The Epiphytic Genus Gambierdiscus (Dinophyceae) in the Kermadec Islands and Zealandia Regions of the Southwestern Pacific and the Associated Risk of Ciguatera Fish Poisoning.

Tom Trnski,Kirsty Smith,Sam Murray,Lesley Rhodes,Rex Munday,D. Harwood

doi:10.3390/md15070219

Tom Trnski, Kirsty Smith + Show 4 more

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https://doi.org/10.3390/md15070219

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Journal: Marine drugs	Publication Date: Jul 11, 2017
Citations: 32	License type: CC BY 4.0

Affiliation: Cawthron Institute, AgResearch

Abstract

Species in the genus Gambierdiscus produce ciguatoxins (CTXs) and/or maitotoxins (MTXs), which may cause ciguatera fish poisoning (CFP) in humans if contaminated fish are consumed. Species of Gambierdiscus have previously been isolated from macroalgae at Rangitahua (Raoul Island and North Meyer Islands, northern Kermadec Islands), and the opportunity was taken to sample for Gambierdiscus at the more southerly Macauley Island during an expedition in 2016. Gambierdiscus cells were isolated, cultured, and DNA extracted and sequenced to determine the species present. Bulk cultures were tested for CTXs and MTXs by liquid chromatography-mass spectrometry (LC-MS/MS). The species isolated were G. australes, which produced MTX-1 (ranging from 3 to 36 pg/cell), and G. polynesiensis, which produced neither MTX-1 nor, unusually, any known CTXs. Isolates of both species produced putative MTX-3. The risk of fish, particularly herbivorous fish, causing CFP in the Zealandia and Kermadec Islands region is real, although in mainland New Zealand the risk is currently low. Both Gambierdiscus and Fukuyoa have been recorded in the sub-tropical northern region of New Zealand, and so the risk may increase with warming seas and shift in the distribution of Gambierdiscus species.

Highlights

Gambierdiscus Adachi and Fukuyo is an epiphytic dinoflagellate genus found attached to macroalgae, dead corals and volcanic sands throughout the world’s tropical regions [1,2]
The toxins produced by some Gambierdiscus species include ciguatoxins (CTXs), maitotoxin (MTX) and its analogues, gambieric acids, gambieroxide, gambierol and gambierone [3]
Isolates of Gambierdiscus from Macauley Island were predominantly the MTX-1 producer, G. australes, and the best producers have been retained for further research, including full characterisation of MTX-3

Summary

Introduction

Gambierdiscus Adachi and Fukuyo is an epiphytic dinoflagellate genus found attached to macroalgae, dead corals and volcanic sands throughout the world’s tropical regions [1,2]. In the Pacific region, Gambierdiscus is found on macroalgae, filamentous red macroalgae, coralline turfs, and the calcareous green genus, Halimeda, and on the volcanic debris that is common in the active zones. Species in the Gambierdiscus genus are the causative organisms of ciguatera fish poisoning (CFP) [2]. The toxins produced by some Gambierdiscus species include ciguatoxins (CTXs), maitotoxin (MTX) and its analogues, gambieric acids, gambieroxide, gambierol and gambierone [3]. CTXs are considered the main cause of CFP, the economic impacts of which on Pacific Island communities are just beginning to be recognized. The illness is widely under-reported and may include gastrointestinal and neurological

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