Phylogeography of Ostreopsis along West Pacific Coast, with Special Reference to a Novel Clade from Japan

BACKGROUND: A dinoflagellate genus Ostreopsis is known as a potential producer of Palytoxin derivatives. Palytoxin is the most potent non-proteinaceous compound reported so far. There has been a growing number of reports on palytoxin-like poisonings in southern areas of Japan; however, the distribution of Ostreopsis has not been investigated so far. Morphological plasticity of Ostreopsis makes reliable microscopic identification difficult so the employment of molecular tools was desirable. METHODS/PRINCIPAL FINDING: In total 223 clones were examined from samples mainly collected from southern areas of Japan. The D8-D10 region of the nuclear large subunit rDNA (D8-D10) was selected as a genetic marker and phylogenetic analyses were conducted. Although most of the clones were unable to be identified, there potentially 8 putative species established during this study. Among them, Ostreopsis sp. 1-5 did not belong to any known clade, and each of them formed its own clade. The dominant species was Ostreopsis sp. 1, which accounted for more than half of the clones and which was highly toxic and only distributed along the Japanese coast. Comparisons between the D8-D10 and the Internal Transcribed Spacer (ITS) region of the nuclear rDNA, which has widely been used for phylogenetic/phylogeographic studies in Ostreopsis, revealed that the D8-D10 was less variable than the ITS, making consistent and reliable phylogenetic reconstruction possible. CONCLUSIONS/SIGNIFICANCE: This study unveiled a surprisingly diverse and widespread distribution of Japanese Ostreopsis. Further study will be required to better understand the phylogeography of the genus. Our results posed the urgent need for the development of the early detection/warning systems for Ostreopsis, particularly for the widely distributed and strongly toxic Ostreopsis sp. 1. The D8-D10 marker will be suitable for these purposes

Characterisation of new analogues of palytoxin isolated from an Ostreopsis mascarenensis bloom in the south-western Indian Ocean

A preliminary screening of toxins of the crude extract of Ostreopsis mascarenensis Quod, a benthic dinoflagellate from the south-western Indian Ocean, revealed a neurotoxicity in mice similar to that induced by palytoxin,one of the most potent marine toxins involved in seafood poisoning. The highest toxicity was retained in the butanol-soluble fraction, revealing a strong haemolytic activity, as found for palytoxin. Analyses usinghigh-performance liquid chromatography with ultraviolet detection allowed the detection of two new toxins named mascarenotoxins (McTXs). Their mass spectrum profile and fragmentation pattern, obtained by advancednano-ESI-Q-TOF mass spectrometry of purified McTXs, were similar to those of a reference palytoxin. They were identified as palytoxin analogues, with the characterisation of a specific fragment ion m/z 327. O. mascarenensisis a species not previously known to produce palytoxin analogues

Incidence and clinical characteristics of ciguatera fish poisoning in Guadeloupe (French West Indies) between 2013 and 2016: a retrospective cases-series

Abstract This retrospective case study analysed the incidence and symptoms of ciguatera fish poisoning (ciguatera) in Guadeloupe (French West Indies) between 2013 and 2016. Cases attending the emergency departments of the two public hospitals and the reports received by the regional health authority in charge of monitoring (ARS) were compiled. Two hundred and thirty-four cases of poisoning were observed, with a mean annual incidence of 1.47/10,000 (95% CI): 1.29–1.66), i.e 5 times higher than the previously reported incidence (1996–2006). The main species described as being responsible for poisoning were fish from the Carangidae family (n = 47) (jack), followed by fish from the Lutjanidae family (n = 27) (snapper), Serranidae family (n = 15) (grouper), Sphyraenidae family (n = 12) (barracuda), and Mullidae family (n = 12) (goatfish). One case of lionfish ciguatera was observed. 93.9% of patients experienced gastrointestinal symptoms, 76.0% presented neurological signs (mainly paresthesia, dysesthesia and pruritus) and 40.3% presented cardiovascular symptoms (bradycardia and/or hypotension). A high frequency (61.4%) of hypothermia (body temperature <36.5 °C) was observed. This study reports for the first time the relatively high frequency of cardiac symptoms and low body temperature. The monitoring of ciguatera poisoning throughout the Caribbean region must be improved, notably after reef disturbance due to Irma and Maria major cyclones

Multi-disciplinary approach for coral reef management in Eparses Islands, SWIO

International audienceOral presentation about Multi-disciplinary approach for coral reef management in Eparses Islands, SWIO in 12th International Coral Reef Symposiu

Multi-disciplinary approach for coral reef management in Eparses Islands, SWIO

International audienceOral presentation about Multi-disciplinary approach for coral reef management in Eparses Islands, SWIO in 12th International Coral Reef Symposiu

First ciguatera outbreak in Germany in 2012

Im November 2012 traten in Deutschland nach dem Verzehr von importiertem Tropenfisch (Lutjanus spp.) 23 Vergiftungen mit der für Ciguatera typischen Kombination gastrointestinaler und neurologischer Symptome auf. Anhand eines Fragebogens wurden der Krankheitsverlauf und Informationen zum Fischverzehr erfasst. Alle Patienten litten an der pathognomonischen Kaltallodynie. Zwei Patienten hatten schwere Symptome, die anderen Fälle verliefen mittelschwer. Im Rahmen des 3‑Jahres-Follow-up berichteten sieben Patienten von länger als ein Jahr anhaltenden Parästhesien. Bei zwei Patienten konnten fast drei Jahre anhaltende Neuropathien detailliert dokumentiert werden. Die Patienten können acht Clustern in sieben deutschen Städten zugeordnet werden. Ein weiteres potenzielles Cluster wurde durch den geglückten Rückruf bereits verkaufter, Ciguatoxin-haltiger Ware verhindert. Drei Cluster wurden durch den Nachweis von Ciguatoxin in Rückruf- und Verdachtsproben objektiviert. Eine Hochrechnung auf der Basis Ciguatoxin-haltiger Proben ergab etwa 20 verhinderte Erkrankungsfälle. Im Rahmen der Ausbruchsaufklärung wurden irrtümlich widersprüchliche Kennzeichnungen auf den Lieferpapieren hinsichtlich der an den Einzelhandel gelieferten Fischart sowie deren Fanggebiet bekannt. Durch die uneinheitliche Vorgehensweise bei den Meldungen an Giftinformationszentren, Veterinär- und Gesundheitsämter erwiesen sich die Erfassung der Fälle und die Aufklärung des Ciguatera-Ausbruchs als schwierig. Vielen Ärzten in Deutschland ist das durch Tropenfisch verursachte Krankheitsbild bislang unzureichend bekannt. Das Auftreten weiterer Ausbrüche in den Folgejahren unterstreicht die zunehmende Bedeutung von Ciguatera in Deutschland.In November 2012, 23 cases of ciguatera with typical combinations of gastrointestinal and neurological symptoms occurred in Germany after consumption of imported tropical fish (Lutjanus spp.). A questionnaire was used to gather information on the disease course and fish consumption. All patients suffered from pathognomonic cold allodynia. Aside from two severe courses of illness, all other cases showed symptoms of moderate intensity. During a three-year follow-up, seven patients reported prolonged paresthesia for more than one year. Two of them reported further neuropathies over almost three years. This is the first time that long-term persistence of symptoms has been documented in detail. Outbreak cases were allocated to eight clusters in seven German cities. A further cluster was prevented by the successful recall of ciguatoxic fish. Three clusters were confirmed by the detection of ciguatoxin in samples of suspicious and recalled fish. An extrapolation on the basis of ciguatoxic samples revealed twenty prevented cases of ciguatera. Further officially unknown cases should be assumed. During the outbreak investigations, inadvertently falsely labelled fish species and fishing capture areas on import and retail level documents were observed. The ascertainment of cases and the outbreak investigations proved to be difficult due to inconsistent case reports to poisons centers, local health and veterinary authorities. In Germany, many physicians are unaware of the disease pattern of ciguatera and the risks caused by tropical fish. The occurrence of further outbreaks during the following years emphasizes the increasing significance of ciguatera in Germany

Ciguatoxin and ciguatera

Ciguatera is a disease caused by the consumption of fishes from tropical and subtropical waters that have accumulated lipophilic sodium channel activator toxins known as ciguatoxins (CTXs) to levels sufficient to cause human poisoning. Consumption of these temperature-stable, orally active polycyclic ether compounds leads to the activation of neuronal sodium channels that produces a range of characteristic neurological, gastrointestinal, and cardiovascular signs and symptoms that clinically define the illness. Ciguatera is estimated to affect similar to 50,000 people annually worldwide after accounting for misdiagnosis and non-reporting. Currently there are no clinically validated treatments and no routine tests that can cost-effectively detect ciguatoxins prior to consumption, with government bans on capture or personal avoidance of risk fish species providing the only effective means to mitigate the risk currently. A recently developed rapid extraction method for ciguatoxins coupled to LC/MS/MS detection has potential for surveillance and confirmation of ciguatera outbreaks