Partial purification of Chironex fleckeri (sea wasp) venom by immunochromatography with antivenom

The pharmacology of Malo maxima jellyfish venom extract in isolated cardiovascular tissues: A probable cause of the Irukandji syndrome in Western Australia

The in vitro cardiac and vascular pharmacology of Malo maxima, a newly described jellyfish suspected of causing Irukandji syndrome in the Broome region of Western Australia, was investigated in rat tissues. In left atria, M. maxima crude venom extract (CVE; 1-100μg/mL) caused concentration-dependent inotropic responses which were unaffected by atropine (1μM), but significantly attenuated by tetrodotoxin (TTX; 0.1μM), propranolol (1μM), Mg(2+) (6mM) or calcitonin gene-related peptide antagonist (CGRP(8-37); 1μM). CVE caused no change in right atrial rate until 100μg/mL, which elicited bradycardia. This was unaffected by atropine, TTX, propranolol or CGRP(8-37). In the presence of Mg(2+), CVE 30-100μg/mL caused tachycardia. In small mesenteric arteries CVE caused concentration-dependent contractions (pEC(50) 1.03±0.07μg/mL) that were unaffected by prazosin (0.3μM), ω-conotoxin GVIA (0.1μM) or Mg(2+) (6mM). There was a 2-fold increase in sensitivity in the presence of CGRP(8-37) (3μM). TTX (0.1μM), box jellyfish Chironex fleckeri antivenom (92.6U/mL) and benextramine (3μM) decreased sensitivity by 2.6, 1.9 and 2.1-fold, respectively. CVE-induced maximum contractions were attenuated by C. fleckeri antivenom (-22%) or benextramine (-49%). M. maxima CVE appears to activate the sympathetic, but not parasympathetic, nervous system and to stimulate sensory nerve CGRP release in left atria and resistance arteries. These effects are consistent with the catecholamine excess thought to cause Irukandji syndrome, with additional actions of CGRP release.

Australian venomous jellyfish, envenomation syndromes, toxins and therapy

The seas and oceans around Australia harbour numerous venomous jellyfish. Chironex fleckeri, the box jellyfish, is the most lethal causing rapid cardiorespiratory depression and although its venom has been characterised, its toxins remain to be identified. A moderately effective antivenom exists which is also partially effective against another chirodropid, Chiropsalmus sp. Numerous carybdeids, some unidentified, cause less severe illness, including Carybdea rastoni whose toxins CrTX-A and CrTX-B are large proteins. Carukia barnesi, another small carybdeid is one cause of the 'Irukandji' syndrome which includes delayed pain from severe muscle cramping, vomiting, anxiety, restlessness, sweating and prostration, and occasionally severe hypertension and acute cardiac failure. The syndrome is in part caused by release of catecholamines but the cause of heart failure is undefined. The venom contains a sodium channel modulator. Two species of Physalia are present and although one is potentially lethal, has not caused death in Australian waters. Other significant genera of jellyfish include Tamoya, Pelagia, Cyanea, Aurelia and Chyrosaora.

Cardiovascular actions of the venom from the Irukandji (Carukia barnesi) jellyfish: effects in human, rat and guinea-pig tissues in vitro and in pigs in vitro

1. We have investigated the cardiovascular pharmacology of the crude venom extract (CVE) from the potentially lethal, very small carybdeid jellyfish Carukia barnesi, in rat, guinea-pig and human isolated tissues and anaesthetized piglets. 2. In rat and guinea-pig isolated right atria, CVE (0.1-10 microg/mL) caused tachycardia in the presence of atropine (1 micromol/L), a response almost completely abolished by pretreatment with tetrodotoxin (TTX; 0.1 micromol/L). In paced left atria from guinea-pig or rat, CVE (0.1-3 microg/mL) caused a positive inotropic response in the presence of atropine (1 micromol/L). 3. In rat mesenteric small arteries, CVE (0.1-30 microg/mL) caused concentration-dependent contractions that were unaffected by 0.1 micromol/L TTX, 0.3 micromol/L prazosin or 0.1 micromol/L omega-conotoxin GVIA. 4. Neither the rat right atria tachycardic response nor the contraction of rat mesenteric arteries to CVE were affected by the presence of box jellyfish (Chironex fleckeri) antivenom (92.6 units/mL). 5. In human isolated driven right atrial trabeculae muscle strips, CVE (10 microg/mL) tended to cause an initial fall, followed by a more sustained increase, in contractile force. In the presence of atropine (1 micromol/L), CVE only caused a positive inotropic response. In separate experiments in the presence of propranolol (0.2 micromol/L), the negative inotropic effect of CVE was enhanced, whereas the positive inotropic response was markedly decreased. 6. In anaesthetized piglets, CVE (67 microg/kg, i.v.) caused sustained tachycardia and systemic and pulmonary hypertension. Venous blood samples demonstrated a marked elevation in circulating levels of noradrenaline and adrenaline. 7. We conclude that C. barnesi venom may contain a neural sodium channel activator (blocked by TTX) that, in isolated atrial tissue (and in vivo), causes the release of transmitter (and circulating) catecholamines. The venom may also contain a 'direct' vasoconstrictor component. These observations explain, at least in part, the clinical features of the potentially deadly Irukandji syndrome.

Jellyfish envenoming syndromes: unknown toxic mechanisms and unproven therapies

Interest in envenoming syndromes caused by Australian jellyfish has been intense since the deaths in early 2002 of two tourists in Queensland, attributed to the Irukandji syndrome. We review current knowledge of these envenoming syndromes, mechanisms of venom action and therapy, focusing on the deadly box jellyfish, Chironex fleckeri, and the array of jellyfish thought to cause the Irukandji syndrome. Current understanding of jellyfish venom activity is very limited, and many treatments are unproven and based on anecdote.

Partial purification of box jellyfish (Chironex fleckeri) nematocyst venom isolated at the beachside

Chironex fleckeri, the northern Australian box jellyfish produces one of, if not, the most potent animal venoms. Study of the venom has been hampered by the limits of the animals' range and the venom's thermolability. Using retained lethality and native polyacrylamide gel electrophoresis (NPAGE), we show that lyophilization of autolysis isolated nematocysts is an effective method of transporting the venom. In addition, Sephadex G-200 chromatography, spin concentration, and NPAGE fail to demonstrate the presence of a 600 kDa protein to which the bulk of the lethal activity has been ascribed. Sodium dodecyl sulfate capillary electrophoresis of crude venom yields several protein bands with a molecular weight range of 30-200 kDa. Freeze-thaw studies show a loss of activity and NPAGE bands after two freeze thaw cycles.

Biologically active polypeptides in the venom of the jellyfish Rhopilema nomadica

A tropical jellyfish, Rhopilema nomadica (Scyphozoa, Rhizostomeae) has recently invaded the eastern Mediterranean. Its painful stings have been the bane of bathers and fishermen from Egypt to Turkey. This paper reports on the presence of haemolytic activity and alpha-chymotrypsin-like serine protease activity in the venom of the R. nomadica nematocysts. In addition, the presence of phospholipase A2 activity, which has been described previously, is confirmed. Some properties of these activities are defined.

Purification and properties of a cytolytic toxin in venom of the jellyfish Carybdea marsupialis

A haemolytic toxin was purified by ion-exchange chromatography and FPLC gel filtration from the nematocysts of the jellyfish Carybdea marsupialis. Sheep red cells, but not human or rabbit red cells, were susceptible to lysis by the toxin. The toxin is a protein with an apparent molecular mass of about 102-107 kDa, is heat labile, highly unstable in polar media, inactivated by reducing agents, and devoid of phospholipase activity. The experimental data speak in favour of a pore-forming mechanism of toxin action.

Monoclonal antibodies neutralizing the haemolytic activity of box jellyfish (Chironex fleckeri) tentacle extracts

1. Three monoclonal antibodies have been produced which neutralize in vitro the haemolytic activity present in tentacle extracts of the box jellyfish (Chironex fleckeri). 2. Two of these monoclonal antibodies bound specifically to a component of relative molecular mass 50,000 in tentacle extract on Western blots. 3. This binding only occurred when the extracts were electrophoresed under non-reducing conditions. 4. The third monoclonal antibody did not display binding to Western blots of tentacle extract under any of our experimental conditions.

Toxins from the box-jellyfish Chironex fleckeri

Two myotoxins (T1 and T2) with mol. wts of approximately 600,000 and 150,000, respectively, and a haemolysin (T3) with a mol. wt of approximately 70,000 were isolated from the crude nematocyst venom of C. fleckeri by the use of Sephadex G-200 chromatography. A neurotoxic fraction (T4) and a haemolytic fraction (T5) containing proteins with apparent mol. wts of approximately 150,000 and 70,000, respectively, were also isolated by Sephadex chromatography from crude extracts of tentacular material from which nematocysts had been removed. The three nematocyst toxins and the two toxic fractions from tentacle extracts were lethal to mice on i.v. injection. After SDS-PAGE the myotoxins T1 and T2 yielded similar major bands corresponding with mol. wts different from those yielded by T3 and the toxic tentacle fractions. T1 and T2 appeared to be comprised of aggregations of subunits with mol. wts of approximately 18,000. On HPLC, crude nematocyst venom and the nematocyst toxins T1 and T2 lost their myotoxic properties. The need for thorough removal of extraneous tentacular material from isolated nematocysts, the need for effective rupture of nematocysts, the need to counter the lability of the nematocyst venom and the need to use myotoxicity as a criterion of venom activity if the active components of the venom are to be purified and characterized are emphasized.

Verapamil potentiation of Chironex (box-jellyfish) antivenom

'Rescue' experiments were performed on mice to compare the efficacy of i.v. verapamil, box-jellyfish antivenom, and a combination of both agents to counter the effects of toxic material extracted from the tentacles of Chironex fleckeri. In each of three series of experiments, four sets of mice were injected with doses of Chironex tentacle extracts containing approximately 4 mg/ml protein which were equivalent to twice the LD50. Three of these groups also received verapamil alone, antivenom alone, or a combination of both treatments. The combination therapy of drug and antivenom was superior to either agent alone. Treatment of verapamil alone appeared to be equivalent to that with only antivenom.

Fatal envenomation by Chironex fleckeri, the north Australian box jellyfish: the continuing search for lethal mechanisms

A child with severe envenomation by Chironex fleckeri presented in cardiac arrest at a hospital between 15 and 20 min after the sting was sustained. Resuscitation was not successful. Objective confirmation of C. fleckeri as the cause of death is described. Four metres of tentacle contact in this case represents the smallest-measured fatal C. fleckeri sting that has been recorded so far. The mechanism of this death was toxic and not allergic. The available clinical information suggests direct myocardial interference, but does not exclude a respiratory hypoxic element. A more widespread venom-induced functional disruption of the cell membrane is postulated, with a resultant dysfunction in several vital organ systems that were acting in concert. Early, vigorous and sustained resuscitation that is performed as a first-aid measure offers the best hope of prehospital survival after a massive C. fleckeri sting, which is the most explosive envenomation process that is presently known to humans. In-hospital resuscitation from unresponsive circulatory arrest should now involve intravenously-administered verapamil (or its equivalent) and additional box-jellyfish antivenom, while the patient is being monitored.

The effectiveness of antivenom in countering the actions of box-jellyfish (Chironex fleckeri) nematocyst toxins in mice

The neutralizing ability of commercially available antivenom prepared against 'milked' box-jellyfish (Chironex fleckeri) venom was tested intravenously in mice against crude nematocyst venom obtained by crushing isolated nematocysts and against each of two lethal toxins (T1 and T2) present in this venom. The in vitro neutralizing ability of the antivenom against crude venom was reduced markedly compared with its reported neutralizing ability against 'milked' venom whilst the in vivo neutralizing ability of the antivenom tested in both prophylactic and rescue experiments involving crude nematocyst venom was reduced approximately threefold. When tested in vitro and prophylactically in vivo the neutralizing ability of the antivenom was much more pronounced against T2 than against T1. This finding was in accord with the view that T1 was absent from the 'milked' venom against which the antivenom was prepared. Doses of crude venom in excess of twice the lethal dose killed mice within 2-3 min emphasizing the need for speed in the administration of antivenom.

Purification of Chironex fleckeri venom components using Chironex immunoaffinity chromatography

A comparison of the purification of the nematocyst venom of Chironex fleckeri by affinity immunochromatography using 13 different monoclonal antibodies was made. Varying degrees of purification of mouse lethal factor, hemolysin and dermonecrotic factors, as well as antigen positive proteins were achieved with each of the monoclonal antibodies. Although the protein curves of the chromatography were similar, each of the monoclonal antibody columns had a distinctive pharmacological and SDS-PAGE profile. At least two hemolysins (120,000 and 70,000 molecular weight), two dermonecrotic principles (120,000, less than 120,000) and three lethal factors (120,000, 70,000 and 14,500 molecular weight) were detected. The degree to which aggregation and fragmentation affects the molecular weights of these proteins is not known. It appears that multiple pharmacological activities are present within the same molecule since it is only with great difficulty that a pharmacological activity can be assigned to a specific molecular weight.

Venomous pelagic coelenterates: chemistry, toxicology, immunology and treatment of their stings

Ten years have elapsed since our last review article on the toxicology of venomous pelagic coelenterates was published (Burnett and Calton, 1977). Investigation on important medusae and the chemistry of their nematocyst venoms have been expanding. The venomous jellyfish discussed here include the Portuguese man-o'war, (Physalia physalis), the sea nettle (Chrysaora quinquecirrha), the box jellyfish (Chironex fleckeri and/or Chiropsalmus quadrigatus), the cabbage head jellyfish (Stomolophus meleagris), the lion's mane jellyfish (Cyanea capillata), the Irukandji jellyfish (Carukia barnesi), the Moreton Bay Carybdeid medusa (Morbakka), and the mauve blubber (Pelagia noctiluca).