OBJECTIVEImpact of the presence of bacteria associated with a marine dinoflagellate, Alexandrium tamarense CI01, on the growth and toxin production of the algae in batch culture was investigated.

METHODSPronounced changes in the activities of the algal culture were observed when the culture was treated with different doses of a mixture of penicillin and streptomycin.

RESULTSIn the presence of antibiotics at the initial concentration of 100 u/mL in culture medium, both algal growth and toxin yield increased markedly. When the concentration of antibiotics was increased to 500 u/mL, the microalgal growth was inhibited, but resumed in a few days to eventually reach the same level of growth and toxin production as at the lower dose of the antibiotics. When the antibiotics were present at a concentration of 1 000 u/mL, the algal growth was inhibited permanently.

CONCLUSIONSThe results indicate that antibiotics can enhance algal growth and toxin production not only through their inhibition of the growth and hence competition for nutrients, but also through their effects on the physiology of the algae.

Animals ; Anti-Bacterial Agents ; pharmacology ; Bacteria ; Dinoflagellida ; microbiology ; pathogenicity ; Eutrophication ; Marine Toxins ; biosynthesis ; Penicillins ; pharmacology ; Saxitoxin ; Streptomycin ; pharmacology

Paralytic shellfish poisoning results from consumption of mollusks that have fed on dinoflagellates capable of producing neurotoxins such as saxitoxin. The saxitoxin is concentrated in the shellfish and acts by decreasing sodium-channel permeability, thereby blocking neuronal transmission in skeletal muscles. Symptoms including paresthesia, perioral numbness, perioral tingling, nausea, vomiting, extremity numbness, extremity tingling, dizziness, ataxia, dysphagia, and weakness have been reported. In serious cases, respiratory hold may occur up to 6~24 hours after ingestion. Generally, the treatment for paralytic shellfish poisoning is supportive care, but mechanical ventilation is needed in serious cases acompanied by respiratory hold. We experienced two cases of paralytic shellfish poisoning. Respiratory hold was presented in one case and only mild paresthesia in the other case. After supportive management, including mechanical ventilation in former case, both patients were discharged without sequalae.
Ataxia ; Deglutition Disorders ; Dinoflagellida ; Dizziness ; Eating ; Extremities ; Humans ; Hypesthesia ; Mollusca ; Muscle, Skeletal ; Nausea ; Neurons ; Neurotoxins ; Paresthesia ; Permeability ; Respiration, Artificial ; Saxitoxin* ; Shellfish ; Shellfish Poisoning* ; Vomiting

AIMTo isolate and purify gonyautoxins from Alexandrium mimutum Halim Amtk2 strain.

METHODSThe ethanol extracts of culture Alexandriun minutum Halim Amtk2 were isolated by means of gel filtration chromatography, the toxin fraction obtained was then purified by ion exchange chromatography.

RESULTSFrom 100 liter of cultivation liquid of Alexandrium mimutum Halim Amtk2 (6.74 +/- 0.31) x 10(9) cells were obtained. The ethanol extracts of Alexandriun minutum Halim purified by gel filtration chromatography obtained gonyautoxins mixture 29.59 mg. 4.06 mg of the mixture was further purified by two steps of ion exchange chromatography, and obtained pure GTX-4 (0.40 +/- 0.002) mg, GTX-1 (5.95 +/- 0.03) x 10(-2) mg, GTX-3 (6.92 +/- 0.05) x 10(-4) mg and GTX-2 (0.11 +/- 0.005) mg.

CONCLUSIONPure gonyautoxins can be obtained by means of gel filtration chromatography and ion exchange chromatography from ethanol extracts of cultured Alexandriun minutum Halim Amtk2 strain.

Animals ; Chromatography, Gel ; methods ; Chromatography, Ion Exchange ; Dinoflagellida ; chemistry ; Marine Toxins ; chemistry ; isolation & purification ; Molecular Structure ; Saxitoxin ; analogs & derivatives ; chemistry ; isolation & purification

This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.
Acrylamides ; chemistry ; isolation & purification ; toxicity ; Animals ; Anthozoa ; pathogenicity ; physiology ; Dinoflagellida ; pathogenicity ; physiology ; Dogs ; Guinea Pigs ; Haplorhini ; Humans ; Lethal Dose 50 ; Marine Toxins ; chemistry ; isolation & purification ; toxicity ; Mice ; Rabbits ; Rats ; Seaweed ; pathogenicity ; physiology ; Shellfish Poisoning ; physiopathology ; Sodium-Potassium-Exchanging ATPase ; metabolism

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.
Amnesia ; chemically induced ; Animals ; China ; epidemiology ; Ciguatoxins ; toxicity ; Diarrhea ; chemically induced ; Dinoflagellida ; Environment ; Eukaryota ; chemistry ; Eutrophication ; Fisheries ; Food Contamination ; Foodborne Diseases ; epidemiology ; etiology ; Humans ; Kainic Acid ; analogs & derivatives ; poisoning ; Lethal Dose 50 ; Marine Toxins ; chemistry ; poisoning ; toxicity ; Neurotoxicity Syndromes ; etiology ; Okadaic Acid ; poisoning ; Oxocins ; poisoning ; Paralysis ; chemically induced ; Seawater ; Shellfish Poisoning