Poisonous Mushroom - testing kit?

[mountainm]

Following on from another thread.

I'm guessing poisonous mushrooms don't actually poison in too many different ways, given this I wonder if it would be possible to develop a testing kit that can help differentiate bad fungi from good fungi.

These are the common ones wikipedia puts forward

• Alpha-amanitin (deadly: causes liver damage 1–3 days after ingestion)–principal toxin in genus Amanita.
• Phallotoxin (causes gastrointestinal upset)–also found in poisonous Amanitas
• Orellanine (deadly: causes kidney failure within 3 weeks after ingestion)–principal toxin in genus Cortinarius.
• Muscarine (sometimes deadly: can cause respiratory failure)–found in genus Omphalotus.
• Gyromitrin (deadly: causes neurotoxicity, gastrointestinal upset, and destruction of blood cells)–principal toxin in genus Gyromitra.
• Coprine (causes illness when consumed with alcohol)–principal toxin in genus Coprinus.
• Ibotenic acid and muscimol (hallucinogenic)–principal toxin in A. muscaria, A. pantherina, and A. gemmata.
• Psilocybin and psilocin (hallucinogenic)–principal 'toxin' in genus Psilocybe.
• Arabitol (causes gastrointestinal irritation in some people).
• Bolesatine a toxin found in Boletus satanas
• Ergotamine (deadly: affects the vascular system and can lead to loss of limbs and death): An alkaloid found in genus Claviceps.

Would be nice to find some way of testing for the presence of these substances in a home kit. Of course there'd be a big Caveat about "does not guarantee safety" - but it would help.

M

 

[blacktimberwolf]

There isn't a kit to test for these toxins but would a mobile laboratory unit with a six person research team, be any good to you ?

 

[forestwalker]

My spontaneous guess -- based on a few years in biochemical labs -- is that it should be quite possible to detect these compounds in a fairly quick test, but that the most likley candidate is some form of immunoassay. In a well developed form this is quick and easy (the home pregnancy tests work in this way), but the chance of someone spending all the funds that is needed for it to get to this level for something as marginal as poisonous mushrooms is slim.

And you might also need a separate test for each compound.

 

[forestwalker]

There isn't a kit to test for these toxins but would a mobile laboratory unit with a six person research team, be any good to you ?

Well, once could separate them from the fungi (my first choice would be liquid chromatography, lyophilization of the aliquots and then FT-IR to detect the toxins), produce (monoclonal) antibodies and then use e.g. an ELIZA or western blot to detect them. Once you have a working test an answer should be available in just a few hours.

Of course, there might already be a working test for most of these, but it is more fun guessing than playing with google schoolar.

 

[mountainm]

My spontaneous guess -- based on a few years in biochemical labs -- is that it should be quite possible to detect these compounds in a fairly quick test, but that the most likley candidate is some form of immunoassay. In a well developed form this is quick and easy (the home pregnancy tests work in this way), but the chance of someone spending all the funds that is needed for it to get to this level for something as marginal as poisonous mushrooms is slim.

And you might also need a separate test for each compound.

If the kit was re-usable then I can see people shelling out a fair bit for them.

 

[forestwalker]

If the kit was re-usable then I can see people shelling out a fair bit for them.

No, it would not be reusable. Possibly one could produce a hand reader and some form of test strips. But for a marginal product like this I predict a fairly steep price. It will NOT be a commercial success.

 

[mountainm]

No, it would not be reusable. Possibly one could produce a hand reader and some form of test strips. But for a marginal product like this I predict a fairly steep price. It will NOT be a commercial success.

That's definitely an emphatic NOT - almost deserves multiple exclamation marks!!!!! Or perhaps bold tags

But we've established it's doable, not re-usable, so some sort of disposable litmus style strips. Expensive initial startup costs, but relatively cheap production costs. Limited market.

Not that I'm going to make the things just sharing ideas,

 

[forestwalker]

That's definitely an emphatic NOT - almost deserves multiple exclamation marks!!!!! Or perhaps bold tags

You forgot the plus-size font.

But we've established it's doable, not re-usable, so some sort of disposable litmus style strips. Expensive initial startup costs, but relatively cheap production costs. Limited market.

Not that I'm going to make the things just sharing ideas,

I suspect that the "litmus" style strips would be a horror to get right, have an horrendous false positive rate (no one would sell them if they had an even measurable false negative rate; imagine the liability once the ambulance chasers get their teeth into it). An immunoassay based test ("thin blue line") would be better, but pricier per test.

Hmm, in a world where your local doctors office may very well have a robot for analysing tests, then someone *may* market a test where you could bring your sample to some testing office, and have them run the test and get back to you in a few hours. Cost: ten pounds or so (WAG warning).

Hmm, it might actually be easier to test the fungi and see what species it is. Something like a PhastGel (Pharmacia^W GE Health something or other these days), either 1d or 2d, might do it in a couple of hours. I mean, a 1d IEF gel can distinguish two related fish species (cod and saithe), so why not?

Yes, I'm nerding out. And looking in the field guide is cheating, of course.

 

[Geoff Dann]

My spontaneous guess -- based on a few years in biochemical labs -- is that it should be quite possible to detect these compounds in a fairly quick test, but that the most likley candidate is some form of immunoassay. In a well developed form this is quick and easy (the home pregnancy tests work in this way), but the chance of someone spending all the funds that is needed for it to get to this level for something as marginal as poisonous mushrooms is slim.

Indeed. Especially since plenty of tests of one sort or another already exist to distinguish mushrooms in the lab, and because you can learn how to safely forage with just your eyes, hands and nose....and a lot of patience.

There is also another problem here. Most of the fungi that are known to be poisonous are known to be poisonous for one of three reasons:

(a) they are very poisonous indeed, so anybody eating even one of them will die, prompting an investigation into the cause.
(b) they are poisonous and very common, so sooner or later somebody will eat a whole plateful and become ill, or die...
(c) they are poisonous and are quite easily confused with something known to be edible, so sooner or later somebody will eat a whole plateful...

This leaves a vast number of species the edibility of which is not known, and it is inevitable that some of them are indeed poisonous but we just don't know about it because not enough people have ever eaten them, become ill, reported it to the authorities and the offending mushroom was successfully identified. Only at that point do any scientists get involved to try to work out what compound(s) is/are responsible. In other words, you could test for all the listed toxins, find that none were present and still end up being poisoned by a toxin currently unknown in fungi (or unknown to science), especially if you don't know what species of mushroom it is or you've got the genus wrong. These tests would instill a false sense of confidence, I think. Better to do it the traditional way and learn how to identify which species it is.

 

[mountainm]

Wow, that rare one off never discovered before mushroom has poisoned my idea.

 

[Geoff Dann]

Wow, that rare one off never discovered before mushroom has poisoned my idea.

You might be surprised how many different species of fungi grow in the UK (well over 10,000), how rare many of them are and how little is known about them. A significant proportion of the fungi in the three of the most comprehensive books for non-professionals (Roger Phillips, Michael Jordan and the Collins book) aren't in the other two, and I regularly come across species that turn out not to be in any of them (I have to get them identified by the people at the Association of British Fungus Groups). Of those 10,000 species, at least three-quarters have an edibility status of "unknown."

If you just went out randomly picking mushrooms in the UK, it would not take you very long before you came across a rare species, simply because there are so many of them. Actually identifying the buggers is not so easy.

 

[mountainm]

But as an aid to ID'ing applied with some common sense.....

 

[Geoff Dann]

But as an aid to ID'ing applied with some common sense.....

It could be done. It just wouldn't make any money, as other people have already pointed out. From a commercial point of view it is a bit pointless.

At the end of the day, the only safe way to forage is to think like a mycological taxonomist - you have to identify the genus and then try to narrow it down to a species - you have to know what it is you are eating, not just what chemicals aren't in it.