RESUMO

Ciguatera Poisoning (CP) is a widespread and complex poisoning syndrome caused by the consumption of fish or invertebrates contaminated with a suite of potent neurotoxins collectively known as ciguatoxins (CTXs), which are produced by certain benthic dinoflagellates species in the genera Gambierdiscus and Fukuyoa. Due to the complex nature of this HAB problem, along with a poor understanding of toxin production and entry in the coral reef food web, the development of monitoring, management, and forecasting approaches for CP has lagged behind those available for other HAB syndromes. Over the past two decades, renewed research on the taxonomy, physiology, and toxicology of CP-causing dinoflagellates has advanced our understanding of the species diversity that exists within these genera, including identification of highly toxic species (so called "superbugs") that likely contribute disproportionately to ciguatoxins entering coral reef food webs. The recent development of approaches for molecular analysis of field samples now provide the means to investigate in situ community composition, enabling characterization of spatio-temporal species dynamics, linkages between toxic species abundance and toxin flux, and the risk of ciguatoxin prevalence in fish. In this study we used species-specific fluorescent in situ hybridization (FISH) probes to investigate Gambierdiscus species composition and dynamics in St. Thomas (USVI) and the Florida Keys (USA) over multiple years (2018-2020). Within each location, samples were collected seasonally from several sites comprising varying depths, habitats, and algal substrates to characterize community structure over small spatial scales and across different host macrophytes. This approach enabled the quantitative determination of communities over spatiotemporal gradients, as well as the selective enumeration of species known to exhibit high toxicity, such as Gambierdiscus silvae. The investigation found differing community structure between St. Thomas and Florida Keys sites, driven in part by differences in the distribution of toxin-producing species G. silvae and G. belizeanus, which were present throughout sampling sites in St. Thomas but scarce or absent in the Florida Keys. This finding is significant given the high toxicity of G. silvae, and may help explain differences in fish toxicity and CP incidence between St. Thomas and Florida. Intrasite comparisons along a depth gradient found higher concentrations of Gambierdiscus spp. at deeper locations. Among the macrophytes sampled, Dictyota may be a likely vector for toxin transfer based on their widespread distribution, apparent colonization by G. silvae, and palatability to at least some herbivore grazers. Given its ubiquity throughout both study regions and sites, this taxa may also serve as a refuge, accumulating high concentrations of Gambierdiscus and other benthic dinoflagellates, which in turn can serve as source populations for highly palatable and ephemeral habitats nearby, such as turf algae. These studies further demonstrate the successful application of FISH probes in examining biogeographic structuring of Gambierdiscus communities, targeting individual toxin-producing species, and characterizing species-level dynamics that are needed to describe and model ecological drivers of species abundance and toxicity.

Assuntos

Ciguatera , Ciguatoxinas , Dinoflagellida , Ciguatoxinas/toxicidade , Florida , Hibridização in Situ Fluorescente , Ilhas Virgens Americanas

RESUMO

Ciguatera, a global issue, lacks adequate capacity for ciguatoxin analysis in most affected countries. The Caribbean region, known for its endemic ciguatera and being home to a majority of the global small island developing states, particularly needs established methods for ciguatoxin detection in seafood and the environment. The radioligand receptor binding assay (r-RBA) is among the in vitro bioassays currently used for ciguatoxin analysis; however, similarly to the other chemical-based or bioassays that have been developed, it faces challenges due to limited standards and interlaboratory comparisons. This work presents a single laboratory validation of an r-RBA developed in a Cuban laboratory while characterizing the performance of the liquid scintillation counter instrument as a key external parameter. The results obtained show the assay is precise, accurate and robust, confirming its potential as a routine screening method for the detection and quantification of ciguatoxins. The new method will aid in identifying high-risk ciguatoxic fish in Cuba and the Caribbean region, supporting monitoring and scientific management of ciguatera and the development of early warning systems to enhance food safety and food security, and promote fair trade fisheries.

Assuntos

Ciguatera , Ciguatoxinas , Animais , Ciguatoxinas/análise , Ciguatera/diagnóstico , Peixes , Ligação Proteica , Bioensaio

RESUMO

Ciguatera poisoning (CP) is one of the most common causes worldwide of marine poisoning associated with fish consumption from tropical areas. Its incidence is underreported. CP cases seem to increase with grouped cases reported during summer. Exposure to ciguatoxins, toxins responsible for CP with sodium-channel agonistic, voltage-gated potassium channel blocking, cholinergic, and adrenergic activities, may result in a large spectrum of manifestations. We aimed to describe the clinical characteristics, management, and outcome of CP in Martinique, French West Indies. We conducted an observational retrospective single-center study during six years (October 2012 to September 2018) including all CP patients managed by the prehospital medical services, admitted to the university hospital emergency department, or declared to the regional health agency. A total of 149 CP patients (81 females/63 males; median age, 46 years (interquartile range, 34-61)) were included. Acute features consisted in general (91%; mainly, myalgia pruritus, and asthenia), gastrointestinal (90%; mainly diarrhea, abdominal pain, and nausea), neurological (72%; mainly, paresthesia, dysgeusia, and impairment of hot/cold feeling), and cardiovascular manifestations (22%; bradycardia, hypotension, and heart conduction disorders). Management was supportive. No patient died but symptoms persisted in 40% of the 77 patients with follow-up at day 15. CP was mainly attributed to the ingestion of trevallies (59%), snappers (13%), and king mackerels (8%) with collective contaminations (71%). Unusual fish (tuna, salmon, and spider conchs) were suspected in rare cases. Ingestion of trevallies was associated with significantly higher persistent symptoms (odds ratio, 3.00; 95% confidence interval, (1.20-8.00); p = 0.03). CP incidence was 0.67 cases per 10,000 patient-years in Martinique over the study period. To conclude, CP represents an increasing public health issue in Martinique, as is the case in other Caribbean islands. Patients present usual but possibly life-threatening features. Outcome is excellent despite frequently prolonged manifestations.

Assuntos

Ciguatera , Ciguatoxinas , Animais , Ciguatera/epidemiologia , Ciguatoxinas/toxicidade , Feminino , Peixes , Humanos , Masculino , Martinica/epidemiologia , Estudos Retrospectivos , Índias Ocidentais

RESUMO

Ciguatera poisoning is a food intoxication associated with the consumption of fish or shellfish contaminated, through trophic transfer, with ciguatoxins (CTXs). In this study, we developed an experimental model to assess the trophic transfer of CTXs from herbivorous parrotfish, Chlorurus microrhinos, to carnivorous lionfish, Pterois volitans. During a 6-week period, juvenile lionfish were fed naturally contaminated parrotfish fillets at a daily dose of 0.11 or 0.035 ng CTX3C equiv. g-1, as measured by the radioligand-receptor binding assay (r-RBA) or neuroblastoma cell-based assay (CBA-N2a), respectively. During an additional 6-week depuration period, the remaining fish were fed a CTX-free diet. Using r-RBA, no CTXs were detectable in muscular tissues, whereas CTXs were measured in the livers of two out of nine fish sampled during exposure, and in four out of eight fish sampled during depuration. Timepoint pooled liver samples, as analyzed by CBA-N2a, confirmed the accumulation of CTXs in liver tissues, reaching 0.89 ng CTX3C equiv. g-1 after 41 days of exposure, followed by slow toxin elimination, with 0.37 ng CTX3C equiv. g-1 measured after the 6-week depuration. These preliminary results, which need to be pursued in adult lionfish, strengthen our knowledge on CTX transfer and kinetics along the food web.

Assuntos

Ciguatoxinas/metabolismo , Peixes/metabolismo , Cadeia Alimentar , Animais , Bioacumulação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ciguatoxinas/toxicidade , Fígado/metabolismo , Camundongos , Músculos/metabolismo

RESUMO

Ciguatera poisoning (CP) poses a significant threat to ecosystem services and fishery resources in coastal communities. The CP-causative ciguatoxins (CTXs) are produced by benthic dinoflagellates including Gambierdiscus and Fukuyoa spp., and enter reef food webs via grazing on macroalgal substrates. In this study, we report on a 3-year monthly time series in St. Thomas, US Virgin Islands where Gambierdiscus spp. abundance and Caribbean-CTX toxicity in benthic samples were compared to key environmental factors, including temperature, salinity, nutrients, benthic cover, and physical data. We found that peak Gambierdiscus abundance occurred in summer while CTX-specific toxicity peaked in cooler months (February-May) when the mean water temperatures were approximately 26-28 °C. These trends were most evident at deeper offshore sites where macroalgal cover was highest year-round. Other environmental parameters were not correlated with the CTX variability observed over time. The asynchrony between Gambierdiscus spp. abundance and toxicity reflects potential differences in toxin cell quotas among Gambierdiscus species with concomitant variability in their abundances throughout the year. These results have significant implications for monitoring and management of benthic harmful algal blooms and highlights potential seasonal and highly-localized pulses in reef toxin loads that may be transferred to higher trophic levels.

Assuntos

Ciguatoxinas/análise , Dinoflagellida , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ciguatera , Ciguatoxinas/toxicidade , Monitoramento Ambiental , Camundongos , Salinidade , Estações do Ano , Ilhas Virgens Americanas , Tempo (Meteorologia)

RESUMO

In Cuba, ciguatera poisoning associated with fish consumption is the most commonly occurring non-bacterial seafood-borne illness. Risk management through fish market regulation has existed in Cuba for decades and consists of bans on selected species above a certain weight; however, the actual occurrence of ciguatoxins (CTXs) in seafood has never been verified. From this food safety risk management perspective, a study site locally known to be at risk for ciguatera was selected. Analysis of the epiphytic dinoflagellate community identified the microalga Gambierdiscus. Gambierdiscus species included six of the seven species known to be present in Cuba (G. caribaeus, G. belizeanus, G. carpenteri, G. carolinianus, G. silvae, and F. ruetzleri). CTX-like activity in invertebrates, herbivorous and carnivorous fishes were analyzed with a radioligand receptor-binding assay and, for selected samples, with the N2A cell cytotoxicity assay. CTX activity was found in 80% of the organisms sampled, with toxin values ranging from 2 to 8 ng CTX3C equivalents g-1 tissue. Data analysis further confirmed CTXs trophic magnification. This study constitutes the first finding of CTX-like activity in marine organisms in Cuba and in herbivorous fish in the Caribbean. Elucidating the structure-activity relationship and toxicology of CTX from the Caribbean is needed before conclusions may be drawn about risk exposure in Cuba and the wider Caribbean.

Assuntos

Ciguatoxinas/análise , Ciguatoxinas/toxicidade , Contaminação de Alimentos/análise , Animais , Recifes de Corais , Cuba , Dinoflagellida , Peixes , Cadeia Alimentar , Invertebrados , Medição de Risco

RESUMO

Ciguatoxins are algal toxins responsible for tens of thousands of human intoxications yearly, both in tropical and subtropical endemic regions as well as worldwide through fish exportation. Previously developed methods for biotoxin surveillance in the environment and seafood include analytical methods and in vivo and in vitro bioassays. The radioligand receptor binding assay (r-RBA) is among the in vitro methodologies currently used for the detection and quantification of marine biotoxins. For the ciguatoxin group, the r-RBA has been widely used as a means to characterize the mode of action and as detection method in various biological matrices. Yet, screening methods have not been standardized, and the details of the ciguatoxin-specific r-RBA are not well-documented, which limit interlaboratory comparison and progress toward method validation. This work presents the development of an optimized r-RBA for ciguatoxins and provides guidance on its use and quality control checks for analysis of environmental samples. We focus on the analysis of critical parameters involved in determining assay acceptability. Calculation of toxin concentrations in fish samples is illustrated with four examples. Thus, this paper provides the detailed information required for a full validation of the r-RBA, a necessary step toward the development and implementation of a regulatory monitoring programme for ciguatoxins in seafood products using the r-RBA.

Assuntos

Ciguatoxinas/análise , Monitoramento Ambiental/métodos , Ensaio Radioligante/métodos , Poluentes da Água/análise

RESUMO

Ciguatera fish poisoning is a seafood-toxin illness resulting from consumption of fish contaminated with ciguatoxins. Managing ciguatera fish poisoning is complex. It is made easier, however, by local fishers from endemic areas reporting regional predictability for local fish species' ciguatera fish poisoning risk, which the present study then tested. We investigated the prevalence of ciguatoxins in 4 commonly marketed and consumed species (Balistes vetula, Haemulon plumierii, Ocyurus chrysurus, and Epinephelus guttatus) across an oceanic gradient (north, south, east, and west) from the US Virgin Islands. Fish muscle extracts were analyzed for Caribbean ciguatoxins using an in vitro mouse neuroblastoma (N2a) cytotoxicity assay and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fish collected from the north location had 0 fish with detectable ciguatoxins; this site also had the greatest wave energy. Caribbean ciguatoxins in fish ranged from 0.01 to 0.11, 0.004 to 0.10, and 0.005 to 0.18 ng Caribbean ciguatoxin-1 eq/g, from the west, east, and south respectively. Ciguatoxin-like activity was detectable by the N2a assay in 40, 41, 50, and 70% of H. plumierii, O. chrysurus, B. vetula, and E. guttatus, respectively. Of the fish collected, 4% had Caribbean ciguatoxin levels exceeding the US Food and Drug Administration guidance of 0.1 ng Caribbean ciguatoxin-1 eq/g fish. These findings concurred with spatial ciguatera fish poisoning prevalence information provided by local fishers in the US Virgin Islands and demonstrate how partnerships between researchers and fishers can aid the improvement of science-based ciguatera fish poisoning management. Environ Toxicol Chem 2018;39:1852-1863. Published 2018 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Assuntos

Ciguatoxinas/análise , Exposição Ambiental/análise , Oceanos e Mares , Perciformes/metabolismo , Animais , Tamanho Corporal , Peso Corporal , Região do Caribe , Linhagem Celular , Cromatografia Líquida , Camundongos , Músculos/química , Ilhas Virgens Americanas

RESUMO

This retrospective case study analysed the incidence and symptoms of ciguatera fish poisoning (ciguatera) in Guadeloupe (French West Indies) between 2013 and 2016. Cases attending the emergency departments of the two public hospitals and the reports received by the regional health authority in charge of monitoring (ARS) were compiled. Two hundred and thirty-four cases of poisoning were observed, with a mean annual incidence of 1.47/10,000 (95% CI): 1.29-1.66), i.e 5 times higher than the previously reported incidence (1996-2006). The main species described as being responsible for poisoning were fish from the Carangidae family (n = 47) (jack), followed by fish from the Lutjanidae family (n = 27) (snapper), Serranidae family (n = 15) (grouper), Sphyraenidae family (n = 12) (barracuda), and Mullidae family (n = 12) (goatfish). One case of lionfish ciguatera was observed. 93.9% of patients experienced gastrointestinal symptoms, 76.0% presented neurological signs (mainly paresthesia, dysesthesia and pruritus) and 40.3% presented cardiovascular symptoms (bradycardia and/or hypotension). A high frequency (61.4%) of hypothermia (body temperature <36.5 °C) was observed. This study reports for the first time the relatively high frequency of cardiac symptoms and low body temperature. The monitoring of ciguatera poisoning throughout the Caribbean region must be improved, notably after reef disturbance due to Irma and Maria major cyclones.

Assuntos

Ciguatera/epidemiologia , Ciguatera/fisiopatologia , Animais , Região do Caribe , Ciguatoxinas/análise , Peixes , Guadalupe , Humanos , Incidência , Perciformes , Estudos Retrospectivos , Alimentos Marinhos/análise , Índias Ocidentais

RESUMO

Historical records of ciguatera in Mexico date back to 1862. This review, including references and epidemiological reports, documents 464 cases during 25 events from 1984 to 2013: 240 (51.72%) in Baja California Sur, 163 (35.12%) in Quintana Roo, 45 (9.69%) in Yucatan, and 16 (3.44%) cases of Mexican tourists intoxicated in Cuba. Carnivorous fish, such as snapper (Lutjanus) and grouper (Epinephelus and Mycteroperca) in the Pacific Ocean, and great barracuda (Sphyraena barracuda) and snapper (Lutjanus) in the Atlantic (Gulf of Mexico and Caribbean Sea), were involved in all cases. In the Mexican Caribbean, a sub-record of ciguatera cases that occurred before 1984 exists. However, the number of intoxications has increased in recent years, and this food poisoning is poorly studied in the region. Current records suggest that ciguatera fish poisoning in humans is the second most prevalent form of seafood poisoning in Mexico, only exceeded by paralytic shellfish poisoning (505 cases, 21 fatalities in the same 34-year period). In this study, the status of ciguatera in Mexico (epidemiological and treatment), and the fish vectors are reviewed. Dinoflagellate species Gambierdiscus, Ostreopsis, and Prorocentrum are related with the reported outbreaks, marine toxins, ecological risk, and the potential toxicological impact.

Assuntos

Ciguatera/epidemiologia , Ciguatoxinas/química , Animais , Peixes , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , México/epidemiologia , Alimentos Marinhos/análise

RESUMO

Dinoflagellate species belonging to the genera Gambierdiscus and Fukuyoa produce ciguatoxins (CTXs), potent neurotoxins that concentrate in fish causing ciguatera fish poisoning (CFP) in humans. While the structures and toxicities of ciguatoxins isolated from fish in the Pacific and Caribbean are known, there are few data on the variation in toxicity between and among species of Gambierdiscus and Fukuyoa. Quantifying the differences in species-specific toxicity is especially important to developing an effective cell-based risk assessment strategy for CFP. This study analyzed the ciguatoxicity of 33 strains representing seven Gambierdiscus and one Fukuyoa species using a cell based Neuro-2a cytotoxicity assay. All strains were isolated from either the Caribbean or Gulf of Mexico. The average toxicity of each species was inversely proportional to growth rate, suggesting an evolutionary trade-off between an investment in growth versus the production of defensive compounds. While there is 2- to 27-fold variation in toxicity within species, there was a 1740-fold difference between the least and most toxic species. Consequently, production of CTX or CTX-like compounds is more dependent on the species present than on the random occurrence of high or low toxicity strains. Seven of the eight species tested (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, Gambierdiscus ribotype 2, G. silvae and F. ruetzleri) exhibited low toxicities, ranging from 0 to 24.5 fg CTX3C equivalents cell-1, relative to G. excentricus, which had a toxicity of 469 fg CTX3C eq. cell-1. Isolates of G. excentricus from other regions have shown similarly high toxicities. If the hypothesis that G. excentricus is the primary source of ciguatoxins in the Atlantic is confirmed, it should be possible to identify areas where CFP risk is greatest by monitoring only G. excentricus abundance using species-specific molecular assays.

Assuntos

Ciguatoxinas/toxicidade , Dinoflagellida/química , Análise de Variância , Animais , Região do Caribe , Linhagem Celular , Golfo do México , Camundongos , Especificidade da Espécie , Testes de Toxicidade

RESUMO

Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area.

Assuntos

Dinoflagellida/química , Toxinas Marinhas/química , Toxinas Marinhas/toxicidade , Oxocinas/química , Oxocinas/toxicidade , Animais , Bioensaio/métodos , Brasil , Região do Caribe , Linhagem Celular Tumoral , Ciguatera/genética , Ciguatera/parasitologia , Ciguatoxinas/toxicidade , Camundongos , Filogenia , Espanha , Especificidade da Espécie

RESUMO

From 2010 to 2012, 35 ciguatera fish poisoning (CFP) events involving 87 individuals who consumed locally-caught fish were reported in Guadeloupe (French West Indies). For 12 of these events, the presence of ciguatoxins (CTXs) was indicated in meal remnants and in uncooked fish by the mouse bioassay (MBA). Caribbean ciguatoxins (C-CTXs) were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Using a cell-based assay (CBA), and the only available standard Pacific ciguatoxin-1 (P-CTX-1), the lowest toxins level detected in fish samples causing CFP was 0.022 µg P-CTX-1 equivalent (eq.)·kg(-1) fish. Epidemiological and consumption data were compiled for most of the individuals afflicted, and complete data for establishing the lowest observable adverse effects level (LOAEL) were obtained from 8 CFP events involving 21 individuals. Based on toxin intakes, the LOAEL was estimated at 4.2 ng P-CTX-1 eq./individual corresponding to 48. 4 pg P-CTX-1 eq.kg(-1) body weight (bw). Although based on limited data, these results are consistent with the conclusions of the European Food Safety Authority (EFSA) opinion which indicates that a level of 0.01 µg P-CTX-1 eq.kg(-1) fish, regardless of source, should not exert effects in sensitive individuals when consuming a single meal. The calculated LOAEL is also consistent with the U.S. Food and Drug Administration guidance levels for CTXs (0.1 µg C-CTX-1 eq.kg(-1) and 0.01 µg P-CTX-1 eq.kg(-1) fish).

Assuntos

Ciguatera/induzido quimicamente , Ciguatoxinas/análise , Ciguatoxinas/toxicidade , Peixes/metabolismo , Alimentos Marinhos/análise , Alimentos Marinhos/toxicidade , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ciguatera/epidemiologia , Relação Dose-Resposta a Droga , Guadalupe , Humanos , Masculino , Camundongos , Testes de Toxicidade/métodos

RESUMO

Lionfish (Pterois spp.) are invasive species that have recently spread throughout the Caribbean. Lionfish are available for purchase in local markets for human consumption in several islands of the region. We examined the prevalence of ciguatoxins (CTXs) in lionfish from the French Antilles, a ciguatera-endemic region. The neuroblastoma-2a (N2a) cell assay was used to assess composite cytotoxicity in 120 fish samples collected from the surrounding waters of Guadeloupe (n = 60), Saint Barthélemy Islands (n = 55) and Saint Martin (n = 5). Twenty-seven of these samples exhibited CTX-like activity by the N2a assay. Ciguatoxin (CTX) was confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple samples that presented highest composite toxicity levels by N2a. Those fish found to contain CTXs were all from Saint Barthélemy. Lionfish from Guadeloupe and Saint Martin did not exhibit toxin activity, although the sample size from Saint Martin was insufficient to draw any conclusions as to the incidence of CTXs. In this study, we provide information about the potential hazard of ciguatera associated with the consumption of lionfish from known endemic areas. We also demonstrate the utility of the cell-based assay combined with LC-MS/MS to assess activity and to provide structural confirmation of CTXs respectively.

Assuntos

Ciguatera/epidemiologia , Ciguatoxinas/análise , Ciguatoxinas/toxicidade , Contaminação de Alimentos/análise , Toxinas Marinhas/análise , Toxinas Marinhas/toxicidade , Perciformes , Animais , Região do Caribe/epidemiologia , Guadalupe/epidemiologia , Humanos , Incidência , Prevalência , Índias Ocidentais/epidemiologia

RESUMO

Invasive Indo-Pacific lionfish (Pterois volitans) have rapidly expanded in the Western Atlantic over the past decade and have had a significant negative impact on reef fish biodiversity, habitat, and community structure, with lionfish out-competing native predators for resources. In an effort to reduce this population explosion, lionfish have been promoted for human consumption in the greater Caribbean region. This study examined whether the geographical expansion of the lionfish into a known ciguatera-endemic region can pose a human health threat for ciguatera fish poisoning (CFP). More than 180 lionfish were collected from waters surrounding the US Virgin Islands throughout 2010 and 2011. Ciguatoxin testing included an in vitro neuroblastoma cytotoxicity assay for composite toxicity assessment of sodium-channel toxins combined with confirmatory liquid chromatography tandem mass spectrometry. A 12% prevalence rate of ciguatoxic lionfish exceeding the FDA guidance level of 0.1 µg/kg C-CTX-1 equivalents was identified in fish from the U.S. Virgin Islands, highlighting a potential consumption risk in this region. This study presents the first evidence that the invasive lionfish, pose a direct human health risk for CFP and highlights the need for awareness and research on this food safety hazard in known endemic areas.

Assuntos

Ciguatera/epidemiologia , Peixes/fisiologia , Biologia Marinha , Alimentos Marinhos/efeitos adversos , Animais , Oceano Atlântico , Biodiversidade , Região do Caribe , Cromatografia Líquida de Alta Pressão , Ciguatoxinas/química , Ecossistema , Inocuidade dos Alimentos , Humanos , Indicadores e Reagentes , Toxinas Marinhas/toxicidade , Carne/análise , Carne/toxicidade , Neuroblastoma/patologia , Comportamento Predatório , Bloqueadores dos Canais de Sódio/toxicidade , Espectrometria de Massas em Tandem , Testes de Toxicidade , Ilhas Virgens Americanas

RESUMO

Ciguatera in humans is typically caused by the consumption of reef fish that have accumulated Ciguatoxins (CTXs) in their flesh. Over a six month period, we captured 38 wild adult great barracuda (Sphyraena barracuda), a species commonly associated with ciguatera in The Bahamas. We sampled three tissues (i.e., muscle, liver, and blood) and analysed them for the presence of ciguatoxins using a functional in vitro N2A bioassay. Detectable concentrations of ciguatoxins found in the three tissue types ranged from 2.51 to 211.74pg C-CTX-1 equivalents/g. Blood and liver toxin concentrations were positively correlated (ρ=0.86, P=0.003), indicating that, for the first time, blood sampling provides a non-lethal method of detecting ciguatoxin in wild fish. Non-lethal blood sampling also presents opportunities to couple this approach with biotelemetry and biologging techniques that enable the study of fish distribution and movement. To demonstrate the potential for linking ciguatoxin occurrence with barracuda spatial ecology, we also present a proof-of-concept case study where blood samples were obtained from 20 fish before releasing them with acoustic transmitters and tracking them in the coastal waters using a fixed acoustic telemetry array covering 44km(2). Fish that tested positive for CTX may have smaller home ranges than non-toxic fish (median distance travelled, U=2.21, P=0.03). Results presented from this study may help identify high risk areas and source-sink dynamics of toxins, potentially reducing the incidence and human health risk of ciguatera fish poisoning. Moreover, development of the non-lethal sampling approach and measurement of ciguatera from blood provide future opportunities to understand the mechanistic relationship between toxins and the spatial ecology of a broad range of marine fish species.

Assuntos

Comportamento Animal , Coleta de Amostras Sanguíneas/métodos , Ciguatoxinas/sangue , Monitoramento Ambiental/métodos , Peixes/fisiologia , Telemetria/métodos , Acústica , Animais , Bahamas , Fígado/química , Músculos/química , Estações do Ano , Estatísticas não Paramétricas

Assuntos

Ciguatera/diagnóstico , Transtornos Neurológicos da Marcha/etiologia , Alimentos Marinhos/efeitos adversos , Animais , Canadá/etnologia , Chile , Ciguatera/fisiopatologia , Ciguatoxinas/efeitos adversos , Ciguatoxinas/química , Dinoflagellida/química , Etanol/efeitos adversos , Feminino , Peixes , Humanos , Paris , Recidiva , Bloqueadores dos Canais de Sódio/efeitos adversos , Bloqueadores dos Canais de Sódio/química , Viagem , Adulto Jovem

RESUMO

Algunos dinoflagelados de hábitos bénticos están relacionados con la ciguatera, por consumo de pescado, en áreas tropicales. En el Caribe mexicano la ciguatera es un padecimiento relativamente común, sin embargo solo existe un trabajo sobre este tema y muy pocos antecedentes publicados sobre fitoplancton y microalgas bénticas. En este estudio se analizó material recolectado en varios puntos a lo largo de las costas del Estado de Quintana Roo, tanto con red de fitoplancton (54 mm), como de sedimento y epífitas de plantas macroscópicas, para estudiar los dinoflagelados tóxicos y asociados. Se registra la presencia de tres especies del género Gambierdiscus, asociadas con la producción de toxinas causantes de la ciguatera: G. belizeanus, G. toxicus y G. yasumotoi, todas distribuídas en áreas costeras poco profundas, incluyendo lagunas costeras. Las especies han sido estudiadas con microscopía de luz y electrónica de barrido. Para el reconocimiento de las especies se emplearon los caracteres morfológicos usuales, pero eventualmente se pueden usar caracteres fisiológicos, ecológicos y moleculares. La llamada "comunidad ciguatoxigénica" también está formada por especies de los géneros Prorocentrum, Ostreopsis y Coolia, cuyo estudio florístico y taxonómico se recomienda ampliamente, así como investigaciones complementarias de aspectos biológicos, ecológicos, fisiológicos y epidemiológicos de esta comunidad

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Some dinoflagellates with benthic habits are related to ciguatera intoxication by fish consumption, especially in tropical areas. In the Mexican Caribbean, ciguatera is relatively common, but only one paper seems to have been published on the subject, and there are very few publicactions on phytoplankton and benthic microalgae. Material collected along the coast of the State of Quintana Roo with phytoplankton net (54 mm) and directly from sediment and epiphytes of macroscopic plants, was searched for toxic and other associated dinoflagellates. Samples were studied by light and scanning electron microscopy. Morphological characters were useful for species identification, but eventually physiological, ecological and molecular characters could also be used. Three species of Gambierdiscus, related to the production of ciguatera toxins, were identified: G. belizeanus, G. toxicus and G. yasumotoi. They are distributed in shallow coastal areas, including coastal lagoons

Assuntos

Animais , Ciguatera , Ciguatoxinas/metabolismo , Dinoflagellida/classificação , Contagem de Células , Região do Caribe/epidemiologia , Ciguatera/epidemiologia , Ciguatoxinas/toxicidade , Dinoflagellida/metabolismo , Dinoflagellida/ultraestrutura , Ecossistema , México/epidemiologia , Fitoplâncton/classificação , Fitoplâncton/metabolismo , Fitoplâncton/ultraestrutura

RESUMO

La región costera del Pacífico de Centro y Norte America ha sido afectada de manera frecuente por fenómenos que se denominan proliferaciones algales nocivas o en inglés, "Harmful Algal Blooms" (HAB). A pesar de la gran cantidad de efectos en la salud pública, las actividades económicas y el medio ambiente, aún existe una abrumadora carencia de información en el tema. Esto no permite establecer si las causas principales de este evidente aumento en el número e intensidad de los eventos son naturales o antropogénicas. La incrementada utilización de las zonas costeras para actividades humanas encuentra paralelo en el denominado cambio climático, lo que dificulta discriminar entre la posible influencia de estos dos fenómenos. Series de datos de larga duración en regiones reducidas, así como las observaciones esporádicas realizadas cuando se presenta algún evento, nos permite comparar regímenes climáticos, condiciones geográficas, disponibilidad de nutrientes (incluyendo la eutroficación) y parámetros oceanográficos que promueven o permiten el desarrollo y mantenimiento de las proliferaciones, haciendo evidentes cambios drásticos en la biodiversidad y la biogeografía de los organismos productores de HAB

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The Pacific coast of Central and North America has long been and still is impacted by the flourishing of microalgal populations known as Harmful Algal Blooms (HABs). The organisms that have caused recent HABs episodes in the region are among others, Gymnodinium catenatum, Pyrodinium bahamense var. compressum, and recently Cochlodinium cf. catenatum. In spite of the accumulated effects on the human health, the economic activities and the environment, scarce information is available on the subject. The augmented use of coastal zones for human activities is also paralleled by increased awareness of global climate changes. Thus, it is not an easy task to discriminate anthropogenic or natural phenomena, or both, as the major driving forces. The long-term data sets available for limited regions, as well as some sporadic observations during notorious blooms, allowed us to discriminate major changes in the biodiversity and biogeography of HAB organisms. Main changes refer to number of events, covered area, duration and frequency, number of blooming species and appearance of not previously reported harmful taxa. The variables more clearly related to these dynamic phenomena, seems to be sea surface temperature and wind force, but it is not yet possible to weight their contributions. The participation of rain is not fully evaluated to date. The collaborative communication among small-budget monitoring operations in the region allowed to "pass the voice" about peaking concentrations of HAB organisms, diminishing the risk of poisoning

Assuntos

Humanos , Animais , Dinoflagellida/crescimento & desenvolvimento , Monitoramento Ambiental , Eutrofização , Toxinas Marinhas/toxicidade , América Central/epidemiologia , Ciguatera/epidemiologia , Ciguatoxinas/toxicidade , Conservação dos Recursos Naturais/tendências , Ecossistema , América do Norte/epidemiologia , Oceano Pacífico , Densidade Demográfica , Dinâmica Populacional , Saxitoxina/toxicidade , Clima Tropical

RESUMO

Analyses of ciguatoxicity in the great barracuda Sphyraena barracuda and quantity of toxic benthic dinoflagellates on coastal reefs (correlated with the number of cases of human ciguatera intoxications in Puerto Rico) were used to construct a model formulated on data obtained during the period of 1985-1988. The validity of the proposed model has been questioned by recent data obtained during the period of 1990-2000. Barracuda ciguatoxicity no longer showed a prominent seasonality while the fraction of randomly caught barracuda that were ciguatoxic significantly increased during this period. These two changes, accompanied by the discovery that ciguatoxic fish contained a variety of multiple toxins, appear to be correlated with the steadily increasing periods of elevated sea surface temperatures in this region

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Pruebas de ciguatoxicidad en la gran barracuda, Sphyraena barracuda y la cantidad de dinoflagelados bentónicos tóxicos en los arrecifes de la costa están correlacionados con el número de casos de intoxicaciones por ciguatera en humanos, en Puerto Rico. Estos hechos fueron utilizados para construir un modelo que fue formulado con la información recopilada durante el período de 1985- 1988. La validez de este modelo propuesto ha sido cuestionada debido a la información recientemente obtenida durante el período 1990-2000. La ciguatoxicidad en la barracuda ya no demostraba una marcada asociación con las temporadas mientras que la cantidad de barracuda ciguatóxica capturada al azar tuvo un aumento significativo durante este período. Estos dos cambios estuvieron acompañados por el descubrimiento de que peces ciguatóxicos contienen una gran variedad de toxinas que parecen estar relacionadas con los períodos de elevadas temperaturas en la superficie del mar. Estas temperaturas continúan aumentando de manera que a su vez continúan en un aumento estable en esta región

Assuntos

Humanos , Animais , Ciguatera/epidemiologia , Ciguatoxinas/análise , Dinoflagellida/isolamento & purificação , Eutrofização , Peixes Venenosos , Estações do Ano , Região do Caribe/epidemiologia , Distribuição Aleatória , Água do Mar/análise , Temperatura , Fatores de Tempo