chironex

Jellyfish envenomation is a global public health risk; Cubozoans (box jellyfish) are a prevalent jellyfish class with some species causing potent and potentially fatal envenomation in tropical Australian waters. Previous studies have explored the mechanism of action of venom from the lethal Cubozoan Chironex fleckeri and from Carukia barnesi (which causes "Irukandji syndrome"), but mechanistic knowledge to develop effective treatment is still limited. This study performed an in-vitro cytotoxic examination of the venoms of Chiropsella bronzie and Malo maxima, two understudied species that are closely related to Chironex fleckeri and Carukia barnesi respectively...

BACKGROUND: Jellyfish envenomation is common in many coastal regions and varies in severity depending upon the species. Stings cause a variety of symptoms and signs including pain, dermatological reactions, and, in some species, Irukandji syndrome (which may include abdominal/back/chest pain, tachycardia, hypertension, cardiac phenomena, and, rarely, death). Many treatments have been suggested for these symptoms, but their effectiveness is unclear. This is an update of a Cochrane Review last published in 2013...

The relative lack of marine venom pharmaceuticals can be anecdotally attributed to difficulties in working with venomous marine animals, including how to maintain venom bioactivity during extraction and purification. The primary aim of this systematic literature review was to examine the key factors for consideration when extracting and purifying jellyfish venom toxins to maximise their effectiveness in bioassays towards the characterisation of a single toxin.An up-to-date database of 119 peer-reviewed research articles was established for all purified and semi-purified venoms across all jellyfish, including their level of purification, LD50, and the types of experimental toxicity bioassay used (e...

An increasing presence on many beaches worldwide, jellyfish are a diverse group of Cnidarians equipped with stinging cells termed cnidocytes. Though few of the over 10,000 species are dangerous to humans, and most that are produce no more than a painful sting, some jellyfish can produce systemic symptoms and even death. Chironex fleckeri, the Australian box jellyfish, has a venom potent enough to kill in less than 10 minutes, and for which there is an antivenom of debatable efficacy. Stings from Carukia barnesi can cause Irukandji syndrome, characterised by severe pain and hypertension...

Jellyfish are ubiquitous animals registering a high and increasing number of contacts with humans in coastal areas. These encounters result in a multitude of symptoms, ranging from mild erythema to death. This work aims to review the state-of-the-art regarding pathophysiology, diagnosis, treatment, and relevant clinical and forensic aspects of jellyfish stings. There are three major classes of jellyfish, causing various clinical scenarios. Most envenomations result in an erythematous lesion with morphological characteristics that may help identify the class of jellyfish responsible...

Lethal jellyfish envenoming is a very rare event. Two illustrative cases of fatalities following envenomation from the multi-tentacled box jellyfish, Chironex fleckeri, are reported that involved a six-year-old boy and a three-year-old girl, both of whom had been playing in shallow beach waters in remote Northern Territory communities (Australia). A recommended approach to autopsy in suspected cases is described, which should include examination of the clothing and skin surfaces for the fine tentacles of Chironex fleckeri...

The exumbrellar surfaces of six pelagic cnidarians from three classes were ultra-structurally compared to reveal their structural diversity in relation to their gelatinous, transparent bodies. We examined two hydrozoans ( Diphyes chamissonis and Colobonema sericeum ), a cubozoan ( Chironex yamaguchii ), and three scyphozoans ( Atolla vanhöffeni , Aurelia coerulea , and Mastigias papua ). The exumbrellar surfaces of the mesoglea in D. chamissonis , Ch. yamaguchii , Au. coerulea , and M. papua were covered with a simple epidermis; the shapes of the epidermal cells were remarkably different among the species...

Background: Most jellyfish species are poisonous. Human victims of jellyfish sting each year are 120 million. Chironex fleckeri is a venomous box jellyfish that inflicts painful and potentially fatal stings to humans. The CfTX-1 is one of the antigenic proteins of venom that is suggested to stimulate the immune system for treatment and vaccine. This study aimed to clone and express the CfTX-1 antigen in E. coli and then to determine the synthesis of related antibody in the mice. Methods: The study was performed in the Persian Gulf and Oman Sea Ecology Research Center, Bandar Abbas, Iran in autumn 2016...

Box jellyfish are extremely potent venom-producing marine organisms. While they have been found worldwide, the highest health burden has been anticipated to be the tropical Indo-Pacific of Southeast Asia (SEA). At least 12 Cubozoan species have now been documented in Thai waters, and many of them inflict acutely lethal strings, especially those under the order Chirodropida. Our previous study has successfully differentiated species of box jellyfish using DNA sequencing to support the morphological study. In this study, we specifically designed polymerase chain reaction (PCR) primers for the 16S ribosomal RNA (rRNA) gene and the mitochondrial DNA cytochrome oxidase subunit I (COI) gene of lethal Thai Chironex species...

Biological investigations on free ranging marine species are regarded as challenging throughout the scientific community. This is particularly true for 'logistically difficult species' where their cryptic natures, low abundance, patchy distributions and difficult and/or dangerous sampling environments, make traditional surveys near impossible. What results is a lack of ecological knowledge on such marine species. However, advances in UAV technology holds potential for overcoming these logistical difficulties and filling this knowledge gap...

Both Chironex fleckeri venom (CFV) and Carukia barnesi venoms (CBV) are known to cause significant cardiac morbidity and mortality. Many animal studies have demonstrated cardiac dysfunction with these venoms. This study specifically examines the systolic and diastolic cardiac functions using non-invasive pulse wave doppler. Mitral and aortic doppler sonograms of anaesthetised mice were obtained utilising a 10 MHz doppler probe. These continuous sonograms were analysed to ascertain changes in cardiac function before and after the parenteral administration of the test venoms...

The large box jellyfish Chironex fleckeri is found in northern Australian waters. A sting from this cubozoan species can kill within minutes. From clinical and animal studies, symptoms comprise severe pain, welts, scarring, hypotension, vasospasms, cardiac irregularities and cardiac arrest. At present, there is no cure and opioids are used to manage pain. Antivenom is available but controversy exists over its effectiveness. Experimental and combination therapies performed in vitro and in vivo have shown varied efficacy...

The emergence of novel venom extraction techniques over the last half-century has greatly facilitated advances in the field of cnidarian research. A new recovery protocol utilizing ethanol as the primary stimulant in nematocyst discharge was recently published, however in vitro examination of the venom on organic models was not performed. This present study reports an original comparison of the chemically-induced discharge technique in vitro with a commonly used saltwater extraction method. Size-exclusion chromatography revealed distinct differences in venom profiles between the two methods: the saltwater recovery method FPLC profile and SDS-PAGE gel were similar to previously published results, whereas the ethanol-induced method was not...

Cubozoan nematocyst venoms contain known cytolytic and hemolytic proteins, but small molecule components have not been previously reported from cubozoan venom. We screened nematocyst extracts of Alatina alata and Chironex yamaguchii by LC-MS for the presence of small molecule metabolites. Three isomeric compounds, cnidarins 4A ( 1 ), 4B ( 2 ), and 4C ( 3 ), were isolated from venom extracts and characterized by NMR and MS, which revealed their planar structure as cyclic γ-linked tetraglutamic acids. The full configurational assignments were established by syntheses of all six possible stereoisomers, comparison of spectral data and optical rotations, and stereochemical analysis of derivatized degradation products...

Aim: Jellyfish known as "habu-kurage" ( Chironex yamaguchii ) inhabit the waters surrounding Okinawa and Amami, Japan, and jellyfish stings are limited to areas outside the Japanese main island. However, the shifts promoted by global warming and increasingly intensive interactions with people have led to concerns regarding the possibility of increased jellyfish stings on the main island of Japan. Similar concerns are being raised all over the world. However, studies examining clinical characteristics of jellyfish stings have been limited to Australia, the USA, Europe, and South-East Asia...

The box jellyfish Chironex fleckeri is extremely venomous, and envenoming causes tissue necrosis, extreme pain and death within minutes after severe exposure. Despite rapid and potent venom action, basic mechanistic insight is lacking. Here we perform molecular dissection of a jellyfish venom-induced cell death pathway by screening for host components required for venom exposure-induced cell death using genome-scale lenti-CRISPR mutagenesis. We identify the peripheral membrane protein ATP2B1, a calcium transporting ATPase, as one host factor required for venom cytotoxicity...

BACKGROUND: The phyla Cnidaria, Placozoa, Ctenophora, and Porifera emerged before the split of proto- and deuterostome animals, about 600 million years ago. These early metazoans are interesting, because they can give us important information on the evolution of various tissues and organs, such as eyes and the nervous system. Generally, cnidarians have simple nervous systems, which use neuropeptides for their neurotransmission, but some cnidarian medusae belonging to the class Cubozoa (box jellyfishes) have advanced image-forming eyes, probably associated with a complex innervation...

The Australian jellyfish Chironex fleckeri , belongs to a family of cubozoan jellyfish known for their potent venoms. CfTX-1 and -2 are two highly abundant toxins in the venom, but there is no structural data available for these proteins. Structural information on toxins is integral to the understanding of the mechanism of these toxins and the development of an effective treatment. Two regions of CfTX-1 have been predicted to have helical structures that are involved with the mechanism of action. Here we have synthesized peptides corresponding to these regions and analyzed their structures using NMR spectroscopy...

Our team aimed to create a new, simple, and inexpensive technique for collecting and transferring of toxic jellyfish specimens and for nematocysts identification. We collected tentacles of Chironex spp., Morbakka spp., and Physalia spp., and transferred them from the beaches by standard and by 'vacuum sticky tape' (VST) techniques. For the VST technique, our team placed the sticky tape on a tentacle and then folded it over to seal the tentacle in the equivalent of a vacuum. We kept the VST in room temperature...

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