RESUMO
Ciguatera is a common seafood poisoning in Western Atlantic and French West Indies. Ciguatera fish poisoning in the Caribbean is a public health problem. A toxicological study was carried out on 178 Caribbean fish specimens (26 species) captured off Guadeloupe and Saint Barthelemy between 1993 and 1999. The mouse bioassay and the chick feeding test were used to control fish edibility. Ciguatoxins presence was assumed when symptomatology was typical of ciguatera in mouse and chick. Fishes were classified in three groups: non toxic fish (edible), low toxic fish (not edible) and toxic fish (not edible). 75% of fishes were non toxic. Toxic fish specimens belonged to four families of high trophic level carnivores: Carangidae, Lutjanidae, Serranidae et Sphyraenidae. Percentages of toxic fishes to humans reached 55% for Caranx latus and 33% for Caranx bartholomaei and Caranx lugubris. Only a significant correlation between weight and toxicity was only found for C. latus and snappers. Small carnivorous groupers (Serranidae) were also toxic. Atoxic fish species were (a) pelagic fish (Coryphaena hippurus, Auxis thazard and Euthynnus pelamis), (b) invertebrates feeders (Malacanthus plumieri, Balistes vetula), (c) small high-risk fish or (d) fish of edible benthic fish families. Liver of four fishes (Mycteroperca venenosa, Caranx bartholomaei, Seriola rivoliana, Gymnothorax funebris) contained ciguatoxins at a significant level although their flesh was safe. This study confirms the usefulness of mouse and chick bioassays for sanitary control of fish.
Assuntos
Bioensaio/métodos , Ciguatoxinas/efeitos adversos , Peixes Venenosos/classificação , Animais , Bioensaio/normas , Galinhas , Ciguatera/epidemiologia , Ciguatera/etiologia , Ciguatoxinas/análise , Guadalupe/epidemiologia , Humanos , Fígado/química , Camundongos , Saúde PúblicaRESUMO
A grey snapper (Lutjanus griseus), a grouper (Serranidae) and a black jack (Caranx lugubris) were implicated in three different ciguatera poisonings in Guadeloupe, French West Indies. A mouse bioassay indicated toxicity for each specimens: 0.5-1, > or = 1 and > 1 MUg g(-1), respectively. After purification by gel filtration chromatography, the samples were analysed by high-performance liquid chromatography coupled to mass spectrometry (LC-MS). The toxin profiles differ from one fish to another. C-CTX-1 was detected at 0.24, 0.90 and 13.8 ng g(-1) flesh in the snapper, grouper and jack, respectively. It contributed only to part of the whole toxicity determined by the mouse bioassay. Other toxins identified were C-CTX-2 (a C-CTX-1 epimer), three additional isomers of C-CTX-1 or-2, and five ciguatoxin congeners (C-CTX-1127, C-CTX-1143 and its isomer C-CTX-1143a, and C-CTX-1157 and its isomer C-CTX-1157b). Putative hydroxy-polyether-like compounds were also detected in the flesh of the grouper with [M+ + H]+ ions at m/z 851.51, 857.50, 875.51, 875.49 and 895.54 Da. Some of these compounds have the same mass range as some known dinoflagellate toxins. In conclusion, this study confirms the usefulness of LC-MS analysis to determine the ciguatoxins levels and the toxin profile in fish flesh hazardous to humans.
Assuntos
Ciguatera/etiologia , Ciguatoxinas/análise , Peixes/metabolismo , Adulto , Animais , Cromatografia Líquida de Alta Pressão , Ciguatera/epidemiologia , Ciguatoxinas/análogos & derivados , Surtos de Doenças , Feminino , Guadalupe/epidemiologia , Humanos , Masculino , Espectrometria de Massas , Camundongos , Pessoa de Meia-IdadeRESUMO
Ciguatera fish poisoning (ciguatera), a common poisoning caused by fish ingestion, is reviewed in the Western Atlantic and the Caribbean waters. It is endemic from Florida coasts (northern limit) to Martinique Island (southern limit), with outbreaks occurring from time to time. In the Caribbean, ciguatera causes a polymorphic syndrome with gastrointestinal, cardiovascular, and neurological signs and symptoms. Neurological and muscular dysfunctions can be treated by intravenous injection of D-mannitol. The lipid-soluble toxins involved are ciguatoxins that are likely produced by the dinoflagellate Gambierdiscus toxicus. G. toxicus strains are endemic in the Caribbean Sea and in theWestern Atlantic. Although it is likely that blooms of G. toxicus are ingested by herbivorous fishes, they are not implicated in ciguatera in the Caribbean. Rather, large carnivores (barracudas, jacks, snappers, groupers), consumers of smaller benthic fish, are often involved in ciguatera. Fish toxicity depends on fishing area and depth, fish size and tissues, and climatic disturbances. Ciguatoxins have been isolated and purified from Caribbean fish species. The structure of two epimers, C-CTX-1 and C-CTX-2 from horse-eye jack, comprise 14 trans-fused ether-linked rings and a hemiketal in terminal ring. Caribbean ciguatoxins are mainly detected in the laboratory by chicken, mouse, mosquito, or cell bioassays, and by analytical HPLC/tandem mass spectrometry down to parts per billion (ppb). A ciguatera management plan that integrates epidemiology, treatment, and a simple method of detection is required to ensure the protection of consumers.
Assuntos
Ciguatera , Alimentos Marinhos/toxicidade , Animais , Oceano Atlântico , Ciguatera/epidemiologia , Ciguatera/fisiopatologia , Ciguatera/terapia , Humanos , Fatores de Risco , Alimentos Marinhos/efeitos adversos , Estados Unidos/epidemiologia , Índias Ocidentais/epidemiologiaRESUMO
1. Cigautoxins (CTX) were extracted from flesh and viscera of seven large roving predatory fishes: Caranx bartholomaei, Caranx latus, Seriola dumerili, Alectis crinitus, Scomberomorus cavalla, Sphyraena barracuda and Gymnothorax funebris. 2. Generally each extract consisted of close-related CTX which were separated according to their polarity by Florisil column chromatography into a fast-acting CTX containing group and a slow-acting CTX containing group. 3. The shortest survival time of mice (ts) was low for the former group (less than 10 min) and high for the latter (greater than or equal to 29 min). 4. The level of purity had no influence on the range of ts values. The presence of these two CTX groups in different extracts did not from experimental conditions. 5. Attempts to convert fast-acting CTX to slow-acting CTX and vice-versa were negative. G. funebris and S. barracuda had an especially high content of unstable fast-acting CTX. 6. Purification of the slow-acting CTX was achieved by fast elution chromatography and Sephadex LH20 gel filtration. 7. The ts values of these CTX were identical for five species (40-44 min) but not for S. barracuda (29-32 min). 8. Thus ciguatoxic extracts from Caribbean fish were composed of several close-related CTX.
Assuntos
Ciguatoxinas/isolamento & purificação , Peixes/metabolismo , Toxinas Marinhas/isolamento & purificação , Músculos/análise , Vísceras/análise , Animais , Fracionamento Químico , Ciguatoxinas/toxicidade , Índias OcidentaisRESUMO
Ciguatoxin-like substances were extracted from the viscera or the flesh of eight Caribbean fish species, including small invertebrate feeders and large carnivores. The had similar properties, i.e. pharmacological action, solubility, chromatographic behaviour on silicic acid or Sephadex LH 20 column, stability in a weak acid solution and instability in alkaline medium. However, Florisil column and thin-layer chromatography showed different ciguatoxins whose number depended on tissue or species but not on fish trophic level. Less polar ciguatoxins appeared in salted and dried flesh. Thus, fish ciguatoxins are believed to be closely related substances, possibly changing in structure according to particular experimental conditions.
Assuntos
Ciguatoxinas/isolamento & purificação , Toxinas Marinhas/isolamento & purificação , Animais , Peixes , Especificidade da Espécie , Relação Estrutura-Atividade , Índias OcidentaisRESUMO
Ciguatera poisoning was studied in the chicken where it gave rise to internal hypersalivation, acute motor ataxia, low rectal temperature and arrested growth. LD50 figures indicated that the chicken is two to five time at least more sensitive to ciguatoxin than the mouse. So the chick is very convenient for laboratory studies in ciguatera research.
Assuntos
Ciguatoxinas/toxicidade , Toxinas Marinhas/toxicidade , Animais , Ataxia/induzido quimicamente , Galinhas , Ciguatoxinas/administração & dosagem , Transtornos do Crescimento/induzido quimicamente , Hipotermia/induzido quimicamente , Camundongos , Sialorreia/induzido quimicamente , Índias OcidentaisRESUMO
A total of 259 specimens of 32 potentially ciguatoxic fish species from St-Barthelemy, Leeward Islands in the Caribbean sea were checked for ciguatoxin. It was found that flesh and viscera from 229 specimens belonging to 27 species (essentially bottom-dwelling species) were ciguatoxic. No correlation between toxicity and species size or diet was demonstrated since five of the six highly ciguatoxic species Seriola dumerili, Caranx latus, Caranx bartholomaei, Caranx ruber and Scomberomorus cavalla are large roving predators feeding mainly on fishes while the last species (Alphestes afer) is a benthic resident of very small size (less than 300 g) which feeds mainly on invertebrates. Small (less than 1 kg) benthic carnivorous fishes (invertebrate feeders), such as Bodianus rufus, Priacanthus arenatus, Mulloidichtys martinicus, Malacanthus plumieri and Halichoeres radiatus, are significantly ciguatoxic and play an important role in the transmission of ciguatoxin in the food chain. Other ciguatoxic species included large carnivorous fishes and the small surgeon Acanthurus bahianus. Furthermore, additional results suggest that most of edible benthic species from Saint-Barthelemy harbour ciguatoxin as well, though at an extremely low level. The ciguatera food chain in the Caribbean sea is therefore comparable with that described in the Pacific Ocean, except concerning small invertebrate feeders since their role in this chain is demonstrated for the first time.
Assuntos
Ciguatoxinas/análise , Peixes , Toxinas Marinhas/análise , Animais , Índias OcidentaisRESUMO
This report deals with some of the biological and chemical properties of a liposoluble poison extracted from Caranx bartholomaei (yellow jack), a toxic fish from the French West Indies (St Barth's island). Within a single fish, poison concentration is higher in the viscera; toxicity level is uniform throughout the flesh. In the few specimens tested, liver toxicity variations parallel those of flesh. The poison is heat stable so that cooking does not impair the toxicity. It is soluble in acetone, diethyl ether, chloroform, benzene, methanol and ethanol, but insoluble in n. hexane. Crude toxin injection or ingestion induces ciguateric disease in cats, mice or newly born chicken. Crude toxin stability is good after 30 minutes at 90 degrees C in a 0,5 N solution of a weak acid but not of a weak base. In the same conditions, loss of activity is nearly complete with a strong acid or a strong base. Moreover, rapid alkali treatment at room temperature destroys more than 50 per cent of the toxicity. The toxin is eluted by chloroform-methanol (9:1) from a silicic acid column and by acetone-methanol (9,5:0,5) from a Florisil column. DEAE cellulose column chromatography clearly separates the toxin into two lethal components; but thin layer chromatography of crude or fractionated toxin indicates only one toxic band in three different solvent systems. As a conclusion, in spite of a few differences related to instability in alkalin medium and elution from DEAE cellulose, this poison is quite similar to those carried by ciguatoxic fishes from the Pacific area. The differences noted above could be accounted for either by a specific metabolism of the species studied or by differences in the causative agent due to geographical location, or both.