Ciguatera Fish Poisoning: Treatment,Prevention and Management

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world, and it causes substantial physical and functional impact. It produces a myriad of gastrointestinal, neurologic and/or cardiovascular symptoms which last days to weeks, or even months. Although there are reports of symptom amelioration with some interventions (e.g. IV mannitol), the appropriate treatment for CFP remains unclear to many physicians. We review the literature on the treatments for CFP, including randomized controlled studies and anecdotal reports. The article is intended to clarify treatment options, and provide information about management and prevention of CFP, for emergency room physicians, poison control information providers, other health care providers, and patients.     

中国珊瑚礁毒鱼类的研究

本文较全面地叙述珊瑚礁毒鱼中毒的定义,珊瑚礁鱼毒素的毒源、毒理作用,中毒症状、治疗及预防,毒鱼种类。经２０多年来的调查研究,在中国的台湾、西沙群岛、海南岛南部共发现４５种珊瑚礁鱼类为有毒种。     

ASE-SPE-HPLC/MS/MS检测鱼体内的雪卡毒素

雪卡毒素中毒是一种全球暴发的海洋食源性疾病,食用含有0.1 μg雪卡毒素的珊瑚鱼即可引起中毒。研究建立了一套快速、高效、高灵敏度的ASE-SPE-HPLC/MS/MS检测方法来保证人类健康,该方法在1.0～50.0 μg·kg-1范围内线性良好,相关系数在0.99以上,检出限为0.03 μg·kg-1,定量下限为0.1 μg·kg-1,基质加标的回收率在95%以上。较之传统方法,该方法有较好的回收率和提取效率。     

中国珊瑚礁毒鱼类的研究

本文较全面地叙述珊瑚礁毒鱼中毒的定义，珊瑚礁鱼毒素的毒源、毒理作用，中毒症状、治疗及预防，毒鱼种类。经２０多年来的调查研究，在中国的台湾、西沙群岛、海南岛南部共发现４５种珊瑚礁鱼类为有毒种。     

雪卡毒素中毒的现状及检测分析概况

介绍了雪卡毒素的化学结构、雪卡毒素的药理作用与提取及合成、雪卡毒素中毒的现状、中毒症状和检测分析方法。对于预防和减少雪卡毒素中毒具有重要的意义。     

Update on Methodologies Available for Ciguatoxin Determination: Perspectives to Confront the Onset of Ciguatera Fish Poisoning in Europe []

Ciguatera fish poisoning (CFP) occurs mainly when humans ingest finfish contaminated with ciguatoxins (CTXs). The complexity and variability of such toxins have made it difficult to develop reliable methods to routinely monitor CFP with specificity and sensitivity. This review aims to describe the methodologies available for CTX detection, including those based on the toxicological, biochemical, chemical, and pharmaceutical properties of CTXs. Selecting any of these methodological approaches for routine monitoring of ciguatera may be dependent upon the applicability of the method. However, identifying a reference validation method for CTXs is a critical and urgent issue, and is dependent upon the availability of certified CTX standards and the coordinated action of laboratories. Reports of CFP cases in European hospitals have been described in several countries, and are mostly due to travel to CFP endemic areas. Additionally, the recent detection of the CTX-producing tropical genus Gambierdiscus in the eastern Atlantic Ocean of the northern hemisphere and in the Mediterranean Sea, as well as the confirmation of CFP in the Canary Islands and possibly in Madeira, constitute other reasons to study the onset of CFP in Europe [1]. The question of the possible contribution of climate change to the distribution of toxin-producing microalgae and ciguateric fish is raised. The impact of ciguatera onset on European Union (EU) policies will be discussed with respect to EU regulations on marine toxins in seafood. Critical analysis and availability of methodologies for CTX determination is required for a rapid response to suspected CFP cases and to conduct sound CFP risk analysis.     

Effects of Low Does Irradiation on the K-Value and Hypoxanthine Concentration of Fish Fillets

Fillets of five fish species were irradiated at 0,1 and 3kGy to investigate whether the K-value test of freshness can be applied to irradiated fish. Following irradiation, the fillets were stored on ice and sampled regularly for K-value analysis. Hypoxanthine (Hx) and total nucleotide content were also determined on fillets of two species. K-Values of irradiated fillets were generally lower than those of unirradiated controls. Hypoxanthin levels paralleled the K-value changes. These results indicated that quality standards based on K-values or Hx levels that have been set fro unirradiated species cannot be directly applied to fish that had been irradiated. Total nucleotide content did not appear to be affected by irradiation.     

西加毒素小鼠生物学检测法的建立

旨在建立西加毒素小鼠生物学检测法.采用19 g～21 g的昆明系雄性小鼠,将一系列不同浓度的西加毒素(P-CTX-1)标准溶液通过腹腔注入小鼠体内,观察其中毒症状,确定1个鼠单位(mu)所代表的毒素剂量,并且建立剂量-中间死亡时间曲线.结果表明对我国昆明系雄性小鼠腹腔注射西加毒素,1个鼠单位所对应的P-CTX-1剂量值约为9.10 ng,其95%可信限为8.67 ng～9.56 ng;剂量-中间死亡时间曲线方程为y=244.9x-1.393 7;其中y代表致死时间,x表剂量;将死亡时间t变为时间倒数1/t,对CTX的毒性mu取对数即logmu,得直线回归方程y=1.207 6 x-0.047,R2=0.992 1,其中y代表西加毒素毒性的对数(logmu),x代表小鼠死亡时间倒数(1/t),R为相关系数.同时利用该方法在0.1、0.2、0.3 ppb 3个浓度水平进行验证试验,结果表明,方法的总体平均回收率为46.58%～50.23%,相对标准偏差范围为1.17%～2.28%.     

Identification of New CTX Analogues in Fish from the Madeira and Selvagens Archipelagos by Neuro-2a CBA and LC-HRMS

Ciguatera Poisoning (CP) is caused by consumption of fish or invertebrates contaminated with ciguatoxins (CTXs). Presently CP is a public concern in some temperate regions, such as Macaronesia (North-Eastern Atlantic Ocean). Toxicity analysis was performed to characterize the fish species that can accumulate CTXs and improve understanding of the ciguatera risk in this area. For that, seventeen fish specimens comprising nine species were captured from coastal waters inMadeira and Selvagens Archipelagos. Toxicity was analysed by screening CTX-like toxicity with the neuroblastoma cell-based assay (neuro-2a CBA). Afterwards, the four most toxic samples were analysed with liquid chromatography-high resolution mass spectrometry (LC-HRMS). Thirteen fish specimens presented CTX-like toxicity in their liver, but only four of these in their muscle. The liver of one specimen of Muraena augusti presented the highest CTX-like toxicity (0.270 ± 0.121 µg of CTX1B equiv·kg⁻¹). Moreover, CTX analogues were detected with LC-HRMS, for M. augusti and Gymnothorax unicolor. The presence of three CTX analogues was identified: C-CTX1, which had been previously described in the area; dihydro-CTX2, which is reported in the area for the first time; a putative new CTX m/z 1127.6023 ([M+NH₄]⁺) named as putative C-CTX-1109, and gambieric acid A.     

Pacific-Ciguatoxin-2 and Brevetoxin-1 Induce the Sensitization of Sensory Receptors Mediating Pain and Pruritus in Sensory Neurons

Ciguatera fish poisoning (CFP) and neurotoxic shellfish poisoning syndromes are induced by the consumption of seafood contaminated by ciguatoxins and brevetoxins. Both toxins cause sensory symptoms such as paresthesia, cold dysesthesia and painful disorders. An intense pruritus, which may become chronic, occurs also in CFP. No curative treatment is available and the pathophysiology is not fully elucidated. Here we conducted single-cell calcium video-imaging experiments in sensory neurons from newborn rats to study in vitro the ability of Pacific-ciguatoxin-2 (P-CTX-2) and brevetoxin-1 (PbTx-1) to sensitize receptors and ion channels, (i.e., to increase the percentage of responding cells and/or the response amplitude to their pharmacological agonists). In addition, we studied the neurotrophin release in sensory neurons co-cultured with keratinocytes after exposure to P-CTX-2. Our results show that P-CTX-2 induced the sensitization of TRPA1, TRPV4, PAR2, MrgprC, MrgprA and TTX-r NaV channels in sensory neurons. P-CTX-2 increased the release of nerve growth factor and brain-derived neurotrophic factor in the co-culture supernatant, suggesting that those neurotrophins could contribute to the sensitization of the aforementioned receptors and channels. Our results suggest the potential role of sensitization of sensory receptors/ion channels in the induction or persistence of sensory disturbances in CFP syndrome.