Presence of CTXs in moray eels and dusky groupers in the marine environment of the Canary Islands

Evidence for the Range Expansion of Ciguatera in French Polynesia: A Revisit of the 2009 Mass-Poisoning Outbreak in Rapa Island (Australes Archipelago)

“…Another observed difference concerns the single fish (i.e., L. vaigiensis #211) in which CTXs could be detected in quantifiable amounts by LC-MS/MS, whereas rRBA and CBA-N2a were able to quantify CTX-like toxicity in all seven positive samples. This quantitation divergence between functional and chemical methods has been previously documented in large-scale field surveys conducted in the Kiribati and the Canary Islands [11,36]. It is well established that LC-MS/MS is a methodology with higher detection limits, which, additionally, can quantify only known targeted CTX analogs and may overlook congeners not yet described, while rRBA and CBA-N2a rather reflect a global response indicative of the binding affinity or cytotoxic effects of the suite of CTX compounds present in fish samples [11,36].…”

“…This quantitation divergence between functional and chemical methods has been previously documented in large-scale field surveys conducted in the Kiribati and the Canary Islands [11,36]. It is well established that LC-MS/MS is a methodology with higher detection limits, which, additionally, can quantify only known targeted CTX analogs and may overlook congeners not yet described, while rRBA and CBA-N2a rather reflect a global response indicative of the binding affinity or cytotoxic effects of the suite of CTX compounds present in fish samples [11,36]. Additional factors may also explain these observed differences, such as the use of various extraction techniques for samples analyzed in the present study (see Section 5.4), which may have affected both the extraction efficiency and recovery of CTX compounds.…”

“…Until the 2000s, the distribution of ciguatera-causing organisms and ciguatoxic fish were thought to be limited to regions between latitudes 35 • N and 35 • S, with the highest poisoning incidence rates consistently reported from two tropical, historical CP-endemic areas, the Pacific and Caribbean regions [4] (for review and references therein) and [25,26], which is a situation due in part to the strong reliance of local communities on marine resources. The first reports of consumer illness and/or detection of ciguatoxic fish caught in previously non-endemic areas can be found in the literature as early as 2004 from localized areas such as the Macaronesia (Canary Islands, Madeira) [27][28][29][30][31][32][33][34][35][36], the eastern Mediterranean [37], the Gulf of Mexico [38], or the coast of Cameroon in West Africa [21]. In most of these instances, confirmation of the presence of CTXs in implicated toxic meals was consistent with the detection of Gambierdiscus species within the respective regions [38][39][40][41][42][43][44][45][46][47][48].…”

Characteristic Distribution of Ciguatoxins in the Edible Parts of a Grouper, Variola louti

“…In recent years, there have been a series of reports of CFP in areas where it does not typically occur. For example, cases were recorded in the Canary (Spain) and Madeira (Portugal) Islands, which belong to Macaronesia in northwestern Africa in the eastern Atlantic Ocean, in 2004, and occurrences have continued since then [7,8]. Therefore, there are concerns about the expansion of CFP endemic areas.…”

Revisiting the Neuroblastoma Cell-Based Assay (CBA-N2a) for the Improved Detection of Marine Toxins Active on Voltage Gated Sodium Channels (VGSCs)

“…The most significant modification was the use of two different O/V treatments, i.e., 100/10 and 300/30 µM, in order to induce 20% and 80% of cell mortality, respectively, for a more reliable assessment of the effects of VGSC toxin activators and inhibitors on N2a cells [83]. Several changes were also made to the final reaction volume (230 µL) at the last step of the CBA-N2a, i.e., cell exposure to toxin standards or biological samples, with volumes varying from 100 to 210 µL [32][33][34][35][36]45,49,51,53,59,61,63,64,69,73,75,[77][78][79][80]84,[86][87][88][89][90]95]. Moreover, measuring cell viability by means of the MTT colorimetric assay is classically performed at 570 nm, however, different wavelengths were also tested that ranged from 490 to 595 nm [33,35,36,[38][39][40][41][42]45,50,56,57,61,64,[67][68][69]…”