ciguatera

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...

Ciguatera fish poisoning (CFP) is a foodborne illness affecting > 50,000 people worldwide annually. It is caused by eating marine invertebrates and fish that have accumulated ciguatoxins (CTXs). Recently, the risk of CFP to human health, the local economy, and fishery resources have increased; therefore, detection methods are urgently needed. Functional assays for detecting ciguatoxins in fish include receptor binding (RBA) and neuroblastoma cell-based assay (N2a assay), which can detect all CTX congeners...

Tropical epibenthic dinoflagellate communities produce a plethora of bioactive secondary metabolites, including the toxins ciguatoxins (CTXs) and potentially gambierones, that can contaminate fishes, leading to ciguatera poisoning (CP) when consumed by humans. Many studies have assessed the cellular toxicity of causative dinoflagellate species to better understand the dynamics of CP outbreaks. However, few studies have explored extracellular toxin pools which may also enter the food web, including through alternative and unanticipated routes of exposure...

Ciguatoxins (CTXs) are marine neurotoxins that cause ciguatera poisoning (CP), mainly through the consumption of fish. The distribution of CTXs in fish is known to be unequal. Studies have shown that viscera accumulate more toxins than muscle, but little has been conducted on toxicity distribution in the flesh, which is the main edible part of fish, and the caudal muscle is also most commonly targeted for the monitoring of CTXs in the Canary Islands. At present, whether this sample is representative of the toxicity of an individual is undisclosed...

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...

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...

Fish poisoning (FP) affects human health, trade and livelihood in Fiji, where management has depended mainly on traditional ecological knowledge (TEK). This paper investigated and documented this TEK through a 2-day stakeholder workshop, group consultation, in-depth interviews, field observations, and analyses of survey data from the Ministry of Fisheries, Fiji. Six TEK topics were identified and classified as preventative and treatment options. The preventive approach involves identifying toxic reef fishes, the spawning season of edible seaworms, hotspot areas of toxic fishes, folk tests, and locating and removing toxic organs...

Ciguatera Poisoning is an emerging risk in the east Atlantic Ocean. Despite characterization efforts, the complete profile of ciguatoxin chemical species in these waters is still unknown. These efforts have been complicated by a lack of reference materials and scarcity of fish contaminated with high levels of ciguatoxins. Development and application of analytical methods with enhanced selectivity and sensitivity is essential for ciguatoxin characterization. Here, we developed an analytical characterization approach using capillary liquid chromatography coupled to high resolution mass spectrometry applied to reference materials obtained from ciguatoxin contaminated fish...

Ciguatera is a common marine, toxin-borne illness caused by the consumption of fish that contain toxins that activate voltage-sensitive sodium channels. The clinical manifestations of ciguatera are typically self-limited, but chronic symptoms may occur in a minority of patients. This report describes a case of ciguatera poisoning with chronic symptoms, including pruritus and paresthesias. A 40-y-old man was diagnosed with ciguatera poisoning after consuming amberjack while vacationing in the US Virgin Islands...

Viet Nam has a coastline of 3,200 km with thousands of islands providing diverse habitats for benthic harmful algal species including species of Gambierdiscus. Some of these species produce ciguatera toxins, which may accumulate in large carnivore fish potentially posing major threats to public health. This study reports five species of Gambierdiscus from Vietnamese waters, notably G. australes, G. caribaeus, G. carpenteri, G. pacificus, and G. vietnamensis sp. nov. All species are identified morphologically by LM and SEM, and identifications are supported by molecular analyses of nuclear rDNA (D1-D3 and D8-D10 domains of LSU, SSU, and ITS1-5...

The genus Amphidinium has been the subject of recent attention due to the production of polyketide metabolites. Some of these compounds have shown significant bioactivities and could be related to species interactions in the natural benthic microenvironment. Among these compounds, amphidinols (AMs) are suspected to be related to fish kills and probably implicated in ciguatera symptoms associated with the occurrence of benthic harmful algal blooms (bHABs). Here, we present the first report of a variety of AMs produced by cultured strains from several species from the Mexican Pacific, the Gulf of California, and the Gulf of Mexico...

The dinoflagellates Gambierdiscus and Fukuyoa can produce Ciguatoxins (CTXs) and Maitotoxins (MTXs) that lead to ciguatera poisoning (CP). The CP hotspots, however, do not directly relate to the occurrence of the ciguatoxic Gambierdiscus and Fukuyoa. Species-wide investigations often showed no association between CTX level and the molecular identity of the dinoflagellates. In the Pacific region, Kiribati is known as a CP hotspot, while Malaysia has only three CP outbreaks reported thus far. Although ciguatoxic strains of Gambierdiscus were isolated from both Kiribati and Malaysia, no solid evidence on the contribution of ciguatoxic strains to the incidence of CP outbreak was recorded...

Marine toxins have a significant impact on seafood resources and human health. Up to date, mainly based on bioassays results, two genera of toxic microalgae, Gambierdiscus and Fukuyoa have been hypothesized to produce a suite of biologically active compounds, including maitotoxins (MTXs) and ciguatoxins (CTXs) with the latter causing ciguatera poisoning (CP) in humans. The global ubiquity of these microalgae and their ability to produce (un-)known bioactive compounds, necessitates strategies for screening, identifying, and reducing the number of target algal species and compounds selected for structural elucidation...

The benthic dinoflagellate genus Gambierdiscus is the primary producer of toxins responsible for ciguatera poisoning (CP), a food intoxication endemic in tropical and subtropical areas of the world. We used high-performance liquid chromatography tandem high-resolution mass spectrometry (HPLC-HRMS) to investigate the toxin profile of Gambierdiscus balechii 1123M1M10, which was obtained from Marakei Island (2°01'N, 173°15'E), Republic of Kiribati, located in the central Pacific Ocean. Four new gambierone analogues including 12,13-dihydro-44-methylgambierone, 38-dehydroxy-12,13-dihydro-44-methylgambierone, 38-dehydroxy-44-methylgambierone, and desulfo-hydroxyl gambierone, and two known compounds, gambierone and 44-methylgambierone, were proposed by analyzing their fragmentation behaviors and pathways...

Ciguatera poisoning (CP) is a foodborne disease known for centuries; however, little research has been conducted on the effects of ciguatoxins (CTXs) on fish metabolism. The main objective of this study was to assess different hepatic compounds observed in goldfish ( Carassius auratus ) fed C-CTX1 using nuclear magnetic resonance (NMR)-based metabolomics. Thirteen goldfish were treated with C-CTX1-enriched flesh and sampled on days 1, 8, 15, 29, 36, and 43. On day 43, two individuals, referred to as 'Detox', were isolated until days 102 and 121 to evaluate the possible recovery after returning to a commercial feed...

Convergent and scalable synthesis of the ABCDE-ring fragment of Caribbean ciguatoxin C-CTX-1, the major causative toxin for ciguatera poisoning in the Caribbean Sea and the Northeast Atlantic areas, is described in detail. The key features of the synthesis include an iterative use of 2,2,6,6-tetramethyl piperidine 1-oxyl (TEMPO)/PhI(OAc)2 -mediated oxidative lactonization and Suzuki-Miyaura coupling en route to the DE-ring system and a convergent fragment coupling to form the ABCDE-ring skeleton via the Suzuki-Miyaura coupling strategy...

Dinoflagellates of the genera Gambierdiscus and Fukuyoa are able to produce potent neurotoxins like ciguatoxins (CTXs), which, after biooxidation in fish, are responsible for ciguatera intoxication. An isolate of G. australes from the Canary Islands, that revealed the presence of CTX-like compounds by immunosensing tools, was studied by immunocytochemistry to localize intracellular CTX-like compounds, using 8H4 monoclonal antibody that specifically recognizes the right wing of CTX1B and CTX3C analogues. Confocal microscopy observations of immunostained whole cells revealed a strong positive reaction on cell surface and all along the cell outline, while no reaction was detected inside the cells, probably because the antibody was not able to pass through thecal plates...

Harmful algal blooms (HABs) are a significant global environmental management challenge, especially with respect to microalgae that produce dangerous natural toxins. Examples of HAB toxin diseases with major global health impact include: ciguatera poisoning, paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), diarrhetic shellfish poisoning (DSP), and neurotoxic (brevetoxin) shellfish poisoning (NSP). Such diseases affect communities globally and contribute to health inequalities within the United States and beyond...

Cells in a clonal culture of the WC1/1 strain of Gambierdiscus that produced ciguatoxin and maitotoxin-3 were observed to spontaneously fuse during the light phase of culture growth. Cells in the process of fusion were indistinguishable from other cells under the light microscope, except that at least one (often both) of the fusing cells displayed an extendible, finger-like protrusion (presumed peduncle) arising from near the sulcul region. Fusion started with one of the cells turning 90° to place the planes of the girdles approximately at right angles to each other, and movement of the transverse flagella ceased in both cells, or in the cell seen in girdle (lateral) view...

Ciguatera fish poisoning (CFP) is recognized as the most frequent seafood poisoning due to the consumption of fish containing the principal toxins, ciguatoxins (CTXs). In Japan, CFP events have been reported annually from Okinawa and Amami Islands, locating subtropical regions. In addition, there have been reported several outbreaks due to consumption of the fish caught from the Pacific coast of the Mainland and they were often caused by the matured spotted knifejaw, Oplegnathus punctatus. As part of our research on CFP in Japan, we investigated CTXs analysis by LC-MS/MS on 176 individuals of O...