]

Abstract Vibrio parahaemolyticus constitutes an important foodborne pathogen frequently associated with seafood-borne illness. This bacterium can form biofilms on food and food contact surfaces during early stages of food processing, which makes it difficult to control using traditional methods. Consequently, new techniques to control its transmission via food are necessary. A promising option comprises lytic bacteriophages, which are viruses that can lethally infect a specific target host such as pathogenic bacteria and reduce their number. In this study, 34 phages specific to V. parahaemolyticus were isolated from surface water during September 2016 to October 2017. All phages were identified by transmission electron microscopy and their host ranges were evaluated. Among these, three phages belonging to different families were selected for further characterisation. One-step growth curve results showed that the three phages presented high burst sizes (458–593). The optimum thermo-tolerance, pH, and salinity concentration were 25–50 °C, 2.0–12.0, and 1.5–5.0%, respectively. The three selected phages and their phage cocktail were tested regarding the ability to prevent biofilm formation and to destroy established biofilms. The data demonstrated that the phages showed promise in preventing the development of V. parahaemolyticus biofilms. However, they were not effective in destroying established biofilms. The results highlight the potential of the three phages for biocontrol of V. parahaemolyticus in the aquaculture industry and as a preventive agent against biofilm formation in production lines. Highlights • Vibrio parahaemolyticus is a foodborne pathogen commonly contaminating seafood. • Of bacteriophages from Shanghai waters, 3 had broad V. parahaemolyticus host range. • The 3 phages were stable under different temperature, pH, and salinity conditions. • The 3 phages effectively controlled biofilm development but not preformed biofilms. • Phages may be good alternatives to control V. parahaemolyticus in aquaculture. [ABSTRACT FROM AUTHOR]

Abstract Vibrio parahaemolyticus is one of the most common causes of seafood-borne illnesses in South Korea and is typically found on traditional Korean raw crab marinated in soy sauce (ganjang-gejang). In this study, we investigated the growth of a cocktail of three V. parahaemolyticus strains (NCCP13712, NCCP13714, and NCCP14551) from ganjang-gejang stored at different temperatures (5 °C, 10 °C, 15 °C, 20 °C, 25 °C, and 30 °C) for up to 144 h. The growth data were fitted to a curve to estimate primary kinetic parameters including lag time (LT), specific growth rate (SGR), and maximum population density (MPD) using DMFit. The model performance was evaluated by calculating bias (B f) (1.0002–1.0032) and accuracy (A f) (1.0226–1.0431). A secondary model of LT, SGR, and MPD was developed as the four-parameter polynomial model (all R 2 = 1). Based on the developed predictive model, we established the time-temperature criteria (TTC) model for determining the time and temperature for ensuring microbiological food safety. According to the model, V. parahaemolyticus on ganjang-gejang increases about 1 log growth ratio (LGR) from the initial cell number after storage for 10.8, 5.2, and 4.7 h at 16 °C, 22 °C, and 28 °C, respectively. If 1 LGR is set as the food safety standard, these time and temperature values are recommended as the appropriate TTC values for V. parahaemolyticus on ganjang-gejang. Thus, the predictive TTC model can provide a guideline for safe storage parameters that ensure microbiological food safety in the context of certain foodborne pathogens. Highlights • Vibrio parahaemolyticus on ganjang-gejang is a major cause of foodborne disease. • We developed a predictive growth model for V. parahaemolyticus. • The time-temperature criteria (TTC) model establishes microbiological food safety. • The model can prevent of foodborne illness caused by inappropriate food storage. [ABSTRACT FROM AUTHOR]

Highlights • Ribosomal 18S/28S rRNA microarray was applied to improve the detection of HAB species. • Microarray was comparable with microscopy in detecting Pseudo-nitzschia spp. and HAB flagellates and dinoflagellates. • Seasonal upwelling induced by northerly winds was found to be the driving force of HAB events. • Pseudo-nitzschia spp. developed with upwelling events, HAB dinoflagellates occurred during upwelling relaxation. Abstract The study region in Sagres, SW Portugal, is subject to natural eutrophication of coastal waters by wind-driven upwelling, which stimulates high primary productivity facilitating the recent economic expansion of bivalve aquaculture in the region. However, this economic activity is threatened by harmful algal blooms (HAB) caused by the diatoms Pseudo-nitzschia spp., Dinophysis spp. and other HAB dinoflagellates, all of which can produce toxins, that can induce Amnesic Shellfish Poisoning (ASP), Diarrhetic Shellfish Poisoning (DSP) and Paralytic Shellfish Poisoning (PSP). This study couples traditional microscopy with 18S/28S rRNA microarray to improve the detection of HAB species and investigates the relation between HAB and the specific oceanographic conditions in the region. Good agreement was obtained between microscopy and microarray data for diatoms of genus Pseudo-nitzschia and dinoflagellates Dinophysis spp. , Gymnodinium catenatum and raphidophyte Heterosigma akashiwo, with less effective results for Prorocentrum. Microarray provided detection of flagellates Prymnesium spp., Pseudochattonella spp., Chloromorum toxicum and the important HAB dinoflagellates of the genera Alexandrium and Azadinium , with the latter being one of the first records from the study region. Seasonality and upwelling induced by northerly winds were found to be the driving forces of HAB development, with Pseudo-nitzschia spp. causing the risk of ASP during spring and summer upwelling season, and dinoflagellates causing the risk of DSP and PSP during upwelling relaxation, mainly in summer and autumn. The findings were in agreement with the results from toxicity monitoring of shellfish by the Portuguese Institute for Sea and Atmosphere and confirm the suitability of the RNA microarray method for HABs detection and aquaculture management applications. [ABSTRACT FROM AUTHOR]

Abstract The numbers of alerts from the EU's Rapid Alert System for Food and Feed (RASFF) related to crustacean products were compared to numbers of mainstream media stories related to health concerns. An internet search of "farmed shrimp" was also conducted and the content of the websites assessed for subject matter and balance. The study found that the absolute number of RASFF alerts has fallen considerably since legislation controlling testing of food being traded into and within the EU was introduced in 2002 and tracked increasing stringency of EU procedures. There were 1512 alerts from 1980 to 2015 with 44.0% and 21.2% of alerts attributed to farmed and wild shrimp respectively. There were large numbers of alerts reporting antibiotic residues in wild shrimp, which raised questions about the source of the contamination, and natural occurrence of the antimicrobial residues was considered. The number of mainstream media stories closely followed the number of alerts, but 91.2% of media articles concerning the health aspects were concerned with consumption of farmed shrimp. The internet search revealed a much more negative view of farmed shrimp compared to the mainstream media. It is suggested that the internet generally follows an historic negative narrative on farmed seafood, often with little validation which narrows the discourse on seafood production rather than empowering consumers. According to the risk assessment of RASFF data, it was concluded that farmed shrimp does not possess any more risk than wild seafood choices but producers have not been able to communicate the benefits of farmed produce to the consumer. Highlights • Fewer RASFF alerts compared to increased supply over the lifetime of the alerts system suggests reduced consumption risk. • The coverage in the mainstream media has generally reflected the level of risk of consuming farmed shrimp • Social media and internet sources repeat established narratives that perpetuate a bad image of imported farmed aquatic produce • RASFF system is not representative of products available to consumers and therefore not adequate to establish ADIs [ABSTRACT FROM AUTHOR]

Highlights • No clear intra-seasonal variation of benthic dinoflagellate abundances in Guadeloupe and in Martinique. • Benthic dinoflagellates showed a preferential association with certain macrophytes. • Halophila stipulacea, hosted the highest Gambierdiscus spp. abundances. • Sargassum spp. hosted the lowest number of benthic dinoflagellates. Abstract Epibenthic dinoflagellates were monitored monthly over an 18 month period in Guadeloupe and Martinique (Lesser Antilles, Caribbean Sea). These islands are located in the second most affected ciguatera fish poisoning (CFP) region of the world. Guadeloupe presented five times more total epibenthic dinoflagellates and two times less abundant Gambierdiscus spp. compared to Martinique, although the area of frequent CFP outbreaks covers Guadeloupe and not Martinique. Results did not show any clear seasonal variations of benthic dinoflagellates abundances. Temperature and salinity were not driving parameters in the evolution of total benthic dinoflagellate abundances. Preferential associations were found between macrophyte species and epibenthic dinoflagellates. The Phaeophyceae Dictyota spp. hosted the highest abundances of total epibenthic dinoflagellates, composed mainly of Ostrepsis and Prorocentrum genera. The seagrass Halophila stipulacea hosted the highest abundances of Gambierdiscus spp. and Sinophysis spp. whilst the highest abundance of Coolia was determined on Galaxaura spp. The pelagic Sargassum spp. hosted the lowest abundances of benthic dinoflagellates including the genus Gambierdiscus. [ABSTRACT FROM AUTHOR]

Abstract In contaminated fish, bacterial decarboxylases produce histamine from histidine, thereby causing scombroid fish poisoning. European Regulation (EC) No 2073/2005 on microbiological criteria for foodstuffs requires using a fully validated, standardized reference HPLC method for detecting and quantifying histamine. After optimizing this reference method for the quantification of histamine in fish muscle, we organized an inter-laboratory study in 2013 across nine laboratories from seven European countries using defined criteria of method performance. The optimized, validated method was standardized (Standard EN ISO19343) as part of Mandate M381 from the European Commission to the European Committee for Standardization (CEN), signed in December 2010. The standard method was validated for three types of foodstuffs (fish with enzymatic maturation, fish without enzymatic maturation and fish sauce). [ABSTRACT FROM AUTHOR]

Highlights • Temperature and nutrient conditions affected growth and toxin production. • Production of okadaic acid (OA) was induced in all conditions in Prorocentrum hoffmannianum. • Toxin production was enhanced in P-limited conditions at 27 °C. • OA concentrations were 1 order of magnitude higher than in other DSP species. • No OA esters were detected in this strain of Prorocentrum hoffmannianum. Abstract The benthic dinoflagellate Prorocentrum hoffmannianum M.A. Faust is typical of tropical warm waters and produces biotoxins responsible for diarrhetic shellfish poisoning (DSP). In this study, the effect of temperature and nutrient limitation on growth and toxin production of P. hoffmannianum isolated from field samples collected in the Florida Keys was investigated. Batch culture experiments were ran at two temperatures (i.e. 21 ± 0.1 and 27 ± 0.1 °C) and under nitrogen-limited (14.7 μmol L−1 N-NO 3 - and 18.1 μmol L−1 P-PO 4 3-) and phosphorus-limited (441 μmol L−1 N-NO 3 - and 0.6 μmol L−1 P-PO 4 3-) levels with respect to control nutrient conditions (441 μmol L−1 N-NO 3 -and 18.1 μmol L−1 P-PO 4 3-). Both temperature and nutrient conditions significantly affected growth rates and maximum yield of P. hoffmannianum with the maximum values being recorded at the higher temperature and in the replete medium. Production of okadaic acid was induced under all conditions (from 13.5 to 859.8 pg cell−1), with values up to one order of magnitude higher than those observed in other DSP toxin producing species. Toxin production was enhanced under P limitation at 27 °C, corroborating the theory that toxin production is modulated by cell physiological conditions, which are in turn affected by a wide spectrum of factors, including environmental stressors such as nutrient availability. Toxin fraction released in the growth medium was negligible. No okadaic acid esters were detected in this strain of P. hoffmannianum. [ABSTRACT FROM AUTHOR]

The oral bioaccessibility of several essential and toxic elements was investigated in raw and cooked commercially available seafood species from European markets. Bioaccessibility varied between seafood species and elements. Methylmercury bioaccessibility varied between 10 (octopus) and 60% (monkfish). Arsenic (>64%) was the toxic element showing the highest bioaccessibility. Concerning essential elements bioaccessibility in raw seafood, selenium (73%) and iodine (71%) revealed the highest percentages. The bioaccessibility of elements in steamed products increased or decreased according to species. For example, methylmercury bioaccessibility decreased significantly after steaming in all species, while zinc bioaccessibility increased in fish (tuna and plaice) but decreased in molluscs (mussel and octopus). Together with human exposure assessment and risk characterization, this study could contribute to the establishment of new maximum permissible concentrations for toxic elements in seafood by the European food safety authorities, as well as recommended intakes for essential elements. [ABSTRACT FROM AUTHOR]

[Display omitted] • Peptide-based competitive ELISA for detection of okadaic acid was developed. • Okadaic acid-specific peptide was successfully identified and chemically synthesized. • Developed peptide-based ELISA exhibit good limit of detection and limit of quantitation. • Our developed ELISA show good performance in a complexed real shellfish samples. Okadaic acid (OA) is a type of marine biotoxin produced by some species of dinoflagellates in marine environments. Consumption of shellfish contaminated with OA can cause diarrhetic shellfish poisoning (DSP) in humans with symptoms that typically include abdominal pain, diarrhea and vomiting. In this study, we developed an affinity peptide-based direct competition enzyme-linked immunosorbent assay (dc-ELISA) for the detection of OA in real samples. The OA-specific peptide was successfully identified via M13 biopanning and a series of peptides were chemically synthesized and characterized their recognition activities. The dc-ELISA system showed good sensitivity and selectivity with a half-maximal inhibitory concentration (IC 50) of 148.7 ng/mL and a limit of detection (LOD) of 5.41 ng/mL (equivalent, 21.52 ng/g). Moreover, the effectiveness of the developed dc-ELISA was validated using OA-spiked shellfish samples, and the developed dc-ELISA showed a high recovery rate. These results suggest that the affinity peptide-based dc-ELISA can be a promising tool for detecting OA in shellfish samples. [ABSTRACT FROM AUTHOR]

The consumption of seafood containing marine biotoxins called ciguatoxins (CTXs) can result in ciguatera poisoning (CP), a globally prevalent seafood-born human illness. The southwestern coast of India is a regional source of seafood attributed to isolated and mass outbreaks of CP since 2015, both locally and exported globally. Samples of frozen snapper product (Lutjanus bohar) described herein, were part of a 7000 kg international shipment into the European Union from southwest India and implicated in a CP outbreak in the Netherlands. DNA barcoding confirmed the species as Lutjanus bohar with a base pair identity of 99%. LC-MS/MS and HRMS analyses describe CTX-3C-group compounds with an in vitro Neuro-2a (cell-based) cytotoxicity MTT-assay based toxicity range of 0.79–5.39 ng CTX-3C equivalent (eq.) per g wet tissue eq. This CP traceback includes an investigation and description of the production chain distribution, catch region, outbreak, toxin-group, and follow-up actions for the seafood products associated with the outbreak. Together this in-depth traceback investigation provides an account of the CP outbreak from harvest to consumption for a region of coastal India with a sizable seafood production industry but with limited CP data. • Ciguatera Poisoning incident in Europe was linked to snapper exported from India. • Fish was identified through DNA barcoding as Lutjanus bohar. • All tissue extracts (n = 7) revealed toxicity in Neuro-2a cell based assay. • Analogues of Ciguatoxin-3C group are described by LC-MS/MS and HRMS. • Traceback to harvest region, outbreak description, follow-up actions are described. [ABSTRACT FROM AUTHOR]

• Reports of BHAB species and related harmful events in South America (SA) were reviewed. • Greater diversity of toxigenic species found in equatorial/tropical areas of the continent. • Prorocentrum lima complex is the most frequent and widespread BHAB taxon in SA. • Ciguatera events reported in Colombia and Venezuela since the 1970s and 80s. • Enhanced analytical capacity and BHAB monitoring are necessary in most parts of SA. Public awareness about Benthic Harmful Algal Blooms (BHABs) and their negative impacts has increased substantially over the past few decades. Even so, reports of BHABs remain relatively scarce in South America (SA). This paper provides a comprehensive overview of the current state of knowledge on BHABs in the continent, by integrating data from published articles, books, and technical reports. We recorded ∼300 different occurrences of potentially toxic BHAB species over the Caribbean, Atlantic and Pacific coasts, mostly in marine (>95%) but also in estuarine areas located from 12⁰36′ N to 54⁰53′ S. Over 70% of the data was published/released within the past 10 years, and ∼85% were concentrated in Brazil, Venezuela, Ecuador and Colombia. Benthic species were mainly associated with macroalgae, seagrass and sediment. Incidental detection in the plankton was also relevant, mainly in places where studies targeting BHAB species are still rare, like Argentina, Uruguay, Chile and Peru. The study listed 31 infrageneric taxa of potentially toxic benthic dinoflagellates and eight of estuarine cyanobacteria occurring in SA, with the greatest species diversity recorded in the equatorial-tropical zone, mainly in northeastern Brazil (Atlantic), Venezuela and Colombia (Caribbean), and the Galapagos Islands, Ecuador (Pacific). Local strains of Amphidinium, Gambierdiscus, Coolia and Prorocentrum spp. produced toxic compounds of emerging concern. Prorocentrum lima species complex was the most common and widely distributed taxon, followed by Ostreopsis cf. ovata. In fact, these two dinoflagellates were associated with most BHAB events in SA. Whereas the former has caused the contamination of multiple marine organisms and cases of Diarrhetic Shellfish Poisoning in subtropical and temperate areas, the latter has been associated with faunal mortalities and is suspected of causing respiratory illness to beach users in tropical places. Ciguatera Poisoning has been reported in Colombia (∼240 cases; no deaths) and Venezuela (60 cases; two deaths), and may be also a risk in other places where Gambierdiscus spp. and Fukuyoa paulensis have been reported, such as the Galapagos Islands and the tropical Brazilian coast. Despite the recent advances, negative impacts from BHABs in SA are intensified by limited research/training funding, as well as the lack of official HAB monitoring and poor analytical capability for species identification and toxin detection in parts of the continent. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZrFe-MOF had superior peroxidase-like activity, stability, and dispersity in aqua. • The reversible inhibition–activation nanozyme activity was controlled by aptamers. • The effect mechanism was unraveled via the structural and electronic interactions. • A facile colorimetric assay was used for the efficient sensing of marine biotoxins. • Multiple discriminations were well achieved by learning the patterned interactions. Marine biotoxins poison seafood under conditions of eutrophication induced by harmful algal blooms, threatening life. It is challenging to construct efficient sensing technologies for trace marine biotoxins. Herein, we utilized Fe(III) and Zr(IV) to prepare bimetal-organic frameworks (ZrFe-MOF). The synergism between the two metals endowed ZrFe-MOF with high peroxidase-like activity, excellent stability, and good dispersity in aqua. Our results demonstrated that the inherent peroxidase-like activity of ZrFe-MOF was inhibited by the aptamers absorbed on this material surface. The effect mechanism was unraveled by clarifying the structural and electronic interactions. Meanwhile, the preferential binding between these specific aptamers and cognate targets triggered the release of rigid complexes from the surface of ZrFe-MOF, resulting in the reactivation of the peroxidase-like activity. Based on the reversible inhibition–activation nanozyme activity controlled by aptamers, a facile ZrFe–MOF-based colorimetric assay was proposed for the detection of marine biotoxins. This strategy was used to determine tetrodotoxin (TTX) as a proof of concept. The limit of detection (LOD) was as low as 0.07 ng/mL, and the detection range was 0.1–200 ng/mL. Furthermore, this assay could be used to successfully analyze natural TTX-contaminated puffer fish and clam samples. Efficient analytical performance was achieved. Notably, the discrimination of multiple marine biotoxins was successfully achieved in seawater based on the pattern recognition process. This study offers a paradigm for tuning MOF nanozyme activity in the presence of nucleic acids. The results bring new insights for developing multi-sensing platforms for various applications. [ABSTRACT FROM AUTHOR]

Background: Ciguatera poisoning is one of the most prevalent types of fish poisoning, but it is often underreported, leading many health practitioners to be unfamiliar in correctly identifying and treating this toxicity.Case Report: We present a case of ciguatera toxicity encountered in an emergency department in a Midwest community hospital setting. A 56-year-old woman presented to the ED with symptoms of perioral numbness, generalized pruritis, and hot/cold temperature reversal. Through careful history taking it was determined that the patient had recently returned from vacationing in the Caribbean and had been consuming meals containing various types of fish. A clinical diagnosis of ciguatera toxicity was made, and the patient was treated supportively. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This topic is important in the realm of emergency medicine because it presents a known toxicologic pathogen in an unsuspecting geographic location. This case highlights the importance of maintaining broad differentials and considering a patient's travel and exposure history to make the clinical diagnosis of ciguatoxin as well as the importance of preventative management to avoid recurrence of symptoms. We review the etiology of this fascinating toxin as well as the clinical implications in the diagnosis and management of this toxicity. [ABSTRACT FROM AUTHOR]

Abstract Mercury concentrations in the ocean have increased considerably since the industrial revolution and will continue to increase in the next 50 years. Therefore, it is important to monitor Hg levels in fish and to evaluate the health risks in populations with high fish consumption. In the present study, a total of 238 samples of commercial fish and shellfish, were analyzed from the Central Gulf of California, Mexico. Concentrations of total Hg in fish ranged from < DL (detection limit) up to 1.22 μg g-1, with a mean of 0.15 ± 0.19 μg g-1, the majority of the samples were lower than the maximum permissible level. To evaluate the risk, a total of 110 food frequency questionnaires were applied to women (16–68 years old) from 15 coastal fishing villages of Sonora. Results indicated a high seafood consumption at these communities (mean = 307 g day-1), and a high hazard risk (HQ = 6.2) due to methyl mercury ingestion. It is recommended to limit seafood consumption in pregnant women to 4 portions of fish per week, preferably of low mercury concentrations so that all the benefits of seafood consumption are obtained without the negative health effects of methyl mercury. Highlights • Total mercury concentrations of collected fish and shellfish were below maximum permissible levels. • Seafood consumption patterns in fishing villages were high (307 g day−1) compared with other coastal regions of the world. • The hazard risk (HQ) obtained indicated a potential health risk for women and newborn children. [ABSTRACT FROM AUTHOR]

Abstract Okadaic acid (OA) is one of the most common and widespread marine toxins and causes acute gastrointestinal symptoms known as diarrheic shellfish poisoning (DSP) in humans. Although OA is not classified as a typical neurotoxin, an increasing number of studies have reported its neurotoxic effects. However, most of the available studies have focused on OA-induced inhibition of serine/threonine protein phosphatases, while the molecular mechanism of OA-induced neurotoxicity remains largely unclear. To better understand the potentially toxicological profile of OA, cell cycle arrest, DNA damage and alterations in gene expression in the human neuroblastoma cell line SHSY5Y upon OA exposure were determined using flow cytometry, comet assay, and transcriptome microarray. The results showed that OA could induce cell cycle arrest at S phase and might be involved in significant DNA strand breaks. Gene expression profiling indicated that the differentially expressed genes after OA exposure were significantly enriched in the “DNA replication” and “cell cycle” pathways. Real-time PCR result had further validated that down-regulation of the Cdc45/Mcm2-7/GINS complex might be the major factor regulating those alterations. These findings provide new insight into the molecular mechanisms of OA-induced neurotoxicity, and the current data may also provide a basis for future studies. Highlights • Toxicogenomic approach as a tool to investigate the neurotoxicity of OA. • Gene expression profiling reveals that “DNA replication” and “cell cycle” as the major causes due to OA exposure. • OA induces cell cycle arrest at S phase. • OA induces S phase arrest and DNA damage probably due to down-regulation of the Cdc45-MCM-GINS complex. [ABSTRACT FROM AUTHOR]

Seafood consumption is a major route for human exposure to environmental contaminants of emerging concern (CeCs). However, toxicological information about the presence of CeCs in seafood is still insufficient, especially considering the effect of cooking procedures on contaminant levels. This study is one among a few who evaluated the effect of steaming on the levels of different CeCs (toxic elements, PFCs, PAHs, musk fragrances and UV-filters) in commercially relevant seafood in Europe, and estimate the potential risks associated with its consumption for consumers. In most cases, an increase in contaminant levels was observed after steaming, though varying according to contaminant and seafood species (e.g. iAs, perfluorobutanoate, dibenzo(ah)anthracene in Mytilus edulis , HHCB-Lactone in Solea sp., 2-Ethylhexyl salicylate in Lophius piscatorius ). Furthermore, the increase in some CeCs, like Pb, MeHg, iAs, Cd and carcinogenic PAHs, in seafood after steaming reveals that adverse health effects can never be excluded, regardless contaminants concentration. However, the risk of adverse effects can vary. The drastic changes induced by steaming suggest that the effect of cooking should be integrated in food risk assessment, as well as accounted in CeCs regulations and recommendations issued by food safety authorities, in order to avoid over/underestimation of risks for consumer health. [ABSTRACT FROM AUTHOR]

Synthetic polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants and known to occur in most food items. Consumer fish products have been identified as having some of the highest PBDE levels found in USA food sources. Natural formation of hydroxylated (OH-) and methoxylated (MeO-) PBDEs are also known to occur in simple marine organisms, which may be bioaccumulated by seafood. In this study, we report findings of an initial survey of PBDE, OH-PBDE and MeO-PBDE content in common seafood items available to residents living in the Puget Sound region of Washington State. Seafood samples were either purchased from local grocery stores or caught off the coast of SE Alaska and in Puget Sound. The edible portions of the seafood were analyzed, which for finfish was white muscle (skinless fillets) and for shellfish, either the entire soft tissue (bivalves) or processed meat (calamari, shrimp and scallops). Results indicated that finfish typically had higher levels of PBDEs compared to shellfish with BDE-47 and BDE-99 as the most common congeners detected. Among shellfish, bivalves (clams and mussels) were notable for having much higher levels of OH- and MeO-PBDEs compared to other types of seafood with 6′-OH-BDE-47 and 2′-MeO-BDE-68 being the more common OH- and MeO- congeners, respectively. Based on our results and recent updates to daily fish consumption rates, estimated intake rates for Washington State residents will be between 34 and 644 ng PBDEs/day, depending on species consumed. For the OH- and MeO- forms, daily exposure is much more variable but typically would range between 15 and 90 ng/day for most seafood types. If shellfish are primarily consumed, OH-PBDE intake could be as high as 350 ng/day. These daily intake rates for PBDEs are higher than most dietary intake rates calculated for populations in other world regions. [ABSTRACT FROM AUTHOR]

Ciguatoxins (CTXs) and brevetoxins (PbTxs) are phycotoxins that can accumulate along the marine food chain and thus cause seafood poisoning in humans, namely “ciguatera fish poisoning” (CFP) and “neurotoxic shellfish poisoning” (NSP), respectively. CFP is characterized by early gastrointestinal symptoms and typical sensory disorders (paraesthesia, pain, pruritus and cold dysaesthesia), which can persist several weeks and, in some cases, several months or years. NSP is considered a mild form of CFP with similar but less severe symptoms. After inhaled exposure, PbTxs can also cause respiratory tract irritation in healthy subjects and asthma exacerbations in predisposed subjects, whose respiratory functions may be disrupted for several days following PbTx inhalation. Mechanistically, it is well established that CTX- or PbTx-induced disturbances are primarily mainly due to voltage-gated sodium channel activation in sensory and motor peripheral nervous system. However, little is known about the pathophysiology or a potential individual susceptibility to long lasting effects of CFP/NSP. In addition to their action on the nervous system, PbTxs and CTXs were also shown to exert effects on the immune system. However, their role in the pathophysiology of syndromes induced by CTX or PbTx exposure is poorly documented. The aim of this review is to inventory the literature thus far on the inflammatory and immune effects of PbTxs and CTXs. [ABSTRACT FROM AUTHOR]