Further Advance of Gambierdiscus Species in the Canary Islands, with the First Report of Gambierdiscus belizeanus

Abstract

Ciguatera Poisoning (CP) is a human food-borne poisoning that has been known since ancient times to be found mainly in tropical and subtropical areas, which occurs when fish or very rarely invertebrates contaminated with ciguatoxins (CTXs) are consumed. The genus of marine benthic dinoflagellates Gambierdiscus produces CTX precursors. The presence of Gambierdiscus species in a region is one indicator of CP risk. The Canary Islands (North Eastern Atlantic Ocean) is an area where CP cases have been reported since 2004. In the present study, samplings for Gambierdiscus cells were conducted in this area during 2016 and 2017. Gambierdiscus cells were isolated and identified as G. australes, G. excentricus, G. caribaeus, and G. belizeanus by molecular analysis. In this study, G. belizeanus is reported for the first time in the Canary Islands. Gambierdiscus isolates were cultured, and the CTX-like toxicity of forty-one strains was evaluated with the neuroblastoma cell-based assay (neuro-2a CBA). G. excentricus exhibited the highest CTX-like toxicity (9.5–2566.7 fg CTX1B equiv. cell−1) followed by G. australes (1.7–452.6.2 fg CTX1B equiv. cell−1). By contrast, the toxicity of G. belizeanus was low (5.6 fg CTX1B equiv. cell−1), and G. caribaeus did not exhibit CTX-like toxicity. In addition, for the G. belizeanus strain, the production of CTXs was evaluated with a colorimetric immunoassay and an electrochemical immunosensor resulting in G. belizeanus producing two types of CTX congeners (CTX1B and CTX3C series congeners) and can contribute to CP in 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)

“…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].…”

Epibenthic Harmful Marine Dinoflagellates from Fuerteventura (Canary Islands), with Special Reference to the Ciguatoxin-Producing Gambierdiscus

“…In the Canary archipelago, ciguatera outbreaks could be related with local Gambierdiscus spp. including those identified until date: G. australes, G. caribaeus, G. carolinianus, G. excentricus G. silvae and G. belizeanum [15,30]. The morphometric study of these first five species performed by Bravo et al [26] was applied in the present study with the aim to identify them in samples of Fuerteventura -take into account that the publication of the detection of G. belizeanum in the region was almost coincident with that of the present manuscript.…”

“…G. excentricus displays the highest content of CTXs so far [23,24,50] and its CTX-like toxicity has been comparable to that of G. polynesiensis, the predominant CTX producer in the South Pacific, a ciguatera endemic region. In contrast to the consistent toxicity characteristics of G. excentricus, analyses of G. australes have yielded variable results depending on the strains and their origins [24,30,85,86]. The toxicity of the rest of Gambierdiscus species from the Canary Islands has been very scarcely studied; neuroblastoma cell-based assay (neuro-2a CBA) revealed lower CTX-like toxicity than the former ones (or even none for G. caribaeus), although high intraspecific variability has been also reported [24,30].…”

“…In the present study, Gambierdiscus cells were morphologically characterized to determine to what extent their differences in morphology and size are useful for their specific identification. The methodology used was based on the parameters described by Bravo et al [26] for the five species found in the Canary Islands so far, excepting the very recently reported G. belizeanus by Tudó et al [30]. These morphological traits include cell depth measurement and the shapes of the second apical (2 ) and second antapical (2"") plates, as well as the position of the Po plate.…”

Ciguatera Mini Review: 21st Century Environmental Challenges and the Interdisciplinary Research Efforts Rising to Meet Them

“…Currently, 18 species of Gambierdiscus and 3 of Fukuyoa are described [ 16 , 72 ], exhibiting differences (within- and among-species) in toxicity and compound production [ 29 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ]. Of these, only a few species (i.e., F. paulensis [ 82 ], G. australes [ 83 ], G. toxicus [ 19 , 83 , 84 ], G. polynesiensis [ 20 , 78 , 81 , 85 ]) have thus far been documented to produce significant amounts of CTXs (CTX3B, -3C, -4A, -4B, 2-OH-CTX3C, M-Seco-CTX3C).…”