When ingested by humans, saxitoxin causes paralytic shellfish poisoning, or PSP, symptoms of which include tingling, numbness, and, if consumed in high enough quantities, paralysis, asphyxiation and death. There is no known cure for saxitoxin poisoning.
What is the cause of saxitoxin?
Exposure to saxitoxin most commonly occurs following ingestion of certain fish that contain it in their tissues. Ingestion of saxitoxin can cause numbness of the oral mucosa as quickly as 30 minutes after exposure.
Where is saxitoxin found?
Saxitoxins are produced in freshwater and marine environments. In marine environments, they are often referred to as PSPs. Most human saxitoxin toxicoses have been associated with the ingestion of marine shellfish, which accumulate saxitoxins produced by marine dinoflagellates (Cusick and Sayler, 2013).
How is saxitoxin treated?
While most patients recover without treatment, weakness may rapidly progress to respiratory paralysis and asphyxiation. Currently there are no antidotes to saxitoxin and treatment is supportive.
What organisms use saxitoxin?
Saxitoxins represent an extraordinary class of potent neurotoxins as they can be produced by marine eukaryotic dinoflagellates (e.g. Alexandrium and Gymnodinium) as well as freshwater and marine prokaryotic cyanobacteria (e.g. Anabaena, Cylindrospermopsis, Lyngbya and Trichodesmium).
How does saxitoxin cause paralysis?
Saxitoxin, like CTX and tetrodotoxin, causes paralysis by blocking sodium channels in nerve cell membranes. It is 50 times more potent than curare. Saxitoxin and other toxins that cause PSP are heat stable and are not destroyed by normal cooking procedures, marinating, or freezing.
How do you prevent saxitoxin?
- Buy shellfish from reliable and licensed seafood shops;
- Remove the viscera, gonads and roe before cooking;
- Eat a smaller amount of shellfish in any one meal and avoid consuming the cooking liquid;
What is saxitoxin biology?
Saxitoxin is a neurotoxin that acts as a selective, reversible, voltage-gated sodium channel blocker. One of the most potent known natural toxins, it acts on the voltage-gated sodium channels of neurons, preventing normal cellular function and leading to paralysis.
Is saxitoxin a bacteria?
Saxitoxin is made by aquatic bacteria and plankton. Although humans can die from eating shellfish contaminated with it, the compound’s nerve-blocking activity might make it useful as a long-lasting anaesthetic.
Is saxitoxin a neurotoxin?
Saxitoxin and its derivatives, collectively referred to as paralytic shellfish toxins (PSTs), are unique among neurotoxins in that they are found in both marine and freshwater environments by organisms inhabiting two kingdoms of life.
Is saxitoxin a protein?
Dinoflagelates and cyanobacteria produce saxitoxin (STX), a lethal bis-guanidinium neurotoxin causing paralytic shellfish poisoning. A number of metazoans have soluble STX-binding proteins that may prevent STX intoxication.
Do dinoflagellates produce saxitoxin?
In general, saxitoxin is produced by freshwater cyanobacteria and marine dinoflagellates [3].
Can you get sick from mussels?
It has been known for a long time that consumption of mussels and other bivalve shellfish can cause poisoning in humans, with symptoms ranging from diarrhea, nausea, and vomiting to neurotoxicological effects, including paralysis and even death in extreme cases.
Can red tide be cooked out?
Boiling does not destroy the toxin. … Cutting off and discarding the black tip of butter clam necks removes much of the toxin, but the rest of the clam could still contain hazardous amounts of the toxin. Soaking the live shellfish in water from a PSP-free area to purge them is unreliable.
How do you treat mussel poisoning?
There is no specific cure available for shellfish poisoning, and antibiotics do not shorten the illness. Drugs used to control diarrhea, vomiting, and stomach cramps should not be used except for bismuth (Pepto-Bismol). These drugs are referred to as antimotility drugs since they decrease stomach and intestine motion.
How does Batrachotoxin affect action potential?
Lipid-soluble toxins such as batrachotoxin act directly on sodium ion channels involved in action potential generation and by modifying both their ion selectivity and voltage sensitivity.
What produces microcystin?
Microcystins (MCs) are a family of chemically stable cyclic peptide toxins produced by several genera of aquatic cyanobacteria including Microcytis, Anabaena, Planktothrix (Oscillatoria), Hapalosiphon and Nostoc [1].
What are shellfish toxins?
Paralytic Shellfish Poison (PSP) is a naturally occurring marine biotoxin that is produced by some species of microscopic algae. Shellfish eat these algae and can retain the toxin. People can become ill from eating shellfish contaminated with Paralytic Shellfish Poison.
Which plant food contains the most toxin?
Many types of beans contain toxins called lectins, and kidney beans have the highest concentrations – especially red kidney beans. As few as 4 or 5 raw beans can cause severe stomachache, vomiting and diarrhoea.
What is Scombrotoxin?
What is Scombrotoxin (Histamine): Scombrotoxin is a foodborne toxin most associated with the consumption of certain fish species, e.g. mackerel and tuna. Histamine is a biogenic amine and can be produced during and/or storage of fish and certain other foods, usually by the action of spoilage bacteria.
How long after eating bad mussels do you get sick?
Symptoms. DSP symptom onset is fairly rapid, and begins between 30 minutes to 15 hours after eating contaminated shellfish. Usually the symptoms start in one or two hours.
What fish contain toxins naturally?
Examples of fish species recently identified with the hazard of natural toxins are lobster, specifically the tomalley, containing PSP, anchovies containing ASP, and lionfish have been found with levels of CFP that can cause illness.
What is abrin toxin?
Abrin is a natural poison that is found in the seeds of a plant called the rosary pea or jequirity pea. These seeds are red with a black spot covering one end. Abrin is similar to ricin, a toxin that also is found in the seeds of a plant (the castor bean plant).
What is neurotoxic poison?
neurotoxin, substance that alters the structure or function of the nervous system. More than 1,000 chemicals are known to have neurotoxic effects in animals. The substances include a wide range of natural and human-made chemical compounds, from snake venom and pesticides to ethyl alcohol, heroin, and cocaine.
What is the name of the potent neurotoxin release by Gonyaulax?
Gonyaulax is a genus of dinoflagellates with the type species Gonyaulax spinifera (Claparède et Lachmann) Diesing. Gonyaulax belongs to red dinoflagellates and commonly causes red tides. It secretes a poisonous toxin known as “saxitoxin” which causes paralysis in humans.
What causes paralytic shellfish poisoning?
Causes. Paralytic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Algal blooms of dinoflagellates, usually during the warmer months of June to October, result in toxin accumulation in filter feeders such as bivalves.
What does Brevetoxin cause?
Brevetoxins are neurotoxins that bind to voltage-gated sodium channels in nerve cells, leading to disruption of normal neurological processes and causing the illness clinically described as neurotoxic shellfish poisoning (NSP).
Where does okadaic acid come from?
Okadaic acid is a polycyclic ether that is produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish. A polyketide, polyether derivative of a C38 fatty acid, it is one of the primary causes of diarrhetic shellfish poisoning (DSP).
Is abrin soluble in water?
Abrin is a water-soluble lectin. Abrin in powdered form is yellowish-white. It is a stable substance and can withstand extreme environmental conditions.
What is domoic acid poisoning?
Domoic acid (DA) is a kainic acid-type neurotoxin that causes amnesic shellfish poisoning (ASP). It is produced by algae and accumulates in shellfish, sardines, and anchovies. When sea lions, otters, cetaceans, humans, and other predators eat contaminated animals, poisoning may result.
Is botulinum toxin A protein?
Botulinum neurotoxins (BoNTs) are protein neurotoxins produced by neurotoxigenic strains of anaerobic and spore forming bacteria of the genus Clostridium (Clostridium botulinum, Clostridium butyrricum, Clostridium barati, and Clostridium argentinensis) (Smith et al., 2015).
Which of the following algae secretes Saxitoxins?
The dinoflagellates (class Dinophyceae) are the most notorious producers of toxins. Paralytic shellfish poisoning is caused by the neurotoxin saxitoxin or any of at least 12 related compounds, often produced by the dinoflagellates Alexandrium tamarense and Gymnodinium catenatum.
What causes red tide?
A “red tide” is a common term used for a harmful algal bloom. … This bloom, like many HABs, is caused by microscopic algae that produce toxins that kill fish and make shellfish dangerous to eat. The toxins may also make the surrounding air difficult to breathe.
Is saxitoxin heat resistant?
Saxitoxins are heat stable and water soluble. They are tasteless and odorless, and are not destroyed by cooking (Trevino, 1998). Saxitoxins can be accumulated in freshwater fish such as tilapia (Galvao et al., 2009). Figure 31.5.
How fast can a dinoflagellate swim?
Dinoflagellates are mobile in the water column. They have two flagella, one around the cingulum and the other longitudinal, which permit swimming with a spiral-like ‘whirling’ motion with a speed ranging from a few centimeters to a few meters per hour.
Why do mussels smell like poop?
Mussels that have died begin to smell. This is because the mussel has already begun to rot. Some have described the smell as similar to sewage or poop, for lack of better descriptions.
How do you know if mussels are OK to eat?
They should smell fresh and briny like the ocean and beach, but not have a strong fishy smell. Squeeze the open mussels with your fingers or tap the ones that are open against the counter. They should close by themselves, and although some might close slowly, they are still good and alive.
How can you tell if mussels are bad?
Buy mussels that look and smell fresh, with closed shells.
Press together the shells of any that are open. If the shell doesn’t close, the mussel is dead and should be discarded (also toss any with broken shells).