1
|
Kobayashi M, Masuda J, Oshiro N. Detection of Extremely Low Level Ciguatoxins through Monitoring of Lithium Adduct Ions by Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry. Toxins (Basel) 2024; 16:170. [PMID: 38668595 PMCID: PMC11053878 DOI: 10.3390/toxins16040170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 03/19/2024] [Accepted: 03/21/2024] [Indexed: 04/29/2024] Open
Abstract
Ciguatera poisoning (CP) is the most common type of marine biotoxin food poisoning worldwide, and it is caused by ciguatoxins (CTXs), thermostable polyether toxins produced by dinoflagellate Gambierdiscus and Fukuyoa spp. It is typically caused by the consumption of large fish high on the food chain that have accumulated CTXs in their flesh. CTXs in trace amounts are found in natural samples, and they mainly induce neurotoxic effects in consumers at concentrations as low as 0.2 µg/kg. The U.S. Food and Drug Administration has established CTX maximum permitted levels of 0.01 µg/kg for CTX1B and 0.1 µg/kg for C-CTX1 based on toxicological data. More than 20 variants of the CTX1B and CTX3C series have been identified, and the simultaneous detection of trace amounts of CTX analogs has recently been required. Previously published works using LC-MS/MS achieved the safety levels by monitoring the sodium adduct ions of CTXs ([M+Na]+ > [M+Na]+). In this study, we optimized a highly sensitive method for the detection of CTXs using the sodium or lithium adducts, [M+Na]+ or [M+Li]+, by adding alkali metals such as Na+ or Li+ to the mobile phase. This work demonstrates that CTXs can be successfully detected at the low concentrations recommended by the FDA with good chromatographic separation using LC-MS/MS. It also reports on the method's new analytical conditions and accuracy using [M+Li]+.
Collapse
Affiliation(s)
- Manami Kobayashi
- Shimadzu Corporation, 3-25-40, Tonomachi, Kawasaki-Ku, Kawasaki 210-0821, Kanagawa, Japan;
| | - Junichi Masuda
- Shimadzu Corporation, 3-25-40, Tonomachi, Kawasaki-Ku, Kawasaki 210-0821, Kanagawa, Japan;
| | - Naomasa Oshiro
- Division of Biomedical Food Research, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-Ku, Kawasaki 210-9501, Kanagawa, Japan;
| |
Collapse
|
2
|
Parsons ML, Richlen ML, Smith TB, Anderson DM, Abram AL, Erdner DL, Robertson A. CiguaMOD I: A conceptual model of ciguatoxin loading in the Greater Caribbean Region. HARMFUL ALGAE 2024; 131:102561. [PMID: 38212086 PMCID: PMC10784636 DOI: 10.1016/j.hal.2023.102561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/01/2023] [Accepted: 12/18/2023] [Indexed: 01/13/2024]
Abstract
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.
Collapse
Affiliation(s)
- Michael L Parsons
- The Water School, Florida Gulf Coast University, 10501 FGCU Blvd South, Fort Myers, FL 33965, USA.
| | - Mindy L Richlen
- Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Tyler B Smith
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, US Virgin Islands 00802, USA
| | - Donald M Anderson
- Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Ashley L Abram
- The Water School, Florida Gulf Coast University, 10501 FGCU Blvd South, Fort Myers, FL 33965, USA
| | - Deana L Erdner
- University of Texas Marine Science Institute, Port Aransas, TX 78373, USA
| | - Alison Robertson
- School of Marine and Environmental Sciences, University of South Alabama, Mobile, AL 36688, USA; Dauphin Island Sea Lab, Dauphin Island, AL 36528, USA
| |
Collapse
|
3
|
Clausing RJ, Ben Gharbia H, Sdiri K, Sibat M, Rañada-Mestizo ML, Lavenu L, Hess P, Chinain M, Bottein MYD. Tissue Distribution and Metabolization of Ciguatoxins in an Herbivorous Fish following Experimental Dietary Exposure to Gambierdiscus polynesiensis. Mar Drugs 2023; 22:14. [PMID: 38248639 PMCID: PMC10817614 DOI: 10.3390/md22010014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/23/2024] Open
Abstract
Ciguatoxins (CTXs), potent neurotoxins produced by dinoflagellates of the genera Gambierdiscus and Fukuyoa, accumulate in commonly consumed fish species, causing human ciguatera poisoning. Field collections of Pacific reef fish reveal that consumed CTXs undergo oxidative biotransformations, resulting in numerous, often toxified analogs. Following our study showing rapid CTX accumulation in flesh of an herbivorous fish, we used the same laboratory model to examine the tissue distribution and metabolization of Pacific CTXs following long-term dietary exposure. Naso brevirostris consumed cells of Gambierdiscus polynesiensis in a gel food matrix over 16 weeks at a constant dose rate of 0.36 ng CTX3C equiv g-1 fish d-1. CTX toxicity determination of fish tissues showed CTX activity in all tissues of exposed fish (eight tissues plus the carcass), with the highest concentrations in the spleen. Muscle tissue retained the largest proportion of CTXs, with 44% of the total tissue burden. Moreover, relative to our previous study, we found that larger fish with slower growth rates assimilated a higher proportion of ingested toxin in their flesh (13% vs. 2%). Analysis of muscle extracts revealed the presence of CTX3C and CTX3B as well as a biotransformed product showing the m/z transitions of 2,3-dihydroxyCTX3C. This is the first experimental evidence of oxidative transformation of an algal CTX in a model consumer and known vector of CTX into the fish food web. These findings that the flesh intended for human consumption carries the majority of the toxin load, and that growth rates can influence the relationship between exposure and accumulation, have significant implications in risk assessment and the development of regulatory measures aimed at ensuring seafood safety.
Collapse
Affiliation(s)
- Rachel J. Clausing
- Dipartimento di Scienze della Terra dell’Ambiente e della Vita, Università degli Studi di Genova, 16132 Genova, Italy
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA
| | - Hela Ben Gharbia
- IAEA Marine Environment Laboratories, International Atomic Energy Agency, 98000 Monaco, Monaco; (H.B.G.); (K.S.); (L.L.)
| | - Khalil Sdiri
- IAEA Marine Environment Laboratories, International Atomic Energy Agency, 98000 Monaco, Monaco; (H.B.G.); (K.S.); (L.L.)
| | - Manoëlla Sibat
- Ifremer, ODE/PHYTOX/METALG, Rue de l’île d’Yeu, F-44300 Nantes, France; (M.S.); (P.H.)
| | - Ma. Llorina Rañada-Mestizo
- IAEA Collaborating Center on Harmful Algal Bloom (HAB) Studies, Chemistry Research Section, Department of Science and Technology, Philippine Nuclear Research Institute (DOST-PNRI), Diliman, Quezon City 1101, Philippines;
| | - Laura Lavenu
- IAEA Marine Environment Laboratories, International Atomic Energy Agency, 98000 Monaco, Monaco; (H.B.G.); (K.S.); (L.L.)
| | - Philipp Hess
- Ifremer, ODE/PHYTOX/METALG, Rue de l’île d’Yeu, F-44300 Nantes, France; (M.S.); (P.H.)
| | - Mireille Chinain
- Laboratoire des Biotoxines Marines, UMR 241 EIO, Institut Louis Malardé, BP 30, Papeete-Tahiti 98713, French Polynesia;
| | | |
Collapse
|
4
|
Tang JQ, Shen QH, Han YY, Wu Y, He XF, Li DW, Huang Y. Analysis of research status and trends on marine benthic dinoflagellate toxins: A bibliometric study based on web of science database and VOSviewer. ENVIRONMENTAL RESEARCH 2023; 238:117179. [PMID: 37748671 DOI: 10.1016/j.envres.2023.117179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 09/27/2023]
Abstract
Marine benthic dinoflagellate toxins, potent bioactive compounds with wide-ranging presence in marine ecosystems, have surged in response to global climate change and human activities, prompting an urgent and imperative inquiry. This study conducts an in-depth review of contemporary research concerning these toxins, employing meticulous bibliometric analysis. Leveraging a dataset of 736 relevant literatures sourced from the Web of Science (spanning from 2000 to May 2023), our analysis delves comprehensively into the scientific discourse surrounding these toxic compounds. Employing tools such as VOSviewer, co-citation analysis, co-occurrence analysis, and cluster analysis, our study yields nuanced insights into the intricate characteristics and trajectories of the field. The co-citation analysis underscores the pivotal role played by benthic and epiphytic dinoflagellates like Ostreopsis and Gambierdiscus in shaping prevailing research trends. Our study identifies four distinct research directions, encompassing the domains of ecology, toxicology, toxin production, and taxonomy. Moreover, it traces the evolutionary journey of research stages, marking the transition from a focus on taxonomy to an emphasis on unraveling molecular mechanisms. The culmination of our comprehensive analysis yields three pertinent research recommendations: a call for widescale global studies, the advancement of rapid toxin monitoring techniques, and a deeper exploration of the factors influencing toxin synthesis and toxicity. These findings provide invaluable insights to researchers grappling with the complex realm of harmful algal blooms and substantially enrich the understanding of this pivotal and pressing field.
Collapse
Affiliation(s)
- Jing-Qian Tang
- Department of Subject Service and Consultation, Jinan University Library, Guangzhou, 510632, China
| | - Qian-Hui Shen
- Department of Subject Service and Consultation, Jinan University Library, Guangzhou, 510632, China
| | - Yao-Yao Han
- Department of Subject Service and Consultation, Jinan University Library, Guangzhou, 510632, China
| | - Yang Wu
- Department of Subject Service and Consultation, Jinan University Library, Guangzhou, 510632, China
| | - Xiang-Feng He
- Library of Zhuhai Campus, Jinan University, Zhuhai, 519070, China
| | - Da-Wei Li
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
| | - Yong Huang
- Library of Zhuhai Campus, Jinan University, Zhuhai, 519070, China.
| |
Collapse
|
5
|
Chinain M, Gatti Howell C, Roué M, Ung A, Henry K, Revel T, Cruchet P, Viallon J, Darius HT. Ciguatera poisoning in French Polynesia: A review of the distribution and toxicity of Gambierdiscus spp., and related impacts on food web components and human health. HARMFUL ALGAE 2023; 129:102525. [PMID: 37951623 DOI: 10.1016/j.hal.2023.102525] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/26/2023] [Accepted: 10/07/2023] [Indexed: 11/14/2023]
Abstract
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.
Collapse
Affiliation(s)
- M Chinain
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia.
| | - C Gatti Howell
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - M Roué
- Institut de Recherche pour le Développement (IRD), UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 6570, Faa'a, Tahiti 98702, French Polynesia
| | - A Ung
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - K Henry
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - T Revel
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - P Cruchet
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - J Viallon
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| | - H T Darius
- Institut Louis Malardé (ILM), Laboratory of Marine Biotoxins, UMR 241-EIO (IFREMER, ILM, IRD, UPF), P.O. Box 30, Papeete, Tahiti 98713, French Polynesia
| |
Collapse
|
6
|
Li Q, Mahmudiono T, Mohammadi H, Nematollahi A, Hoseinvandtabar S, Mehri F, Hasanzadeh V, Limam I, Fakhri Y, Thai VN. Concentration ciguatoxins in fillet of fish: A global systematic review and meta-analysis. Heliyon 2023; 9:e18500. [PMID: 37554806 PMCID: PMC10404960 DOI: 10.1016/j.heliyon.2023.e18500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 07/10/2023] [Accepted: 07/19/2023] [Indexed: 08/10/2023] Open
Abstract
In the current study, an attempt was made to meta-analyze and discuss the concentration of ciguatoxins (CTXs) in fillets of fish based on country and water resources subgroups. The search was conducted in Scopus and PubMed, Embase and Web of Science to retrieve papers about the concentration of CTXs in fillet fish until July 2022. Meta-analysis concentration of CTXs was conducted based on countries and water resources subgroups in the random effects model (REM). The sort of countries based on the pooled concentration of CTXs was Kiribati (3.904 μg/kg) > Vietnam (1.880 μg/kg) > Macaronesia (1.400 μg/kg) > French (1.261 μg/kg) > China (0.674 μg/kg) > Japan (0.572 μg/kg) > USA (0.463 μg/kg) > Spain (0.224 μg/kg) > UK (0.170 μg/kg) > Fiji (0.162 μg/kg) > Mexico (0.150 μg/kg) > Australia (0.138 μg/kg) > Portugal (0.011 μg/kg). CTXs concentrations in all countries are higher than the safe limits of CTX1C (0.1 μg/kg). However, based on the safe limits of CTX1P, the concentrations of CTXs in just Portugal meet the regulation level (0.01 μg/kg). The minimum and maximum concentrations of CTXs were as observed in Selvagens Islands (0.011 μg/kg) and St Barthelemy (7.875 μg/kg) respectively. CTXs concentrations in all water resources are higher than safe limits of CTX1C (0.1 μg/kg) and CTX1B (0.01 μg/kg). Therefore, it is recommended to carry out continuous control pans of CTXs concentration in fish in different countries and water sources.
Collapse
Affiliation(s)
- Qingxiao Li
- College of Grain Engineering, Henan Industry and Trade Vocational College, Zhengzhou,451191, Henan Province, China
| | - Trias Mahmudiono
- Department of Nutrition, Faculty of Public Health, Universitas Airlangga, Surabaya, Indonesia
| | - Hossein Mohammadi
- Department of Bioimaging, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Amene Nematollahi
- Department of Food Safety and Hygiene, School of Health, Fasa University of Medical Sciences, Fasa, Iran
| | - Somayeh Hoseinvandtabar
- Student Research Committee, School of Public Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereshteh Mehri
- Nutrition Health Research Center, Center of Excellence for Occupational Health, Research Center for Health Sciences, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Vajihe Hasanzadeh
- Department of Environmental Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Intissar Limam
- Laboratory of Materials, Treatment and Analysis, National Institute of Research and Physicochemical Analysis; and High School for Science and Health Techniques of Tunis, University of Tunis El Manar, Tunisia
| | - Yadolah Fakhri
- Food Health Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Van Nam Thai
- HUTECH Institute of Applied Sciences, HUTECH University, 475A, Dien Bien Phu, Ward 25, Binh Thanh District, Ho Chi Minh City, Vietnam
| |
Collapse
|
7
|
Pottier I, Lewis RJ, Vernoux JP. Ciguatera Fish Poisoning in the Caribbean Sea and Atlantic Ocean: Reconciling the Multiplicity of Ciguatoxins and Analytical Chemistry Approach for Public Health Safety. Toxins (Basel) 2023; 15:453. [PMID: 37505722 PMCID: PMC10467118 DOI: 10.3390/toxins15070453] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 06/29/2023] [Accepted: 07/01/2023] [Indexed: 07/29/2023] Open
Abstract
Ciguatera is a major circumtropical poisoning caused by the consumption of marine fish and invertebrates contaminated with ciguatoxins (CTXs): neurotoxins produced by endemic and benthic dinoflagellates which are biotransformed in the fish food-web. We provide a history of ciguatera research conducted over the past 70 years on ciguatoxins from the Pacific Ocean (P-CTXs) and Caribbean Sea (C-CTXs) and describe their main chemical, biochemical, and toxicological properties. Currently, there is no official method for the extraction and quantification of ciguatoxins, regardless their origin, mainly due to limited CTX-certified reference materials. In this review, the extraction and purification procedures of C-CTXs are investigated, considering specific objectives such as isolating reference materials, analysing fish toxin profiles, or ensuring food safety control. Certain in vitro assays may provide sufficient sensitivity to detect C-CTXs at sub-ppb levels in fish, but they do not allow for individual identification of CTXs. Recent advances in analysis using liquid chromatography coupled with low- or high-resolution mass spectrometry provide new opportunities to identify known C-CTXs, to gain structural insights into new analogues, and to quantify C-CTXs. Together, these methods reveal that ciguatera arises from a multiplicity of CTXs, although one major form (C-CTX-1) seems to dominate. However, questions arise regarding the abundance and instability of certain C-CTXs, which are further complicated by the wide array of CTX-producing dinoflagellates and fish vectors. Further research is needed to assess the toxic potential of the new C-CTX and their role in ciguatera fish poisoning. With the identification of C-CTXs in the coastal USA and Eastern Atlantic Ocean, the investigation of ciguatera fish poisoning is now a truly global effort.
Collapse
Affiliation(s)
- Ivannah Pottier
- Normandie Univ, UNICAEN, UNIROUEN, ABTE, 14000 Caen, France;
| | - Richard J. Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | | |
Collapse
|
8
|
Mudge EM, Miles CO, Ivanova L, Uhlig S, James KS, Erdner DL, Fæste CK, McCarron P, Robertson A. Algal ciguatoxin identified as source of ciguatera poisoning in the Caribbean. CHEMOSPHERE 2023; 330:138659. [PMID: 37044143 DOI: 10.1016/j.chemosphere.2023.138659] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/06/2023] [Accepted: 04/08/2023] [Indexed: 05/03/2023]
Abstract
Ciguatera poisoning (CP) is a severe seafood-borne disease, caused by the consumption of reef fish contaminated with Caribbean ciguatoxins (C-CTXs) in the Caribbean and tropical Atlantic. However, C-CTXs have not been identified from their presumed algal source, so the relationship to the CTXs in fish causing illness remains unknown. This has hindered the development of detection methods, diagnostics, monitoring programs, and limited fundamental knowledge on the environmental factors that regulate C-CTX production. In this study, in vitro and chemical techniques were applied to unambiguously identify a novel C-CTX analogue, C-CTX5, from Gambierdiscus silvae and Gambierdiscus caribaeus strains from the Caribbean. Metabolism in vitro by fish liver microsomes converted algal C-CTX5 into C-CTX1/2, the dominant CTX in ciguatoxic fish from the Caribbean. Furthermore, C-CTX5 from G. silvae was confirmed to have voltage-gated sodium-channel-specific activity. This finding is crucial for risk assessment, understanding the fate of C-CTXs in food webs, and is a prerequisite for development of effective analytical methods and monitoring programs. The identification of an algal precursor produced by two Gambierdiscus species is a major breakthrough for ciguatera research that will foster major advances in this important seafood safety issue.
Collapse
Affiliation(s)
- Elizabeth M Mudge
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
| | - Christopher O Miles
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada
| | - Lada Ivanova
- Chemistry and Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway
| | - Silvio Uhlig
- Chemistry and Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway
| | - Keiana S James
- School of Marine & Environmental Sciences, University of South Alabama, 600 Clinic Drive, AL, 36688, USA; Marine Ecotoxicology Group, Dauphin Island Sea Lab, 101 Bienville Blvd, Dauphin Island, Dauphin Island, AL, 36528, USA
| | - Deana L Erdner
- Marine Science Institute, University of Texas at Austin, 750 Channel View Dr, Port Aransas, TX, 78373, USA
| | - Christiane K Fæste
- Chemistry and Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada
| | - Alison Robertson
- School of Marine & Environmental Sciences, University of South Alabama, 600 Clinic Drive, AL, 36688, USA; Marine Ecotoxicology Group, Dauphin Island Sea Lab, 101 Bienville Blvd, Dauphin Island, Dauphin Island, AL, 36528, USA.
| |
Collapse
|
9
|
Holmes MJ, Lewis RJ. Model of the Origin of a Ciguatoxic Grouper ( Plectropomus leopardus). Toxins (Basel) 2023; 15:toxins15030230. [PMID: 36977121 PMCID: PMC10055633 DOI: 10.3390/toxins15030230] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/16/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Published data were used to model the transfer of ciguatoxins (CTX) across three trophic levels of a marine food chain on the Great Barrier Reef (GBR), Australia, to produce a mildly toxic common coral trout (Plectropomus leopardus), one of the most targeted food fishes on the GBR. Our model generated a 1.6 kg grouper with a flesh concentration of 0.1 µg/kg of Pacific-ciguatoxin-1 (P-CTX-1 = CTX1B) from 1.1 to 4.3 µg of P-CTX-1 equivalents (eq.) entering the food chain from 0.7 to 2.7 million benthic dinoflagellates (Gambierdiscus sp.) producing 1.6 pg/cell of the P-CTX-1 precursor, P-CTX-4B (CTX4B). We simulated the food chain transfer of ciguatoxins via surgeonfishes by modelling Ctenochaetus striatus feeding on turf algae. A C. striatus feeding on ≥1000 Gambierdiscus/cm2 of turf algae accumulates sufficient toxin in <2 days that when preyed on, produces a 1.6 kg common coral trout with a flesh concentration of 0.1 µg/kg P-CTX-1. Our model shows that even transient blooms of highly ciguatoxic Gambierdiscus can generate ciguateric fishes. In contrast, sparse cell densities of ≤10 Gambierdiscus/cm2 are unlikely to pose a significant risk, at least in areas where the P-CTX-1 family of ciguatoxins predominate. The ciguatera risk from intermediate Gambierdiscus densities (~100 cells/cm2) is more difficult to assess, as it requires feeding times for surgeonfish (~4-14 days) that overlap with turnover rates of turf algae that are grazed by herbivorous fishes, at least in regions such as the GBR, where stocks of herbivorous fishes are not impacted by fishing. We use our model to explore how the duration of ciguatoxic Gambierdiscus blooms, the type of ciguatoxins they produce, and fish feeding behaviours can produce differences in relative toxicities between trophic levels. Our simple model indicates thresholds for the design of risk and mitigation strategies for ciguatera and the variables that can be manipulated to explore alternate scenarios for the accumulation and transfer of P-CTX-1 analogues through marine food chains and, potentially, for other ciguatoxins in other regions, as more data become available.
Collapse
Affiliation(s)
- Michael J Holmes
- Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| |
Collapse
|
10
|
Holmes MJ, Lewis RJ. Origin of Ciguateric Fish: Quantitative Modelling of the Flow of Ciguatoxin through a Marine Food Chain. Toxins (Basel) 2022; 14:toxins14080534. [PMID: 36006196 PMCID: PMC9414493 DOI: 10.3390/toxins14080534] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/28/2022] [Accepted: 07/30/2022] [Indexed: 02/01/2023] Open
Abstract
To begin to understand the impact of food chain dynamics on ciguatera risk, we used published data to model the transfer of ciguatoxins across four trophic levels of a marine food chain in Platypus Bay, Australia. The data to support this first attempt to conceptualize the scale of each trophic transfer step was limited, resulting in broad estimates. The hypothetical scenario we explored generated a low-toxicity 10 kg Spanish mackerel (Scomberomorus commerson) with a flesh concentration of 0.1 µg/kg of Pacific-ciguatoxin-1 (P-CTX-1, also known as CTX1B) from 19.5–78.1 µg of P-CTX-1 equivalents (eq.) that enter the marine food chain from a population of 12–49 million benthic dinoflagellates (Gambierdiscus sp.) producing 1.6 × 10−12 g/cell of the P-CTX-1 precursor, P-CTX-4B. This number of Gambierdiscus could be epiphytic on 22–88 kg of the benthic macroalgae (Cladophora) that carpets the bottom of much of Platypus Bay, with the toxin transferred to an estimated 40,000–160,000 alpheid shrimps in the second trophic level. This large number of shrimps appears unrealistic, but toxic shrimps would likely be consumed by a school of small, blotched javelin fish (Pomadasys maculatus) at the third trophic level, reducing the number of shrimps consumed by each fish. The Spanish mackerel would accumulate a flesh concentration of 0.1 µg/kg P-CTX-1 eq. by preying upon the school of blotched javelin and consuming 3.6–14.4 µg of P-CTX-1 eq. However, published data indicate this burden of toxin could be accumulated by a 10 kg Spanish mackerel from as few as one to three blotched javelin fish, suggesting that much greater amounts of toxin than modelled here must at certain times be produced and transferred through Platypus Bay food chains. This modelling highlights the need for better quantitative estimates of ciguatoxin production, biotransformation, and depuration through marine food chains to improve our understanding and management of ciguatera risk.
Collapse
|