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The Selvagens Islands, which are a marine protected area located at the southernmost point of the Portuguese maritime zone, have been associated with fish harboring ciguatoxins (CTX) and linked to ciguatera fish poisonings. This study reports the results of a field sampling campaign carried out in September 2018 in these remote and rarely surveyed islands. Fifty-six fish specimens from different trophic levels were caught for CTX-like toxicity determination by cell-based assay (CBA) and toxin content analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Notably, high toxicity levels were found in fish with an intermediate position in the food web, such as zebra seabream (Diplodus cervinus) and barred hogfish (Bodianus scrofa), reaching levels up to 0.75 µg CTX1B equivalent kg−1. The LC-MS/MS analysis confirmed that C-CTX1 was the main toxin, but discrepancies between CBA and LC-MS/MS in D. cervinus and top predator species, such as the yellowmouth barracuda (Sphyraena viridis) and amberjacks (Seriola spp.), suggest the presence of fish metabolic products, which need to be further elucidated. This study confirms that fish from coastal food webs of the Selvagens Islands represent a high risk of ciguatera, raising important issues for fisheries and environmental management of the Selvagens Islands.
Pedro Reis Costa; Pablo Estévez; Lucía Soliño; David Castro; Susana Margarida Rodrigues; Viriato Timoteo; José Manuel Leao-Martins; Carolina Santos; Neide Gouveia; Jorge Diogène; Ana Gago-Martínez. An Update on Ciguatoxins and CTX-like Toxicity in Fish from Different Trophic Levels of the Selvagens Islands (NE Atlantic, Madeira, Portugal). Toxins 2021, 13, 580 .
AMA StylePedro Reis Costa, Pablo Estévez, Lucía Soliño, David Castro, Susana Margarida Rodrigues, Viriato Timoteo, José Manuel Leao-Martins, Carolina Santos, Neide Gouveia, Jorge Diogène, Ana Gago-Martínez. An Update on Ciguatoxins and CTX-like Toxicity in Fish from Different Trophic Levels of the Selvagens Islands (NE Atlantic, Madeira, Portugal). Toxins. 2021; 13 (8):580.
Chicago/Turabian StylePedro Reis Costa; Pablo Estévez; Lucía Soliño; David Castro; Susana Margarida Rodrigues; Viriato Timoteo; José Manuel Leao-Martins; Carolina Santos; Neide Gouveia; Jorge Diogène; Ana Gago-Martínez. 2021. "An Update on Ciguatoxins and CTX-like Toxicity in Fish from Different Trophic Levels of the Selvagens Islands (NE Atlantic, Madeira, Portugal)." Toxins 13, no. 8: 580.
Dinoflagellate species of the genera Gambierdiscus and Fukuyoa are known to produce ciguatera poisoning-associated toxic compounds, such as ciguatoxins, or other toxins, such as maitotoxins. However, many species and strains remain poorly characterized in areas where they were recently identified, such as the western Mediterranean Sea. In previous studies carried out by our research group, a G. australes strain from the Balearic Islands (Mediterranean Sea) presenting MTX-like activity was characterized by LC-MS/MS and LC-HRMS detecting 44-methyl gambierone and gambieric acids C and D. However, MTX1, which is typically found in some G. australes strains from the Pacific Ocean, was not detected. Therefore, this study focuses on the identification of the compound responsible for the MTX-like toxicity in this strain. The G. australes strain was characterized not only using LC-MS instruments but also N2a-guided HPLC fractionation. Following this approach, several toxic compounds were identified in three fractions by LC-MS/MS and HRMS. A novel MTX analogue, named MTX5, was identified in the most toxic fraction, and 44-methyl gambierone and gambieric acids C and D contributed to the toxicity observed in other fractions of this strain. Thus, G. australes from the Mediterranean Sea produces MTX5 instead of MTX1 in contrast to some strains of the same species from the Pacific Ocean. No CTX precursors were detected, reinforcing the complexity of the identification of CTXs precursors in these regions.
Pablo Estevez; David Castro; José Manuel Leão-Martins; Manoëlla Sibat; Angels Tudó; Robert Dickey; Jorge Diogene; Philipp Hess; Ana Gago-Martinez. Toxicity Screening of a Gambierdiscus australes Strain from the Western Mediterranean Sea and Identification of a Novel Maitotoxin Analogue. Marine Drugs 2021, 19, 460 .
AMA StylePablo Estevez, David Castro, José Manuel Leão-Martins, Manoëlla Sibat, Angels Tudó, Robert Dickey, Jorge Diogene, Philipp Hess, Ana Gago-Martinez. Toxicity Screening of a Gambierdiscus australes Strain from the Western Mediterranean Sea and Identification of a Novel Maitotoxin Analogue. Marine Drugs. 2021; 19 (8):460.
Chicago/Turabian StylePablo Estevez; David Castro; José Manuel Leão-Martins; Manoëlla Sibat; Angels Tudó; Robert Dickey; Jorge Diogene; Philipp Hess; Ana Gago-Martinez. 2021. "Toxicity Screening of a Gambierdiscus australes Strain from the Western Mediterranean Sea and Identification of a Novel Maitotoxin Analogue." Marine Drugs 19, no. 8: 460.
Ciguatoxins (CTXs) are a group of neurotoxins responsible for the syndrome ciguatera fish poisoning (CFP) as a result of the consumption of contaminated fish. The presence of these toxins has been detected around the Pacific, Caribbean and Indian coasts. Recent reports indicate the emergence of CFP in other geographic areas, in particular in European coasts, of the Canary Islands (Spain) and Madeira (Portugal). A neuroblastoma cell line of murine origin (N2a) has been applied to assay different groups of neurotoxins, acting on voltage-gated sodium channel (VGSC) of excitable cells, N2a-MTT. The great potential of N2a-MTT as a sensitive tool for the CTXs screening is clearly recognized, notably because it allows the detection of these toxins at levels below recommended as security levels. However, the complexity of the matrix is a critical point on the application of N2a-MTT, which needs to be evaluated. The aim of this work is to provide recommendations for an implemented N2a-MTT method for CTXs determination in fish that avoids matrix effects, particularly those related to high lipid content.
David Castro; Ronald Manger; Oscar Vilariño; Ana Gago-Martínez. Evaluation of Matrix Issues in the Applicability of the Neuro-2a Cell Based Assay on the Detection of CTX in Fish Samples. Toxins 2020, 12, 308 .
AMA StyleDavid Castro, Ronald Manger, Oscar Vilariño, Ana Gago-Martínez. Evaluation of Matrix Issues in the Applicability of the Neuro-2a Cell Based Assay on the Detection of CTX in Fish Samples. Toxins. 2020; 12 (5):308.
Chicago/Turabian StyleDavid Castro; Ronald Manger; Oscar Vilariño; Ana Gago-Martínez. 2020. "Evaluation of Matrix Issues in the Applicability of the Neuro-2a Cell Based Assay on the Detection of CTX in Fish Samples." Toxins 12, no. 5: 308.
The presence of emerging contaminants in food and the sources of the contamination are relevant issues in food safety. The impact of climate change on these contaminations is a topic widely debated; however, the consequences of climate change for the food system is not as deeply studied as other human and animal health and welfare issues. Projections of climate change in Europe have been evaluated through the EU Commission, and the impact on the marine environment is considered a priority issue. Marine biotoxins are produced by toxic microalgae and are natural contaminants of the marine environment. They are considered to be an important contaminant that needs to be evaluated. Their source is affected by oceanographic and environmental conditions; water temperature, sunlight, salinity, competing microorganisms, nutrients, and wind and current directions affect the growth and proliferation of microalgae. Although climate change should not be the only reason for this increase and other factors such as eutrophication, tourism, fishery activities, etc. could be considered, the influence of climate change has been observed through increased growth of dinoflagellates in areas where they have not been previously detected. An example of this is the recent emergence of ciguatera fish poisoning toxins, typically found in tropical or subtropical areas from the Pacific and Caribbean and in certain areas of the Atlantic Sea such as the Canary Islands (Spain) and Madeira (Portugal). In addition, the recent findings of the presence of tetrodotoxins, typically found in certain areas of the Pacific, are emerging in the EU and contaminating not only the fish species where these toxins had been found before but also bivalve mollusks. The emergence of these marine biotoxins in the EU is a reason for concern in the EU, and for this reason, the risk evaluation and characterization of these toxins are considered a priority for the European Food Safety Authorities (EFSA), which also emphasize the search for occurrence data using reliable and efficient analytical methods.
Pablo Estevez; David Castro; Ana Pequeño-Valtierra; Jorge Giraldez; Ana Gago-Martinez. Emerging Marine Biotoxins in Seafood from European Coasts: Incidence and Analytical Challenges. Foods 2019, 8, 149 .
AMA StylePablo Estevez, David Castro, Ana Pequeño-Valtierra, Jorge Giraldez, Ana Gago-Martinez. Emerging Marine Biotoxins in Seafood from European Coasts: Incidence and Analytical Challenges. Foods. 2019; 8 (5):149.
Chicago/Turabian StylePablo Estevez; David Castro; Ana Pequeño-Valtierra; Jorge Giraldez; Ana Gago-Martinez. 2019. "Emerging Marine Biotoxins in Seafood from European Coasts: Incidence and Analytical Challenges." Foods 8, no. 5: 149.
Ciguatera Fish Poisoning is a worldwide concern caused by the consumption of fish contaminated with ciguatoxins not only in endemic regions in the Pacific Ocean or the Caribbean Sea but also in emerging areas of Macaronesia on the eastern Atlantic. The recent emergence of these toxins in other coastal areas worldwide, prompted the need for the characterization of the risk in these areas. This Ciguatera Fish Poisoning risk has been recently identified as a potential threat in subtropical areas of the Atlantic coast and scientific efforts are being focused in the identification and confirmation of the toxins involved in this potential risk. Neuroblastoma cell assay has been widely used for the evaluation of the toxicity in several marine biotoxin groups, and found to be a very useful tool for toxicity screening. LC-MS/MS has been also used for confirmatory purposes although the main limitation of the advances on LC-MS/MS development is due to commercial unavailability of reference materials and hampers method implementation and validation or even confirmation of the ciguatoxins (CTXs) responsible for the toxic profiles. While neuroblastoma cell assay (N2a) is typically used for toxicity screening as mentioned above, being necessary to confirm this N2a toxicity by LC-MS/MS, this study is designed using N2a as a tool to confirm the toxicity of the fractions obtained corresponding to potential CTXs analogues according to the analysis by LC-MS/MS. With this aim, an amberjack sample (Seriola fasciata) from Selvagen Islads (Portugal) and implicated in Ciguatera Fish Poisoning was analyzed by LC-MS/MS and Caribbean Ciguatoxins were found to be mainly responsible for the toxicity. N2a was used in this work as a tool to help in the confirmation of the toxicity of fractions obtained by HPLC. Caribbean Ciguatoxin-1 was found as the main analogue responsible for the N2a toxicity while three Caribbean Ciguatoxin-1 (C-CTX1) metabolites which contribute to the total toxicity were also identified.
Pablo Estevez; David Castro; Ana Pequeño-Valtierra; José M. Leao; Oscar Vilariño; Jorge Diogène; Ana Gago-Martínez. An Attempt to Characterize the Ciguatoxin Profile in Seriola fasciata Causing Ciguatera Fish Poisoning in Macaronesia. Toxins 2019, 11, 221 .
AMA StylePablo Estevez, David Castro, Ana Pequeño-Valtierra, José M. Leao, Oscar Vilariño, Jorge Diogène, Ana Gago-Martínez. An Attempt to Characterize the Ciguatoxin Profile in Seriola fasciata Causing Ciguatera Fish Poisoning in Macaronesia. Toxins. 2019; 11 (4):221.
Chicago/Turabian StylePablo Estevez; David Castro; Ana Pequeño-Valtierra; José M. Leao; Oscar Vilariño; Jorge Diogène; Ana Gago-Martínez. 2019. "An Attempt to Characterize the Ciguatoxin Profile in Seriola fasciata Causing Ciguatera Fish Poisoning in Macaronesia." Toxins 11, no. 4: 221.
The increased emergence of Ciguatera Fish Poisoning in the Canary Islands and Madeira demanded the development of confirmatory methods by liquid chromatography coupled to tandem mass spectrometry to characterize the risk. Efforts were particularly focused on the optimization of sample pretreatment, especially in the sample cleanup step, to efficiently remove matrix interferences as a critical factor to consider in mass spectrometry detection. Two different LC-MS/MS approaches have been used for confirmation purposes, the first one using the sodium adduct as precursor and product ion to allow an increased sensitivity in the detection, whereas additional fragments were also monitored for further confirmation. The optimized conditions above mentioned allowed the confirmation of Caribbean Ciguatoxin-1 as the main responsible for the samples analyzed from these geographical areas, while the presence of a new hydroxyl metabolite of C-CTX1 was also confirmed in one sample analyzed in this study.
Pablo Estevez; David Castro; J. Manuel Leao; Takeshi Yasumoto; Robert Dickey; Ana Gago-Martinez. Implementation of liquid chromatography tandem mass spectrometry for the analysis of ciguatera fish poisoning in contaminated fish samples from Atlantic coasts. Food Chemistry 2018, 280, 8 -14.
AMA StylePablo Estevez, David Castro, J. Manuel Leao, Takeshi Yasumoto, Robert Dickey, Ana Gago-Martinez. Implementation of liquid chromatography tandem mass spectrometry for the analysis of ciguatera fish poisoning in contaminated fish samples from Atlantic coasts. Food Chemistry. 2018; 280 ():8-14.
Chicago/Turabian StylePablo Estevez; David Castro; J. Manuel Leao; Takeshi Yasumoto; Robert Dickey; Ana Gago-Martinez. 2018. "Implementation of liquid chromatography tandem mass spectrometry for the analysis of ciguatera fish poisoning in contaminated fish samples from Atlantic coasts." Food Chemistry 280, no. : 8-14.
Ciguatoxins (CTXs), endemic from tropical and subtropical regions of the Pacific and Indian Ocean and the Caribbean Sea, have caused several human poisonings during the last decade in Europe. Ciguatera fish poisonings (CFP) in Madeira and Canary Islands appear to be particularly related with consumption of fish caught close to Selvagens Islands, a Portuguese natural reserve composed of three small islands that harbor high fish biomass. In this study, fish specimens considered as potential vectors of CTXs were caught in Madeira and Selvagens archipelagos for toxins determination via sensitive liquid chromatography with tandem mass spectrometry detection (LC–MS/MS). CTXs were found in most of the fish samples from Selvagens and none from Madeira. Caribbean ciguatoxin-1 (C-CTX1) was the only toxin congener determined, reaching the highest value of 0.25 µg C-CTX1 kg−1 in a 4.6 kg island grouper (Mycteroperca fusca). This study indicates that a diversity of fish from different trophic levels contains CTXs, Selvagens appear to be one of the most favorable locations for CTXs food web transfer and finally, this study highlights the need of further research based on intensive environmental and biological sampling on these remote islands.
Pedro Reis Costa; Pablo Estevez; David Castro; Lucía Soliño; Neide Gouveia; Carolina Santos; Susana Margarida Rodrigues; José Manuel Leao; Ana Gago-Martínez. New Insights into the Occurrence and Toxin Profile of Ciguatoxins in Selvagens Islands (Madeira, Portugal). Toxins 2018, 10, 524 .
AMA StylePedro Reis Costa, Pablo Estevez, David Castro, Lucía Soliño, Neide Gouveia, Carolina Santos, Susana Margarida Rodrigues, José Manuel Leao, Ana Gago-Martínez. New Insights into the Occurrence and Toxin Profile of Ciguatoxins in Selvagens Islands (Madeira, Portugal). Toxins. 2018; 10 (12):524.
Chicago/Turabian StylePedro Reis Costa; Pablo Estevez; David Castro; Lucía Soliño; Neide Gouveia; Carolina Santos; Susana Margarida Rodrigues; José Manuel Leao; Ana Gago-Martínez. 2018. "New Insights into the Occurrence and Toxin Profile of Ciguatoxins in Selvagens Islands (Madeira, Portugal)." Toxins 10, no. 12: 524.