Immunomodulatory effects of brevetoxin (PbTx-3) upon in vitro exposure in bottlenose dolphins (Tursiops truncatus)

Gebhard, Erika; Levin, Milton; Bogomolni, Andrea L.; Guise, Sylvain De

doi:10.1016/j.hal.2015.02.010

Cited by 14 publications

(6 citation statements)

References 41 publications

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“…Feces and gastric samples are only proxies for uptake and assimilation of toxins, and feces and urine as indicators of detoxification and depuration via renal and biliary routes do not provide information on real-time health impacts. In vitro exposure of dolphin peripheral blood cells to PbTx is known to increase proliferation of multiple immune cell types, and this merits investigation as a complementary data set to those used in the present study (Gebhard et al, 2015). In addition, targeted fine-scale seawater sampling combined with tracking movements of live dolphins immediately prior to health assessments may give more accurate estimates of individual exposure to K. brevis cells and reduce the impact of patchy cell distribution on future analyses.…”

Section: Discussionmentioning

confidence: 99%

“…Sarasota Bay, Florida (27 • N, 82 • W), a coastal barrier island estuary of approximately 125 km 2 , was selected as the location for the present study since it (1) experiences frequent, severe K. brevis blooms, (2) is a region of continuous HAB monitoring by multiple phytoplankton ecology research programs, and (3) is inhabited by a population of about 150 bottlenose dolphins that have been intensively studied for over 50 years (Scott et al, 1990;Wells, 2003;FWC, 2019;MML, 2019). Through long-term study of this population, the majority of these animals are individually identifiable in the field, have known sexes, ages, and spatial use and ranging patterns, and are therefore known to have high site fidelity to Sarasota Bay (Wells, 2014;Tyson and Wells, 2016).…”

Section: Study Site and Target Populationmentioning

confidence: 99%

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Utility of Red Tide (Karenia brevis) Monitoring Data as a Predictive Tool to Estimate Brevetoxin Accumulation in Live, Free-Ranging Marine Mammals

et al. 2021

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Exposure of common bottlenose dolphins (Tursiops truncatus) to brevetoxins (PbTx) produced by blooms of the toxic phytoplankton Karenia brevis frequently results in severe health impacts, including illness and large-scale mortality events. Although PbTx accumulation in dead-stranded dolphins is well documented, there are limited data for corresponding brevetoxin exposure in live dolphins. In addition, the severity of impacts on living survivors of such toxic blooms is difficult to assess due to a lack of data on the relationship between K. brevis bloom severity and corresponding PbTx concentrations in exposed animals. Here we present results of PbTx analysis of urine, serum, milk, gastric fluid, and feces samples collected from live, free-ranging dolphins (n = 253) from Sarasota Bay, Florida during 2000–2018, and investigate the relationship between PbTx concentrations detected and corresponding K. brevis cell abundances that are temporally (within 30 days) and spatially (within 16 km) associated with each individual. We found that 28% of dolphins were associated with elevated K. brevis abundances (10,000–60,000,000 cells/L), with 41% (n = 104) of dolphins testing positive for PbTx in at least one sample type. The proportion of PbTx-positive animals was significantly greater in animals exposed to elevated cell abundances vs. those exposed to background cell abundances (<10,000 cells/L), with 60 and 34% testing positive, respectively (p < 0.001). PbTx was detected most frequently in feces (57%, n = 38), followed by gastric (35%, n = 37), urine (32%, n = 55), and blood (7%, n = 17). PbTx concentrations by sample type were highest in feces (2–231 ng/g; mean 46), followed by urine (0.8–90 ng/g; mean 7.2), gastric (0.8–61 ng/g; mean 12), and blood (0.3–5 ng/g; mean 1.3). Regression analyses of K. brevis cell abundance as an index of exposure vs. corresponding PbTx concentration found no statistically significant relationship for feces (p = 0.120), gastric (p = 0.349), urine (p = 0.053), or blood (p = 0.729) samples. PbTx concentrations typically ranged over two orders of magnitude between minimum and maximum values and did not scale with corresponding indices of exposure, which ranged over three orders of magnitude or more. Our results indicate that K. brevis cell abundance alone is a poor predictor of brevetoxin accumulation in bottlenose dolphins, and suggest that alternative methods (e.g., endocrine or immunological biomarkers) should be investigated as more appropriate methods for determining the severity of health impacts due to red tides.

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Section: Discussionmentioning

confidence: 99%

Section: Study Site and Target Populationmentioning

confidence: 99%

Utility of Red Tide (Karenia brevis) Monitoring Data as a Predictive Tool to Estimate Brevetoxin Accumulation in Live, Free-Ranging Marine Mammals

et al. 2021

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“…Brevetoxins have been implicated in the death of large numbers of fish and in morbidity and mortality of marine mammals ( Gebhard et al, 2015 ).…”

Section: Neurotoxic Shellfish Poisoningmentioning

confidence: 99%

Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods

et al. 2016

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Harmful algal blooms are natural phenomena caused by the massive growth of phytoplankton that may contain highly toxic chemicals, the so-called marine biotoxins causing illness and even death to both aquatic organisms and humans. Their occurrence has been increased in frequency and severity, suggesting a worldwide public health risk. Marine biotoxins can accumulate in bivalve molluscs and regulatory limits have been set for some classes according to European Union legislation. These compounds can be distinguished in water- and fat-soluble molecules. The first group involves those of Paralytic Shellfish Poisoning and Amnesic Shellfish Poisoning, whereas the toxins soluble in fat can cause Diarrheic Shellfish Poisoning and Neurotoxic Shellfish Poisoning. Due to the lack of long-term toxicity studies, establishing tolerable daily intakes for any of these marine biotoxins was not possible, but an acute reference dose can be considered more appropriate, because these molecules show an acute toxicity. Dietary exposure assessment is linked both to the levels of marine biotoxins present in bivalve molluscs and the portion that could be eaten by consumers. Symptoms may vary from a severe gastrointestinal intoxication with diarrhea, nausea, vomiting, and abdominal cramps to neurological disorders such as ataxia, dizziness, partial paralysis, and respiratory distress. The official method for the detection of marine biotoxins is the mouse bioassay (MBA) showing some limits due to ethical restrictions and insufficient specificity. For this reason, the liquid chromatography–mass spectrometry method has replaced MBA as the reference technique. However, the monitoring of algal blooms producing marine biotoxins should be regularly assessed in order to obtain more reliable, accurate estimates of bloom toxicity and their potential impacts.

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“…Brevetoxins (BTXs) have been implicated in contributing to the morbidity and mortality of marine mammals [ 6 ]. While CTXs and MTX are accumulated in fish, BTXs accumulate mainly in shellfish.…”

Section: Compounds Produced By Karenia and Their Physiological Efmentioning

confidence: 99%

“…Neurotoxic shellfish poisoning (NSP) [ 4 ] shows symptoms similar to CFP, although this has less severe forms in humans. However, it is highly dangerous for big marine animals, such as bottlenose dolphins [ 5 , 6 ]. In this case, the source of toxins is another unicellular dinoflagellate microalga Karenia brevis.…”

Section: Introductionmentioning

confidence: 99%

Ladder-Shaped Ion Channel Ligands: Current State of Knowledge

Shmukler

Никишин

2017

Marine Drugs

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Ciguatoxins (CTX) and brevetoxins (BTX) are polycyclic ethereal compounds biosynthesized by the worldwide distributed planktonic and epibenthic dinoflagellates of Gambierdiscus and Karenia genera, correspondingly. Ciguatera, evoked by CTXs, is a type of ichthyosarcotoxism, which involves a variety of gastrointestinal and neurological symptoms, while BTXs cause so-called neurotoxic shellfish poisoning. Both types of toxins are reviewed together because of similar mechanisms of their action. These are the only molecules known to activate voltage-sensitive Na+-channels in mammals through a specific interaction with site 5 of its α-subunit and may compete for it, which results in an increase in neuronal excitability, neurotransmitter release and impairment of synaptic vesicle recycling. Most marine ciguatoxins potentiate Nav channels, but a considerable number of them, such as gambierol and maitotoxin, have been shown to affect another ion channel. Although the extrinsic function of these toxins is probably associated with the function of a feeding deterrent, it was suggested that their intrinsic function is coupled with the regulation of photosynthesis via light-harvesting complex II and thioredoxin. Antagonistic effects of BTXs and brevenal may provide evidence of their participation as positive and negative regulators of this mechanism.

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Immunomodulatory effects of brevetoxin (PbTx-3) upon in vitro exposure in bottlenose dolphins (Tursiops truncatus)

Cited by 14 publications

References 41 publications

Utility of Red Tide (Karenia brevis) Monitoring Data as a Predictive Tool to Estimate Brevetoxin Accumulation in Live, Free-Ranging Marine Mammals

Utility of Red Tide (Karenia brevis) Monitoring Data as a Predictive Tool to Estimate Brevetoxin Accumulation in Live, Free-Ranging Marine Mammals

Marine Biotoxins: Occurrence, Toxicity, Regulatory Limits and Reference Methods

Ladder-Shaped Ion Channel Ligands: Current State of Knowledge

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